JP6371501B2 - Probe unit - Google Patents

Description

  The present invention relates to a probe unit used for inspection of an inspection object. The inspection object refers to an element or electronic component that requires continuity inspection, such as an IC package substrate, a printed circuit board, a liquid crystal panel substrate, various connectors, a semiconductor wafer, and a power semiconductor.

  In recent years, various circuit boards have been used, such as high-density mounting boards used in mobile phones and the like, or IC package boards such as BGA (Ball Grid Array) and CSP (Chip Size Package) incorporated in personal computers. Yes. Such a circuit board is subjected to, for example, a measurement of a direct current resistance value or a continuity test in steps before and after mounting, and the electrical characteristics of the circuit board are inspected. The inspection of the electrical characteristics is performed using a continuity inspection jig (hereinafter referred to as a “probe unit”) connected to an inspection device that measures the electrical characteristics. For example, a probe mounted on the probe unit. The circuit board side end (referred to as a first end) is brought into contact with an electrode of the circuit board (hereinafter also referred to as “measurement object”) (see, for example, Patent Document 1). ).

  FIG. 11 is a schematic cross-sectional view for explaining a method for inspecting the electrical characteristics of a measurement object using a conventional probe unit. The probe 101 used in this probe unit 100 is covered with an insulating film 103 in a region other than both ends (102a, 102b) of the linear metal conductor 2 having a spring property, and is in contact with the electrode 112 of the measured object 111. A first end portion 102a that contacts the lead wire 150 on the inspection apparatus side. The probe unit 100 includes a plurality of to several thousand probes 101, a guide plate 130 with a second end side guide hole for guiding the second end side of the probe 101, and a first end 102a of the probe 1. Includes at least a guide plate 120 having a first end side guide hole for guiding the first end side of the probe 101 so as to be in contact with the electrode 112 of the measurement object 111.

  In the inspection of the electrical characteristics, the probe unit 100 or the measured object 111 is relatively moved up and down, and the first end 102a of the probe 101 is attached to the electrode 112 of the measured object 111 by using the elastic force of the probe 101. This is done by pressing with pressure. At this time, the probe 101 bent by the force pressed against the electrode 112 brings the second end 102 b into strong contact with the lead wire 150, and an electrical signal from the measured object 112 passes through the lead wire 150 and is inspected. Sent to a device (not shown). In the inspection of the electrical characteristics using the probe unit 100, the probe 101 is prevented from falling off from the probe unit 100 as shown in FIG. 11A in the guide hole provided in the guide plate 120. This is done by hitting the insulating coating end 103a. The setting of the probe 101 to the probe unit 100 is performed by inserting the probe 101 from a guide hole provided in the guide plate 130.

JP 2007-322369 A

  As described above, in the inspection of the electrical characteristics, as shown in FIG. 11B, the probe 101 is bent by the force with which the first end 102a of the probe 101 is pressed against the electrode 112, and the bent probe 101 is bent. Due to this elastic force, the second end portion 102 b of the probe 101 comes into strong and accurate contact with the lead wire 150, and an electrical signal from the measured object 112 is sent to the inspection device through the lead wire 150. At this time, the first end 102a of the probe 101 is always in contact with a new inspection object (electrode 112), but the second end 102b of the probe 101 is always in contact with the end surface 151 of the same lead wire 150. It will be.

  As shown in FIG. 12, the second end portion 102b of the probe 101 is usually hemispherical, and therefore the end surface 151 of the lead wire 150 is formed in the hemispherical second end portion 102b as shown in FIG. Point contact with. Therefore, the load at the time of contact is concentrated at one point, and the end surface 151 of the lead wire 150 is plastically deformed, and when it is repeated, it is worn so as to be wrinkled. As the wear progresses, as shown in FIGS. 12B and 12C, the end surface 151 of the lead wire 150 may be deformed, and there is a possibility that the point contact is changed to the surface contact. The change from point contact to surface contact may increase the contact area and decrease the contact pressure, leading to instability of contact resistance between the second end portion 102b of the probe 101 and the end surface 151 of the lead wire 150.

  Further, as shown in FIG. 12, the length until the lead wire 150 hits the end surface 151 is increased by Δ1 or Δ2, the bending of the probe 101 is reduced, and the contact pressure to the end surface 151 of the lead wire 150 is reduced. The contact resistance between the second end portion 102b of the probe 101 and the end surface 151 of the lead wire 150 may increase. Further, the wear powder generated by the wear of the end surface 151 of the lead wire 150 may cause the contact with the second end portion 102b of the probe 101 to become unstable, or the wear powder may cause the first wear of the probe 101 to become unstable. There is also a possibility of becoming a contaminant of the measurement object on the one end 102a side.

  The present invention has been made in order to solve the above-described problems, and the object thereof is to enable stable contact between the second end portion of the probe and the end surface of the lead wire for a long period of time, and wear and wear. It is providing the probe unit which can suppress generation | occurrence | production of powder | flour.

  In order to solve the above problems, a probe unit according to the present invention has a first end on the measured object side in contact with the measured object, and a second end on the inspection apparatus side in contact with the inspection apparatus connecting metal. A plurality of probes for measuring the electrical characteristics of the object to be measured with the inspection device, two sets of guide plates arranged to guide the both end sides of the probe and leave a space in between, An inspection apparatus connecting metal that contacts the second end of the probe guided by a guide plate on the inspection apparatus side, wherein the probe is a metal conductor and at least other than both ends of the metal conductor. An insulating coating provided in the region, and the shape of the second end portion of the probe has a flat portion in contact with the inspection device connecting metal, and the second end portion and the inspection device connection Metal and the plow Wherein the contacting with the metal angular range of 0.5 ° to 5 ° with the virtual axis as a normal line of the test device connection metal conductors constituting the.

  According to this invention, the second end portion of the probe constituting the probe unit has a flat portion, and the second end portion and the inspection device connecting metal are inspected with the virtual axis of the metal conductor constituting the probe. Since the contact is made in the range of 0.5 ° to 5 ° with respect to the normal line of the device connecting metal, the edge between the outer peripheral surface of the second end and the flat portion hits the inspection device connecting metal. In this case, since the contact form between the second end of the bent probe and the metal for connecting the inspection apparatus easily and instantaneously shifts from the point contact at the edge to the surface contact at the flat part. In addition, wear of inspection equipment connecting metal does not increase. As a result, problems (decrease in contact pressure, instability of contact resistance) due to conventional point contact can be solved, stable contact can be realized for a long time, and increase in contact resistance and instability can be prevented. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

  In the probe unit according to the present invention, the ratio (d / D) between the diameter d of the flat portion of the second end portion and the conductor diameter D of the metal conductor is 0.6 to 1 when D is 150 μm. 110 μm 0.5 to 0.9, D 90 μm 0.4 to 0.8, D 70 μm 0.3 to 0.6, D 50 μm 0.3 to 0.6, D 30 μm The relationship between the diameter d and the conductor diameter D is a graph in which the conductor diameter D is the horizontal axis and the d / D is the vertical axis. It is preferable to satisfy a range surrounded by a line connecting the lower limit values of D and a line connecting the upper limit values of each d / D.

  According to the present invention, since the diameter d of the flat portion of the second end portion of the probe constituting the probe unit and the conductor diameter D of the metal conductor satisfy the above relationship, the second end portion of the probe satisfying this relationship. Can be prevented from coming into contact with a large pressure exceeding 100 MPa, for example, and the contact between the second end of the probe and the end face of the lead wire can be performed stably for a long period of time. be able to. The reason is that the contact form between the second end of the bent probe and the metal for connecting the inspection apparatus is easily and instantly changed from a point contact where the stress is concentrated locally to a surface contact where the stress is not concentrated locally. This is because the wear of the metal for connecting the inspection device based on the contact does not increase. As a result, problems (decrease in contact pressure, instability of contact resistance) due to conventional point contact can be solved, stable contact can be realized for a long time, and increase in contact resistance and instability can be prevented. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

  In the probe unit according to the present invention, the second end portion on the inspection device side is connected to the inspection device so that a contact pressure between the flat portion of the second end portion and the metal for connecting the inspection device is 25 MPa or more and 100 MPa or less. Contact the connecting metal.

  According to this invention, since the second end portion on the inspection device side is brought into contact with the inspection device connection metal so that the contact pressure between the flat portion of the second end portion and the inspection device connection metal falls within the above range, The contact pressure within that range can solve the problems caused by conventional point contact (decrease in contact pressure, instability of contact resistance), achieve stable contact for a long period of time, and prevent increase in contact resistance and instability. be able to. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

  According to the probe unit of the present invention, when the second end hits the inspection device connecting metal, the contact between the bent second end of the probe and the inspection device connecting metal is at the edge. Since the transition from the point contact to the surface contact at the flat part easily and instantaneously, the wear of the inspection apparatus connecting metal based on the contact does not increase. As a result, problems (decrease in contact pressure, instability of contact resistance) due to conventional point contact can be solved, stable contact can be realized for a long time, and increase in contact resistance and instability can be prevented. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

It is typical sectional drawing which shows an example of the probe unit which concerns on this invention. It is a typical external view which shows an example of the probe used for the probe unit which concerns on this invention. It is a schematic diagram explaining the shape of the 2nd end part of a probe. It is a graph which shows the range which can implement | achieve the effect of this invention about the relationship between the conductor diameter D of a metal conductor, and the diameter d of the flat part of the 2nd end part of a metal conductor. It is a graph which shows the contact pressure of the flat part and the metal for a test | inspection apparatus connection when the various probes from which the conductor diameter D of a metal conductor differs from the diameter d of the flat part of the 2nd end part of a metal conductor are used. . It is a schematic diagram which shows the contact form of the 2nd end part of a probe, and the metal for an inspection apparatus connection. It is a schematic diagram of the surface form of the inspection apparatus connecting metal after the second end of the probe repeatedly contacted, (A) is an example using the probe according to the present invention, (B) is a conventional probe It is an example used. It is a schematic diagram which shows the contact form of the 2nd end part of a probe, and the metal for an inspection apparatus connection. It is a microscope picture of the end surface of the metal for a test | inspection apparatus connection after performing the contact 200,000 times with the probe of Example 1. FIG. It is a microscope picture of the end surface of the metal for a test | inspection apparatus connection after performing the contact 200,000 times with the probe of the comparative example 1. FIG. It is a schematic cross section for demonstrating the method to test | inspect the electrical property of a to-be-measured body using a probe unit. It is a schematic diagram for demonstrating the problem which generate | occur | produces by the contact with the 2nd edge part of the conventional probe, and the metal for an inspection apparatus connection.

  Hereinafter, a probe unit and a probe according to the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment.

<Probe unit>
As shown in FIG. 1, the probe unit 10 according to the present invention guides a plurality of probes 1 and both ends 2a and 2b of the probe 1 and two sets of guides arranged with a space S in the middle. The plates 20 and 30 and the inspection apparatus connecting metal 50 that contacts the second end 2b of the probe 1 guided by the inspection apparatus side guide plate 30 are provided. Then, the first end 2a of the probe 1 is brought into contact with the measured object 11, and the second end 2b on the inspection apparatus side is brought into contact with the end surface 51 of the inspection apparatus connecting metal 50, whereby the electric power of the measured object 11 is measured. This is for measuring the physical characteristics with an inspection device.

  In the probe unit 10, as shown in FIG. 2, the shape of the second end 2 b of the probe 1 has a flat portion 2 d that contacts the inspection device connecting metal 50, and the second end 2 b and the inspection device are connected. As shown in FIG. 6, the working metal 50 is 0.5 ° or more and 5 ° or less in the angle θ between the virtual axis a1 of the metal conductor 2 constituting the probe 1 and the normal line a2 of the inspection device connecting metal 50. In the range of contact.

  Hereinafter, each configuration will be described in detail. In FIG. 2, reference numeral 2 a is a “first end” disposed on the measured object side and in contact with the electrode 12 of the measured object 11, and reference numeral 2 b is disposed on the inspection apparatus side and is an inspection apparatus ( It is a “second end” that contacts a lead wire (not shown) (metal for inspection apparatus connection) 50.

[probe]
The probe 1 has the first end 2a on the measured object side in contact with the measured object 11, and the second end 2b on the inspection apparatus side is a metal conductor constituting the probe 1 on the inspection apparatus connecting metal 50. 2 is used to measure the electrical characteristics of the object to be measured by bringing the angle θ between the virtual axis a1 of 2 and the normal line a2 of the inspection apparatus connecting metal 50 within a range of 0.5 ° to 5 °. Is.

  As shown in FIGS. 2 and 3, the probe 1 includes a metal conductor 2 and an insulating coating 3 provided in a region other than at least both ends 2 a and 2 b of the metal conductor 2.

(Metal conductor)
As the metal conductor 2, a metal wire (also referred to as “metal spring wire”) having high conductivity and high spring property is used. Examples of the metal used for the metal conductor 2 include metals having a wide elastic range, for example, copper alloys such as beryllium copper, phosphor bronze, copper silver alloy, tungsten, rhenium tungsten, steel (for example, high speed steel: SKH). Etc.) can be preferably used. Such metal conductor 2 is usually subjected to plastic working such as cold or hot wire drawing until the metal becomes a linear conductor of a predetermined diameter.

  From the viewpoint of ease of mounting the probe 1 to the probe unit 10, the metal conductor 2 preferably has a high straightness. Specifically, the straightness is preferably 1000 mm or more in terms of the radius of curvature R. The metal conductor 2 having high straightness can be usually obtained by performing straightening treatment in advance before the insulating coating 3 is provided. The straightening process here is performed, for example, by a rotary die type straightening apparatus or the like. By providing such straightness, it is possible to prevent the probe 1 from entering the guide holes of the guide plates 20 and 30 when the probe 1 is attached to the probe unit 10 as shown in FIG.

  The metal conductor 2 has a first end 2a on the measured object side and a second end 2b on the inspection apparatus side, both of which have exposed portions of predetermined lengths A and B without the insulating coating 3. Yes.

  The shape of the first end 2a is not particularly limited and may be any one selected from a conical shape, a conical shape having a hemispherical shape at the top, a conical shape having a flat shape at the top, and the like. The “hemispherical shape” and “conical shape” here include an accurate hemisphere and a cone, but also include a substantially cone and a substantially hemisphere. In addition, when the 1st end part 2a is processed by electropolishing or an etching process, the front-end | tip or edge shape turns into a slightly round shape, However, It is not necessarily limited to such a shape.

  The second end 2b has a flat portion 2d that contacts the inspection device connecting metal 50, and the inspection device connecting metal 50 has a virtual axis a1 of the metal conductor 2 and a normal line a2 of the inspection device connecting metal. Contact is made in the range of 0.5 ° or more and 5 ° or less at an angle θ. The present invention is characterized in that the second end 2b of the probe 1 has such a shape and contact mode. This will be described in detail later.

  The first end 2a and / or the second end 2b of the metal conductor 2 has a plating layer for suppressing an increase in the contact resistance value between the metal conductor 2 and the measured object 11 or the lead wire 50 of the inspection apparatus. May be provided. Examples of the metal constituting the plating layer include metals such as nickel, gold, and rhodium, and alloys such as gold alloys. The plating layer may be a single layer or a multilayer. Preferred examples of the multi-layered plating layer include those in which a gold plating layer is formed on a nickel plating layer.

(Insulation coating)
The insulating coating 3 is provided on the metal conductor 2 other than the end exposed at predetermined lengths A and B, and prevents the probes from contacting each other when inspecting the electrical characteristics of the measured object 11, thereby preventing a short circuit. Acts as follows. The insulating coating 3 may be provided on the outer periphery of the metal conductor 2 over the longitudinal direction, may be provided directly, or may be provided via another layer.

  The insulating coating 3 is not particularly limited as long as it is an insulating coating, but any one or two selected from polyurethane resin, nylon resin, polyester resin, epoxy resin, polyesterimide resin, polyamide resin and polyamideimide resin The above is preferable. Usually, it is formed of one kind of resin. One layer or two or more layers may be used. Since the insulating coating 3 made of these resins has different heat resistance, it can be arbitrarily selected in consideration of the heat generated during the inspection. For example, when more heat resistance is required, the insulating coating 3 is preferably formed of a polyesterimide resin, a polyamideimide resin, or the like. Especially, it is preferable that the insulating film 3 is formed as a baking enamel film. As will be described later, the baking enamel coating is formed in a continuous process by repeated coating and baking of the paint, so that the productivity is good, the adhesion between the metal conductor is high, and the coating strength is higher. Can do.

  The length of the probe 1 configured in this manner is usually 10 mm to 100 mm, although it varies depending on the wire diameter. Further, the insulating coating 3 is usually peeled off at a length of about 2 mm to 6 mm on the first end portion 2a side, and the insulating film 3 is also usually insulated at a length of about 0.1 mm to 3.0 mm on the second end portion 2b side. The coating 3 is peeled off. Such peeling is performed by various peeling means such as laser peeling.

(Shape of the second end)
As shown in FIGS. 6 and 8, the feature of the present invention is that the second end 2b of the probe 1 has a flat portion 2d that comes into contact with the inspection apparatus connecting metal, and the inspection apparatus connecting metal 50 is made of metal. The contact between the virtual axis a1 of the conductor 2 and the normal line a2 of the inspection apparatus connecting metal is in the range of 0.5 ° or more and 5 ° or less.

  When the edge between the outer peripheral surface and the flat portion 2d hits the end surface 51 of the inspection apparatus connecting metal 50, the second end section 2b and the inspection apparatus 2 are bent. Since the contact form with the connecting metal 50 easily and instantaneously shifts from the point contact at the edge to the surface contact at the flat portion 2d, the wear of the inspection apparatus connecting metal 50 based on the contact does not increase. As a result, problems (decrease in contact pressure, instability of contact resistance) due to conventional point contact can be solved, stable contact can be realized for a long time, and increase in contact resistance and instability can be prevented. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

  The shape of the second end 2b may be any shape having a flat tip surface, and specifically, a truncated cone shape as shown in FIGS. 3 and 6, a cylindrical shape as shown in FIG. Can be mentioned. The second end 2b may be an accurate truncated cone, cylinder, or the like, or may have a slightly rounded edge as shown in FIG. 3B. When the second end 2b is processed by electropolishing or etching, the edge shape of the flat portion 2d is a slightly rounded shape.

  Among these shapes, the second end portion 2b is, in particular, (1) a shape in which the longitudinal cross-sectional shape is a trapezoid whose width becomes narrower toward the tip side, or (2) a diameter of the flat portion 2d. It is preferable that d and the conductor diameter D of the metal conductor 2 have a shape satisfying the relationship shown in FIG.

  (1) Examples of the trapezoidal shape whose width becomes narrower as the longitudinal cross-sectional shape goes to the tip end side include a truncated cone shape and a truncated pyramid shape. By forming the second end 2b in such a shape, the slope 2c from the flat part 2d to the outer peripheral surface of the metal conductor 2 becomes smooth, and the edge between the slope 2c and the flat part 2d becomes an obtuse angle. Become. Therefore, as shown in FIG. 6, when the edge hits the end face 51 of the inspection apparatus connecting metal 50, the bent second end 2 b of the probe 1 and the end face 51 of the inspection apparatus connecting metal 50 are formed. The contact easily and instantaneously shifts from the point contact at the edge to the surface contact at the flat portion 2d. As a result, the point contact where the load is concentrated does not occur, the wear of the end face 51 of the inspection apparatus connecting metal 50 based on the contact does not increase, and the above-described effects can be made even more advantageous. .

  Further, (2) the shape in which the diameter d of the flat portion 2d and the conductor diameter D of the metal conductor 2 satisfy the relationship shown in FIG. 4 is the diameter d of the flat portion 2d and the conductor diameter D of the metal conductor 2 When the ratio (d / D) is 0.6 to 1 when D is 150 μm, 0.5 to 0.9 when D is 110 μm, 0.4 to 0.8 when D is 90 μm, and D is 70 μm 0.3 to 0.6, 0.3 to 0.6 when D is 50 μm, 0.7 to 1 when D is 30 to 15 μm, and the relationship between the diameter d and the conductor diameter D is As shown in FIG. 4, in a graph with the conductor diameter D as the horizontal axis and d / D as the vertical axis, a line connecting the lower limit value of each d / D and a line connecting the upper limit value of each d / D It is a shape satisfying the range R surrounded by. By making the 2nd end part 2b into such a shape, the contact pressure with respect to the test | inspection apparatus connection metal 50 becomes an appropriate range, and the problem by the conventional point contact can be eliminated. This effect will be described based on the experimental results shown in FIG.

  The range R shown in FIG. 4 is derived from the results shown in FIG. FIG. 5 shows the connection between the flat portion 2d and the inspection apparatus when various probes 1 having a different conductor diameter D of the metal conductor 2 and a diameter d of the flat portion 2d of the second end 2b of the metal conductor 2 are used. It is a graph which shows a contact pressure with a metal. As shown in FIG. 5, in the probe 1 having each conductor diameter D, the contact pressure increases as the diameter d of the flat portion 2d decreases, and the contact pressure decreases as the diameter d of the flat portion 2d increases and approaches the conductor diameter D. did. And when the form after the contact of the end face 51 of the inspection apparatus connecting metal 50 against which the second end 2b is pressed is observed, when the contact pressure is 25 MPa or more and 100 MPa or less, there is a remarkable abnormality in the form of the end face 51. I couldn't see it. On the other hand, when the contact pressure exceeds 100 MPa, a noticeable abnormality is likely to occur in the form of the end face 51, and an ugly form may be seen. Further, when the contact pressure is less than 25 MPa, although no remarkable abnormality is seen in the form of the end face 51, the contact is insufficient and the contact resistance may increase.

  Thus, in the present invention, the second end 2b on the inspection device side is set so that the contact pressure between the flat portion 2d of the second end 2b and the end surface 51 of the inspection device connecting metal 50 is 25 MPa or more and 100 MPa or less. Is preferably pressed against the end face 51 of the inspection device connecting metal 50, so that the contact pressure within that range eliminates the problems caused by conventional point contact (reduction of contact pressure, instability of contact resistance). It is possible to achieve stable contact over a long period of time, and to prevent an increase in contact resistance and instability. In addition, it is possible to suppress wear and wear powder that are likely to occur in the case of point contact.

  Note that the relationship shown in FIG. 5 is that the probe 1 with each conductor diameter D having various tip widths (the diameter d of the flat portion 2d) is brought into contact with the end face 51 of the inspection apparatus connecting metal 50 and then 0.2 mm. It is the result obtained using the probe unit designed to push in. The length of the probe 1 used is 10 to 30 mm, the probe 1 bends by the length of 0.2 mm that has been pushed in, and the second end 2 b of each contact pressure is applied to the end face 51 of the inspection apparatus connecting metal 50. It is pressed by. The contact pressure at this time was obtained by dividing the load measured by a precision universal testing machine (manufactured by Shimadzu Corporation, model number: AG-I) by the area of the flat portion of the second end 2b of the probe 1. It is.

  As described above, the probe 1 satisfying the above relationship prevents contact with a large pressure exceeding, for example, 100 MPa when the second end 2b hits the end surface 51 of the inspection apparatus connecting metal 50. Therefore, the contact between the second end 2b of the probe 1 and the end surface 51 of the lead wire can be performed stably for a long period of time. The reason is that the contact form between the bent second end 2b of the probe 1 and the inspection apparatus connecting metal 50 is easily changed from a point contact where the stress is concentrated locally to a surface contact where the stress is not concentrated locally. This is because the transition is instantaneous, and the wear of the inspection apparatus connecting metal 50 based on the contact does not increase.

(Guide plate)
As shown in FIG. 1, the guide plate (guide plate with the front end side guide hole 21) 20 and the guide plate (guide plate with the second end side guide hole 31) 30 are arranged with a space S therebetween. .

  The guide plate 20 with the distal end side guide hole 21 guides the lower side of the probe 1 so that the first end 2 a of the probe 1 is in contact with the electrode 12 of the measured object 11, and the second end side guide The guide plate 30 with the hole 31 guides the upper side of the probe 1. Each guide plate 20, 30 may be composed of a single plate, or may be composed of a plurality of plates as in this embodiment.

  Each guide plate 20, 30 has a large number of guide holes 21, 31 opened at a minute pitch. When the guide plates 20, 30 are stacked, the upper and lower guide holes 21, 31 are positioned in plan view. Are designed to be slightly displaced in the parallel direction.

  One probe 1 is inserted into each of the guide holes 21 and 31 of each guide plate 20 and 30. The probe 1 inserted into the guide plates 20 and 30 is slightly displaced in the parallel direction between the upper and lower guide holes 21 and 31 of the respective guide plates 20 and 30. When the second end 2b comes into contact with the end face 51 of the inspection apparatus connecting metal 50, the angle θ between the virtual axis a1 of the metal conductor 2 constituting the probe 1 and the normal line a2 of the inspection apparatus connecting metal 50 is 0. Inclined to be 5 ° or more and 5 ° or less. The number of probes 1 attached to each guide plate 20 and 30 can be appropriately selected according to the measurement object 11, and is usually from a plurality to several thousands.

  In the inspection of the electrical characteristics by the probe unit 10, the probe unit 10 or the measured object 11 is relatively moved up and down, and the probe 1 is applied to the electrode 12 of the measured object 11 with a predetermined pressure by using the elastic force of the probe 1. It is done by pressing with. At this time, the second end 2b of the probe 1 bent by the force pressed against the electrode 12 makes strong contact with the lead wire 50, and an electrical signal from the measured object 11 passes through the lead wire 50 and the inspection device. (Not shown). In the inspection of the electrical characteristics using the probe unit 10, the probe 1 is prevented from falling off from the probe unit 10 as shown in FIG. 1 in the guide hole 21 provided in the guide plate 20 in the end portion of the insulating film of the probe 1. This is done by hitting 3a. The setting of the probe 1 to the probe unit 10 is performed by inserting the probe 1 from the guide hole 31 provided in the guide plate 30. In FIG. 1, reference numeral 40 denotes a lead wire holding plate.

(Contact mode)
In the probe unit 10, as shown in FIGS. 6 and 8, the second end 2 b of the probe 1 and the end surface 51 of the inspection device connecting metal 50 are connected to the virtual axis a 1 of the metal conductor 2 constituting the probe 1, and The inspection device connecting metal 50 is configured to contact within a range of 0.5 ° or more and 5 ° or less at an angle θ with the normal line a2.

  When the second end 2b comes into contact with the end face 51 of the inspection apparatus connecting metal 50 by making contact at an angle θ in this range, the second end 2b of the bent probe 1 and the inspection apparatus connecting metal 50 are not bent. The contact with the end surface 51 can be easily and instantaneously shifted from the point contact at the edge of the second end 2b to the surface contact at the flat portion 2d. As a result, the point contact where the load is concentrated does not occur, and wear of the end face 51 of the inspection apparatus connecting metal 50 based on the contact can be prevented from increasing. Such an angle θ can be adjusted by shifting one of the upper and lower guide plates 20 and 30 of the probe unit 10 while slightly shifting in the parallel direction.

  If the angle θ is less than 0.5 °, the direction in which the probe bends is random, and the adjacent probes tend to interfere with each other. On the other hand, when the angle θ exceeds 5 °, the contact between the second end 2b and the end surface 51 of the inspection apparatus connecting metal 50 is not instantaneously changed from point contact to surface contact, and the load at the time of point contact Concentration increases, deformation or damage of the end face 51 of the inspection apparatus connecting metal 50 increases, and the contact resistance at the time of transition to surface contact thereafter increases or fluctuates and may become unstable. A preferable range of the angle θ is 1 ° or more and less than 3 °. By setting it as this range, the above-mentioned effect can be made more stable.

  FIG. 7 is a schematic view of the surface form of the end face 51 of the inspection apparatus connecting metal 50 after the second end 2b of the probe 1 has repeatedly contacted. FIG. 7A is an example using the probe 1 according to the present invention having a flat portion 2d at the tip of the second end 2b, and FIG. 7B shows a flat portion at the tip of the second end 2b. This is an example using the conventional probe 1 that does not have 2d and has a round tip. As shown in FIG. 7A, when the probe 1 of the present invention is used, the edge of the second end portion 2b makes point contact with the contact portion 52 of the end surface 51 with a high contact pressure. However, after the point contact, the surface transition is instantaneously made, and the flat portion 2d of the second end portion 2b and the end surface 51 are in surface contact with each other over a wide area, so that the end surface 51 is deformed or dented and wears. There is no contact resistance, and stable conduction can be realized.

  On the other hand, as shown in FIG. 7B, when a conventional probe having a rounded tip is used, the rounded hemispherical tip of the second end 2b is pointed at a high contact pressure on the contact 52 of the end surface 51. Contact. The load at the time of point contact is concentrated at one point, and the end face 51 is plastically deformed, and is worn so that it is repeatedly bent. As the wear progresses, for example, as shown in FIGS. 7B, 12B, and 12C, the end face 51 may be deformed, and there is a possibility that the point contact is changed to the surface contact. The change from the point contact to the surface contact is that the contact area is increased and the contact pressure is decreased, and the generated wear powder is interposed between the second end 2b of the probe 1 and the end surface 51 of the lead wire 50. There was a risk of instability of resistance.

  Note that by bringing the second end 2b and the end face 51 of the inspection apparatus connecting metal 50 into contact with each other at such an angle θ, the direction of bending as shown in FIG. Will bend in the same direction. As a result, the probe unit 10 with a narrow pitch between the probes 1 can be configured. Even in this case, the bending direction of the probe 1 is not disturbed, stable inspection can be performed stably for a long period of time, and wear. And generation of wear powder can be suppressed.

  The contact resistance between the flat portion 2d of the second end 2b and the end surface 51 of the inspection apparatus connecting metal 50 is not particularly limited. For example, the sum of the conductor resistance and the contact resistance of the probe is about 100Ω or less, preferably 30Ω. It is about the following. In the probe unit 10 of the present invention, even when repeatedly contacted, the contact resistance does not increase and can be stabilized.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
As the metal conductor 2, a long straight tungsten wire (diameter D: 0.070 mm) whose straightness was straightened to 1500 mm with a radius of curvature R in advance was used. A polyurethane insulating coating 3 having a thickness of 10 μm was continuously baked on the metal conductor 2 to produce a straight tungsten wire with an insulating coating (hereinafter abbreviated as an insulating straight tungsten wire). Next, the insulating straight tungsten wire is cut into a length of 30 mm with a standard cutting device, and then the rear end thereof is polished into a trapezoid shape with a grinding device and has a trapezoidal shape (taper angle) with a flat portion 2d of d = 50 μm. 30 °) of the second end 2b was formed, and the first end 2a was also hemispherically polished. The polishing process was performed by pressing the rear end of an insulating straight tungsten wire cut on a rotating disk with emery paper. Next, the insulating coating 3 of the 2nd end part 2b and the 1st end part 2a was peeled with the laser apparatus so that it might become B = 2mm and A = 3mm. Finally, two-layer plating consisting of a nickel plating layer (film thickness 1 μm) and a gold plating layer (film thickness 0.1 μm) is applied to the first end 2a and the second end 2b where the metal conductor 2 is exposed. Five probes 1 (see FIG. 3) were prepared. The diameter Do of the entire probe was 0.090 mm.

[Example 2]
In Example 1, each tungsten wire having a diameter D of 0.015 mm, 0.030 mm, 0.050 mm, 0.070 mm, 0.090 mm, 0.110 mm, and 0.150 mm is used as the metal conductor 2, and the diameter of the flat portion 2d. The 2nd end part 2b which changed variously was formed. Other than that was carried out similarly to Example 1, and produced each probe 1. FIG.

[Comparative Example 1]
In Example 1, five probes 1 of Comparative Example 1 were produced in the same manner as Example 1 except that the shape of the second end 2b was hemispherical.

[Evaluation 1]
FIG. 9 shows a case where repeated contact is performed 200,000 times using five samples of the probe 1 of Example 1 under the conditions of an angle θ of 2 °, an indentation length of 0.2 mm after contact, and a buckling load of 3 gf. It is a microscope picture of the end surface 51 of the inspection apparatus connection metal 50 after performing. In either case, although there was a discolored portion, the end face 51 was not damaged by plastic deformation or the like.

  At the same time, the electric resistance value was measured at five end faces 51. Table 1 shows the electrical resistance value at each contact number, and Table 2 shows the average value and standard deviation of the electrical resistance values. From Tables 1 and 2, it was found that the probe of Example 1 had a smaller increase in contact resistance value than the probe of Comparative Example 1, and the electrical resistance value was stable.

[Evaluation 2]
FIG. 10 shows an inspection apparatus connection after repeated contact 200,000 times with the probe of Comparative Example 1 under the conditions of an angle θ of 2 °, an indentation length of 0.2 mm after contact, and a buckling load of 3 gf. 2 is a photomicrograph of an end face 51 of a metal 50. Any end face 51 was damaged by plastic deformation or the like.

[Evaluation 3]
FIG. 5 shows the flat portion 2d and the inspection when various probes of Example 2 in which the conductor diameter D of the metal conductor 2 and the diameter d of the flat portion 2d of the second end 2b of the metal conductor 2 are different are used. It is a graph which shows a contact pressure with the metal for apparatus connection. Based on this result, the relationship between the conductor diameter D of the metal conductor in which the contact pressure is in the range of 25 MPa to 100 MPa and the diameter d of the flat portion 2d at the second end of the metal conductor is shown in FIG. In FIG. 4, the ratio (d / D) between the diameter d of the flat portion 2d and the conductor diameter D of the metal conductor 2 is 0.6 to 1 when D is 150 μm, and 0.5 to 0 when D is 110 μm. .9, 0.4 to 0.8 when D is 90 μm, 0.3 to 0.6 when D is 70 μm, 0.3 to 0.6 when D is 50 μm, 0 when D is 30 μm to 15 μm It was in the range of 7-1.

DESCRIPTION OF SYMBOLS 1 Probe 2 Metal conductor 2a 1st edge part 2b 2nd edge part 2c Slope 2d Flat surface 3 Insulation film 3a Insulation film edge part 10 Probe unit 11 Measured object 12 Electrode 20 Guide plate of measured object side 30 Guide on inspection apparatus side Plate 40 Metal holding plate for inspection device connection 50 Metal for inspection device connection (lead wire)
51 End face of inspection apparatus connecting metal (lead wire) 52 Contact portion of second end portion of probe according to the present invention 52 ′ Contact portion of second end portion of conventional probe 53 Second end portion of probe according to the present invention 53 'Contact point of the flat part 53' Contact point of the second end of the conventional probe

A Length of the metal conductor region exposed on the first end side B Length of the metal conductor region exposed on the second end side b Distance in the axial direction from the tip of the second end portion to the outer diameter surface of the metal conductor d Diameter of flat portion of second end d ′ Diameter of portion where flat portion of second end contacts metal for inspection apparatus connection Diameter of entire probe D Diameter of metal conductor L Length of probe a1 Configure probe Virtual axis of metal conductor a2 Normal of metal for inspection device connection θ Angle between virtual axis of metal conductor and normal of metal for inspection device S Space between guide plates Δ1, Δ2 Length until contact with metal for inspection device connection Change in length R range

Claims (3)

The first end on the measured object side is brought into contact with the measured object, and the second end on the inspection apparatus side is brought into contact with the metal for connecting the inspection apparatus, and the electrical characteristics of the measured object are measured with the inspection apparatus. A plurality of probes, a pair of guide plates arranged to guide both ends of the probe and spaced in the middle, and a second of the probes guided by the guide plate on the inspection apparatus side In a probe unit having an inspection device connecting metal that repeatedly contacts an end,
The probe includes a metal conductor and an insulating coating provided in a region other than at least both ends of the metal conductor, and the shape of the second end of the probe contacts the inspection apparatus connecting metal. Has a flat part,
When the edge between the outer peripheral surface of the second end portion and the flat portion hits the inspection device connecting metal, the flat portion is connected to the inspection device connection with the second end portion of the probe that is bent. From the point contact at the edge to the surface contact at the flat part, the form of contact with the inspection metal is easily and instantaneously shifted from the guide plate on the inspection apparatus side toward the inspection apparatus connection metal. Protruding,
The second end portion and the inspection device connecting metal are in a range of 0.5 ° to 5 ° in an angle between a virtual axis of the metal conductor constituting the probe and a normal line of the inspection device connecting metal. A probe unit that is brought into contact with   The ratio (d / D) of the diameter d of the flat portion of the second end portion to the conductor diameter D of the metal conductor is 0.6 to 1 when D is 150 μm, and 0.5 to 0 when D is 110 μm. 9, D is 90 to 80 μm, 0.4 to 0.8, D is 70 μm, 0.3 to 0.6, D is 50 μm, 0.3 to 0.6, D is 30 to 15 μm, 0.7 to 1 The relationship between the diameter d and the conductor diameter D is a graph in which the conductor diameter D is the horizontal axis and the d / D is the vertical axis, and the line connecting the lower limit values of the respective d / D 2. The probe unit according to claim 1, wherein the probe unit satisfies a range surrounded by a line connecting the upper limit values of each d / D.   The second end portion on the inspection device side is brought into contact with the inspection device connection metal so that a contact pressure between the flat portion of the second end portion and the inspection device connection metal is 25 MPa or more and 100 MPa or less. Item 3. The probe unit according to Item 1 or 2.