WO2019146696A1

WO2019146696A1 - Sensor chip and force sensor device

Info

Publication number: WO2019146696A1
Application number: PCT/JP2019/002263
Authority: WO
Inventors: 真也山口
Original assignee: ミネベアミツミ株式会社; 真也山口
Priority date: 2018-01-29
Filing date: 2019-01-24
Publication date: 2019-08-01
Also published as: CN111670349A; CN111670349B

Abstract

This sensor chip comprises: a base plate; first supporting portions; a second supporting portion around which the first supporting portions are disposed, and which is disposed at the center of the base plate; first detection beams linking the first supporting portions that are adjacent to one another; force application points to which a force is applied, disposed on the first detection beams; and a plurality of strain detecting elements disposed at prescribed positions on the first detection beams. The plurality of strain detecting elements include first strain detecting elements formed on the first detection beams, between the first supporting portions and the force application points, wherein a second beam width, which is the width of the first detection beams in positions in which the first strain detecting elements are formed, is smaller than a first beam width, which is the width of the first detection beams in positions in which the first detection beams are linked to the first supporting portions or to the force application points. Further, the first detection beams each includes a straight-line portion, and an inclined portion linked to the straight-line portion by means of a linking portion, and the plurality of strain detecting elements include first strain detecting elements disposed on the inclined portion side of the linking portion.

Description

Sensor chip and force sensor device

The present invention relates to a sensor chip and a force sensor device.

Conventionally, there is known a force sensor device that detects a multiaxial force by attaching a plurality of strain gauges to a metal strain body and converting a strain when an external force is applied into an electric signal. . However, since it is necessary to manually attach the strain gauges one by one, this force sensor device has problems in accuracy and productivity, and it has been difficult to miniaturize it structurally.

On the other hand, a force sensor device has been proposed which solves the problem of bonding accuracy and realizes miniaturization by replacing the strain gauge with a sensor chip for detecting strain (for example, see Patent Document 1). .

Patent No. 4011345

By the way, in the above-mentioned force sensor device using the MEMS sensor chip, when the input is a single axis (one of the six axes [Fx, Fy, Fz, Mx, My, Mz] (In the case of the direction along (1)), the force sensor can obtain high accuracy.

However, if the input is a complex input (a complex input along any two or more of six axes [Fx, Fy, Fz, Mx, My, Mz]), the axis separation is Because of the insufficient force, the error of the force sensor is increased, and the accuracy is reduced. In particular, in the case of complex inputs, there are combinations of axes of complex inputs that do not meet the target value of accuracy.

The present invention has been made in view of the above-described points, and an object thereof is to improve axial separation of a sensor chip with respect to complex inputs and improve sensor accuracy.

The present sensor chip (110) has a substrate, a first support (111a, 111b, 111c, 111d), and the second support disposed at the center of the substrate with the first support disposed around the periphery. In the first detection beam (113a, 113d, 113g, 113j) for connecting the support portion (111e), the adjacent first support portions, and the force disposed on the first detection beam, And a plurality of strain detection elements disposed at predetermined positions of the first detection beam, the plurality of strain detection elements including the force points (114a, 114b, 114c, 114d) to be applied. And a first strain detection element (MzR1, MzR2, MzR3, MzR4, MzR1 ', MzR2', Mzr3 ', MzR4') formed on the first detection beam between the supporting portion 1 and the point of force; For the first detection The first detection of the position where the first strain detection element is formed by the first beam width which is the width of the first detection beam at a position where the first support portion or the force point is connected The requirement is that the second beam width, which is the width of the beam, is smaller.

In the sensor chip (110), the substrate, the first supports (111a, 111b, 111c, 111d), and the first support disposed around the periphery, and the sensor chip (110) is disposed at the center of the substrate 2, and the first detection beams (113a, 113d, 113g, 113j) for connecting the first support portions adjacent to each other, and the first detection beams, A force detection point (114a, 114b, 114c, 114d) to which a force is applied, and a plurality of strain detection elements arranged at predetermined positions of the first detection beam; A linear portion (113n1) and inclined portions (113n2 and 113n3) connected to the linear portion by a connecting portion, and the plurality of strain detection elements are arranged closer to the inclined portion than the connecting portion First strain detection element (FzR1, The requirement to include a zR2).

The reference numerals in the parentheses above are given for ease of understanding, and are merely examples, and the present invention is not limited to the illustrated embodiment.

According to the disclosed technology, it is possible to improve the shaft separation for the complex input of the sensor chip and to improve the sensor accuracy.

It is a perspective view showing an example of a force sensor device concerning an embodiment. It is a perspective view which shows an example of the sensor chip of the force sensor apparatus concerning embodiment, and a strain body. It is the figure seen from the Z-axis direction upper side of an example of the sensor chip concerning an embodiment. It is the figure seen from the Z-axis direction lower side of an example of the sensor chip concerning an embodiment. It is a figure explaining the code | symbol which shows the force concerning each axis which concerns on embodiment, and a moment. It is a figure which shows arrangement | positioning of the piezo-resistance element of an example of the sensor chip which concerns on embodiment. It is a figure (the 1) which shows an example of the strain generating body which concerns on embodiment. It is a figure (the 2) which shows an example of the strain generating body which concerns on embodiment. It is a figure (the 3) which shows an example of the strain generating body which concerns on embodiment. It is a figure (the 1) showing an example of a manufacturing process of a force sensor device concerning an embodiment. It is a figure (the 2) showing an example of a manufacturing process of a force sensor device concerning an embodiment. It is a figure (the 3) which shows an example of the manufacturing process of the force sensor apparatus which concerns on embodiment. It is the top view to which the principal part of an example of the sensor chip which concerns on embodiment was expanded. It is the top view which expanded the principal part of the other example of the sensor chip which concerns on embodiment. It is a figure (stress contour figure) which shows the result of having computed the stress when applying force or moment to the sensor chip of a reference example by simulation. It is a figure (stress contour view) which shows the result of having computed the stress when applying force or moment to the sensor chip of an embodiment by simulation. It is a figure (stress contour view) which shows the result of having computed the stress when applying force or moment to the sensor chip of an embodiment by simulation. It is a figure (stress contour view) which shows the result of having computed the stress when applying force or moment to the sensor chip of an embodiment by simulation. It is a figure explaining simulation of other axis ingredient to a sensor chip of a reference example. It is a figure explaining the simulation of the other axis ingredient to the sensor chip of another example of an embodiment. It is a figure explaining simulation of other axis ingredient to a sensor chip of a reference example. It is a figure explaining the simulation of the other axis ingredient to the sensor chip of another example of an embodiment. It is a figure explaining simulation of other axis ingredient to a sensor chip of a reference example. It is a figure explaining the simulation of the other axis ingredient to the sensor chip of another example of an embodiment. It is a figure explaining simulation of the other axis ingredient to a sensor chip of an embodiment. It is the top view to which the principal part of an example of the sensor chip which concerns on embodiment was expanded. It is the top view which expanded the principal part of the other example of the sensor chip which concerns on embodiment. It is the top view to which the principal part of an example of the sensor chip which concerns on embodiment was expanded. It is the top view to which the principal part of an example of the sensor chip which concerns on embodiment was expanded. It is a figure (stress contour view) which shows the result of having computed the stress when the force of the direction of the X-axis is impressed to the sensor chip of an embodiment by simulation. It is a figure (stress contour view) which shows the result of having computed the stress when the force of the direction of the Z-axis is impressed to the sensor chip of an embodiment by simulation. It is the top view which expanded the principal part of the sensor chip which concerns on a reference example. It is a figure (stress contour view) which shows the result of having computed the stress when the force of the direction of the X-axis was applied to the sensor chip of a reference example by simulation. It is a figure (stress contour view) which shows the result of having computed the stress when the force of the direction of the Z-axis is impressed to the sensor chip of a reference example by simulation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and redundant description may be omitted.

First Embodiment
(Schematic Configuration of Force Sensor Device 1)
FIG. 1 is a perspective view illustrating a force sensor device according to the first embodiment. FIG. 2 is a perspective view illustrating a sensor chip and a strain generating body of the force sensor device according to the first embodiment. Referring to FIGS. 1 and 2, the force sensor device 1 includes a sensor chip 110, a strain generating body 20, and an input / output substrate 30. The force sensor device 1 is, for example, a multi-axis force sensor device mounted on an arm, a finger or the like of a robot used for a machine tool or the like.

The sensor chip 110 has a function of detecting a maximum of six axial displacements in a predetermined axial direction. The strain generating body 20 has a function of transmitting the applied force to the sensor chip 110.

The sensor chip 110 is bonded to the upper surface side of the strain generating body 20 so as not to protrude from the strain generating body 20. In addition, one end side of an input / output substrate 30 for inputting / outputting a signal to / from the sensor chip 110 is bonded to the upper surface and each side surface of the strain generating body 20 in a properly bent state. The sensor chip 110 and each electrode 31 of the input / output substrate 30 are electrically connected by a bonding wire or the like (not shown).

In the input / output substrate 30, an active component 32 and a passive component 39 are mounted in a region disposed on the first side surface of the strain generating body 20. In the input / output substrate 30, an active component 33 and a passive component 39 are mounted in a region disposed on the second side surface of the strain generating body 20. An active component 34 and a passive component 39 are mounted on a region of the input / output substrate 30 disposed on the third side surface of the strain generating body 20. In the input / output substrate 30, an active component 35 and a passive component 39 are mounted in a region disposed on the fourth side surface of the strain generating body 20.

The active component 33 detects, for example, an analog electrical signal from a bridge circuit that detects a force Fx in the X-axis direction output from the sensor chip 110 and a bridge that detects a force Fy in the Y-axis direction output from the sensor chip 110 It is an IC (AD converter) that converts an analog electrical signal from a circuit into a digital electrical signal.

The active component 35 rotates, for example, an analog electrical signal from a bridge circuit that detects a moment My rotating about the Y axis output from the sensor chip 110 and a Z axis output from the sensor chip 110 as an axis It is an IC (AD converter) that converts an analog electrical signal from a bridge circuit that detects a moment Mz into a digital electrical signal.

Active component 32 performs predetermined operations on digital electrical signals output from

active components

33, 34 and 35, for example, and indicates forces Fx, Fy and Fz, and moments Mx, My and Mz. It is an IC that generates a signal and outputs it to the outside. The passive component 39 is, for example, a resistor or a capacitor connected to the active components 32 to 35.

The number of ICs to realize the functions of the active components 32 to 35 can be arbitrarily determined. Alternatively, the active components 32 to 35 may be mounted on the external circuit side connected to the input / output substrate 30 without being mounted on the input / output substrate 30. In this case, an analog electrical signal is output from the input / output board 30.

The input / output substrate 30 is bent outward below the first side surface of the strain generating body 20, and the other end side of the input / output substrate 30 is drawn out. At the other end of the input / output board 30, terminals (not shown) capable of electrically inputting / outputting to / from an external circuit (control device etc.) connected to the force sensor device 1 are arranged.

In the present embodiment, for convenience, in the force sensor device 1, the side provided with the sensor chip 110 is referred to as the upper side or one side, and the opposite side is referred to as the lower side or the other side. Further, the surface on the side where the sensor chip 110 is provided in each part is referred to as one surface or the upper surface, and the opposite surface is referred to as the other surface or the lower surface. However, the force sensor device 1 can be used in the upside-down state or can be disposed at an arbitrary angle. Furthermore, planar view refers to viewing the object from the normal direction (Z-axis direction) of the upper surface of the sensor chip 110, and planar shape refers to the normal direction of the upper surface of the sensor chip 110 (Z-axis direction It refers to the shape viewed from).

(Sensor chip 110)
FIG. 3 is a view of the sensor chip 110 viewed from the upper side in the Z-axis direction, FIG. 3 (a) is a perspective view, and FIG. 3 (b) is a plan view. FIG. 4 is a view of the sensor chip 110 viewed from the lower side in the Z-axis direction, FIG. 4 (a) is a perspective view, and FIG. 4 (b) is a bottom view. In FIG. 4 (b), for convenience, surfaces of the same height are shown in the same textured pattern. The direction parallel to one side of the upper surface of the sensor chip 110 is the X-axis direction, the vertical direction is the Y-axis direction, and the thickness direction of the sensor chip 110 (the normal direction of the upper surface of the sensor chip 110) is the Z-axis direction. . The X axis direction, the Y axis direction, and the Z axis direction are orthogonal to one another.

The sensor chip 110 shown in FIGS. 3 and 4 is a MEMS (Micro Electro Mechanical Systems) sensor chip that can detect up to six axes with one chip, and is formed of a semiconductor substrate such as an SOI (Silicon On Insulator) substrate. The planar shape of the sensor chip 110 can be, for example, a square of about 3000 μm square.

The sensor chip 110 includes five columnar support portions 111a to 111e. The planar shape of the support portions 111a to 111e can be, for example, a square of about 500 μm square. The support portions 111a to 111d, which are the first support portions, are disposed at the four corners of the sensor chip 110. The second support portion 111e is disposed at the center of the support portions 111a to 111d.

The support portions 111a to 111e can be formed of, for example, an active layer, a BOX layer, and a support layer of an SOI substrate, and the thickness thereof can be, for example, about 500 μm.

Between the support portion 111a and the support portion 111b, a reinforcement beam 112a for reinforcing the structure is provided, the ends of which are fixed to the support portion 111a and the support portion 111b (the adjacent support portions are connected). It is done. Between the support portion 111b and the support portion 111c, there are provided reinforcement beams 112b for reinforcing the structure, the ends of which are fixed to the support portion 111b and the support portion 111c (connect adjacent support portions). It is done.

Between the support portion 111c and the support portion 111d, there are provided reinforcement beams 112c for reinforcing the structure, both ends of which are fixed to the support portion 111c and the support portion 111d (connect adjacent support portions). It is done. Between the support portion 111d and the support portion 111a, a reinforcement beam 112d for reinforcing the structure is provided, the ends of which are fixed to the support portion 111d and the support portion 111a (the adjacent support portions are connected). It is done.

In other words, the four reinforcing

beams

112a, 112b, 112c, and 112d, which are the first reinforcing beams, are formed in a frame shape, and the corner portions forming the intersections of the respective reinforcing beams are the

support portions

111b, 111c, and 111d. , 111a.

The inner corner portion of the support portion 111a and the corner portion of the support portion 111e opposed thereto are connected by a reinforcing beam 112e for reinforcing the structure. The inner corner portion of the support portion 111b and the corner portion of the support portion 111e opposed thereto are connected by a reinforcing beam 112f for reinforcing the structure.

The inner corner portion of the support portion 111c and the corner portion of the support portion 111e opposed thereto are connected by a reinforcing beam 112g for reinforcing the structure. The inner corner portion of the support portion 111d and the corner portion of the support portion 111e opposed thereto are connected by a reinforcing beam 112h for reinforcing the structure. The reinforcing beams 112e to 112h, which are the second reinforcing beams, are disposed obliquely with respect to the X-axis direction (Y-axis direction). That is, the reinforcing beams 112e to 112h are disposed nonparallel to the reinforcing

beams

112a, 112b, 112c, and 112d.

The reinforcing beams 112a to 112h can be formed, for example, from the active layer, the BOX layer, and the support layer of the SOI substrate. The thickness (the width in the short direction) of the reinforcing beams 112a to 112h can be, for example, about 140 μm. The upper surfaces of the reinforcing beams 112a to 112h are substantially flush with the upper surfaces of the support portions 111a to 111e.

On the other hand, the lower surface of each of the reinforcing beams 112a to 112h is recessed to the upper surface side by about several tens of micrometers than the lower surfaces of the support portions 111a to 111e and the lower surfaces of the power points 114a to 114d. This is to prevent the lower surfaces of the reinforcing beams 112a to 112h from coming into contact with the opposing surfaces of the straining body 20 when the sensor chip 110 is bonded to the straining body 20.

As described above, the rigidity of the entire sensor chip 110 can be enhanced by arranging a reinforcing beam having a high rigidity and formed thicker than the detection beam separately from the detection beam for detecting the strain. As a result, it becomes difficult to deform other than the detection beam with respect to the input, so that good sensor characteristics can be obtained.

Both ends of the reinforcing beam 112a between the supporting portion 111a and the supporting portion 111b are fixed to the supporting portion 111a and the supporting portion 111b in parallel with a predetermined distance therebetween (adjacent to each other) Support beams are connected to each other), and detection beams 113a for detecting distortion are provided.

A detection beam 113b is provided between the detection beam 113a and the support portion 111e at a predetermined distance from the detection beam 113a and the support portion 111e and in parallel with the detection beam 113a. The detection beam 113b connects the end of the reinforcement beam 112e on the support portion 111e side and the end of the reinforcement beam 112f on the support portion 111e side.

A substantially central portion in the longitudinal direction of the detection beam 113a and a substantially central portion in the longitudinal direction of the detection beam 113b opposed thereto are the detection beam arranged to be orthogonal to the detection beam 113a and the detection beam 113b. It is connected by 113c.

Both ends of the reinforcing beam 112b between the supporting portion 111b and the supporting portion 111c are fixed to the supporting portion 111b and the supporting portion 111c in parallel with a predetermined distance therebetween (adjacent to each other) Support beams are connected to each other), and detection beams 113d for detecting distortion are provided.

Between the detection beam 113d and the support portion 111e, a detection beam 113e is provided in parallel with the detection beam 113d at a predetermined distance from the detection beam 113d and the support portion 111e. The detection beam 113e connects the end of the reinforcement beam 112f on the support portion 111e side and the end of the reinforcement beam 112g on the support portion 111e side.

A substantially central portion in the longitudinal direction of the detection beam 113d and a substantially central portion in the longitudinal direction of the detection beam 113e opposed thereto, the detection beam disposed so as to be orthogonal to the detection beam 113d and the detection beam 113e It is connected by 113f.

Both ends of the reinforcing beam 112c between the supporting portion 111c and the supporting portion 111d are fixed to the supporting portion 111c and the supporting portion 111d in parallel with a predetermined distance therebetween (adjacent to each other) Support portions are connected with each other, and a detection beam 113g for detecting strain is provided.

Between the detection beam 113g and the support portion 111e, a detection beam 113h is provided in parallel with the detection beam 113g with a predetermined interval between the detection beam 113g and the support portion 111e. The detection beam 113h connects the end of the reinforcement beam 112g on the support 111e side and the end of the reinforcement beam 112h on the support 111e.

A substantially central portion in the longitudinal direction of the detection beam 113g and a substantially central portion in the longitudinal direction of the detection beam 113h opposed thereto, the detection beam disposed so as to be orthogonal to the detection beam 113g and the detection beam 113h It is connected by 113i.

Both ends of the reinforcing beam 112d between the supporting portion 111d and the supporting portion 111a are fixed to the supporting portion 111d and the supporting portion 111a in parallel with a predetermined distance therebetween (adjacent to each other) Support beams are connected to each other), and detection beams 113 j for detecting distortion are provided.

Between the detection beam 113j and the support portion 111e, a detection beam 113k is provided in parallel with the detection beam 113j at a predetermined interval from the detection beam 113j and the support portion 111e. The detection beam 113k couples the end of the reinforcement beam 112h on the support portion 111e side and the end of the reinforcement beam 112e on the support portion 111e side.

A substantially central portion in the longitudinal direction of the detection beam 113j and a substantially central portion in the longitudinal direction of the detection beam 113k opposed thereto, the detection beam disposed so as to be orthogonal to the detection beam 113j and the detection beam 113k It is linked by 113 l.

The detection beams 113a to 113l are provided on the upper end side in the thickness direction of the support portions 111a to 111e, and can be formed of, for example, an active layer of an SOI substrate. The thickness (width in the short direction) of the detection beams 113a to 113l can be, for example, about 75 μm. The thickness (the width in the short direction) of the detection beams 113a to 113l may be different depending on the position. The upper surfaces of the detection beams 113a to 113l are substantially flush with the upper surfaces of the support portions 111a to 111e. The thickness of each of the detection beams 113a to 113l can be, for example, about 50 μm.

A force point 114a is provided on the lower surface side of the central portion in the longitudinal direction of the detection beam 113a (the intersection of the detection beam 113a and the detection beam 113c). The detection beams 113a, 113b, and 113c and the force point 114a constitute a set of detection blocks.

A force point 114b is provided on the lower surface side of the central portion in the longitudinal direction of the detection beam 113d (the intersection point of the detection beam 113d and the detection beam 113f). The detection beams 113d, 113e, and 113f and the force point 114b constitute a set of detection blocks.

A force point 114c is provided on the lower surface side of the central portion in the longitudinal direction of the detection beam 113g (the intersection point of the detection beam 113g and the detection beam 113i). The detection beams 113g, 113h, and 113i and the force point 114c constitute a set of detection blocks.

A force point 114d is provided on the lower surface side of the central portion in the longitudinal direction of the detection beam 113j (the intersection of the detection beam 113j and the detection beam 113l). The detection beams 113j, 113k, and 113l and the force point 114d constitute a set of detection blocks.

The force points 114a to 114d are places to which an external force is applied, and can be formed, for example, from the BOX layer and the support layer of the SOI substrate. The lower surfaces of the power points 114a to 114d are substantially flush with the lower surfaces of the support portions 111a to 111e.

As described above, by incorporating forces or displacements from the four force points 114a to 114d, different beam deformations can be obtained for each type of force, so it is possible to realize a sensor with good six-axis separation.

From the viewpoint of suppressing stress concentration in the sensor chip 110, the portion forming the inner angle is preferably R-shaped.

FIG. 5 is a diagram for explaining reference numerals indicating forces and moments applied to the respective axes. As shown in FIG. 5, the force in the X-axis direction is Fx, the force in the Y-axis direction is Fy, and the force in the Z-axis direction is Fz. Further, let Mx be a moment for rotating about the X axis, My be a moment for rotating the Y axis, and Mz be a moment for rotating the Z axis.

FIG. 6 is a diagram illustrating the arrangement of the piezoresistive elements of the sensor chip 110. As shown in FIG. Piezoresistive elements, which are a plurality of strain detection elements, are disposed at predetermined positions of the detection blocks corresponding to the four force points 114a to 114d.

Specifically, referring to FIG. 3 and FIG. 6, in the detection block corresponding to the power point 114a, the piezoresistive elements MxR3 and MxR4 are on the line bisecting the detection beam 113a in the longitudinal direction, and In a region near the detection beam 113c of the detection beam 113a, the detection beam 113c is disposed at a symmetrical position with respect to a line bisecting in the longitudinal direction (Y direction). The piezoresistive elements FyR3 and FyR4 are located on the reinforcing beam 112a side of a line bisecting the detecting beam 113a in the longitudinal direction and in a region farther from the detection beam 113c of the detection beam 113a. They are disposed at symmetrical positions with respect to a line bisecting 113 c in the longitudinal direction.

Further, the piezoresistive elements MzR3 ′ and MzR4 ′ are on a line bisecting the detection beam 113a in the longitudinal direction and at a position where they are connected to the

support portions

111a and 111b of the detection beam 113a and a force point 114a In the vicinity of the middle point of the connection position, the detection beam 113c is disposed at a symmetrical position with respect to a line bisecting the detection beam 113c in the longitudinal direction. Here, the position at which the piezoresistive elements MzR3 ′ and MzR4 ′ are formed from the first beam width which is the width of the detection beam 113a at the position where the detection beam 113a is connected to the

support portions

111a and 111b or the power point 114a. The second beam width, which is the width of the detection beam 113a, is smaller.

In the present embodiment, as shown in FIGS. 3 and 6, in the detection beam 113a, the piezoresistive elements MzR3 'and MzR4' are located from the position where the detection beam 113a is connected to the

support portions

111a and 111b. It has a tapered shape in which the beam width gradually narrows on both sides in the lateral direction of the detection beam 113a to the formed position. The detection beam 113a extends from the position where the detection beam 113a is connected to the power point 114a to the position where the piezoresistive elements MzR3 ′ and MzR4 ′ are formed on both sides in the lateral direction of the detection beam 113a. It has a tapered shape in which the beam width gradually narrows.

That is, in the detection beam 113a, a portion where the beam width is narrowed is formed between the position where it is connected with the

support portions

111a and 111b and the position where it is connected with the force point 114a. Piezoresistive elements MzR3 'and MzR4' are formed on the detection beam 113a.

In the detection block corresponding to the force point 114b, the piezoresistive elements MyR3 and MyR4 are detected on a line bisecting the detection beam 113d in the longitudinal direction and in a region near the detection beam 113f of the detection beam 113d. The beam 113 f is disposed at symmetrical positions with respect to a line bisecting the beam 113 f in the longitudinal direction (X direction). The piezoresistive elements FxR3 and FxR4 are located on the reinforcing beam 112b side of a line bisecting the detecting beam 113d in the longitudinal direction and in a region far from the detection beam 113f of the detection beam 113d. It is disposed at a symmetrical position with respect to a line bisecting 113 f in the longitudinal direction.

Also, the piezoresistive elements MzR3 and MzR4 are connected on the line bisecting the detection beam 113d in the longitudinal direction and at a position where they are connected to the

support portions

111b and 111c of the detection beam 113d and the force point 114b. In the vicinity of the midpoint of the position, the detection beam 113f is disposed at a symmetrical position with respect to a line bisecting the detection beam 113f in the longitudinal direction. Here, the detection beam 113d detects the position where the piezoresistive elements MzR3 and MzR4 are formed from the first beam width which is the width of the detection beam 113d at the position where it is connected to the

support portions

111b and 111c or the force point 114b. The second beam width, which is the width of the beam 113d, is smaller.

In the present embodiment, as shown in FIGS. 3 and 6, in the detection beam 113d, piezoresistive elements MzR3 and MzR4 are formed from the position where the detection beam 113d is connected to the

support portions

111b and 111c. In the lateral direction of the detection beam 113d, the width of the beam gradually narrows. The detection beam 113d extends from the position where the detection beam 113d is connected to the force point 114b to the position where the piezoresistive elements MzR3 and MzR4 are formed, at both sides in the lateral direction of the detection beam 113d. Has a tapered shape that gradually narrows.

That is, in the detection beam 113d, a portion where the beam width is narrowed is formed between the position where it is connected with the

support portions

111b and 111c and the position where it is connected with the force point 114b. Piezoresistive elements MzR3 and MzR4 are formed on the detection beam 113d.

The piezoresistive elements FzR2 and FzR3 are on the line bisecting the detection beam 113e in the longitudinal direction, and in the region near the detection beam 113f of the detection beam 113e, the detection beam 113f is formed in the longitudinal direction. It is placed at a symmetrical position with respect to the dividing line. The piezoresistive elements FzR1 ′ and FzR4 ′ are on the line bisecting the detection beam 113e in the longitudinal direction and in the region far from the detection beam 113f of the detection beam 113e in the longitudinal direction It is disposed at a symmetrical position with respect to the bisecting line.

Here, the detection beam 113e has a linear portion and an inclined portion connected to the linear portion by the connecting portion. The straight portion is a portion where the beam width of the detection beam 113e is substantially constant. The inclined portion is a portion provided at the end of the detection beam 113e or a portion connected to the detection beam 113f, and the beam width of the inclined portion gradually increases as the distance from the connecting portion increases. The piezoresistive elements FzR2, FzR3, FzR1 ', and FzR4' are disposed closer to the inclined portion than the connecting portion in the detection beam 113e having the above-described configuration. That is, it can be said that the piezoresistive elements FzR2, FzR3, FzR1 'and FzR4' are disposed not on the linear portion of the detection beam 113e but inside the inclined portion. Further, in the piezoresistive elements FzR1 'and FzR4', a part of the piezoresistive elements FzR1 'and FzR4' is formed to extend over the reinforcing beam 112g or the reinforcing beam 112f.

In the detection block corresponding to the force point 114c, the piezoresistive elements MxR1 and MxR2 are detected on a line bisecting the detection beam 113g in the longitudinal direction and in a region near the detection beam 113i of the detection beam 113g. The beam 113i is disposed at symmetrical positions with respect to a line bisecting in the longitudinal direction (Y direction). The piezoresistive elements FyR1 and FyR2 are located on the reinforcing beam 112c side of a line bisecting the detecting beam 113g in the longitudinal direction and in a region far from the detection beam 113i of the detection beam 113g. It is disposed at a symmetrical position with respect to a line bisecting 113 i in the longitudinal direction.

The piezoresistive elements MzR1 ′ and MzR2 ′ are connected on a line bisecting the detection beam 113g in the longitudinal direction and at a position where it is connected to the

support portions

111c and 111d of the detection beam 113g and a force point 114c. In the vicinity of the midpoint of the position, the detection beam 113i is disposed at a symmetrical position with respect to a line bisecting the detection beam 113i in the longitudinal direction. Here, the position at which the piezoresistive elements MzR1 ′ and MzR2 ′ are formed from the first beam width which is the width of the detection beam 113g at the position where the detection beam 113g is connected to the

support portions

111c and 111d or the force point 114c. The second beam width, which is the width of the detection beam 113g, is smaller.

In the present embodiment, as shown in FIGS. 3 and 6, in the detection beam 113g, the piezoresistive elements MzR1 ′ and MzR2 ′ are located from the position where the detection beam 113g is connected to the

support portions

111c and 111d. The beam has a tapered shape in which the width of the beam gradually narrows on both sides in the lateral direction of the detection beam 113g to the formed position. The detection beam 113g extends from the position where the detection beam 113g is connected to the force point 114c to the position where the piezoresistive elements MzR1 ′ and MzR2 ′ are formed on both sides in the lateral direction of the detection beam 113g. It has a tapered shape in which the beam width gradually narrows.

That is, in the detection beam 113g, a portion where the beam width is narrowed is formed between the position where it is connected with the

support portions

111c and 111d and the position where it is connected with the force point 114c. Piezoresistive elements MzR1 'and MzR2' are formed on the detection beam 113g.

In the detection block corresponding to the force point 114d, the piezoresistive elements MyR1 and MyR2 are detected on a line bisecting the detection beam 113j in the longitudinal direction and in a region close to the detection beam 113l of the detection beam 113j. The beam 113 l is disposed at a symmetrical position with respect to a line bisecting the longitudinal direction (X direction). The piezoresistive elements FxR1 and FxR2 are located on the reinforcing beam 112d side of a line bisecting the detecting beam 113j in the longitudinal direction and in a region far from the detection beam 113l of the detection beam 113j. It is disposed at a symmetrical position with respect to a line which bisects 113 l in the longitudinal direction.

The piezoresistive elements MzR1 and MzR2 are on a line bisecting the detection beam 113j in the longitudinal direction and at positions where the detection beam 113j is connected to the

support portions

111d and 111a and positions where it is connected to the force point 114d. The detection beam 113l is disposed at a symmetrical position with respect to a line bisecting the detection beam 113l in the longitudinal direction near the middle point of Here, the detection beam 113j detects the position where the piezoresistive elements MzR1 and MzR2 are formed from the first beam width which is the width of the detection beam 113j at the position where it is connected to the

support portions

111d and 111a or the power point 114d. The second beam width, which is the width of the beam 113j, is smaller.

In the present embodiment, as shown in FIGS. 3 and 6, in the detection beam 113j, piezoresistive elements MzR1 and MzR2 are formed from the position where the detection beam 113j is connected to the

support portions

111d and 111a. In the lateral direction of the detection beam 113j, the width of the beam gradually narrows. The detection beam 113j extends from the position where the detection beam 113j is connected to the force point 114d to the position where the piezoresistive elements MzR1 and MzR2 are formed, at both sides in the lateral direction of the detection beam 113j. Has a tapered shape that gradually narrows.

That is, in the detection beam 113j, a portion where the beam width is narrowed is formed between the position where it is coupled with the

support portions

111d and 111a and the position where it is coupled with the force point 114d. Piezoresistive elements MzR1 and MzR2 are formed on the detection beam 113j.

The piezoresistive elements FzR1 and FzR4 are on the line bisecting the detection beam 113k in the longitudinal direction and in the region far from the detection beam 113l of the detection beam 113k in the longitudinal direction. It is placed at a symmetrical position with respect to the dividing line. The piezoresistive elements FzR2 'and FzR3' are on the line bisecting the detection beam 113k in the longitudinal direction, and in the region near the detection beam 113l of the detection beam 113k in the longitudinal direction It is disposed at a symmetrical position with respect to the bisecting line.

Here, the detection beam 113k has a linear portion and an inclined portion connected to the linear portion by the connecting portion. The straight portion is a portion where the beam width of the detection beam 113k is substantially constant. The sloped portion is a portion provided at the end of the detection beam 113k or a portion connected to the detection beam 113l, and the beam width of the sloped portion gradually increases as the distance from the connection portion increases. The piezoresistive elements FzR1, FzR4, FzR2 ', and FzR3' are disposed closer to the inclined portion side than the connection portion in the detection beam 113k having the above-described configuration. That is, it can be said that the piezoresistive elements FzR1, FzR4, FzR2 'and FzR3' are disposed not on the linear portion of the detection beam 113k but inside the inclined portion. Further, in the piezoresistive elements FzR1 and FzR4, a part of the piezoresistive elements FzR1 and FzR4 is formed to extend over the reinforcing beam 112h or the reinforcing beam 112e.

As described above, in the sensor chip 110, a plurality of piezoresistive elements are separately disposed in each detection block. Thus, based on the change in the output of the plurality of piezoresistive elements arranged on the predetermined beam in accordance with the direction (axial direction) of the force applied (transmitted) to the force points 114a to 114d, the predetermined axial direction Up to six axes of displacement can be detected.

In the sensor chip 110, the detection beams 113c, 113f, 113i, and 113l are as short as possible to bring the detection beams 113b, 113e, 113h, and 113k closer to the

detection beams

113a, 113d, 113g, and 113j. The length of the detection beams 113b, 113e, 113h and 113k is secured as much as possible. By this structure, the detection beams 113b, 113e, 113h, and 113k can be easily bent in a bow shape, stress concentration can be relaxed, and load resistance can be improved.

Further, in the sensor chip 110, no piezoresistive element is disposed on the detection beams 113c, 113f, 113i, and 113l. Instead, the stresses of the

detection beams

113a, 113d, 113g and 113j, which are thinner and longer than the detection beams 113c, 113f, 113i and 113l and are easily bent in a bow, and the stresses of the detection beams 113b, 113e, 113h and 113k The piezoresistive elements are arranged in the vicinity of the position where is the largest. As a result, in the sensor chip 110, it is possible to take in stress efficiently, and sensitivity (change in resistance of the piezoresistive element to the same stress) can be improved.

In the sensor chip 110, dummy piezoresistive elements are disposed in addition to the piezoresistive elements used to detect distortion. In the dummy piezoresistive elements, all the piezoresistive elements including the piezoresistive element used for detection of strain are arranged so as to be point-symmetrical with respect to the center of the support portion 111 e.

Here, the piezoresistive elements FxR1 to FxR4 detect the force Fx, the piezoresistive elements FyR1 to FyR4 detect the force Fy, and the piezoresistive elements FzR1 to FzR4 and the FzR1 'to FzR4' detect the force Fz. The piezoresistive elements MxR1 to MxR4 detect the moment Mx, the piezoresistive elements MyR1 to MyR4 detect the moment My, and the piezoresistive elements MzR1 to MzR4 and MzR1 'to MzR4' detect the moment Mz. In the present embodiment, the force Fz may be detected from the piezoresistive elements FzR1 to FzR4 using the piezoresistive elements FzR1 'to FzR4' as a dummy, or vice versa. The moment Mz may be detected from the piezoresistive elements MzR1 to MzR4 using the piezoresistive elements MzR1 'to MzR4' as a dummy, or the opposite relation may be made.

As described above, in the sensor chip 110, a plurality of piezoresistive elements are separately disposed in each detection block. Thereby, based on the change of the output of the plurality of piezoresistive elements arranged on the predetermined beam according to the direction (axial direction) of the force or displacement applied (transferred) to the force points 114a to 114d, the predetermined axis It is possible to detect up to 6 axes of displacement in the direction.

Specifically, in the sensor chip 110, the displacement (Mx, My, Fz) in the Z-axis direction can be detected based on the deformation of a predetermined detection beam. That is, the moments (Mx, My) in the X-axis direction and the Y-axis direction can be detected based on the deformation of the

detection beams

113a, 113d, 113g, and 113j, which are the first detection beams. Further, the force (Fz) in the Z-axis direction can be detected based on the deformation of the

detection beams

113e and 113k, which are the second detection beams.

Further, in the sensor chip 110, displacements (Fx, Fy, Mz) in the X-axis direction and the Y-axis direction can be detected based on the deformation of a predetermined detection beam. That is, the forces (Fx, Fy) in the X-axis direction and the Y-axis direction can be detected based on the deformation of the

detection beams

113a, 113d, 113g, and 113j, which are the first detection beams. Further, the moment (Mz) in the Z-axis direction can be detected based on the deformation of the

detection beams

113a, 113d, 113g and 113j, which are the first detection beams.

By varying the thickness and width of each detection beam, it is possible to make adjustments such as uniform detection sensitivity and improvement of detection sensitivity.

However, it is also possible to reduce the number of piezoresistive elements and to use a sensor chip that detects displacement in a predetermined axial direction of five or less axes.

In the sensor chip of the present embodiment described above, the detection beam 113a is formed so that the beam width becomes narrow near the middle point between the position where it is connected with the

support portions

111a and 111b and the position where it is connected with the force point 114a. Piezoresistive elements MzR3 'and MzR4' are formed on the detection beam 113a at the portion where the beam width is narrowed. The same applies to the

detection beams

113d, 113g, and 113j and the piezoresistive elements MzR1, MzR2, MzR3, MzR4, MzR1 ', and MzR2'. This configuration and the effect thereof will be described later as a first configuration and an effect.

According to the above-described sensor chip according to the present embodiment, deformation of the beam when a force is applied is changed by providing a portion where the beam width is narrowed due to the tapered shape or the concave shape in the middle portion of the beam. , Can create a new location where stress can be detected. Thereby, it is possible to control the stress generation point. In addition, by detecting the stress generated at different locations of the beam (locations away from the beam) depending on the type of input, axis separation with less interference can be realized, and high accuracy can be achieved for multiple inputs. It can be detected. In the sensor chip according to the present embodiment, a high effect can be obtained particularly for axial separation of Mz and My. In addition, since a plurality of types of force and torque can be accurately detected with one beam without increasing the beam or the force point, the sensor chip can be miniaturized.

In the sensor chip of the present embodiment, the detection beam 113e has a linear portion and an inclined portion connected to the linear portion by the connecting portion, and the piezoresistive elements FzR2, FzR3, FzR1 ′, FzR4. In the detection beam 113e of the above configuration, 'is disposed closer to the inclined portion than the connection portion. The detection beam 113k has a linear portion and an inclined portion connected to the linear portion by the connecting portion, and the piezoresistive elements FzR1, FzR4, FzR2 ', and FzR3' have the above-described detection beam 113k. , Are arranged on the side of the inclined portion with respect to the connecting portion. This configuration and the effect thereof will be described later as a second configuration and effect.

According to the above-described sensor chip according to the present embodiment, by providing the sloped portion at the root of the beam, the deformation of the beam when a force is applied is changed, and it is possible to create a new place where stress can be detected. . Thereby, it is possible to control the stress generation point. In addition, by detecting the stress generated at different locations of the beam (locations away from the beam) depending on the type of input, axis separation with less interference can be realized, and high accuracy can be achieved for multiple inputs. It can be detected. In the sensor chip according to the present embodiment, high effects can be obtained particularly on axial separation of Fx and Fz, and axial separation of Fx and Mx, My. In addition, since a plurality of types of force and torque can be accurately detected with one beam without increasing the beam or the force point, the sensor chip can be miniaturized. In addition, by providing the sloped portion at the root of the beam, the rigidity of the beam can be enhanced and the load resistance can be improved.

(Eroded body 20)
FIG. 7 is a diagram (part 1) illustrating the strain generating body 20, FIG. 7 (a) is a perspective view, and FIG. 7 (b) is a side view. FIG. 8 is a diagram (part 2) illustrating the strain generating body 20, and FIG. 8 (a) is a plan view, and FIG. 8 (b) is a longitudinal sectional perspective view taken along line AA of FIG. 8 (a). It is. In FIG. 8A, for the sake of convenience, surfaces having the same height are shown in the same textured pattern. FIG. 9 is a diagram (part 3) illustrating the strain generating body 20, and FIG. 9 (a) is a longitudinal sectional view taken along the line BB of FIG. 8 (a), and FIG. 9 (b) is a diagram Fig. 9 is a cross-sectional view taken along the line C-C of 9 (a).

As shown in FIGS. 7 to 9, the strain-generating body 20 is separated from the base 21 directly attached to the fixed portion, the pillar 28 serving as a sensor chip mounting portion for mounting the sensor chip 110, and the periphery of the pillar 28. And columns 22a-22d.

More specifically, in the strain generating body 20, four columns 22a to 22d are arranged on the upper surface of the substantially circular base 21 so as to be uniform (point-symmetrical) with respect to the center of the base 21. The four beams 23a to 23d, which are the first beams connecting the two, are provided in a frame shape. A pillar 28 is disposed above the center of the top surface of the base 21. The planar shape of the base 21 is not limited to a circle, and may be a polygon or the like (for example, a square or the like).

The column 28 is formed thicker and shorter than the columns 22a to 22d. The sensor chip 110 is fixed on the column 28 so as not to protrude from the top surfaces of the columns 22a to 22d.

The pillars 28 are not directly fixed to the upper surface of the base 21, but are fixed to the pillars 22a to 22d via connecting beams 28a to 28d. Therefore, there is a space between the upper surface of the base 21 and the lower surface of the column 28. The lower surface of the column 28 and the lower surface of each of the connecting beams 28a to 28d can be flush with each other.

The cross-sectional shape of the portion to which the connection beams 28a to 28d of the column 28 are connected is, for example, a rectangle, and the four corners of the rectangle and the columns 22a to 22d opposed to the four corners of the rectangle are connected via the connection beams 28a to 28d. It is done. The positions 221 to 224 where the connecting beams 28a to 28d are connected to the columns 22a to 22d are preferably lower than the middle in the height direction of the columns 22a to 22d. The reason will be described later. The cross-sectional shape of the portion to which the connection beams 28a to 28d of the column 28 are connected is not limited to a rectangle, and may be a circle, a polygon or the like (for example, a hexagon or the like).

The connection beams 28a to 28d are disposed substantially parallel to the upper surface of the base 21 at a predetermined distance from the upper surface of the base 21 so as to be uniform (point-symmetrical) with respect to the center of the base 21. The thickness and thickness (rigidity) of the connecting beams 28a to 28d are preferably thinner than the columns 22a to 22d and the beams 23a to 23d so as not to prevent the deformation of the strain generating body 20.

Thus, the upper surface of the base 21 and the lower surface of the column 28 are separated by a predetermined distance. The predetermined distance can be, for example, about several millimeters. The technical significance of separating the upper surface of the base 21 and the lower surface of the column 28 by a predetermined distance without directly fixing the column 28 on the upper surface of the base 21 will be described later with reference to FIGS. 17 to 22.

The base 21 is provided with a through hole 21x for fastening the strain-generating body 20 to a portion to be fixed using a screw or the like. In the present embodiment, four through holes 21 x are provided in the base 21, but the number of through holes 21 x can be arbitrarily determined.

The schematic shape of the strain generating body 20 excluding the base 21 can be, for example, a rectangular solid having a length of about 5000 μm, a width of about 5000 μm, and a height of about 7000 μm. The cross-sectional shape of the columns 22a to 22d can be, for example, a square of about 1000 μm square. The cross-sectional shape of the column 28 can be, for example, a square of about 2000 μm square.

However, from the viewpoint of suppressing stress concentration in the strain generating body 20, it is preferable that the portion forming the inner angle be R-shaped. For example, it is preferable that the center side surface of the upper surface of the base 21 of the columns 22a to 22d be formed in an R-shape at the top and bottom. Similarly, the surface of the beams 23a to 23d facing the upper surface of the base 21 is preferably formed in an R shape on the left and right.

At the central portion in the longitudinal direction of the upper surface of each of the beams 23a to 23d, a projecting portion projecting upward from the central portion in the longitudinal direction of the beams 23a to 23d is provided. To 24 d are provided. The input portions 24a to 24d are portions to which a force is applied from the outside, and when a force is applied to the input portions 24a to 24d, the beams 23a to 23d and the columns 22a to 22d are deformed accordingly.

Thus, by providing the four input parts 24a to 24d, it is possible to improve the load resistance of the beams 23a to 23d, for example, as compared with the structure of one input part.

Four pillars 25a to 25d are disposed at four corners of the top surface of the pillar 28, and a pillar 25e which is a fourth pillar is disposed at the center of the top surface of the pillar 28. The columns 25a to 25e are formed at the same height.

That is, the upper surfaces of the columns 25a to 25e are located on the same plane. The upper surface of each of the pillars 25a to 25e is a joint bonded to the lower surface of the sensor chip 110.

At the central portion in the longitudinal direction of the inner side surface of each of the beams 23a to 23d, beams 26a to 26d are provided which project inward in the horizontal direction from the inner surface of each of the beams 23a to 23d. The beams 26a to 26d are second beams for transmitting the deformation of the beams 23a to 23d and the columns 22a to 22d to the sensor chip 110. Further, on the tip end side of the upper surface of each of the beams 26a to 26d, there are provided protrusions 27a to 27d which project upward from the tip end side of the upper surface of each of the beams 26a to 26d.

The protrusions 27a to 27d are formed at the same height. That is, the upper surfaces of the protrusions 27a to 27d are located on the same plane. The upper surface of each of the protrusions 27a to 27d is a bonding portion bonded to the lower surface of the sensor chip 110. The beams 26a to 26d and the protrusions 27a to 27d are connected to the beams 23a to 23d serving as movable parts, and therefore deform when the force is applied to the input units 24a to 24d.

When no force is applied to the input portions 24a to 24d, the upper surfaces of the columns 25a to 25e and the upper surfaces of the protrusions 27a to 27d are located on the same plane.

In the strain generating body 20, each portion of the base 21, the columns 22a to 22d, the columns 28, the beams 23a to 23d, the input parts 24a to 24d, the columns 25a to 25e, the beams 26a to 26d, and the protrusions 27a to 27d have rigidity Preferably, they are integrally formed from the viewpoint of securing and manufacturing with high accuracy. As a material of the strain generating body 20, for example, a hard metal material such as SUS (stainless steel) can be used. Among them, it is preferable to use SUS630 which is particularly hard and has high mechanical strength.

As described above, similarly to the sensor chip 110, when the strain-generating body 20 also has a column and a beam, the six-axis separability can be obtained because each of the six axes exhibits different deformation depending on the applied force. Good deformation can be transmitted to the sensor chip 110.

That is, the force applied to the input portions 24a to 24d of the strain generating body 20 is transmitted to the sensor chip 110 through the columns 22a to 22d, the beams 23a to 23d, and the beams 26a to 26d, and the displacement is detected by the sensor chip 110. Detect Then, in the sensor chip 110, the output of each axis can be obtained from a bridge circuit formed one for each axis.

(Manufacturing process of force sensor device 1)
10 to 12 illustrate the manufacturing process of the force sensor device 1. First, as shown in FIG. 10A, the strain generating body 20 is manufactured. The strain generating body 20 can be integrally formed, for example, by molding, cutting, wire discharge, or the like. As a material of the strain generating body 20, for example, a hard metal material such as SUS (stainless steel) can be used. Among them, it is preferable to use SUS630 which is particularly hard and has high mechanical strength. In the case of producing the strain generating body 20 by molding, for example, a metal particle and a resin to be a binder are put in a mold and formed, and thereafter, the strain is formed by sintering by evaporating the resin. The body 20 can be made.

Next, in a step shown in FIG. 10B, the adhesive 41 is applied to the upper surfaces of the pillars 25a to 25e and the upper surfaces of the protrusions 27a to 27d. For example, an epoxy-based adhesive can be used as the adhesive 41. The adhesive 41 preferably has a Young's modulus of 1 GPa or more and a thickness of 20 μm or less from the viewpoint of resistance to a force applied from the outside.

Next, in a process shown in FIG. 11A, the sensor chip 110 is manufactured. The sensor chip 110 can be manufactured by, for example, a known method in which an SOI substrate is prepared and the prepared substrate is subjected to etching (for example, reactive ion etching). The electrodes and the wirings can be produced, for example, by forming a metal film such as aluminum on the surface of the substrate by sputtering or the like and then patterning the metal film by photolithography.

Next, in the process shown in FIG. 11B, the sensor chip 110 is in contact with the adhesive 41 applied to the upper surfaces of the pillars 25a to 25e and the upper surfaces of the protrusions 27a to 27d in the lower surface of the sensor chip 110. The pressure is placed in the strain generating body 20 while being arranged. Then, the adhesive 41 is heated to a predetermined temperature to be cured. Thereby, the sensor chip 110 is fixed in the strain generating body 20. Specifically, the support portions 111a to 111d of the sensor chip 110 are fixed on the pillars 25a to 25e, the support portion 111e is fixed on the pillar 25e, and the force points 114a to 114d are fixed on the protrusions 27a to 27d, respectively. Be done.

Next, in the step shown in FIG. 12A, the adhesive 42 is applied to the top surfaces of the columns 22a to 22d. For example, an epoxy-based adhesive can be used as the adhesive 42. The adhesive 42 is for fixing the input / output substrate 30 on the strain-generating body 20, and a general-purpose adhesive can be used because a force is not applied from the outside.

Next, in the process shown in FIG. 12B, the input / output substrate 30 on which the active components 32 to 35 and the passive components 39 are mounted is prepared, and the lower surface of the input / output substrate 30 is applied to the upper surfaces of the columns 22a to 22d. The input / output substrate 30 is disposed on the strain generating body 20 so as to be in contact with the adhesive 42. Then, the adhesive 42 is heated to a predetermined temperature and cured while pressing the input / output substrate 30 to the strain generating body 20 side. Thereby, the input / output substrate 30 is fixed to the strain generating body 20.

The input / output board 30 is fixed to the strain generating body 20 so as to expose the sensor chip 110 and the input parts 24a to 24d. The electrodes 31 of the input / output substrate 30 are preferably disposed on the columns 22a to 22d of the strain generating body 20 with the least distortion when a force is applied to the input portions 24a to 24d.

Thereafter, the portions (except the input terminal side) of the input / output substrate 30 protruding in the horizontal direction from the strain generating body 20 are bent to the side surfaces of the strain generating body 20. Then, corresponding portions of the input / output substrate 30 and the sensor chip 110 are electrically connected by bonding wires or the like (not shown). Thus, the force sensor device 1 is completed.

As described above, since the force sensor device 1 can be manufactured using only the three components of the sensor chip 110, the strain generating body 20, and the input / output substrate 30, assembly is easy and the position alignment position can be minimized. And deterioration in accuracy due to mounting can be suppressed.

Further, in the strain generating body 20, since all the connection points with the sensor chip 110 (the upper surfaces of the columns 25a to 25e and the upper surfaces of the protrusions 27a to 27d) are on the same plane, the position of the sensor chip 110 with respect to the strain generating body 20. The alignment can be performed once, and it is easy to mount the sensor chip 110 on the strain generating body 20.

The first and second configurations and effects will be described below.

[First configuration and effect]
(Details of shape of detection beam)
FIG. 13A is an enlarged plan view of an essential part of an example of the sensor chip according to the present embodiment. The

detection beams

113a, 113d, 113g, and 113j shown in FIGS. 3 and 6 are collectively shown by the detection beam 113m. The detection beams 113b, 113e, 113h and 113k are collectively shown by the detection beam 113n. The detection beams 113c, 113f, 113i and 113l are collectively shown by the detection beam 113o. Further, the piezoresistive elements MzR1, MzR2, MzR3, MzR4, MzR1 ', MzR2', MzR3 'and MzR4' are represented by MzR1 and MzR2 as a representative.

In the detection beam 113m of the sensor chip shown in FIG. 13, the detection beam 113m extends from the position where the detection beam 113m is connected to the support to the position where the piezoresistive elements MzR1 and MzR2 are formed. At both sides, it has a tapered shape in which the beam width gradually narrows. The detection beam 113m has a beam width on both sides in the lateral direction of the detection beam 113m from the position where the detection beam 113m is connected to the force point to the position where the piezoresistive elements MzR1 and MzR2 are formed. It has a tapered shape that narrows gradually. That is, from the first beam width W3 'which is the width of the detection beam 113m at the position connected to the support portion or the power point, the second width which is the width of the detection beam 113m at the position where the piezoresistive elements MzR1 and MzR2 are formed The beam width W1 'is smaller. Thus, in the detection beam 113m, a portion where the beam width is narrowed is formed between the position where it is connected with the support portion and the position where it is connected with the power point. Piezoresistive elements MzR1 and MzR2 are formed on the detection beam 113m.

In the sensor chip of the present embodiment described above, when a moment (Mz) in the Z-axis direction is input, the stress generated in the detection beam 113m is the location 113q of the detection beam 113m at which the beam width is narrowed and the stress It grows in the vicinity. Therefore, the piezoresistive elements MzR1 and MzR2 disposed at the portion 113q where the beam width is narrowed have high sensitivity to the moment (Mz) in the Z-axis direction. The position of the portion 113 q where the beam width is narrowed is, for example, a midpoint between or near the position where the detection beam 113 m is connected to the support portion and the position where the force point is connected. The stress at the time of input of the moment (Mz) in the Z-axis direction becomes large at the location 113q where the beam width of the detection beam 113m becomes narrow, so the position of the location 113q where the beam width becomes narrow is for detection The beam 113m is not limited to be at or near the middle point of the position where it is connected to the support portion and the position where it is connected to the power point, and may be closer to the support portion side or the power point side than the above middle point. In this case, the piezoresistive elements MzR1 and MzR2 may be formed on the detection beam 113m at the portion 113q where the beam width is narrowed.

On the other hand, when force (Fx) in the X-axis direction is input to the sensor chip, stress is generated at the location 113q where the beam width of the detection beam 113m is reduced, where the piezoresistive elements MzR1 and MzR2 are formed. It hardly happens. In addition, when moment (My) in the Y-axis direction is input to the sensor chip, stress is generated at the location 113q where the beam width of the detection beam 113m is narrowed, where the piezoresistive elements MzR1 and MzR2 are formed. It hardly happens.

According to the sensor chip of the present embodiment, axial separation between the moment (Mz) in the Z-axis direction, the force (Fx) in the X-axis direction and the moment (My) in the Y-axis direction is enhanced. It is possible to improve the axis separation for the complex input of the sensor chip and to improve the sensor accuracy.

In the sensor chip of the present embodiment, it is preferable that the second beam width W1 '/ the first beam width W3' be 0.5 or less. As a result, the stress when the moment (Mz) in the Z-axis direction is input can be increased at the portions where the beam widths of the

detection beams

113a, 113d, 113g, and 113j are narrowed. For example, the first beam width W3 'is about 100 μm to 115 μm, and the second beam width W1' is about 50 μm.

In the above, the case is described in which both sides of the detection beam 113m in the lateral direction have a tapered shape in which the beam width gradually narrows, but one side of the detection beam 113m in the lateral direction The configuration may have a tapered shape in which the width gradually narrows.

FIG. 13B is an enlarged plan view of the detection beam 113m. For the length A of the tapered portion of the detection beam 113m and the length B of the tapered portion of the detection beam 113m, the formula of A: B = 1: 8.5 to 1: 10.5 It is preferable that the tapered shape has values of A and B that satisfy If the taper angle is insufficient, stress at the time of Mz input may occur in an area other than the portion where the beam width of the detection beam is narrowed. If the taper angle is excessive, the mechanical strength of the portion where the beam width of the detection beam is narrowed may be reduced.

FIGS. 14A and 14B are enlarged plan views of the main part of another example of the sensor chip according to the present embodiment. Beams corresponding to the

detection beams

113a, 113d, 113g, and 113j shown in FIGS. 3 and 6 are collectively shown by a detection beam 113m. Beams corresponding to the detection beams 113b, 113e, 113h, and 113k are collectively shown by the detection beam 113n. Beams corresponding to the detection beams 113c, 113f, 113i, and 113l are collectively shown by the detection beam 113o. The piezoresistive elements MzR1, MzR2, MzR3, MzR4, MzR1 ', MzR2', MzR3 'and MzR4' are represented by MzR1 and MzR2 as a representative.

In the sensor chip shown in FIG. 14, concave shapes 113p are provided on both sides in the short direction of the detection beam 113m. Thus, the beam width of the detection beam 113m is narrowed. Piezoresistive elements MzR1 and MzR2 for detecting a moment in the Z-axis direction are provided on the detection beam 113m in a portion where the concave shape 113p is provided and the beam width is narrowed. That is, from the first beam width W3 which is the width of the detection beam 113m at the position connected to the support portion or the power point, the second beam which is the width of the detection beam 113m at the position where the piezoresistive elements MzR1 and MzR2 are formed. The width W1 is smaller. As described above, in the detection beam 113m, a portion where the beam width is narrowed is formed between the position where it is connected with the support portion and the position where it is connected with the power point. Detection of the portion where the beam width becomes narrow Piezoresistive elements MzR1 and MzR2 are formed on the beam 113m.

In the sensor chip shown in FIG. 14, when a moment (Mz) in the Z-axis direction is input, the stress generated in the detection beam 113m is the concave shape 113p where the beam width of the detection beam 113m is narrowed and its vicinity It becomes large. On the other hand, when force (Fx) in the X-axis direction is input to the sensor chip, stress is applied to the concave shape 113p where the beam width of the detection beam 113m is narrowed, where the piezoresistive elements MzR1 and MzR2 are formed. Rarely occurs. In addition, when a moment (My) in the Y-axis direction is input to the sensor chip, stress is applied to the concave shape 113p where the beam width of the detection beam 113m is narrowed, in which the piezoresistive elements MzR1 and MzR2 are formed. Rarely occurs. Thus, axial separation between the moment (Mz) in the Z-axis direction and the force (Fx) in the X-axis direction and the moment (My) in the Y-axis direction is enhanced. It is possible to improve the axis separation for the complex input of the sensor chip and to improve the sensor accuracy.

In the sensor chip shown in FIG. 14, the position of the concave shape 113p is, for example, the middle point of the position where the detection beam 113m is connected with the support portion and the position where it is connected with the power point or nearby. It may be nearer to the support part side or the power point side than the above-mentioned middle point. In this case, the piezoresistive elements MzR1 and MzR2 may be formed on the detection beam 113m at a position where the beam width is narrowed due to the concave shape 113p.

For example, the first beam width W3 is about 100 μm to 115 μm, and the second beam width W1 is about 50 μm. The second beam width W1 / the first beam width W3 is preferably 0.5 or less. The third beam width W2, which is the beam width of the detection beam 113m at a position connected to the support portion or the force point and a portion excluding the concave shape 113p, is about 80 μm, for example. The second beam width W1 / the third beam width W2 is preferably 0.7 or less. The third beam width W2 / the first beam width W3 is preferably 0.3 or more and 0.6 or less.

Further, as shown in FIG. 14B, the width (the length in the longitudinal direction of the detection beam 113m of the concave shape 113p) L1 of the concave shape 113p formed on both sides in the lateral direction of the detection beam 113m. The length L2 in the longitudinal direction of the detection beam 113m from the end of the concave shape 113p to the portion where the beam width is constant at W2, and the beam width W2 at the position where the detection beam 113m is connected with the support portion L1 / L3 is preferably 0.5 or less, and L1 / L2 is 0.3 or less with respect to the length L3 in the longitudinal direction of the detection beam 113m until the width is expanded to the beam width W3. L2 / L3 is preferably 0.5 or more and 0.9 or less. For example, L1 is about 100 μm, L2 is about 187.5 μm, and L3 is about 125 μm.

In addition, a concave shape may be formed on one side of the detection beam 113m in the short side direction to narrow the beam width.

(First embodiment)
FIG. 15 is a diagram (stress contour diagram) showing the results of simulation calculation of stress when a moment (Mz) in the Z-axis direction is applied to the sensor chip of the reference example. Mark the "+" and "-" signs where the tensile or compressive stress is locally maximal, so that the gradation density becomes higher towards "+", or the gradation density towards "-" The thinner the, the greater the tensile or compressive stress. In the reference example of FIG. 15, unlike the case of FIGS. 13 and 14, in the detection beam 113m, a portion where the beam width is narrowed is formed between the position connected with the support portion and the position connected with the power point. Not. In the sensor chip according to the reference example, the stress generated at the position where the detection beam 113m is connected with the support and the position where the detection beam 113m is connected at the time of Mz input are large.

FIG. 16 is a diagram showing a result of simulation calculation of stress generated in the sensor chip when a moment (Mz) in the Z-axis direction is applied to the sensor chip according to another example of the present embodiment shown in FIG. (Stress contour view). A concave shape is formed on the detection beam 113m between the position connected to the support portion and the position connected to the power point, and the beam width is narrowed. At the time of Mz input, a concave shape was formed, and the stress generated at the portion where the beam width became narrow was large.

FIG. 17 is a diagram showing the result of simulation calculation of stress generated in the sensor chip when a force (Fx) in the X-axis direction is applied to the sensor chip according to another example of the present embodiment shown in FIG. (Stress contour view). In the detection beam 113m, a concave shape 113p is formed between the position connected to the support portion and the position connected to the power point, and the beam width is narrowed. At the time of Fx input, the concave shape 113p was formed, and almost no stress was generated at the portion where the beam width became narrow. Also, when a moment (My) in the Y-axis direction is applied instead of the force (Fx) in the X-axis direction, the stress is almost equal to the location where the concave shape 113p is formed and the beam width is narrowed. It did not occur.

FIG. 18 is a diagram showing the results of simulation calculation of stress generated in the sensor chip when a force (Fx) in the X-axis direction is applied to the sensor chip according to the present embodiment shown in FIG. 13 (stress contour diagram ). In the detection beam 113m, a portion 113q in which the beam width is narrowed is formed between the position connected to the support portion and the position connected to the power point. At the time of Fx input, almost no stress was generated at the portion 113 q where the beam width became narrow. Also, when a moment (My) in the Y-axis direction was applied instead of the force (Fx) in the X-axis direction, similarly, almost no stress was generated at the portion 113 q where the beam width became narrow.

According to the sensor chip of the present embodiment, it is confirmed that axial separation between the moment (Mz) in the Z-axis direction, the force (Fx) in the X-axis direction and the moment (My) in the Y-axis direction is enhanced. The

Second Embodiment
FIG. 19 is a diagram for explaining the simulation of the other axis component with respect to the sensor chip according to the reference example. The sensor chip according to the reference example is the same as the sensor chip shown in FIG. 15, and in the detection beam 113m, the beam width is narrowed between the position connected with the support portion and the position connected with the power point No part has been formed. Furthermore, the piezoresistive element for detecting Mz is formed on the detection beam 113m in the vicinity of the position where the detection beam 113m and the support portion are connected. FIG. 19 shows an error (N) between Fx input and Fx output when the sensor chip according to the reference example is subjected to input in which four axes selected as shown in the column of the input axis at the bottom of the drawing are combined. It is a figure which shows the result of having calculated | required the error (N) of Fy input and Fy output, and the error (N) of Fz input and Fz output by simulation. The sensor chip is required to have an error within 5% for each axis. As shown in FIG. 19, in the sensor chip according to the reference example, there were combinations of composite inputs in which the error of the output of Fz exceeded 5%.

FIG. 20 is a diagram for explaining a simulation of another axis component with respect to the sensor chip according to another example of the present embodiment. The sensor chip according to another example of the present embodiment is the same as the sensor chip shown in FIG. 14, and concave shapes are formed on both sides in the short direction in the detection beam 113m, and the beam width is narrow. A portion where the beam is not formed is formed, and a piezoresistive element for detecting Mz is formed at a portion where the beam width is narrowed. FIG. 20 shows Fx input and Fx when a sensor chip according to another example of the present embodiment is subjected to combined input of four axes selected as shown in the column of the input axis at the bottom of the figure. It is a figure which shows the result of having calculated | required the difference | error (N) of an output, the difference (N) of Fy input and Fy output, and the difference (N) of Fz input and Fz output by simulation. As shown in FIG. 20, in the sensor chip according to another example of the present embodiment, the outputs of Fx, Fy, and Fz all have an error of 5% or less. The error of the outputs of Fx, Fy, and Fz was greatly improved from the reference example of FIG.

FIG. 21 is a diagram for explaining the simulation of the other axis component with respect to the sensor chip according to the reference example. Error (N · m) between Mx input and Mx output when a combination of four axes selected as shown in the column of the input axis at the bottom of the figure is input to the sensor chip according to the reference example, My The result of having calculated | required the error (N * m) of an input and My output, and the error (N * m) of Mz input and Mz output by simulation is shown. The sensor chip is required to have an error within 5% for each axis. As shown in FIG. 21, in the sensor chip according to the reference example, there was a combination of composite inputs in which the error of the outputs of Mx and Mz exceeded 5%.

FIG. 22 is a diagram for explaining the simulation of the other axis component with respect to the sensor chip according to another example of the present embodiment. When a sensor chip according to another example of the present embodiment performs an input in which four axes selected as shown in the column of the input axis at the bottom of the drawing are combined, an error between Mx input and Mx output ( The result of having calculated | required the simulation (Nm), the error (Nm) of My input and My output, and the error (Nm) of Mz input and Mz output is shown. As shown in FIG. 22, in the sensor chip according to another example of the present embodiment, a part of Mx exceeded 5%, but the other outputs of Mx and the outputs of My and Mz are all The error was less than 5%. The errors in the outputs of Mx, My, and Mz were greatly improved from the reference example of FIG.

Third Embodiment
FIG. 23 is a diagram for explaining the simulation of the other axis component with respect to the sensor chip according to the reference example. The sensor chip according to the reference example is the same as the sensor chip shown in FIG. 15, and in the detection beam 113m, the beam width is narrowed between the position connected with the support portion and the position connected with the power point No part has been formed. Furthermore, the piezoresistive element for detecting Mz is formed on the detection beam 113m in the vicinity of the position where the detection beam 113m and the support portion are connected. FIG. 23 shows the sensor chip according to the reference example when single-axis direction, two-axis composite input, three-axis composite input, four-axis composite input, five-axis composite input, and six-axis composite input , Fx input and Fx output error (N), Fy input and Fy output error (N), Fz input and Fz output error (N), Mx input and Mx output error (N · m), My input It is a figure which shows the result of having calculated | required the error (N * m) of My output, and the error (N * m) of Mz input and Mz output by simulation. Here, the error (N) of Fx output, the error (N) of Fy output, and the error (N) of Fz output are F systems, and the average value (Avg.) And the maximum value (Max.) Are calculated. Also, the error (N · m) of the Mx output, the error (N · m) of the My output, and the error (N · m) of the Mz output are M systems, and the average value (Avg.) And the maximum value (Max.) Calculated.

As shown in FIG. 23, in the sensor chip according to the reference example, the error of F-system average value (Avg.) From single-axis to 6-axis composite was 5% or less, but the maximum value of F-system (Max ) Is 3 to 6 axes composite and the error is over 5%. The mean value (Avg.) Of the M system was 5 to 6 axis composite, and the error exceeded 5%. The maximum value (Max.) Of the M system was 5% or more for the 5-axis to 6-axis composite.

FIG. 24 is a diagram for explaining simulation of other-axis components with respect to the sensor chip according to another example of the present embodiment. The sensor chip according to another example of the present embodiment is similar to the sensor chip shown in FIG. As shown in FIG. 24, in the sensor chip according to another example of the present embodiment, the average value (Avg.) And the maximum value (Max.) Of the F system are 5% error from single-axis to six-axis composite. It was below. In addition, the average value (Avg.) Of the M system was less than 5% from single-axis to six-axis composite. On the other hand, the maximum value (Max.) Of the M system was more than 5% in a 2- to 5-axis composite. From the simulation of the other axis component for the sensor chip according to another example of the present embodiment shown in FIG. 24, it is confirmed that the axis separation can be greatly improved.

FIG. 25 is a diagram for explaining a simulation of another axis component with respect to the sensor chip according to an example of the present embodiment. The sensor chip according to an example of the present embodiment is similar to the sensor chip shown in FIG. As shown in FIG. 25, in the sensor chip according to an example of the present embodiment, the average value (Avg.) And the maximum value (Max.) Of the F system are 5% or less in error from single axis to 6-axis compound. there were. In addition, the average value (Avg.) And the maximum value (Max.) Of the M system also showed an error of 5% or less from uniaxial to 6-axis composite. From the simulation of the other axis component for the sensor chip according to the example of the present embodiment shown in FIG. 25, it is confirmed that the axis separation can be greatly improved.

[Second configuration and effect]
(Details of shape of detection beam)
FIG. 26 is an enlarged plan view of an essential part of an example of the sensor chip according to the present embodiment. The

detection beams

113a, 113d, 113g, and 113j shown in FIGS. 3 and 6 are collectively shown by the detection beam 113m. The detection beams 113b, 113e, 113h and 113k are collectively shown by the detection beam 113n. The detection beams 113c, 113f, 113i and 113l are collectively shown by the detection beam 113o. The reinforcing

beams

112e, 112f, 112g, and 112h are collectively shown as a reinforcing beam 112i. The piezoresistive elements FzR1, FzR2, FzR3, FzR4, FzR1 ', FzR2', FzR3 'and FzR4' are represented by FzR1 and FzR2.

In the sensor chip shown in FIG. 26, the detection beam 113n has a linear portion 113n1 and inclined portions 113n2 and 113n3 connected to the linear portion 113n1 by a connecting portion. The boundary between the linear portion 113n1 and the inclined portion 113n2 and the boundary between the linear portion 113n1 and the inclined portion 113n3 are connection portions. The linear portion 113n1 is a portion where the beam width of the detection beam 113n is substantially constant. The inclined portions 113n2 and 113n3 are portions provided at the end of the detection beam 113n or a portion connected to the detection beam 113o, and the beam widths of the inclined portions 113n2 and 113n3 gradually increase as the distance from the connection portion increases. The piezoresistive elements FzR1 and FzR2 are disposed closer to the inclined portions 113n2 and 113n3 than the connecting portion in the detection beam 113n having the above-described configuration. That is, it can be said that the piezoresistive elements FzR1 and FzR2 are disposed not on the linear portion 113n1 of the detection beam 113n but inside the inclined portions 113n2 and 113n3. Further, in the piezoresistive element FzR1, a part of the piezoresistive element FzR1 is formed so as to overlap the reinforcing beam 112i.

In the sensor chip of the present embodiment described above, when a force (Fz) in the Z-axis direction is input, the stress generated in the detection beam 113n is large at the inclined portions 113n2 and 113n3 of the detection beam 113n and in the vicinity thereof. Become. Therefore, the piezoresistive elements FzR1 and FzR2 disposed in the inclined portions 113n2 and 113n3 have high sensitivity to the force (Fz) in the Z-axis direction. Here, with regard to the piezoresistive element FzR1, a part of the piezoresistive element FzR1 is formed to extend over the reinforcing beam 112i. Fz is a force applied in the Z-axis direction which is the thickness direction of the sensor, and the stress at the time of Fz input becomes large near the reinforcing beam 112i. Therefore, as for the piezoresistive element FzR1, it is preferable to arrange the piezoresistive element FzR1 so that a part of the piezoresistive element FzR1 is placed on the reinforcing beam 112i.

On the other hand, when a force (Fx) in the X-axis direction is input to the sensor chip, the stress increases near the connecting portion which is the boundary between the straight portion 113n1 and the inclined portions 113n2 and 113n3, but the piezoresistive element FzR1 and Almost no stress is generated inside the inclined portions 113n2 and 113n3 of the detection beam 113n in which the FzR2 is formed.

According to the sensor chip of the present embodiment, axial separation between the force in the Z-axis direction (Fz) and the force in the X-axis direction (Fx) can be enhanced. It is possible to improve the axis separation for the complex input of the sensor chip and to improve the sensor accuracy.

FIG. 27 is a plan view enlarging an essential part of another example of the sensor chip according to the present embodiment. The

detection beams

113a, 113d, 113g, and 113j shown in FIGS. 3 and 6 are collectively shown by the detection beam 113m. The detection beams 113b, 113e, 113h and 113k are collectively shown by the detection beam 113n. The detection beams 113c, 113f, 113i and 113l are collectively shown by the detection beam 113o. Further, the piezoresistive elements MxR1, MxR2, MxR3, MxR4, MyR1, MyR2, MyR3, and MyR4 are represented by MxyR1. Here, MxyR1 corresponds to MxR1, MxR2, MxR3, MxR4 when formed on the

detection beams

113a and 113g whose longitudinal direction is the X-axis direction, and detection beam 113d whose longitudinal direction is the Y-axis direction , 113j corresponds to MyR1, MyR2, MyR3 and MyR4.

In the sensor chip shown in FIG. 27, the detection beam 113m has a linear portion 113m1 and inclined portions 113m2 and 113m3 connected to the linear portion 113m1 by a connecting portion. The boundary between the straight portion 113m1 and the inclined portion 113m2 and the boundary between the straight portion 113m1 and the inclined portion 113m3 are respectively connected portions. The linear portion 113m1 is a portion where the beam width of the detection beam 113m is substantially constant. The inclined portions 113m2 and 113m3 are portions provided at the end of the detection beam 113m or a portion connected to the detection beam 113o, and the beam widths of the inclined portions 113m2 and 113m3 gradually increase with distance from the connecting portion. The piezoresistive element MxyR1 is disposed closer to the inclined portion 113m2 than the connecting portion in the detection beam 113m having the above configuration. That is, it can be said that the piezoresistive element MxyR1 is disposed not on the straight portion 113m1 of the detection beam 113m but inside the inclined portion 113m2.

In the sensor chip of the present embodiment described above, when a moment (Mx) in the X-axis direction or a moment (My) in the Y-axis direction is input, the stress generated in the detection beam 113m is the inclination of the detection beam 113m. It becomes large in the part 113 m 2 and its vicinity. Therefore, the piezoresistive element MxyR1 disposed in the inclined portion 113m2 has high sensitivity to the moment (Mx) in the X-axis direction or the moment (My) in the Y-axis direction.

On the other hand, when a force (Fx) in the X-axis direction is input to the sensor chip, the stress increases near the connecting portion which is the boundary between the straight portion 113m1 and the inclined portions 113m2 and 113m3, but the piezoresistive element MxyR1 Almost no stress is generated inside the inclined portion 113m2 of the detection beam 113m which is formed.

According to the sensor chip of the present embodiment, axial separation between the force (Fz) in the Z-axis direction, the moment (Mx) in the X-axis direction, and the moment (My) in the Y-axis direction is enhanced. It is possible to improve the axis separation for the complex input of the sensor chip and to improve the sensor accuracy.

The detection beam 113n shown in FIG. 26 has a linear portion 113n1 and inclined portions 113n2 and 113n3 connected to the linear portion 113n1 by a connecting portion, and the piezoresistive elements FzR1 and FzR2 are inclined from the connecting portion 113n2. , The detection beam 113m shown in FIG. 27 has a linear portion 113m1 and inclined portions 113m2 and 113m3 connected to the linear portion 113m1 by a connecting portion, and the piezoresistance is provided. The configuration in which the element MxyR1 is disposed closer to the inclined portion 113m2 than the coupling portion may be either one or both of them.

FIGS. 28A and 28B are enlarged plan views of the main parts of another example of the sensor chip according to the present embodiment. Beams corresponding to the

detection beams

113a, 113d, 113g, and 113j shown in FIGS. 3 and 6 are collectively shown by a detection beam 113m. Beams corresponding to the detection beams 113b, 113e, 113h, and 113k are collectively shown by the detection beam 113n. Beams corresponding to the detection beams 113c, 113f, 113i, and 113l are collectively shown by the detection beam 113o.

In the sensor chip of this embodiment, the beam width of the linear portion 113n1 of the detection beam 113n is the first beam width W1, and the beam width of the portion of the inclined portion 113n3 where the beam width is the widest is the second beam width W2. At this time, it is preferable that the first beam width W1 / the second beam width W2 be 0.5 or less. Thus, by providing the Fz piezoresistive element inside the inclined portion, it is possible to sufficiently keep the piezoresistive element of Fz away from the stress generation point at the time of Fx input and to improve the axial separation of Fx and Fz. For example, the first beam width W1 is about 30 μm to 50 μm, and the second beam width W2 is about 75 μm to 100 μm.

Further, for the length L1 of the straight portion 113n1 and the length L2 of the inclined portion 113n3 in the longitudinal direction of the detection beam 113n, for example, L1 is 140 to 265 μm and L2 is about 100 to 150 μm.

FIG. 28B is an enlarged plan view of the detection beam 113n. For the length A of the tapered portion of the detection beam 113n and the length B of the tapered portion of the detection beam 113n, the formula of A: B = 1: 8.5 to 1: 10.5 It is preferable that the tapered shape has values of A and B that satisfy If the taper angle is insufficient, there is a possibility that the Fz piezoresistive element can not be sufficiently distanced from the stress generation point at the time of Fx input. If the taper angle is excessive, the mechanical strength of the portion where the beam width of the detection beam is narrowed may be reduced.

In the sensor chip shown in FIGS. 26 and 27, the concave shape 113p is provided on both sides in the lateral direction of the detection beam 113m, and the beam width of the detection beam 113m is narrowed. However, the present invention is not limited to this, and as shown in FIGS. 6 and 28, the beam width of the detection beam 113m may have a tapered shape in which the beam width gradually narrows.

(First embodiment)
FIG. 29 is an enlarged plan view of an essential part of an example of the sensor chip according to the embodiment, and is a plan view of the sensor chip for which stress simulation shown in FIGS. 30 and 31 is performed. Similar to the sensor chip according to the present embodiment shown in FIG. 26, the

detection beams

113a, 113d, 113g, 113j shown in FIGS. 3 and 6 are collectively shown by the detection beam 113m. The detection beams 113b, 113e, 113h and 113k are collectively shown by the detection beam 113n. The detection beams 113c, 113f, 113i and 113l are collectively shown by the detection beam 113o. The piezoresistive elements FzR1, FzR2, FzR3, FzR4, FzR1 ', FzR2', FzR3 'and FzR4' are represented by FzR1 and FzR2.

The detection beam 113n has a linear portion 113n1 and inclined portions 113n2 and 113n3 connected to the linear portion 113n1 by a connecting portion. The piezoresistive elements FzR1 and FzR2 are disposed closer to the inclined portions 113n2 and 113n3 than the connecting portion in the detection beam 113n having the above-described configuration. That is, the piezoresistive elements FzR1 and FzR2 are disposed not on the linear portion 113n1 of the detection beam 113n but inside the inclined portions 113n2 and 113n3. In the piezoresistive element FzR1, a part of the piezoresistive element FzR1 is formed to extend over the reinforcing beam 112i. In the sensor chip of FIG. 29, the detection beam 113m does not have a portion where the beam width is narrowed between the position where it is connected to the support portion and the position where it is connected to the power point.

FIG. 30 is a diagram (stress contour view) showing the results of simulation calculation of stress when a force (Fx) in the X-axis direction is applied to the sensor chip of the present embodiment shown in FIG. Mark the "+" and "-" signs where the tensile or compressive stress is locally maximal, so that the gradation density becomes higher towards "+", or the gradation density towards "-" The thinner the, the greater the tensile or compressive stress. When a force (Fx) in the X-axis direction is input to the sensor chip, the stress increases in the vicinity of the connecting portion which is the boundary between the straight portion 113n1 and the inclined portions 113n2 and 113n3, but the piezoresistive elements FzR1 and FzR2 Almost no stress is generated inside the inclined portions 113n2 and 113n3 of the detection beam 113n.

FIG. 31 is a diagram (stress contour view) showing the result of simulation calculation of stress when a force (Fz) in the Z-axis direction is applied to the sensor chip of the present embodiment shown in FIG. When a force (Fz) in the Z-axis direction is input to the sensor chip, the stress generated in the detection beam 113n becomes larger at the inclined portions 113n2 and 113n3 of the detection beam 113n and in the vicinity thereof. Therefore, the piezoresistive elements FzR1 and FzR2 disposed in the inclined portions 113n2 and 113n3 have high sensitivity to the force (Fz) in the Z-axis direction.

FIG. 32 is an enlarged plan view of an essential part of a sensor chip according to a reference example, and is a plan view of a sensor chip for which stress simulation shown in FIGS. 33 and 34 is performed. Unlike the sensor chip according to the present embodiment shown in FIG. 29, the piezoresistive elements FzR1 and FzR2 are adjacent to the connecting portion between the linear portion 113n1 and the inclined portions 113n2 and 113n3 from the linear portion 113n1 to the inclined portion 113n2. It is arranged to straddle 113n3.

FIG. 33 is a diagram (stress contour view) showing the result of simulation calculation of stress when a force (Fx) in the X-axis direction is applied to the sensor chip of the present embodiment shown in FIG. When a force (Fx) in the X-axis direction is input to the sensor chip, the stress becomes large in the vicinity of the connecting portion which is the boundary between the straight portion 113n1 and the inclined portions 113n2 and 113n3. The piezoresistive elements FzR1 and FzR2 arranged in the vicinity of the coupling portion have sensitivity to Fx input, and the axis separation becomes low.

FIG. 34 is a diagram (stress contour view) showing the results of simulation calculation of stress when a force (Fz) in the Z-axis direction is applied to the sensor chip of the present embodiment shown in FIG. When a force (Fz) in the Z-axis direction is input to the sensor chip, the stress generated in the detection beam 113n increases in the vicinity of the connection between the straight portion 113n1 and the inclined portions 113n2 and 113n3. The piezoresistive elements FzR1 and FzR2 arranged in the vicinity of the connecting portion have high sensitivity to the force (Fz) in the Z-axis direction.

According to the sensor chip of the present embodiment, it is confirmed that the axial separation between the force (Fz) in the Z-axis direction and the force (Fx) in the X-axis direction can be enhanced with respect to the reference example.

Although the preferred embodiments have been described above in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions may be made to the above-described embodiments without departing from the scope described in the claims. Can be added.

This application claims the priority of Basic Application No. 2018-012924 filed on Jan. 29, 2018 at the Japan Patent Office and Basic Application No. 2018-012925 filed on Jan. 29, 2018 at the Japanese Patent Office. The entire contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Force sensor apparatus 20 Strain generating body 21 Bases 22a to 22d, 25a to 25d, 28 pillars 23a to 23d, 26a to 26d Beams 24a to 24d Input parts 27a to 27d Protrusions 30 Input / output substrate 31 Electrodes 32 to 35 Active parts 39 Passive component 40 Force receiving plate 40x, 40z Recess 40y Through

hole

41, 42 Adhesive 110 Sensor chip 111a-111e Support part 112a-112h Reinforcement beam 113a-113o Detection beam 113n1 Straight part 113n2, 113n3 Inclined part 113p Concave shape 113q Beam width narrows 114a to 114d Force points FzR1 to FzR4, FzR1 'to FzR4, MzR1 to MzR4, MzR1' to MzR4 ', FxR1 to FxR4, FyR1 to FyR4, MxR1 to MxR4, MyR4 surface resistance

Claims

A substrate,
A first support,
A second support disposed at the periphery of the substrate, the first support being disposed around the periphery;
A first detection beam connecting the adjacent first supports;
A point of force on the first sensing beam, to which a force is applied;
And a plurality of strain detection elements disposed at predetermined positions of the first detection beam,
The plurality of strain detection elements include a first strain detection element formed on the first detection beam between the first support portion and the force point,
The first strain detection element is formed by a first beam width which is a width of the first detection beam at a position where the first detection beam is connected to the first support portion or the power point. A sensor chip having a smaller second beam width which is the width of the first detection beam at a position.
A second detection beam provided parallel to the first detection beam, between the first detection beam and the second support;
And a third detection beam connecting the first detection beam and the second detection beam in a set of the first detection beam and the second detection beam provided in parallel. , And
The sensor chip according to claim 1, wherein the force point is disposed at an intersection of the first detection beam and the third detection beam.
The sensor chip according to claim 1, wherein the second beam width / the first beam width is 0.5 or less.
The sensor chip according to claim 1, wherein the first detection beam at a position where the first strain detection element is formed has a concave shape for narrowing the beam width of the first detection beam.
The sensor chip according to claim 4, wherein the concave shape is formed on both sides of the first detection beam at a position where the first strain detection element is formed.
The width of the first detection beam gradually increases from the position where the first detection beam is connected to the first support portion or the force point to the position where the first strain detection element is formed. The sensor chip according to claim 1, wherein the sensor chip has a tapered shape that narrows down.
The sensor chip according to claim 6, wherein the sensor chip has a tapered shape in which the beam width is gradually narrowed on both sides in the lateral direction of the first detection beam.
When the thickness direction of the substrate is the Z-axis direction,
The sensor chip according to claim 1, wherein the first strain detection element is capable of detecting a force in a direction of rotating the Z-axis.
A first reinforcing beam provided on an outer side of the first detection beam in parallel with the first detection beam, the first reinforcement beam connecting the adjacent first support portions;
And a second reinforcing beam connecting the first support portion and the second support portion,
The second reinforcing beam is disposed nonparallel to the first reinforcing beam,
The first reinforcement beam and the second reinforcement beam are formed to be thicker than the first detection beam, the second detection beam, and the third detection beam.
The sensor chip according to claim 2, wherein the second detection beam connects end portions of the adjacent second support beam on the second support portion side.
A sensor chip according to claim 1;
And a strain sensor for transmitting an applied force to the sensor chip.
A substrate,
A first support,
A second support disposed at the periphery of the substrate, the first support being disposed around the periphery;
A first detection beam connecting the adjacent first supports;
A point of force on the first sensing beam, to which a force is applied;
And a plurality of strain detection elements disposed at predetermined positions of the first detection beam,
The first detection beam has a linear portion and an inclined portion connected to the linear portion by a connecting portion,
The plurality of strain detection elements include a first strain detection element disposed closer to the inclined portion than the connection portion. Sensor chip.
A second detection beam provided parallel to the first detection beam, between the first detection beam and the second support;
The second detection beam has a plurality of strain detection elements arranged at a predetermined position, a linear portion, and an inclined portion connected to the linear portion by a connecting portion,
The sensor chip according to claim 11, wherein the plurality of strain detection elements include a second strain detection element disposed closer to the inclined portion than the connection portion.
And a third detection beam connecting the first detection beam and the second detection beam in a set of the first detection beam and the second detection beam provided in parallel. , Equipped,
The sensor chip according to claim 12, wherein the force point is disposed at an intersection of the first detection beam and the third detection beam.
The sensor chip according to claim 11, wherein the sloped portion is a portion provided at an end portion of the first detection beam, and a beam width of the sloped portion gradually increases as the distance from the connecting portion increases.
The inclined portion is a portion provided at an end of the first detection beam or the second detection beam or a portion connected to the third detection beam, and the beam width of the inclined portion is The sensor chip according to claim 13, wherein the thickness gradually increases as the distance from the connection portion increases.
When the thickness direction of the substrate is the Z-axis direction,
The sensor chip according to claim 12, wherein the first strain detection element is capable of detecting a force in the Z-axis direction, and is formed on the second detection beam.
When the thickness direction of the substrate is the Z-axis direction,
The sensor chip according to claim 11, wherein the first strain detection element is capable of detecting a force in a direction of rotating an axis perpendicular to the Z axis, and is formed on the first detection beam.
Assuming that the beam width of the straight portion is a first beam width, and the beam width of a portion of the inclined portion where the beam width is wide is a second beam width, the first beam width / the second beam width is 0. The sensor chip according to claim 11, which is 5 or less.
A first reinforcing beam provided on an outer side of the first detection beam in parallel with the first detection beam, the first reinforcement beam connecting the adjacent first support portions;
And a second reinforcing beam connecting the first support portion and the second support portion,
The second reinforcing beam is disposed nonparallel to the first reinforcing beam,
The first reinforcement beam and the second reinforcement beam are formed to be thicker than the first detection beam, the second detection beam, and the third detection beam.
The sensor chip according to claim 13, wherein the second detection beam connects ends of the adjacent second support beam on the second support portion side.
A sensor chip according to claim 11;
And a strain sensor for transmitting an applied force to the sensor chip.