JP6287717B2 - Terminal connection structure, heating device, and electrostatic chuck device - Google Patents

Description

  The present invention relates to a terminal connection structure, a heating device, and an electrostatic chuck device.

  2. Description of the Related Art Conventionally, in a semiconductor manufacturing apparatus using plasma such as a plasma etching apparatus and a plasma CVD apparatus, an electrostatic chuck apparatus is used as an apparatus for simply mounting and fixing a wafer on a sample stage and maintaining the wafer at a desired temperature. Is used.

As such an electrostatic chuck device, for example, a ceramic base in which a plate electrode for electrostatic adsorption is embedded inside, and a base portion in which a refrigerant flow path for refrigerant circulation is formed inside are used as an adhesive layer. Are known to be joined together.
With the recent increase in semiconductor diameter and pattern miniaturization, characteristics required for electrostatic chuck devices are also increasing.

Patent Document 1 proposes an electrostatic chuck device with a heater function in which a heating member is attached between a ceramic base and a base portion in order to make the temperature distribution on a surface on which a wafer is placed uniform. The heating member is a strip-like wiring made of a metal foil or a sheet-like conductive member, and is attached to the back surface of the ceramic substrate with an adhesive.
Since this electrostatic chuck device with a heater function can create a temperature distribution locally within the wafer, the wafer surface temperature distribution can be set on the wafer by setting it according to the film deposition rate and plasma etching rate. Thus, local film formation such as pattern formation and local plasma etching can be performed efficiently.

JP 2008-300491 A

A connection terminal for supplying electric power to the heating member is connected to the wiring-like heating member bonded and fixed to the back surface of the ceramic substrate. For connection between the heating member and the connection terminal, a connection method such as welding, bonding with a conductive adhesive, or brazing is used.
In the connection portion between the heating member and the connection terminal, thermal stress due to heat generation due to power supply and stress due to a difference in thermal expansion coefficient between components such as a ceramic substrate are generated. The connection structure between the heating member and the connection terminal is required to suppress damage due to the stress.
It is an object of the present invention to provide a terminal connection structure that is a connection structure between wiring and a connection terminal for supplying power and that is not easily damaged during use.

  The terminal connection structure of the present invention includes a strip-shaped wiring and a connection terminal disposed at an end of the wiring, and the connection terminal has a circular opposing surface facing the end, and the end Are welded by three or more welds, and the welds are arranged symmetrically with respect to an axis of symmetry passing through the center of the opposing surface and extending in the direction of the wiring, and the opposing surface 2 or more on the side where the wiring extends and one or more on the opposite side with respect to a reference axis that passes through the center of the wire and is orthogonal to the symmetry axis.

According to this configuration, three or more welded portions are provided on the facing surface of the connection terminal, and each welded portion is provided on the side where the wiring extends from the center of the facing surface. The current supplied from the connection terminal to the strip-shaped wiring flows along the direction in which the wiring extends. By providing two or more welded portions on the side where the wiring extends from the center of the opposing surface, the current is not dispersed and the current flowing through each welded portion is not concentrated in one location. Thereby, it can suppress that temperature rises locally by concentration of an electric current.
Furthermore, since the welded portion is positioned in line symmetry with respect to the axis of symmetry, even when the number of welded portions is small (for example, three locations), the welded portion equidistant from the wire is located on the side where the wire extends. Two are arranged. Thereby, it can prevent reliably that an electric current concentrates on a specific welding part.
In addition, since one or more welded portions are disposed on the side opposite to the side where the wiring extends, the welded portions are disposed in a balanced manner on the facing surface of the connection terminal. Accordingly, when an external force is applied to the connection terminal from an arbitrary direction, the force for peeling off the facing surface from the wiring can be distributed in a balanced manner to each welded portion, and damage to the welded portion can be suppressed.

  Moreover, said terminal connection structure WHEREIN: The said welding part may be located inside the periphery of the said opposing surface.

  According to this configuration, when an external force is applied to the connection terminal and a force is generated to tilt the connection terminal with respect to the welding surface of the wiring with the peripheral edge of the facing surface as a fulcrum, the welded portion is By being provided inside the periphery, the starting point of breakage is less likely to occur in the welded portion.

  In the terminal connection structure, the welded portion may be arranged rotationally symmetrically with respect to the center of the facing surface.

  According to this configuration, since the welded portion is rotationally symmetric with respect to the center of the opposing surface, the welded portion is evenly arranged in the circumferential direction. Accordingly, when an external force is applied to the connection terminal from an arbitrary direction, the force for peeling off the facing surface from the wiring can be distributed in a balanced manner to each welded portion, and damage to the welded portion can be suppressed.

  Further, in the terminal connection structure, the welded portion is arranged on a virtual circle concentric with the facing surface, and a ratio of the welded portion is 50% or less with respect to a circumferential length of the virtual circle. Also good.

  According to this structure, the part which is not welded of the distance more than the magnitude | size of a welding part will be provided between adjacent welding parts. When the wiring and the connection terminal are relatively displaced due to thermal expansion, thermal contraction, or moisture absorption, the welded part is deformed, and the relative displacement between the wiring and the connection terminal can be allowed, and the stress applied to the welded part is increased. Can be distributed.

  In the terminal connection structure described above, the weld portion may be formed by electron beam welding.

  According to this configuration, the welded portion can be formed by spot welding with an electron beam. Therefore, the process time of the welding process can be shortened. Further, by irradiating the surface opposite to the facing surface of the connection terminal with the electron beam, the facing surface and the wiring can be welded, and the welding process can be simplified. In addition, since electron beam welding has a small amount of heat input applied to the welded portion, distortion after welding can be suppressed.

  In the above terminal connection structure, the connection terminal is provided with a plurality of through holes reaching the facing surface, and the welded portion is an interface between the opening on the facing surface side of the through hole and the end portion. It may be formed by laser welding over a part or the entire circumference.

  According to this structure, a welding process can be efficiently performed by irradiating a laser directly on a welding part. Therefore, it is possible to perform welding while reducing the influence of heat on the wiring, the connection terminals, and the members disposed around them.

  The heating device according to the embodiment of the terminal connection structure includes a ceramic plate-like body made of a ceramic sintered body, a heater pattern as the wiring bonded and fixed to the ceramic plate-like body, and the heater pattern. And the terminal connection structure provided at the end.

  Moreover, the electrostatic chuck apparatus which concerns on embodiment has the said heating apparatus.

  According to the terminal connection structure of the present invention, even when a thermal stress due to heat generation due to the power supply to the heating member and a stress due to a difference in thermal expansion coefficient between components such as a ceramic substrate occur, the connection portion It is possible to suppress the occurrence of damage.

It is sectional drawing which shows the electrostatic chuck apparatus provided with the 1st, 2nd terminal connection structure of 1st Embodiment. It is a top view which shows an example of the plane pattern of the heating member of the electrostatic chuck apparatus shown in FIG. It is a perspective view which shows the 1st terminal connection structure of 1st Embodiment. The 1st terminal connection structure of 1st Embodiment is shown, Fig.4 (a) is sectional drawing, FIG.4 (b) is a top view. It is a top view which shows the 2nd terminal connection structure of 1st Embodiment. It is a top view which shows the terminal connection structure of the modification 1 of 1st Embodiment. It is a top view which shows the terminal connection structure of the modification 2 of 1st Embodiment. It is a top view which shows the terminal connection structure of the modification 3 of 1st Embodiment. The terminal connection structure of 2nd Embodiment is shown, Fig.9 (a) is sectional drawing, FIG.9 (b) is a top view. It is a top view which shows the terminal connection structure of the modification 1 of 2nd Embodiment. It is a top view which shows the terminal connection structure of the modification 2 of 2nd Embodiment.

  Embodiments of the electrostatic chuck device will be described below with reference to the drawings. In the drawings used in the following description, for the purpose of emphasizing the feature portion, the feature portion may be shown in an enlarged manner for convenience, and the dimensional ratios of the respective constituent elements are not always the same as in practice. Absent. In addition, for the same purpose, portions that are not characteristic may be omitted from illustration.

<< First Embodiment >>
FIG. 1 is a cross-sectional view showing an electrostatic chuck device 100 provided with a first terminal connection structure 1 and a second terminal connection structure 2 of the first embodiment.
The electrostatic chuck device 100 includes a disk-shaped electrostatic chuck portion (ceramic plate-like body) 20 on which the plate-shaped sample W is installed, a disk-shaped cooling base portion 50 that cools the electrostatic chuck portion 20, and these And a resin layer 80 for bonding and integrating. In other words, the electrostatic chuck device 100 has a structure in which the cooling base portion 50, the resin layer 80, and the electrostatic chuck portion 20 are stacked in this order in the + Z direction (height direction) in FIG.

The electrostatic chuck portion 20 has a first surface 20a on which the plate-like sample W is placed and a second surface 20b on the opposite side. A heating member (wiring, heater pattern) 7 bonded and fixed by the adhesive 6 is provided on the second surface 20b.
The electrostatic chuck 20 penetrates in the thickness direction of the electrostatic chuck 20 from the electrostatic chuck internal electrode 23 and the electrostatic chuck internal electrode 23, and applies a voltage to the electrostatic chuck internal electrode 23. Internal electrode terminal 24.

The cooling base unit 50 includes a first surface 50 a that faces the electrostatic chuck unit 20, and a second surface 50 b that is the opposite side and serves as a mounting surface of the electrostatic chuck device 100.
The cooling base portion 50 is provided with a through hole 51 that penetrates in the thickness direction. An insulating tube (insulator) 15 is embedded in the through hole 51. A power supply terminal 32, a fixing plate 16, a connection line 33, and a connection terminal 40 are inserted into the insulating tube 15. The connection terminal 40 is joined to the heating member 7 by welding to constitute the first terminal connection structure 1 or the second terminal connection structure 2.
The electrostatic chuck unit 20, the heating member 7, and the first and second terminal connection structures 1 and 2 constitute a heating device 5.

Hereinafter, the configuration of each unit will be described in detail with reference to FIG.
<Electrostatic chuck (ceramic plate)>
The electrostatic chuck unit 20 includes a mounting plate 21 on which a plate-like sample W such as a semiconductor wafer, a metal wafer, or a glass substrate is installed, a support plate 22 that is disposed so as to face the mounting plate 21, and the mounting plate 21 and the support. An internal electrode 23 for electrostatic attraction sandwiched between the plates 22 and an internal electrode terminal 24 embedded in the support plate 22 are provided.

The mounting plate 21 and the support plate 22 have a disk shape with the same shape of the superimposed surfaces, and are an aluminum oxide-silicon carbide (Al ₂ O ₃ —SiC) composite sintered body, aluminum oxide (Al _2). Insulating ceramics having mechanical strength, corrosive gas and durability against plasma, such as O ₃ ) sintered body, aluminum nitride (AlN) sintered body, yttrium oxide (Y ₂ O ₃ ) sintered body It is preferable to consist of a sintered body.
Moreover, it is good also as a cheap structure by making the mounting board 21 into said ceramic sintered compact and making the support plate 22 into insulating resin, such as a polyimide.

A plurality of projections 26 having a diameter smaller than the thickness of the plate-like sample W are formed on the first surface 20a on which the plate-like sample W is placed, which is one surface of the mounting plate 21, and the projections 26 are plate-like. The configuration is such that the sample W is supported.
The support plate 22 is provided with a hole 22a penetrating in the thickness direction. The internal electrode terminal 24 is inserted through the hole 22a.

The internal electrode 23 for electrostatic adsorption is used as an electrode for an electrostatic chuck for generating an electric charge and fixing the plate-like sample W with electrostatic adsorption force. Adjust as appropriate.
The material of the internal electrode 23 for electrostatic attraction is selected in consideration of the difference in thermal expansion from the materials used for the mounting plate 21 and the support plate 22 and heat resistance. For example, the internal electrode 23 for electrostatic adsorption includes an aluminum oxide-tantalum carbide (Al ₂ O ₃ —Ta ₄ C ₅ ) conductive composite sintered body, an aluminum oxide-tungsten (Al ₂ O ₃ —W) conductive composite sintered body. Combined body, aluminum oxide-silicon carbide (Al ₂ O ₃ -SiC) conductive composite sintered body, aluminum nitride-tungsten (AlN-W) conductive composite sintered body, aluminum nitride-tantalum (AlN-Ta) conductive Conductive ceramics such as composite sintered bodies, yttrium oxide-molybdenum (Y ₂ O ₃ -Mo) conductive composite sintered bodies, or high melting point metals such as tungsten (W), tantalum (Ta), and molybdenum (Mo) Alternatively, silver (Ag), carbon (C), or the like can be used.
The electrostatic adsorption internal electrode 23 can be easily formed by a film forming method such as a sputtering method or a vapor deposition method, or a coating method such as a screen printing method.

The internal electrode terminal 24 is provided to apply a DC voltage to the electrostatic adsorption internal electrode 23. The internal electrode terminal 24 extends through the hole 22a from the internal electrode 23 for electrostatic attraction and extends in the thickness direction, and is exposed to the second surface 20b of the electrostatic chuck portion 20. A DC power supply circuit (not shown) is connected to the internal electrode terminal 24 so that a voltage is applied to the internal electrode 23 for electrostatic adsorption.
The material of the internal electrode terminal 24 is not particularly limited as long as it is a conductive material having excellent heat resistance, but the thermal expansion coefficient approximates that of the electrostatic adsorption internal electrode 23 and the support plate 22. Those are preferred. For example, a conductive ceramic constituting the internal electrode 23 for electrostatic adsorption or a metal material such as tungsten (W), tantalum (Ta), molybdenum (Mo), niobium (Nb), Kovar alloy, or the like is preferably used. It is done.

<Resin layer>
As shown in FIG. 1, the resin layer 80 is interposed between the second surface 20 b of the electrostatic chuck portion 20 and the first surface 50 a of the cooling base portion 50. The resin layer 80 bonds and integrates the electrostatic chuck portion 20 to which the heating member 7 is bonded and the cooling base portion 50, and has a thermal stress relieving action.
The resin layer 80 has voids in the interior, the second surface 20b of the electrostatic chuck portion 20, the lower surface (the surface on the −Z side) of the heating member 7, and the interface with the first surface 50a of the cooling base portion 50. It is desirable that there are few defects. If voids or defects are formed, the heat transfer property may be reduced, and the soaking property of the plate sample W may be hindered.

The resin layer 80 is made of, for example, a cured body obtained by heat-curing a silicone resin composition or an acrylic resin. The resin layer 80 is preferably formed by filling a fluid resin composition between the electrostatic chuck portion 20 and the cooling base portion 50 and then heat-curing the resin composition. The heating member 7 is provided on the first surface 50a of the cooling base 50, thereby forming irregularities. Further, the first surface 50a of the cooling base unit 50 and the second surface 20b of the electrostatic chuck unit 20 are not necessarily flat. A fluid resin composition is filled between the cooling base portion 50 and the electrostatic chuck portion 20 and then cured to form the resin layer 80, thereby causing unevenness between the electrostatic chuck portion 20 and the cooling base portion 50. Thus, the generation of voids in the resin layer 80 can be suppressed. Thereby, the heat conduction characteristic of the resin layer 80 can be made uniform in the surface, and the thermal uniformity of the electrostatic chuck portion 20 can be improved.
A connection terminal 40 for supplying power to the heating member 7 is fixed to the end portions 8A and 8B of the heating member 7 by welding. In the step of forming the resin layer 80, it is preferable to mask the resin layer 80 so as not to enter the end portions 8A and 8B.

<Cooling base part>
The cooling base part 50 is for adjusting the electrostatic chuck part 20 to a desired temperature, and has a thick disk shape.
As the cooling base unit 50, for example, a liquid cooling base in which a flow path (not shown) for circulating a refrigerant is formed is suitable.
The material constituting the cooling base portion 50 is not particularly limited as long as it is a metal excellent in thermal conductivity, conductivity, and workability, or a composite material containing these metals. For example, aluminum (Al), aluminum alloy , Copper (Cu), copper alloy, stainless steel (SUS) and the like are preferably used. It is preferable that at least the surface of the cooling base portion 50 exposed to plasma is anodized or an insulating film such as alumina is formed.
In addition, an insulating resin sheet such as polyimide may be attached to the first surface 50a of the cooling base portion 50 facing the electrostatic chuck portion 20 to improve the withstand voltage characteristics.

The cooling base portion 50 is provided with a through hole 51. The insulating tube 15, the power supply terminal 32, the connection line 33, the connection terminal 40, and the fixing plate 16 are inserted into the through hole 51.
In addition, in the cooling base portion 50, a through hole in which a power feeding portion for applying a voltage to the internal electrode terminal 24 is arranged, and a through hole for inserting a lift pin for pushing up the wafer in the processing process of the plate sample W In addition, a plurality of through holes are provided depending on purposes such as a through hole for supplying a cooling gas to be supplied between the plate-like sample W and the electrostatic chuck unit 20.

<Heating member (wiring, heater pattern)>
The heating member 7 is a strip-like wiring, and is fixed to the second surface 20 b of the electrostatic chuck portion 20 via the adhesive 6.
FIG. 2 shows an example of a planar pattern of the heating member 7 formed on the second surface 20b. The heating member 7 includes two heaters (an inner heater 7a and an outer heater 7b) that are independent of each other. The inner heater 7a is formed at the center of the second surface 20b, and the outer heater 7b is a peripheral portion of the second surface 20b and is formed in an annular outer shape outside the inner heater 7a.

Each of the inner heater 7a and the outer heater 7b is a metal material heater pattern meandering in a strip shape, that is, a wiring, and is fixed to the entire second surface 20b.
A connection terminal 40 is connected to the end 8B of the inner heater 7a and the end 8A of the outer heater 7b. Due to the current supplied from the connection terminal 40, the inner heater 7a and the outer heater 7b generate heat.
The planar pattern of the heating member 7 may be constituted by two or more heater patterns independent from each other as described above, but may be constituted by one heater pattern. However, as in the present embodiment, by configuring with a plurality of mutually independent heaters (inner heater 7a, outer heater 7b), the inner heater 7a and outer heater 7b are individually controlled, and the mounting plate 21 The in-plane temperature distribution of the plate-like sample W fixed to the placement surface by electrostatic adsorption can be controlled freely and accurately.

The heating member 7 has a constant thickness of 0.2 mm or less, preferably 0.1 mm or less.
When the thickness of the heating member 7 exceeds 0.2 mm, the pattern shape of the heating member 7 is reflected as the temperature distribution of the plate sample W, and the in-plane temperature of the plate sample W can be maintained in a desired temperature pattern. It becomes difficult.
In addition, by setting the heating member 7 to a constant thickness, the amount of heat generated by the heating member 7 can also be made constant over the entire heating surface. Thereby, temperature distribution in the 1st surface 20a of electrostatic chuck part 20 can be made uniform.

The heating member 7 is preferably made of a non-magnetic metal thin plate. For example, a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate, or the like is etched into a desired heater pattern by photolithography. Can be formed.
By forming the heating member 7 from a nonmagnetic metal, the heating member 7 does not self-heat due to the high frequency even when the electrostatic chuck device 100 is used in a high frequency atmosphere. Therefore, it is easy to maintain the in-plane temperature of the plate-like sample W at a desired constant temperature or a constant temperature pattern even in a high-frequency atmosphere.

The adhesive 6 is provided to adhere the heating member 7 to the second surface 20 b of the electrostatic chuck portion 20 and has the same planar shape as the heating member 7.
The adhesive 6 is a sheet-like or film-like adhesive resin, and preferably has heat resistance and insulation, and a polyimide resin, a silicone resin, an epoxy resin, or the like can be employed.
The thickness of the adhesive 6 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. The in-plane thickness variation of the adhesive 6 is preferably within 10 μm. If the in-plane thickness variation of the adhesive 6 exceeds 10 μm, the in-plane spacing between the electrostatic chuck portion 20 and the heating member 7 will exceed 10 μm. As a result, the in-plane uniformity of the heat transmitted from the heating member 7 to the electrostatic chuck unit 20 is lowered, and the in-plane temperature on the mounting surface of the electrostatic chuck unit 20 may be non-uniform.

<Insulation tube>
The insulating tube 15 is embedded in the through hole 51. A power supply terminal 32, a fixed plate 16, a connection line 33, and a connection terminal 40 are inserted into the insulating tube 15.
Note that four insulating tubes 15 are provided corresponding to the end portions 8B and 8B of the inner heater 7a and the end portions 8A and 8A of the outer heater 7b shown in FIG. 32, the fixing plate 16, the connecting wire 33, and the connecting terminal 40 are respectively inserted to supply current to the heating member 7.
The material of the insulating tube 15 may be made of resin or ceramics, but is preferably made of ceramics in terms of heat conduction, heat resistance, withstand voltage, dimensional accuracy, cost, and aluminum oxide. It can be suitably employed.

<Power supply terminal>
The power supply terminal 32 is a female connector. A male connector (not shown) for supplying electricity to the electrostatic chuck device 100 from an external power source can be connected to the power supply terminal 32. The material of the power supply terminal 32 is not limited as long as it is conductive. The power supply terminal 32 is fixed to the through hole 51 of the cooling base unit 50 via the fixing plate 16. A connection line 33 is connected to the power supply terminal 32.

<Fixed plate>
The fixing plate 16 is attached to the opening on the lower surface (−Z side) of the through hole 51. The fixing of the power supply terminal 32 and the fixing plate 16 and the fixing of the fixing plate 16 and the cooling base unit 50 can be performed, for example, by screwing. Further, the fixing plate 16 may be structured to be fixed to the insulating tube 15. Ceramics, insulating resin, or the like is appropriately selected as the material for the fixing plate 16.

<Connection line>
The connection line 33 is provided to electrically connect the connection terminal 40 and the power supply terminal 32. As the connection line 33, it is preferable to use an electric cable having flexibility and be accommodated in a space between the connection terminal 40 and the power supply terminal 32 in a relaxed state.
When a flexible electric cable is used as the connection line 33 and stored in a relaxed state, the cooling base 50 is thermally expanded and contracted, and the distance between the connection terminal 40 and the power supply terminal 32 changes. Even so, changes in distance can be absorbed. Therefore, it is possible to prevent a load from being applied to the connection terminal 40, the power supply terminal 32, and these connection portions. In addition, the connection line 33 can be prevented from being transmitted to the connection terminal 40 even when an external force or impact is applied to the power supply terminal 32, and damage to the connection terminal 40 and its connection portion can be prevented.

<Connection terminal>
The connection terminal 40 includes a circular flange 41 provided on the facing surface 41 a side (+ Z side) joined to the heating member 7, and a columnar portion 42 erected from the flange 41.
The material of the connection terminal 40 is a metal or a composite of metal and ceramics, and is preferably the same material as the material of the heating member 7 or a composite material of the same material as the material of the heating member 7 and another material.

  A connection line 33 is connected to the end face 42 a of the cylindrical portion 42. The connection terminal 40 and the connection line 33 are connected by a connection method such as welding or soldering. Further, the cylindrical portion 42 of the connection terminal 40 is divided into a male screw portion and a female screw portion, for example, so that the connection line 33 is mechanically sandwiched between the male screw portion and the female screw portion to make an electrical connection. You can go.

  The connection between the connection terminal 40 and the end 8A (see FIG. 2) of the heating member 7 is performed by welding to form the first terminal connection structure 1. Similarly, the connection terminal 40 and the end 8B of the heating member 7 form the second terminal connection structure 2 by welding. The first and second terminal connection structures 1 and 2 will be described below.

<< Terminal connection structure >>
The first terminal connection structure 1 is configured by connecting the end 8A of the outer heater 7b of the heating member 7 and the connection terminal 40 by welding.
3 and 4 show the first terminal connection structure 1. 3 is a perspective view of the first terminal connection structure 1, FIG. 4A is a cross-sectional view of the first terminal connection structure 1 along the symmetry axis L1, and FIG. 2 is a plan view of the terminal connection structure 1. FIG. In addition, illustration of the connection line 33 is abbreviate | omitted in FIG. 4 (a), (b).
The first terminal connection structure 1 includes a heating member 7 that is a strip-shaped wiring, and a connection terminal 40 that is disposed at an end 8A of the heating member 7. In addition, the first terminal connection structure 1 has six welds 61 at the interface between the end 8 </ b> A of the heating member 7 and the facing surface 41 a of the connection terminal 40.

  The end 8 </ b> A is located at the end of the heating member 7 and is formed in a circular shape having a larger diameter than the line width of the heating member 7. The center O1 of the end portion 8A formed in a circular shape is disposed on a straight line obtained by extending the widthwise central axis of the heating member 7 formed in a band shape toward the end portion 8A side.

The flange 41 of the connection terminal 40 has a facing surface 41a that faces the end 8A of the heating member 7, and a back surface 41b that is located on the opposite side of the facing surface 41a.
The connection terminal 40 is disposed such that the opposed surface 41a faces the end 8A. The connection terminal 40 is disposed such that the center O2 of the facing surface 41a coincides with the center O1 of the end portion 8A.

  The weld 61 is formed at the interface between the facing surface 41 a of the connection terminal 40 and the end 8 </ b> A of the heating member 7. The weld 61 is a spot weld formed by electron beam welding. The planar shape of the welded portion 61 is a circular shape that is an electron beam irradiation shape (spot shape).

As shown in FIG. 4A, the welded portion 61 is formed by irradiating the back surface 41 b of the flange portion 41 with a spot 62 of the electron beam EB. The electron beam EB heats the flange portion 41 in the thickness direction at the spot 62. As a result, a heated portion 62 a is formed inside the collar portion 41. Further, the heating by the electron beam EB reaches the facing surface 41a and heats the end 8A and the connection terminal 40. As a result, the end portion 8 </ b> A and the facing surface 41 a are welded and a welded portion 61 is formed. Such electron beam welding is performed in a vacuum.
In FIG. 4A, the electron beam EB and the heated portion 62a are shown for convenience in order to show the welding process.

  As shown in FIG.4 (b), the six welding parts 61 of the 1st terminal connection structure 1 are arrange | positioned at the opposing surface 41a. Each welding part 61 is arranged on the virtual circle P concentric with the circular opposing surface 41a. Moreover, each welding part 61 is arrange | positioned in rotational symmetry (six-fold symmetry) with respect to the center O2 of the opposing surface 41a.

The back surface 41 b is a region from the peripheral surface of the cylindrical portion 42 to the peripheral edge of the flange portion 41.
The spot 62 is located at the center in the radial direction of the back surface 41b. Therefore, the welding part 61 is located inside the periphery of the opposing surface 41a.

As shown in FIG. 4A, it is assumed that an external force F is applied to the cylindrical portion 42 of the connection terminal 40. When the external force F is applied, the connection terminal 40 is tilted with the point on the opposite side of the external force F as the fulcrum B at the peripheral portion of the opposed surface 41a, and a rotational moment is generated that tries to peel the opposed surface 41a from the end 8A.
In the first terminal connection structure 1, the six welds 61 are rotationally symmetric with respect to the center O <b> 2 of the facing surface 41 a, so that the welds 61 are evenly arranged in the circumferential direction. Therefore, even if the external force F is applied from any direction, it is possible to suppress the damage of the welded portion 61 against the force to peel the opposing surface 41a from the end portion 8A.
Moreover, the 1st terminal connection structure 1 becomes difficult to produce the origin of a failure | damage in the welding part 61 when the external force F is added because the welding part 61 is provided inside the periphery of the opposing surface 41a.

In the first terminal connection structure 1, the ratio of the length of the welded portion 61 that overlaps the virtual circle P to the circumferential length of the virtual circle P is 50% or less. Therefore, an unwelded portion having a distance equal to or larger than the diameter of the welded portion 61 is provided between the adjacent welded portions 61. The positions of the end portion 8A and the connection terminal 40 of the first terminal connection structure 1 are relatively displaced by a member to be fixed, thermal expansion, thermal contraction, or moisture absorption of the end portion 8A and the connection terminal 40 themselves. There is. The welding part 61 can obtain a softness | flexibility by providing the distance more than the magnitude | size of the welding part 61 between adjacent welding parts 61. FIG. Therefore, the welded portion 61 can be deformed so as to allow relative displacement between the end portion 8A and the connection terminal 40, and the stress applied to the welded portion 61 can be dispersed.
In the first terminal connection structure 1, for the same reason, the ratio of the length of the welded portion 61 that overlaps the virtual circle P to the circumferential length of the virtual circle P is more preferably 30% or less.

As shown in FIG. 4B, the axis of symmetry L1 is set along the direction in which the heating member 7 extends through the center O2 of the facing surface 41a. In addition, a reference axis L2 that passes through the center O2 of the opposing surface 41a and is orthogonal to the symmetry axis L1 is set in the surface of the opposing surface 41a.
Two of the six welds 61 have their centers arranged on the symmetry axis L1. Since the six welds 61 are arranged rotationally symmetrically with respect to the center of the opposing surface 41a, the welds 61 are line symmetric with respect to the symmetry axis L1.
The current that flows from the connection terminal 40 to the heating member 7 flows from each weld 61 in the direction in which the heating member 7 extends.
The potential gradient (electric field) of the welded portion 61 becomes smaller as it approaches the extended end 9 where the heating member 7 extends from the end portion 8A. Therefore, among the six welds 61, the current flows more easily in the welds 61 that are closer to the extension end 9. The symmetry axis L1 passes through the midpoint C of the extended end 9.
In the present embodiment, three of the six welds 61 are provided at positions closer to the heating member 7 than the reference axis L2 of the facing surface 41a. As a result, about half of the total area of the welded portion 61 is disposed in a region near the extended end 9. Since the current flows more easily as it is closer to the extension end 9, it is possible to prevent the current from being concentrated on a specific welded portion 61 by securing half of the total area of the welded portion 61 in a region where the current flows easily.

In addition, since the first terminal connection structure 1 is a connection structure by electron beam welding, the connection resistance is low compared to the case of bonding by conductive adhesive or brazing, and a large amount of heat is generated in the connection process. Hard to do.
When a connection method having a high connection resistance is employed, when a current is passed through the heating member 7 via the connection terminal 40, heat generated at the connection portion increases, and the temperature of the electrostatic chuck portion 20 may not be precisely controlled. Moreover, if a connection method that generates a large amount of heat in the connection process is employed, the adhesive 6 may be deteriorated due to an excessive temperature rise. By employing electron beam welding for the electrostatic chuck device 100, the temperature of the electrostatic chuck portion 20 can be precisely controlled, and deterioration of the adhesive 6 in the connection process can be suppressed.

Next, the second terminal connection structure 2 will be described.
FIG. 5 is a plan view of the second terminal connection structure 2. The second terminal connection structure 2 is configured by connecting the end 8B of the outer heater 7b of the heating member 7 and the connection terminal 40 by welding.
The second terminal connection structure 2 is different from the first terminal connection structure 1 described above in the shape of the end 8B. Constituent elements in the same form as the first terminal connection structure 1 described above are denoted by the same reference numerals and description thereof is omitted.
The 2nd terminal connection structure 2 has the heating member 7 which is a strip | belt-shaped wiring, and the connection terminal 40 arrange | positioned at the edge part 8B of the heating member 7. As shown in FIG. The connection terminal 40 is disposed such that the center O2 of the facing surface 41a coincides with the center O1 of the end 8B.

  The welding part 63 is arrange | positioned six places on the opposing surface 41a. Each welding part 63 is arranged on the virtual circle P concentric with the circular opposing surface 41a. Moreover, each welding part 63 is arrange | positioned by rotational symmetry (six-fold symmetry) with respect to the center O2 of the opposing surface 41a. Moreover, the welding part 63 is located inside the periphery of the opposing surface 41a.

  The end 8 </ b> B is located at the end of the heating member 7 and is formed in a circular shape having a diameter larger than the line width of the heating member 7. The center axis in the width direction of the heating member 7 formed in a band shape does not coincide with the center O1 of the end portion 8B formed in a circle, and one end in the width direction of the heating member 7 is a circle of the end portion 8B. It is continuous as a circumferential tangent. That is, the end portion 8B is formed to bulge to one side in the width direction at the end of the heating member.

As shown in FIG. 5, a symmetry axis L3 passing through the center O2 of the facing surface 41a and the midpoint C of the extending end 10 in the direction in which the heating member 7 extends is set. In the facing surface 41a, a reference axis L4 passing through the center O2 of the facing surface 41a and orthogonal to the symmetry axis L3 is set.
In the second terminal connection structure 2, three of the six welded portions 63 are provided at positions closer to the extending direction of the heating member 7 than the reference axis L4 of the facing surface 41a. As a result, a sufficient area of the welded portion 63 can be ensured in a region near the extended end 10, and current can be prevented from concentrating and flowing to the specific welded portion 63.

  In addition, the second terminal connection structure 2 is configured such that the six welded parts 63 are arranged rotationally symmetrically, and the welded parts 63 are arranged on the inner side of the peripheral edge of the facing surface 41a. Similar to the structure 1, the effect of suppressing breakage of the welded portion 63 is achieved.

<< Modification of First Embodiment >>
In the first terminal connection structure 1 and the second terminal connection structure 2 of the first embodiment, the welded portion 61 and the welded portion 63 are arranged at six locations on the facing surface 41a, but the welded portion is located at three locations. That's all there is to it.
Below, the terminal connection structure 1A, the terminal connection structure 1B, and the terminal connection structure 1C are demonstrated as the modifications 1-3 of 1st Embodiment.

6 to 8 are plan views illustrating the terminal connection structures 1A, 1B, and 1C of Modifications 1 to 3 of the first embodiment, respectively. The terminal connection structures 1A, 1B, and 1C are configured such that the end 8A of the outer heater 7b of the heating member 7 and the connection terminal 40 are connected by welding, and thus the first terminal connection structure 1 of the first embodiment. It is the same. Compared to the first terminal connection structure 1, the terminal connection structure 1 </ b> A is different in that three welding parts 64 are provided, and the terminal connection structure 1 </ b> B is provided with four welding parts 64. The terminal connection structure 1 </ b> C is different in that five welds 64 are provided.
Hereinafter, each modification will be specifically described. In addition, about the component of the same aspect as the above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

As shown in FIG. 6, in the terminal connection structure 1 </ b> A of the first modification, the three welded portions 64 are arranged line-symmetrically with respect to the symmetry axis L <b> 1. Further, two of the three welded portions 64 are arranged on the side where the heating member 7 extends from the reference axis L2.
As a result, the two welded portions 64 arranged on the heating member 7 side of the reference axis L2 are arranged at equal distances from the extended end 9 from which the heating member 7 extends at the end portion 8A. ing. Since the potential gradient (electric field) of each welded portion 64 is determined according to the distance from the extended end 9, the current values flowing through the two welded portions 64 arranged on the extended end 9 side are substantially the same. The current flowing through each welded portion 64 can be made half or less of the entire current. That is, the current does not concentrate on one welded portion 64, and the local increase in temperature due to the current concentration can be suppressed.

  The three welds 64 are preferably provided in rotational symmetry (three-fold symmetry) with respect to the center O2 of the facing surface 41a. As a result, when an external force is applied such that the connection terminal 40 is tilted and the opposing surface 41a is peeled off from the end portion 8A, the force is distributed to each welded portion 64, and damage to the welded portion 64 can be suppressed.

As shown in FIG. 7, in the terminal connection structure 1 </ b> B of the second modification, four welded portions 65 are arranged line-symmetrically with respect to the symmetry axis L <b> 1. Two of the four welded portions 65 are arranged on the side where the heating member 7 extends from the reference axis L2. Therefore, as in the first modification, the current flowing through each welded portion 65 can be made half or less of the entire current. That is, the current does not concentrate on one welded portion 65, and the temperature can be prevented from increasing locally due to the current concentration.
Further, when the four welded portions 65 are arranged in rotational symmetry (four-fold symmetry) with respect to the center O2 of the opposing surface 41a, the stress applied to the welded portion 65 due to an external force is dispersed to 65 damage can be suppressed.

As shown in FIG. 8, in the terminal connection structure 1 </ b> C of the third modification, five welded portions 66 are arranged line-symmetrically with respect to the symmetry axis L <b> 1. Three of the five welds 66 are arranged on the side where the heating member 7 extends from the reference axis L2. Therefore, the current does not concentrate on one welded portion 66, and the local increase in temperature due to the current concentration can be suppressed.
Further, when the five welded portions 66 are arranged in rotational symmetry (5-fold symmetry) with respect to the center O2 of the opposing surface 41a, the stress applied to the welded portion 66 due to external force is dispersed, and the welded portion 66 can be prevented from being damaged.

<< Second Embodiment >>
Next, the terminal connection structure 3 of 2nd Embodiment is demonstrated.
9A is a cross-sectional view of the terminal connection structure 3 along the symmetry axis L1, and FIG. 9B is a plan view of the terminal connection structure 3. FIG. The terminal connection structure 3 is applied instead of the first terminal connection structure 1 in the above-described electrostatic chuck device 100 (see FIG. 1).
The terminal connection structure 3 of the second embodiment is mainly different from the first terminal connection structure 1 in that laser beam welding is employed as a welding method.
In addition, about the component of the same aspect as the above-mentioned 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The terminal connection structure 3 includes a heating member 7 that is a strip-shaped wiring, and a connection terminal 70 that is disposed at an end portion 8A of the heating member 7. Further, the terminal connection structure 3 has six welded portions 67 at the interface between the end portion 8 </ b> A of the heating member 7 and the connection terminal 70.

The connection terminal 70 includes a circular flange 71 provided on the facing surface 71 a side (+ Z side) joined to the heating member 7, and a columnar portion 72 erected from the flange 71. A connection line (not shown) (corresponding to the connection line 33 in FIG. 1) is connected to the cylindrical portion 72.
The connection terminal 70 is disposed so that the facing surface 71a faces and contacts the end 8A. The connection terminal 70 is arranged so that the center O2 of the facing surface 71a coincides with the center O1 of the end 8A having a circular shape.

The flange portion 71 of the connection terminal 70 has a facing surface 71a that faces the end portion 8A of the heating member 7, and a back surface 71b that is located on the opposite side of the facing surface 71a. The collar portion 71 is provided with six through holes 73 reaching from the back surface 71b to the facing surface 71a.
As shown in FIG. 9B, each of the six through holes 73 has a rectangular shape. Each through-hole 73 is formed such that the rectangular longitudinal direction coincides with the radial direction of the opposing surface 71a. Each through-hole 73 is arranged on the virtual circle P concentric with the circular opposing surface 71a. Moreover, each through-hole 73 is arrange | positioned in rotational symmetry (six-fold symmetry) with respect to the center O2 of the opposing surface 71a.

As shown in FIG. 9B, a symmetry axis L1 is set along the direction in which the heating member 7 extends through the center O2 of the facing surface 71a. Further, a reference axis L2 that passes through the center O2 of the opposing surface 71a and is orthogonal to the symmetry axis L1 is set within the opposing surface 71a.
Two of the six welds 67 have their centers passing through the symmetry axis L1. Since the six welds 67 are arranged rotationally symmetrically with respect to the center O2 of the opposing surface 71a, the welds 67 are line symmetric with respect to the symmetry axis L1.

  The welded portion 67 is formed at the interface between the opening of the through hole 73 on the facing surface 71a side and the end portion 8A. The welded portion 67 is line welding formed by laser welding. In addition, the welding part 67 may be formed in a part among four sides which are opening of the through-hole 73 by the side of the opposing surface 71a, and may be formed over the perimeter of four sides.

As shown in FIG. 9A, the welded portion 67 is formed by irradiating the laser LZ within a range covering the inner wall of the through hole 73 and scanning along the shape of the through hole 73. The laser LZ heats the heating member 7 located in the vicinity of the inner wall of the through hole 73 and in the vicinity of the opening of the through hole 73 on the facing surface 71a side. Thereby, a heated portion 68a is formed in the vicinity of the inner wall of the flange portion 71, and a heated portion 68b is formed in the heating member 7 located in the vicinity of the opening of the through hole 73 on the facing surface 71a side. As a result, the end portion 8A and the facing surface 71a are welded together to form a welded portion 67.
In FIG. 9A, the laser LZ and the heated parts 68a and 68b are shown for convenience in order to show the welding process.

The back surface 71 b is a region from the peripheral surface of the cylindrical portion 72 to the peripheral edge of the flange portion 71.
Since the welded portion 67 is formed along the through-hole 73, the welded portion 67 is located on the inner periphery of the opposing surface 71a. Thereby, when an external force is applied, a starting point of breakage is hardly generated in the welded portion 67.

  In the terminal connection structure 3, the ratio of the length of the welded portion 67 overlapping the virtual circle P to the circumferential length of the virtual circle P is 50% or less. Therefore, an unwelded portion having a distance larger than the size of the welded portion 67 is provided between the adjacent welded portions 67. Thus, the welded portion 67 can be deformed so as to give flexibility to the welded portion 67 and allow relative displacement between the end portion 8A and the connection terminal 70, and the stress applied to the welded portion 67 can be dispersed.

The through-hole 73 is not limited to a rectangular shape, and may have an arbitrary shape such as a circular shape or an elliptical shape. Moreover, the notch formed in the radial inside from the peripheral edge of the collar part 71 may be sufficient.
The through-hole 73 is preferably rectangular or elliptical with the inner side in the radial direction of the opposing surface 71a as the longitudinal direction. Thereby, while ensuring the distance of the through-holes 73 enough, the periphery of the opening of the through-hole 73 can be taken long, and the full length of the welding part 67 which is wire welding can be enlarged. Therefore, the terminal connection structure 3 having high strength can be configured while maintaining the flexibility of the welded portion 67.

In addition, since the terminal connecting structure 3 is formed by directly irradiating the interface between the opening on the opposite surface side of the through hole and the end portion with the laser beam, the terminal connection structure 3 is efficiently welded. The work time required for welding can be shortened. Further, since the welding process is performed by direct laser irradiation, it is difficult to affect the members constituting the terminal connection structure 3 and the members disposed around the terminals. Therefore, distortion caused by the welding process and deterioration of the adhesive 6 can be suppressed.
In addition, since the terminal connection structure 3 is laser welding, the connection resistance is low as compared with a case where the terminal connection structure 3 is bonded by a conductive adhesive or brazing. Therefore, by adopting the electrostatic chuck device 100, the temperature of the electrostatic chuck portion 20 can be precisely controlled.

<< Modification of Second Embodiment >>
In the terminal connection structure 3 of the second embodiment, six through holes 73 and six welded portions 67 are provided on the facing surface 71a, but the number of welded portions may be three or more.
As modifications 1 and 2 of the second embodiment, a terminal connection structure 3A and a terminal connection structure 3B will be described.

FIGS. 10 and 11 are plan views showing the terminal connection structures 3A and 3B of Modifications 1 and 2 of the second embodiment, respectively. The terminal connection structure 3A is different from the terminal connection structure 3 in that the terminal connection structure 3A includes a connection terminal 74 provided with three through holes 73A and three welding portions 67A. The terminal connection structure 3B is different from the terminal connection structure 3 in that the terminal connection structure 3B includes connection terminals 75 provided with four through holes 73B and four welding portions 67B.
The terminal connection structures 3A and 3B of Modifications 1 and 2 of the second embodiment are the same as the terminal connection structures 1A, 1B and 1C (see FIGS. 6 to 8) described as Modifications 1 to 3 of the first embodiment. In addition, current does not concentrate on a specific weld, and local heating due to current concentration is suppressed. Moreover, the stress which peels welding part 67A, 67B with external force can be disperse | distributed with sufficient balance, and damage to welding part 67A, 67B can be suppressed.

  Although various embodiments of the present invention have been described above, each configuration in each embodiment and combinations thereof are examples, and addition, omission, replacement, and configuration of configurations are within the scope not departing from the spirit of the present invention. And other changes are possible. Further, the present invention is not limited by the embodiment.

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 2, 3, 3A, 3B ... Terminal connection structure, 5 ... Heating device, 6 ... Adhesive material, 7 ... Heating member (wiring, heater pattern), 7a ... Inner heater, 7b ... Outer heater , 8A, 8B ... end, 9, 10 ... extended end, 20 ... electrostatic chuck (ceramic plate), 23 ... internal electrode for electrostatic adsorption, 32 ... feeding terminal, 33 ... connecting wire, 40, 70, 74, 75 ... connection terminal, 41, 71 ... collar, 41a, 71a ... opposing surface, 41b, 71b ... back surface, 42, 72 ... cylindrical part, 42a ... end face, 50 ... cooling base part, 51 ... through hole , 61, 63, 64, 65, 66, 67, 67A, 67B ... welded part, 62 ... spot, 62a, 68a, 68b ... heated part, 73, 73A, 73B ... through hole, 80 ... resin layer, 100 ... Electrostatic chuck device, B ... fulcrum, C ... mid point, EB ... electronic bee , F ... external force, L1, L3 ... symmetry axis, L2, L4 ... reference axis, LZ ... laser, O1, O2 ... center, P ... virtual circle, W ... plate sample

Claims (8)

Strip-shaped wiring,
A connection terminal disposed at an end of the wiring,
The connection terminal has a circular opposing surface facing the end, and is welded to the end by three or more welds.
The welded portion is disposed in line symmetry with respect to an axis of symmetry that passes through the center of the opposing surface and extends in the direction of the wiring, and passes through the center of the opposing surface and is perpendicular to the axis of symmetry. On the other hand, a terminal connection structure in which two or more locations are arranged on the side where the wiring extends and one or more locations are arranged on the opposite side.   The terminal connection structure according to claim 1, wherein the welded portion is located on an inner side than a peripheral edge of the facing surface.   The terminal connection structure according to claim 1, wherein the welded portion is disposed rotationally symmetrical with respect to the center of the facing surface. The welds are arranged on a virtual circle concentric with the facing surface;
The terminal connection structure according to claim 1, wherein a ratio of the welded portion is 50% or less with respect to a circumferential length of the virtual circle.   The terminal connection structure according to claim 1, wherein the weld is formed by electron beam welding. The connection terminal is provided with a plurality of through holes reaching the facing surface,
The terminal connection as described in any one of Claims 1-4 in which the said welding part is formed by laser welding over a part of interface or the perimeter of the opposing surface side opening of the said through-hole, and the said edge part. Construction. A ceramic plate-like body made of a ceramic sintered body;
A heater pattern as the wiring adhered and fixed to the ceramic plate,
A terminal connecting structure according to any one of claims 1 to 6, provided at an end of the heater pattern.   An electrostatic chuck device comprising the heating device according to claim 7.

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