JP2014151353A - Method for manufacturing solder sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a solder sheet including a metallic ball embedded in a predetermined position and having a uniform thickness.SOLUTION: A hole section 60 having shape capable of supporting a metallic ball 40 (spherical body) is formed in a solder sheet 30 at a predetermined position 50, the metallic ball 40 is placed at the predetermined position 50, and then the metallic ball 40 is pressed in a thickness direction to be embedded in the solder sheet 30.

Description

  The present invention relates to a method for producing a solder sheet containing metal balls.

  In recent years, as a method for efficiently soldering electronic components, a sheet-like solder (hereinafter referred to as a solder sheet) is installed in advance at a joint where soldering is performed, and a substrate or a mounting is mounted on the solder sheet. A soldering method called a reflow method, in which parts are placed and then soldered by heating, has been put into practical use. In particular, this soldering method is used for soldering between a semiconductor constituting a semiconductor module such as an inverter used for an electric vehicle and a cooler or a circuit board.

  At this time, by maintaining the uniformity of the thickness of the solder sheet, the distance between the cooler and the inverter is not uniform unless soldering is performed so that the solder layer has a uniform thickness. Since the inverter cannot ensure the prescribed heat dissipation characteristics, solder the solder sheet with the metal sheet embedded in the solder sheet, keeping the thickness of the solder sheet equal to the diameter of the metal ball. Yes.

  The solder sheet in which the metal spheres are embedded in this way is embedded in the solder sheet by, for example, pressing the transfer sheet, to which the metal spheres are adhered, into the roller together with the solder sheet, and roll-pressing it. (For example, Patent Document 1).

JP 2007-301575 A

  However, according to the manufacturing method of the metal ball-containing solder sheet described in Patent Document 1, when the transfer sheet to which the metal sphere is adhered is pushed into the roller together with the solder sheet, the metal sphere is displaced from the position to which the metal sphere is adhered. As a result, there has been a problem that the place where the metal ball is embedded in the solder sheet is displaced.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a solder sheet in which metal balls are securely embedded in predetermined positions and the thickness of the solder sheet can be kept uniform. .

  The method for manufacturing a solder sheet according to the present invention relates to a method for manufacturing a solder sheet in which metal balls are embedded at predetermined positions.

  That is, the method for manufacturing a solder sheet according to the present invention includes a gap portion surrounded by a wall portion extending in a thickness direction of the solder sheet from the surface of the solder sheet at a predetermined position of the solder sheet, and the wall portion. Forming a hole capable of supporting a metal spherical body in at least a part of the line of intersection with the surface of the solder sheet, disposing the spherical body at the predetermined position, and Pressurizing in the thickness direction of the solder sheet, and embedding in the interior of the solder sheet, and when the pressed spherical body is embedded in the solder sheet, the spherical body is pressed by the spherical body The pressed portion of the solder sheet is deformed, and the pressed portion of the deformed solder sheet enters the gap.

  According to the method of manufacturing a solder sheet configured as described above, after forming a hole having a shape capable of supporting a metal spherical body at a predetermined position of the solder sheet, the spherical body is disposed at the predetermined position, and thereafter When the spherical body is pressed in the thickness direction of the solder sheet and the spherical body is embedded in the solder sheet, the portion to be pressed in the solder sheet pressurized by the spherical body is deformed and thus deformed. Since the pressed part in the solder sheet enters into the void surrounded by the wall constituting the hole, the spherical body can be embedded inside the solder sheet without shifting from the predetermined position. At the same time, since the deformation in the thickness direction of the solder sheet due to the embedded spherical body is suppressed, the thickness of the solder sheet can be kept uniform.

  The solder sheet manufacturing method according to the present invention is characterized in that the hole has at least three support portions for supporting the spherical body at the predetermined position.

  According to the solder sheet manufacturing method configured as described above, the hole is formed so as to include at least three support portions that support the spherical body arranged at a predetermined position. It can be reliably arranged at the position.

  Further, in the method for manufacturing a solder sheet according to the present invention, the hole portion is formed such that the support portion and the gap portion are alternately arranged along a circumferential direction of a closed curve passing through the plurality of support portions. It is characterized by.

  According to the solder sheet manufacturing method configured as described above, the support portions and the gap portions are alternately arranged along the circumferential direction of the closed curve passing through the plurality of support portions, with the hole portion being at the center. Since the support portion pressed by the spherical body is deformed and the deformed support portion moves into the gap adjacent to the support portion, the spherical body is embedded in the solder sheet. However, the deformed support portion does not protrude from the surface of the solder sheet. Therefore, even if the spherical body is embedded, the thickness of the solder sheet can be kept constant.

  In the solder sheet manufacturing method according to the present invention, when the hole portion has the spherical body arranged at the predetermined position, all or a part of the peripheral edge portion of the hole portion forms the support portion. It is formed in this.

  According to the method for manufacturing a solder sheet configured as described above, when the spherical body is disposed at a predetermined position, all or a part of the peripheral edge portion of the hole portion forms a support portion. It can be reliably arranged.

  Moreover, the method for manufacturing a solder sheet according to the present invention is characterized in that the step of forming the hole is performed by pressing.

  According to the solder sheet manufacturing method configured as described above, since the step of forming the hole is performed by pressing, there is no need to perform drilling with a drill, and the device for forming the hole is configured at low cost. can do.

  According to the method for manufacturing a solder sheet according to the present invention, it is possible to manufacture a solder sheet in which the thickness of the solder sheet is kept uniform and metal balls are embedded at predetermined positions.

(A) is a figure which shows an example which used the solder sheet manufactured by this invention for soldering with a cooler and a ceramic substrate. (B) is a figure which shows the structure of the chip | tip and beam lead which are mounted in a ceramic substrate. (A) is sectional drawing which cut | disconnected the mode that the ceramic substrate was soldered to the cooler by the cross section AA of FIG. (B) is sectional drawing which cut | disconnected the mode that the ceramic substrate was soldered to the cooler by the cross section BB of FIG. It is a figure explaining the process by which a metal ball is embedded in a solder sheet, (a) is a figure which shows the solder sheet before a process. (B) is a figure which shows a mode that the hole was formed in the predetermined position of a solder sheet. (C) is a figure which shows a mode that a metal ball is arrange | positioned in the formed hole part. (D) is a figure which shows a mode that the metal ball | bowl was embedded in the formed hole part. (E) is sectional drawing which cut | disconnected the mode that the cooler and the ceramic substrate were soldered using the solder sheet manufactured in this way in the cross section AA of FIG. It is a figure explaining the shape of a hole part. It is a figure explaining another shape of a hole part, (a) is a figure explaining the example whose shape of a hole part is a star shape. (B) is a figure explaining the example whose hole part is a shape which consists of a groove part extended in 3 directions. It is a figure explaining another shape of a hole, (a) is a figure explaining the example whose shape of a hole is circular. (B) is sectional drawing which shows a mode that the metal ball | bowl has been arrange | positioned to the hole of (a). (C) is a figure explaining the example whose shape of a hole is a hexagon.

  Embodiments of a method for producing a solder sheet according to the present invention will be described below with reference to the drawings.

A first embodiment of the present invention will be described below with reference to FIGS.

  A solder sheet manufactured by applying the method for manufacturing a solder sheet of the present invention is used, for example, for manufacturing an inverter that is one of in-vehicle power devices.

  FIG. 1A shows the appearance of a power device that constitutes a drive circuit and a gate circuit of an inverter. On the upper surface of the cooler 10, a plurality of substrates ASSY 20 are respectively soldered and fixed to the surface of the cooler 10 by solder sheets 30.

  FIG. 1B shows the detailed structure of the substrate assembly 20. In the substrate ASSY 20, a chip 26 which is an electronic component such as an IGBT or a diode as a semiconductor element is soldered to the upper surface of the ceramic substrate 22 via a plurality of solder sheets 24. The upper surface of the chip 26 is soldered with a beam lead 28, which is a conductive wiring member made of, for example, a copper plate, which connects different chips 26 with each other via a solder sheet 25. Yes.

[Description of conventional problems]
Next, problems of the conventional solder sheet manufacturing method will be described with reference to FIG. Fig.2 (a) shows the AA sectional drawing of the cooler 10 to which the board | substrate ASSY20 shown in Fig.1 (a) was soldered. That is, the upper surface of the cooler 10 and the lower surface of the ceramic substrate 22 are soldered to the upper surface of the cooler 10 via the solder sheet 30 having a thickness t. A plurality of chips 26 are mounted on the upper surface of the ceramic substrate 22 and are soldered to the upper surface of the ceramic substrate 22 by solder sheets 24, respectively.

  Moreover, FIG.2 (b) shows the BB cross section of the cooler 10 to which the board | substrate ASSY20 shown in Fig.1 (a) was soldered. That is, the solder sheet 30 is placed on the upper surface of the cooler 10, and the upper surface of the cooler 10 and the lower surface of the ceramic substrate 22 are soldered. A plurality of chips 26 are mounted on the upper surface of the ceramic substrate 22 and are soldered to the upper surface of the ceramic substrate 22 by solder sheets 24, respectively. Further, a beam lead 28 is mounted on the upper surface of the chip 26 and soldered to the upper surface of the chip 26 by a solder sheet 25.

  Here, in FIG. 2B, the upper surface of the cooler 10 and the lower surface of the ceramic substrate 22 are not soldered in parallel, and the solder sheet 30 becomes thinner toward the right side of FIG. 2B. Soldered with.

  This is a phenomenon caused when the uniformity of the thickness t of the solder sheet 30 is not sufficiently high. If the gap between the cooler 10 and the ceramic substrate 22 is biased in this way, the ceramic substrate 22 is not sufficiently dissipated in a region where the gap is wide. Further, in a region where the interval is narrow, stress absorption with respect to thermal expansion / contraction of the sheet solder 30 is reduced. In the worst case, the chip 26 may fail due to insufficient cooling, the fatigue of the sheet solder 30 due to insufficient solder thickness, or the failure of an external system connected to the inverter.

[Explanation of Operation of Example 1]
Hereinafter, the operation flow of the first embodiment will be described with reference to FIG.

  First, as shown in FIG. 3A, a solder sheet 30 is prepared.

  Next, as shown in FIG. 3B, holes 60, 61, 63, 65 having a predetermined shape are formed at predetermined positions 50, 52, 54, 56 in the solder sheet 30. The holes 60, 61, 63, 65 may be provided so as to penetrate the solder sheet 30, or may be provided so as not to penetrate the solder sheet 30.

  The positions of the holes 60, 61, 63, 65 formed at this time are set so as to be inside the outer periphery of the ceramic substrate 22 to be soldered to the solder sheet 30. The hole is formed by pressing using a press mold having the shape of the hole.

  The shape of the holes 60, 61, 63, 65 formed at this time will be described later.

  Then, after the formation of the holes 60, 61, 63, 65 is completed, the metal balls 40, 42, 44, 46 are placed at predetermined positions 50, 52, 54, 56, respectively, as shown in FIG. Place. The metal spheres 40, 42, 44, 46 are, for example, nickel spheres, and the diameter thereof is approximately the same as the thickness t of the solder sheet 30.

  Then, the metal balls 40, 42, 44, 46 arranged at the predetermined positions 50, 52, 54, 56 are respectively pressed from the upper surface of the solder sheet 30 as shown in FIG. 30 is press-fitted inside.

  FIG. 3E is a view showing a state in which the above-described soldering is performed using the solder sheet 30 into which the metal balls 40, 42, 44, and 46 are press-fitted. Since the melting points of the metal balls 40, 42, 44, and 46 are much higher than the melting point of the solder sheet 30, the shape of the metal balls is maintained even after soldering.

  As can be seen from FIG. 3 (e), the thickness t of the solder sheet 30 is kept constant by the metal balls press-fitted into the solder sheet 30, so the parallelism between the cooler 10 and the ceramic substrate 22. Thus, the ceramic substrate 22 and the chip 26 soldered thereto can be uniformly cooled.

  That is, for example, when the thickness t of the solder sheet 30 is 0.4 mm and the diameter of the metal sphere is 0.3 mm, the thickness of the solder sheet 30 can be ensured to be 0.3 mm or more.

[Description of hole shape]
Next, the shape of the holes 60, 61, 63, 65 will be described with reference to FIG. FIG. 4 shows the configuration of the hole 60 in detail.

  As shown in FIG. 4, the hole 60 is formed by a cross-shaped groove centered at a predetermined position 50 and penetrates the solder sheet 30. As shown in the sectional view taken along the section CC, each of the groove portions 62, 64, 66, 68 is surrounded by the wall portion 60W, and is separated from the predetermined position 50 by four degrees in four directions. It extends.

  In the vicinity of the predetermined position 50, four support portions 70, 72, 74, 76 in which the surface of the solder sheet 30 and two adjacent groove portions are formed by intersecting lines are formed.

  Here, the width w of the grooves 62, 64, 66, 68 is formed to be smaller than the diameter of the metal balls 40, 42, 44, 46. Therefore, in FIG. 3C, when the metal balls 40, 42, 44, 46 are arranged at the predetermined positions 50, 52, 54, 56, for example, the metal balls 40 are Supported at 4 points.

As described above, the holes 60, 61, 63, and 65 have a circle O ₁ that is a closed curve that passes through the four support portions 70, 72, 74, and 76 around the predetermined positions 50, 52, 54, and 56. Groove portions and support portions are alternately formed along the circumferential direction.

That is, along the circumferential direction of a circle _{O 1} described in FIG. 4, in a counterclockwise direction, the groove 62, the support portion 70, the groove 64, the support portion 72, the groove 66, the support portion 74, the groove 68, the support portion 76 Are formed in order.

[Explanation of deformation of hole during press-fitting of metal ball]
Next, how the holes 60, 61, 63, 65 are deformed when the metal balls 40, 42, 44, 46 shown in FIG. 3 are press-fitted into the holes 60, 61, 63, 65, respectively. To do.

  When the metal ball 40 is placed in a predetermined position 50 of the hole 60 and the metal ball 40 is press-fitted into the solder sheet 30 by applying a load in the thickness direction of the solder sheet 30 from above the metal ball 40, the metal ball 40 Presses the support portions 70, 72, 74, 76 shown in FIG. 4 and enters the solder sheet 30.

  At this time, the pressed support portions 70, 72, 74, and 76 are deformed, and the deformed portion enters the inside of the groove portion adjacent to the support portion.

  That is, the support portion 70 is pressed and deformed in the thickness direction of the solder sheet 30, and the deformed portion enters the groove portion 62 or the groove portion 64 adjacent to the support portion 70.

  Note that, when the support portion 70 is pressed and deformed, whether it enters the inside of the groove portion 62 or the inside of the groove portion 64 depends on the size of the metal sphere 40, the force pressing the metal sphere 40, and the solder sheet 30. Since it depends on the thickness t and the depths of the groove portions 62 and 64, etc., it is not generally determined.

  Similarly, the support portion 72 is pressed and deformed in the thickness direction of the solder sheet 30, and the deformed portion penetrates into the groove portion 64 or the groove portion 66 adjacent to the support portion 72.

  Further, the support portion 74 is pressed and deformed in the thickness direction of the solder sheet 30, and the deformed portion enters the inside of the groove portion 66 or the groove portion 68 adjacent to the support portion 74.

  Further, the support portion 76 is pressed and deformed in the thickness direction of the solder sheet 30, and the deformed portion enters the inside of the groove portion 68 or the groove portion 62 adjacent to the support portion 76.

  Therefore, when the metal ball 40 is press-fitted, the surface of the solder sheet 30 is not swelled or deformed by press-fitting.

[Description of modification of hole shape]
The shape of the hole 60 is not limited to that shown in FIG.

  FIG. 5 shows an example of another shape of the hole. That is, the hole 80 shown in FIG. 5A has a star shape formed at the predetermined position 50. Further, the hole 100 shown in FIG. 5B has a shape formed by a groove formed in a predetermined position 50 and extending in three directions.

  That is, the hole portions 80 and 100 shown in FIG. 5 are different from the hole portion 60 shown in FIG. 4 in the number of grooves and the number of support portions.

  That is, in the example of FIG. 5A, the groove portion 82, the support portion 90, the groove portion 84, the support portion 92, the groove portion 86, the support portion 94, the groove portion 88, and the support portion 96 around the predetermined position 50 counterclockwise. , A groove portion 89 and a support portion 98 are formed in this order.

  In the example of FIG. 5B, the groove portion 102, the support portion 110, the groove portion 104, the support portion 112, the groove portion 106, and the support portion 114 are sequentially formed around the predetermined position 50 in the counterclockwise direction.

  5 (a) and 5 (b), the number of support portions and the number of groove portions are different, but in both examples, the metal sphere can be supported by the support portion. In particular, the example of FIG. 5B is an example in which the support portion is composed of three points, and this is the minimum configuration that can stably arrange the metal balls.

  Further, in both FIGS. 5A and 5B, since the groove portion is formed at a position adjacent to the support portion, when the metal ball is press-fitted into the solder sheet 30, the pressed support portion is deformed. The deformed support portion has a structure that enters the groove portion.

  Therefore, both the hole 80 shown in FIG. 5A and the hole 100 shown in FIG. 5B have the same effects as the hole 60 shown in FIG.

  In the example shown in FIGS. 4 and 5B, the widths of the groove portions are all equal, but a support portion on which metal balls can be arranged is formed even if the width of the groove portions differs depending on the direction. If it is, there exists the same effect.

  Furthermore, FIG. 6 also shows an example of another shape of the hole. That is, the hole 120 shown in FIGS. 6A and 6B is formed at a predetermined position 50 and has a circular shape. Moreover, the hole part 130 shown in FIG.6 (c) is formed in the predetermined position 50, and has hexagonal shape.

  6 (a) and 6 (b) and the hole 130 shown in FIG. 6 (c) are different from the hole 60 shown in FIG. There is no direction. Further, the support portions 124 and 134 are not points, but the edge portions formed by the intersecting lines between the hole portions 120 and 130 and the surface of the solder sheet 30 become the support portions 124 and 134. Further, as shown in the cross-sectional view of FIG. 6B, the hole 120 in FIG. 6A does not penetrate the solder sheet 30 and is surrounded by the wall 120W that forms the groove 122. have. The hole 120 may be formed so as to penetrate the solder sheet 30.

  That is, in the example of FIG. 6A, a circular groove 122 having a predetermined diameter is formed around the predetermined position 50, and the circumferential portion (peripheral portion) of the groove 122 forms the support portion 124. ing.

  When the metal ball 40 is disposed at the predetermined position 50, the metal ball 40 is supported by the support portion 124 formed by the circumferential portion (peripheral portion) of the groove portion 122, as shown in FIG. . In this case, the metal ball 40 is supported in a line contact state by the circumferential portion (peripheral portion) of the groove 122.

  In the example of FIG. 6C, a hexagonal groove 132 is formed around the predetermined position 50, and the outer periphery (peripheral edge) of the groove 132 forms a support portion 134.

  When the metal sphere 40 is disposed at the predetermined position 50, the metal sphere 40 has a midpoint 134a of each side forming the support portion 134 among the support portions 134 formed on the outer periphery (peripheral portion) of the groove portion 132. , 134b, 134c, 134d, 134e, and 134f are supported in a point contact state.

  Next, with respect to the hole 120 of FIG. 6A, deformation of the hole 120 when the metal ball 40 is press-fitted will be described with reference to FIG. 6B.

  FIG. 6B is a cross-sectional view showing a state in which the metal ball 40 is arranged on the support portion 124 formed by the circumferential portion of the groove portion 122 formed in the solder sheet 30.

  When the metal ball 40 is press-fitted into the solder sheet 30 in the state of FIG. 6B, the support portion 124 is pressed toward the inside of the solder sheet 30.

  At this time, the support portion 124 is deformed in a direction along the wall portion 120 </ b> W of the groove portion 122, and the deformed portion moves toward the bottom portion 120 </ b> B of the groove portion 122 with the press-fitting of the metal ball 40. Since the deformed portion is accumulated in the gap between the press-fitted metal ball 40 and the groove portion 122, the surface of the solder sheet 30 is not bulged or deformed by press-fitting.

  Similarly, with respect to the hole 130 shown in FIG. 6C, when the metal ball 40 is press-fitted, the support part 134 is deformed in the direction along the wall part of the groove part 132, and this deformed part is the metal part. As the ball 40 is press-fitted, it moves toward the bottom of the groove 132. Since the deformed portion accumulates in the gap between the press-fitted metal ball 40 and the groove portion 132, the surface of the solder sheet 30 does not rise or deform due to press-fitting.

  As described above, according to the method for manufacturing a solder sheet according to the first embodiment, after the hole 60 having a shape capable of supporting the metal ball 40 (spherical body) is formed in the predetermined position 50 of the solder sheet 30. When the metal ball 40 is disposed at a predetermined position 50 and then the metal ball 40 is pressed in the thickness direction of the solder sheet 30 and embedded in the solder sheet 30, the solder sheet pressed by the metal ball 40 is used. 30 support portions 70, 72, 74, 76 (pressurized portions) are deformed, and thus the deformed support portions 70, 72, 74, 76 of the solder sheet 30 are surrounded by the wall portion 60 </ b> W of the hole portion 60. In order to enter the groove portions 62, 64, 66, 68 (gap portion), the metal ball 40 can be embedded in the solder sheet 30 without being displaced from the predetermined position 50, and the metal ball 40 is embedded. The deformation in the thickness direction of the solder sheet 30 is suppressed by it, can be kept uniform thickness of the solder sheet 30.

  Further, according to the method for manufacturing the solder sheet 30 according to the first embodiment, the hole 60 includes the support portions 70, 72, 74, and 76 that support the metal ball 40 (spherical body) disposed at the predetermined position 50. Therefore, the metal ball 40 can be reliably arranged at the predetermined position 50.

Further, according to the method for manufacturing the solder sheet 30 according to the first embodiment, the hole 60 has a circumference of the circle O ₁ that is a closed curve that passes through the plurality of support portions 70, 72, 74, 76 with the predetermined position 50 as the center. Since the support portions 70, 72, 74, and 76 and the groove portions 62, 64, 66, and 68 (gap portions) are alternately formed along the direction, the metal balls 40 (spherical bodies) are pressed. Since the support portions 70, 72, 74, and 76 that have been formed are deformed to the left and right and the deformed support portions 70, 72, 74, and 76 are moved into the adjacent groove portions 62, 64, 66, and 68, metal Even when the sphere 40 is embedded in the solder sheet 30, the deformed support portions 70, 72, 74, and 76 do not protrude from the surface of the solder sheet 30. Therefore, even if the metal ball 40 is embedded, the thickness of the solder sheet 30 can be kept constant.

  In addition, according to the method for manufacturing the solder sheet 30 according to the first embodiment, when the hole 60 has the metal ball 40 (spherical body) disposed at the predetermined position 50, all or one of the peripheral edges of the hole 60. Since the portion is formed to form the support portion 124, the metal ball 40 can be reliably disposed at the predetermined position 50.

  In addition, according to the method for manufacturing the solder sheet 30 according to the first embodiment, since the process of forming the hole 60 is performed by pressing, there is no need to perform drilling with a drill, and an apparatus for forming a hole is provided. It can be configured at low cost.

  In the first embodiment, the shape of the hole has been described as a cross shape, a star shape, a shape composed of grooves extending in three directions, a circular shape, and a hexagonal shape. Without being limited to these, as long as the metal sphere (spherical body) can be held in the hole, and the metal sphere is embedded in the solder sheet, as long as the escape place of the deformed solder sheet is secured, Similar effects can be obtained with other shapes.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the embodiments are only examples of the present invention, and the present invention is not limited to the configurations of the embodiments. Needless to say, design changes and the like within a range not departing from the gist of the invention are included in the present invention.

10 Cooler 20 Substrate assembly
22 Ceramic substrate 26 Chip 24, 30 Solder sheets 40, 42, 44, 46 Metal balls 50, 52, 54, 56 Predetermined positions 60, 61, 63, 65 Holes

Claims (5)

In a predetermined position of the solder sheet, there is a gap surrounded by a wall portion extending in the thickness direction of the solder sheet from the surface of the solder sheet, and in a line of intersection between the wall portion and the surface of the solder sheet Forming a hole capable of supporting a metal sphere at least in part;
Disposing the spherical body at the predetermined position;
Pressurizing the spherical body in the thickness direction of the solder sheet, and embedding in the solder sheet,
When the pressed spherical body is embedded in the solder sheet, the pressed portion of the solder sheet pressed by the spherical body is deformed, and the pressed portion of the deformed solder sheet is A method for producing a solder sheet, wherein the solder sheet enters into the gap.   2. The method of manufacturing a solder sheet according to claim 1, wherein the hole includes at least three support portions that support the spherical body at the predetermined position.   The said hole part is formed so that a support part and a space | gap part may be alternately arrange | positioned along the circumferential direction of the closed curve which passes through the said several support part. Production method.   The hole portion is formed such that when the spherical body is disposed at the predetermined position, all or a part of a peripheral edge portion constituted by an edge of the hole portion forms the support portion. The method for producing a solder sheet according to claim 2.   The method for producing a solder sheet according to any one of claims 1 to 4, wherein the step of forming the hole is performed by press working.