JP2010194592A - Solder flattening tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solder flattening tool capable of forming a fed solder in a rectangular shape, and preventing occurrence of any defective product. <P>SOLUTION: The solder flattening tool presses a solder 21 fed on a workpiece in a flat shape. The tool includes a rectangular flat pressing face 1 which presses the solder 21 and projects it outwardly, a rectangular outer wall 9 arranged on an outer circumferential side of the pressing face, and a solder guide structure 2 for spreading the solder 21 projected from the pressing face 1 to each ridge 9a including a corner part 9b of the outer wall 9, between the outer wall 9 and the pressing face 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solder flattening jig that presses solder supplied onto a workpiece such as a lead frame.

  The die bonder that bonds the chip to the island of the lead frame has a solder supply mechanism that supplies a certain amount of solder to the island, and the solder on the island that is supplied with the solder is flattened and spread almost flat (the rectangular shape). ) And a bonding mechanism for bonding a chip onto the solder.

  The solder striking mechanism includes a square columnar solder flattening jig 101 as shown in FIG. 5 (Patent Document 1 and Patent Document 2). 6 is a cross-sectional view taken along the line CC in FIG. 5. As shown in FIG. 6, a rectangular recess 103 is provided inside the outer peripheral edge 102. The bottom 104 of the recess 103 is planar.

  As shown in FIG. 7A, when the solder 106 is supplied in a circular shape to the island 105 of the lead frame 107 by the solder supply mechanism, the solder flattening treatment is applied to the supplied solder 106 by a driving mechanism (not shown). The tool is lowered and the concave portion 103 of the heated solder flattening jig is pressed against the solder 106. As a result, the solder 105 is spread outward at the bottom 104 of the recess 103, and the solder is formed into the shape (rectangular shape) of the recess 103.

  The device described in Patent Document 1 discharges air entrained in the recess through the communication hole by providing a communication hole that communicates the bottom of the recess with the outside. In the device described in Patent Document 2, a groove is formed at the peripheral edge of the recess, and excess solder is absorbed into the groove.

JP 2002-273666 A Japanese Patent Application Laid-Open No. 2005-177853

  When the supplied solder 106 is expanded using the one described in Patent Documents 1 and 2, since the bottom 104 of the recess 103 is substantially planar, the solder 106 expands concentrically. For this reason, as shown in FIG.7 (b), the solder 106 protrudes from the recessed part 103 which is rectangular shape, and cannot be shape | molded in a rectangular shape. Note that the dotted line in FIG. 7B indicates the outer edge of the recess 103. Further, if the supply amount of the solder 106 is reduced, it remains circular and cannot be formed into a rectangular shape.

  By the way, when the shape of the chip bonded on the solder is rectangular, it is necessary to supply the solder to the entire area including the corner portion of the chip, so that the shape of the solder also needs to be rectangular. In other words, when the shape of the expanded solder is a small circle, the solder is not supplied to the corner portion of the chip, and when the shape of the expanded solder is a large circle, the solder protrudes from the lead frame. There is a risk of defective products. For this reason, it is necessary to shape the expanded solder into a rectangular shape in accordance with the shape of the chip.

  Therefore, in view of the above problems, the present invention provides a solder flattening jig capable of forming the supplied solder into a rectangular shape and preventing the occurrence of defective products.

  The solder flattening jig of the present invention is a solder flattening jig that presses the solder supplied onto the workpiece to make it flat, and is a rectangular flat shape that presses the solder and protrudes outward. Solder that spreads the solder protruding from the pressing surface to each side including the corner portion of the outer wall between the pressing surface, the rectangular outer wall disposed on the outer peripheral side of the pressing surface, and the outer wall and the pressing surface And a guide structure.

  According to the solder flattening jig of the present invention, by providing the flat pressing surface, the solder can be pressed by the flat pressing surface and protrude outward. Further, since the solder guide structure is provided on the outer peripheral side of the flat pressing surface, the protruding solder can be guided to the outer wall and spread to each side and corner portion of the outer wall. In addition, it is possible to prevent the solder from protruding to the outside at the outer wall. Thereby, the supplied solder can be formed into a rectangular shape.

  The solder guide structure is provided with a stepped concave portion that gradually becomes deeper from the pressing surface side toward each side of the outer wall, or a tapered surface that is inclined so that the bottom surface becomes deeper from the pressing surface toward the outer wall side. Or provided with a concave portion. As a result, the deeper the bottom of the solder guiding structure, the slower the solder flow rate, and the slower the solder flow rate can be from the pressing surface side toward the outer wall side.

  The solder guide structure may be provided with a relief hole for escaping the solder flowing on each side of the outer wall at a portion excluding the vicinity of the corner portion of the outer wall. Since the pressed solder spreads concentrically, it first reaches the center of the side of the outer wall whose distance from the center is the shortest. On the other hand, the corner portion of the outer wall having the longest distance from the center reaches the end after reaching the central portion. For this reason, when a relief hole is provided, the excess solder that has reached the corner portion flows toward the relief hole, and the necessary solder can reach the corner portion during that time. Thereby, it can prevent that solder protrudes from an outer wall.

  A plurality of the escape holes are provided along each side of the outer wall, and the opening area of the escape hole near the corner is made smaller than the opening area of the escape hole on the center side, or the interval between the escape holes is It can be sparse from the center side toward the corner side. That is, since the solder reaches first in the central portion of the side, it takes the least time until the solder reaches after the solder is pressed. On the other hand, the closer to the corner, the slower the solder arrives, so it takes time for the solder to arrive after the solder is pressed. As a result, the time difference between the time when the solder reaches the central portion of the side and the time when the solder reaches the corner portion is the largest, and the amount of solder that needs to escape is maximized on the central portion side. Therefore, on the side of the side of the side, by increasing the opening area of the escape holes or by increasing the distance between the escape holes, the amount of solder flow can be reduced by reducing the amount of solder flowing. It is possible to simultaneously reach the center and the corner.

  The solder guide structure may include a guide groove for guiding the solder from the pressing surface side toward the corner side. Thereby, solder can be supplied linearly from the pressing surface toward the corner portion.

  In the present invention, the supplied solder can be formed into a rectangular shape, and can be formed in a shape substantially in line with the shape of the chip. Thereby, generation | occurrence | production of inferior goods can be prevented.

  The solder guide structure is provided with a stepped concave portion that gradually becomes deeper from the pressing surface side toward each side of the outer wall, or a tapered surface that is inclined so that the bottom surface becomes deeper from the pressing surface toward the outer wall side. If the concave portion is provided, a solder guide structure can be easily formed.

  Providing the escape holes can prevent the solder from protruding from the outer wall, thereby further preventing the occurrence of defective products.

  Increasing the size of the escape holes on the side of the side or increasing the distance between the escape holes can reduce the amount of solder flowing on the side of the side, The arrival and the arrival at the corner can be performed simultaneously, and the solder can be efficiently rectangular.

  Since the solder can be supplied linearly from the pressing surface toward the corner portion, the solder can be supplied quickly and surely to the corner portion, and the solder is made into a rectangular shape more efficiently and stably. be able to.

It is a perspective view of the jig for solder flattening of a 1st embodiment of the present invention. It is the sectional view on the AA line of the said FIG. It is the BB sectional view taken on the line of FIG. It is a top view which shows before and after expanding solder using the jig for solder flattening of a 1st embodiment of the present invention, (a) before expanding solder, (b) after expanding solder It is. It is a perspective view of the conventional solder flattening jig. It is CC sectional view taken on the line of FIG. It is a top view which shows before and after expanding a solder using the jig | tool for the conventional solder flattening, (a) is before expanding a solder, (b) is after expanding a solder.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 shows a perspective view of a solder flattening jig of the present invention, which is provided in a die bonder for bonding a chip to a lead frame. In other words, the die bonder has a solder supply mechanism that supplies a certain amount of solder to the island, and a solder tapping mechanism that flattens and spreads the solder on the island that has received the solder supply into a shape (rectangular shape) that is almost the same as the chip. And a bonding mechanism for bonding the chip onto the solder. The solder flattening jig is provided in a solder hitting mechanism, and presses the solder supplied by the solder supply mechanism onto a work such as a lead frame to make it flat.

  Such a solder flattening jig is formed in a quadrangular prism shape as shown in FIG. 1, and a flat pressing surface 1 that presses the supplied solder and protrudes outward at the center, and The rectangular outer wall 9 disposed on the outer peripheral side of the pressing surface 1 and the solder that is provided between the outer wall 9 and the pressing surface 1 and protrudes from the pressing surface 1 are attached to the corner portion 9b of the outer wall 9. And a solder guide structure 2 that extends to each side 9a.

  FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and the flat pressing surface 1 is a flat surface having a rectangular shape provided at the center. A rectangular outer wall 9 is provided on the outer peripheral side of the flat pressing surface 1. That is, a rectangular flange 10 is provided on the outer peripheral side of the flat pressing surface 1, and the inner peripheral surface of the flange 10 is used as the outer wall 9. The front end portion of the collar portion 10 is provided slightly below the flat pressing surface 1.

  The solder guide structure 2 is provided between the outer wall 9 and the pressing surface 1 and includes a stepped recess 3 that gradually becomes deeper from the pressing surface side toward each side 9 a of the outer wall 9. That is, the stepped recess 3 includes a first step portion 4 provided outside the flat pressing surface 1, a first flat portion 5 provided at a position deeper than the flat pressing surface 1, a second step portion 6, The second flat part 7 is provided at a position deeper than the first flat part 5.

  An escape hole 8 that communicates from the bottom to the outside is provided in a portion of the outer wall 9 excluding the vicinity of the corner. Three escape holes 8 are provided along each side 9a. That is, one escape hole 8a is provided in the central portion of one side 9a, and one escape hole 8b is provided on both sides thereof. In this case, the opening area of the relief hole 8b near the corner is made smaller than the opening area of the relief hole 8a in the center.

  FIG. 3 is a cross-sectional view taken along the line BB in FIG. 1. The solder guide structure 2 is provided with guide grooves 11 for guiding solder from the pressing surface side toward the corner side. The guide groove 11 is a flat groove deeper than the second flat portion 7 and can linearly guide the solder pressed by the flat pressing surface 1 to the corner portion 9b.

  Next, a method for adjusting the shape by pressing the solder supplied onto the lead frame with the solder flattening jig of the present invention will be described. First, as shown in FIG. 4A, a predetermined amount of solder 21 is supplied in a circle to the island 20 of the lead frame 22 by a solder supply mechanism (not shown). Thereafter, the lead frame 22 is transported, and when the lead frame 22 is transported to a position below the solder tapping mechanism, the solder flattening jig is lowered by a driving mechanism (not shown), and the heated solder flattening jig is pressed flat. Press face 1 against solder 21.

  Then, the solder 21 pressed by the flat pressing surface 1 is spread outside the flat pressing surface 1 and protrudes into the solder guide structure 2. As the bottom of the solder guide structure 2 becomes deeper, the flow rate of the solder 21 supplied to the solder guide structure 2 becomes slower and becomes slower from the pressing surface side toward the outer wall side. That is, the flow rate is slow in the first plane part 5 and is further slowed in the second plane part 7. As described above, in the solder guide structure 2, the flow rate of the solder 21 spreads concentrically while decreasing from the pressing surface side toward the outside.

  In addition, the solder 21 extends linearly from the pressing surface side toward the corner portion side through the guide groove 11.

  First, the solder 21 spreading concentrically reaches the central portion of the side 9a of the outer wall 9 having the shortest distance from the center, and then reaches the corner portion 9b of the outer wall 9 having the longest distance from the center. After reaching the center, reach the end. In this case, since the escape holes 8a and 8b are provided in the portions other than the vicinity of the corner portion of the outer wall 9, excess solder that has reached before the corner portion 9b flows toward the escape holes 8a and 8b. . In the meantime, since the necessary solder 21 can reach the corner portion 9b, it is possible to prevent the solder 21 from protruding from the outer wall 9.

  As described above, since the solder 21 first arrives at the central portion of the side 9a, it takes the least time from when the solder 21 is pressed until the solder 21 arrives. On the other hand, the closer to the corner portion 9b, the slower the solder 21 arrives, so it takes time until the solder 21 arrives after the solder 21 is pressed. Thereby, the time difference between the time when the solder reaches the center of the side 9a and the time when the solder reaches the corner 9b becomes the largest, and the amount of the solder 21 that needs to escape on the center side of the side 9a needs to be maximized. Therefore, since the opening area of the escape hole 8a is increased on the center side of the side 9a, the escape amount of the solder 21 can be increased and the amount of the solder 21 flowing can be reduced.

  Meanwhile, the solder 21 passes through the guide groove 11 and linearly expands from the pressing surface 1 toward the corner portion 9b, so that the necessary solder 21 can reach the corner portion 9b. For this reason, the solder 21 can be supplied to the central portion of the side 9a and the corner portion 9b at substantially the same timing. In addition, the outer wall 9 can prevent the solder 21 from protruding outside.

  Thereafter, the solder flattening jig is raised by the driving mechanism. As a result, as shown in FIG. 4B, the solder 21 can be formed in a rectangular shape.

  In the present invention, the supplied solder 21 can be formed into a rectangular shape, and can be shaped substantially in line with the shape of the chip. Thereby, generation | occurrence | production of inferior goods can be prevented.

  When the solder guide structure 2 is provided with the step-like recesses 3 that are gradually deepened from the pressing surface side toward the sides 9a of the outer wall 9, the solder guide structure 2 can be easily formed.

  Providing the escape hole 8 can prevent the solder 21 from protruding from the outer wall 9, thereby further preventing the occurrence of defective products.

  If the size of the escape hole 8 is increased on the side of the side 9a, the amount of the solder 21 flowing on the side of the side 9a can be reduced, reaching the center of the side 9a and reaching the corner 9b. And the solder 21 can be efficiently made rectangular.

  Since the solder can be supplied linearly from the pressing surface 1 toward the corner portion 9b, the solder can be supplied quickly and surely to the corner portion 9b, and the solder can be supplied more efficiently and stably. It can be a shape.

  As a second embodiment, the solder guide structure 2 can be provided with a concave portion having a tapered surface that is inclined so that the bottom surface becomes deeper sequentially from the pressing surface 1 toward the side 9 a of the outer wall 9.

  As a third embodiment, a plurality of escape holes 8 are provided along each side 9a of the outer wall 9, and the interval between the escape holes 8 can be made sparse from the central part side to the corner part side.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the outer wall 9 may be square or rectangular. In the case of a rectangular shape, the number of long-side escape holes 8 can be made larger than the number of short-side escape holes 8. The number of escape holes 8 is not limited to three, and can be reduced or increased, and long holes may be provided. The opening cross section of the escape hole 8 is not limited to a circular shape, and may be an oval shape or a polygonal shape. The shape of the pressing surface 1 is not necessarily rectangular, and may be another shape. The number of stepped portions of the stepped recess 3 is not limited to two, and may be one or three or more.

DESCRIPTION OF SYMBOLS 1 Flat-shaped pressing surface 2 Solder guide structure 3 Step-shaped recessed part 8 Escape hole 9 Outer wall 9a Side 9b Corner part 11 Guide groove 21 Solder 22 Workpiece

Claims (7)

A solder flattening jig that presses the solder supplied onto the workpiece to make it flat.
A rectangular flat pressing surface that presses the solder and protrudes outward;
A rectangular outer wall disposed on the outer peripheral side of the pressing surface, and a solder guide structure for spreading the solder protruding from the pressing surface to each side including the corner portion of the outer wall between the outer wall and the pressing surface. A solder flattening jig characterized by being provided.   2. The solder flattening jig according to claim 1, wherein the solder guide structure includes stepped recesses that are gradually deepened from the pressing surface side toward each side of the outer wall.   2. The solder flattening jig according to claim 1, wherein the solder guide structure includes a concave portion having a tapered surface inclined so that a bottom surface is gradually deepened from a pressing surface toward a side of the outer wall.   4. The solder solder structure according to claim 1, wherein the solder guide structure includes a relief hole for escaping the solder flowing on each side of the outer wall at a portion other than the vicinity of the corner portion of the outer wall. Solder flattening jig.   5. The solder according to claim 4, wherein a plurality of the escape holes are provided along each side of the outer wall, and an opening area of the escape hole near the corner is made smaller than an opening area of the escape hole on the center side. Flattening jig.   5. The solder flattening according to claim 4, wherein a plurality of the relief holes are provided along each side of the outer wall, and the intervals between the relief holes are made sparse from the central part side to the corner part side. jig.   The solder flattening according to any one of claims 1 to 6, wherein the solder guide structure includes a guide groove for guiding the solder from the pressing surface side toward the corner portion side. Jig.

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