JP5086218B2 - Lead frame continuum manufacturing method and heating / cooling processing apparatus - Google Patents

Description

  The present invention relates to a method for manufacturing a lead frame continuum and a heating / cooling apparatus, and more particularly, a continuous lead frame for removing residual strain remaining in a press lead continuum by heating and cooling. The present invention relates to a body manufacturing method and a heating / cooling processing apparatus.

  Conventionally, in a method of manufacturing a lead frame continuum, in order to remove residual strain remaining in a lead frame formed by pressing, after heat treatment is performed in a state where tips of inner leads of the lead frame are connected to each other, The cooling process is performed.

  As a technology related to this, in Patent Document 1, a metal belt wound between a pair of rollers is overlapped in two stages, and a continuum of lead frames is sandwiched between two overlapping metal belts. It describes that heating and cooling are performed while the belt is rotated.

  Further, in Patent Document 2, in a belt-shaped body conveyance device including a pair of stepped rollers for supporting the edge portion of the belt-shaped body, the interval between the stepped rollers is automatically set even if the width of the belt-shaped body changes. It is described that a control device for adjusting to a new width is provided.

In addition, in Patent Document 3, in an etching apparatus for continuously forming a hole in a long metal plate, the metal plate is alternately disposed above and below the metal plate, and only the vicinity of both ends of the metal plate is contacted. It is described that a stepped roller for continuously moving the metal plate while holding it in a wave shape and a nozzle for injecting an etching solution onto the inclined portion of the metal plate are described.
JP 2007-165823 A JP 60-87154 A JP-A-61-91376

  In the heating and cooling processing apparatus used in the method for producing a lead frame continuous body, two metal belts sandwiching the lead frame continuous body are pressed by rollers from the outside. There is a problem of scratches on the surface.

  The present invention has been created in view of the above problems, and manufacture of a continuous body of lead frames in which the continuous body is heated and cooled in order to remove residual strain remaining in the continuous body of pressed lead frames. An object of the method and the heating / cooling processing apparatus is to prevent the surface of the lead frame from being damaged.

In order to solve the above-mentioned problems, the present invention relates to a method for manufacturing a lead frame continuum, wherein the first metal belt is disposed to overlap a first metal belt that travels in one direction and the first metal belt. A second metal belt that travels in the same direction, and a plurality of pressurizations that are disposed on and in contact with the first metal belt and partially pressurize both ends in the width direction of the first metal belt A heating region and a cooling region in a region where the first metal belt and the second metal belt overlap with each other, and a plurality of support rollers disposed in contact with the roller under the second metal belt A lead frame continuum having a width narrower than the width of the first and second metal belts, and the first metal belt and the second metal. In contact with the belt Was supplied to the central portion in the width direction between the first metal belt in a state with the second metal belt, said first, said support outside the both end portions and the pressure roller from the central portion of the second metal belt A first driving roller and a first driven roller including removing residual strain of the continuous body by passing the heating region and the cooling region by running of the metal belt in a state of being clamped by a roller. The first metal belt is wound between a pair of rollers composed of a second drive roller and a second driven roller under the first metal belt which is wound between a pair of rollers. Two metal belts are disposed, and the second metal belt is disposed under the first metal belt.

  In the heating / cooling processing apparatus used in the manufacturing method of the present invention, the second metal belt is disposed so as to overlap the first metal belt, and the metal belts travel in the same direction. Further, a plurality of pressure rollers are disposed on the first metal belt, and a plurality of support rollers are disposed below the second metal belt.

  Then, a lead frame continuum is supplied between the first metal belt and the second metal belt, and the heating region and cooling are performed by running the metal belt in a state where the continuum is sandwiched between the pressure roller and the support roller. Go through the area sequentially. Thereby, residual strain remaining in the lead frame formed by press working is removed.

  The pressure roller has a structure in which both end portions in the width direction of the first metal belt are partially pressed so that the pressure on the lead frame is not directly pressed. For this reason, unlike the case of using a cylindrical body whose rotating curved surface is the same as the whole as a pressure roller, pressure is not applied to the lead frame in a straight line, thereby preventing the surface of the lead frame from being damaged. Is done.

  In a preferred aspect of the present invention, the second driving roller and the second driven roller are disposed under the first metal belt that is wound around a pair of rollers including the first driving roller and the first driven roller, and rotates. A second metal belt that is wound around a pair of rollers and that rotates is disposed, and the second metal belt is disposed under the first metal belt.

  In a preferred aspect of the present invention, the pressure roller is composed of a rotating body connected to the shaft portion and both ends thereof and having a large diameter portion having a diameter larger than that of the shaft portion, and the large diameter portion is the first portion. The metal belt is partially in contact with both ends and pressed.

  As described above, in the present invention, it is possible to prevent the surface of the lead frame from being damaged when the continuous body of the lead frame is heated and cooled.

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

  FIG. 1 is a cross-sectional view showing a heating / cooling apparatus according to an embodiment of the present invention. As shown in FIG. 1, in the heating and cooling processing apparatus 1 of the present embodiment, a first drive roller 10 and a first driven roller 12 are disposed on both ends on the upper side, and second on both ends on the lower side. A driving roller 20 and a second driven roller 22 are disposed. A second driving roller 20 is disposed below the first driving roller 10, and a second driven roller 22 is disposed below the first driven roller 12.

  The first driving roller 10 and the first driven roller 12 constitute a pair of rollers, and the first metal belt 30 is wound endlessly between these rollers. Similarly, the second driving roller 20 and the second driven roller 22 constitute a pair of rollers, and the second metal belt 32 is wound endlessly between these rollers. Thereby, the structure where the 2nd metal belt 32 overlaps under the 1st metal belt 30 is comprised.

  As the first drive roller 10 and the second drive roller 20 are rotated by a driving means such as a motor, the first and second metal belts 30 and 32 are rotated.

  In the vicinity of the inside of the first and second drive rollers 10 and 20, cylinder devices 14a and 14b for pressing them outward are provided, respectively. As a result, the first metal belt 30 and the second metal belt 32 are at a predetermined pressure so as not to bend between the first and second drive rollers 10 and 20 and the first and second driven rollers 12 and 22, respectively. Pulled to run around.

  In the example of FIG. 1, both the first driving roller 10 and the first driven roller 12 rotate to the right (clockwise direction), and both the second driving roller 20 and the second driven roller 22 to the left (counterclockwise direction). Rotate. Thereby, in the area | region where the 1st metal belt 30 and the 2nd metal belt 32 overlap, the 1st, 2nd metal belts 30 and 32 synchronize and drive | work in the same direction (FIG. 1 left side).

  In the region where the first metal belt 30 and the second metal belt 32 overlap, a plurality of pressure rollers 40 are arranged side by side on the first metal belt 30, and a plurality of support rollers are disposed below the second metal belt 32. 42 are arranged side by side. The plurality of pressure rollers 40 and the plurality of support rollers 42 are disposed at corresponding positions.

  The pressure rollers 40 and the support rollers 42 arranged above and below constitute a pair of nipping rollers, and the first metal belt 30 and the second metal belt 32 are nipped from above and below, so that the first, The second metal belts 30 and 32 are overlapped.

  The first driven roller 12 and the second driven roller 22 are both heating rollers provided with a heater, and a region where the first driven roller 12 and the second driven roller 22 are disposed and the vicinity thereof are a heating region A. In the heating area A, a plurality of heaters (not shown) are also provided on the inner wall.

  A region where the first drive roller 10 and the second drive roller 20 are arranged from the outside of the heating region A (left side in FIG. 1) is a cooling region B where no heater is provided. In the cooling region B, cooling may be performed by blowing cooling gas from the upper and lower sides to the first and second metal belts 30 and 32 as necessary.

  In this way, the first metal belt 30 and the second metal belt 32 that are sandwiched and overlapped by the pressure roller 40 and the support roller 42 at a predetermined pressure are first and second driven rollers 12 and 22 from the side. 1. Rotates to the second drive rollers 10 and 20 side, and sequentially passes through the heating area A and the cooling area B.

  Further, an auxiliary heating roller 24 is provided obliquely on the upper right side of the first driven roller 12. In the vicinity of the auxiliary heating roller 24, a supply port 16 for supplying a continuous lead frame is provided, and a preheating portion C is provided outside the supply port 16. The preheating portion C is provided with a guide 18 for guiding insertion of a continuous lead frame. The preheating part C is provided with a heater (not shown), and the preheating part C is heated so as to have a temperature atmosphere substantially the same as that of the heating region A. Further, a tension applying roller 26 is disposed outside the preheating portion C.

  The lead frame continuum 50 (shown in bold in FIG. 1 (sometimes simply referred to as the continuum 50)) is led to the heating area A side by the guide 18 of the preheating section C while being pulled by the tension applying roller 26. It is burned. The continuum 50 that has passed through the preheating portion C is stretched between the first metal belt 30 and the second metal belt 32 sandwiched between the first driven roller 12 and the second driven roller 22 while being pulled by the auxiliary heating roller 24. To be supplied.

  Unlike the present embodiment, when the auxiliary heating roller 24 is omitted, the continuum 50 is bent and conveyed in only one direction along the rotating curved surface of the first driven roller 12 (heating roller). If applied, the continuous body 50 may be warped in the longitudinal direction (long warpage).

  In this embodiment, after the continuous body 50 is bent and conveyed in one direction along the rotation curved surface of the auxiliary heating roller 24, it is bent in the opposite direction along the rotation curved surface of the first driven roller 12 (heating roller). Therefore, the warp in the longitudinal direction (long warp) can be corrected.

  Further, the continuous body 50 passes through the heating region A while being sandwiched between the first metal belt 30 and the second metal belt 32. Since the continuous body 50 is preheated in the preheating part C, the continuous body 50 can be rapidly heated to the desired temperature in the heating region A, and the processing speed can be improved. At this time, the continuous body 50 is conveyed while being pressed with a predetermined clamping pressure by a pressure roller 40 disposed on the first metal belt 30 and a support roller 42 disposed on the second metal belt 32. Is done.

  In this way, the continuous body 50 is heat-treated while sequentially passing through the heating region A in a state of being restrained by the first metal belt 30 and the second metal belt 32.

  Here, an example of the lead frame continuous body 50 used in the present embodiment will be described with reference to FIGS. 2 and 3.

  FIG. 2 shows only a part of the die pad 60 on which the semiconductor chip is mounted and the peripheral inner leads 62 in the lead frame continuum 50. The die pad 60 is connected to a frame part (not shown) by a support bar (not shown), and the inner leads 62 formed so as to surround the die pad 60 are connected to each other by a connecting part 64. Yes.

  Such a lead frame continuum 50 is formed by stamping a thin metal plate by press working, so that the inner lead 62 has a residual strain band. For this reason, when the inner lead 62 having a predetermined shape is obtained by separating the connecting portion 64, the separated inner lead 62 may be twisted or warped due to residual strain, and the leads may come into contact with each other.

  The residual strain of the inner lead 62 is removed by heat-treating the continuous body 50 with the heating / cooling processing apparatus 1 of the present embodiment. As a result, as shown in FIG. 3, it is possible to prevent the occurrence of deformation such as twisting or warping at the distal end portion of the inner lead 62 when the connecting portion 64 is separated in a subsequent process.

  Next, returning to FIG. 1, the continuum 50 that has passed through the heating region A sequentially passes through the cooling region B while being sandwiched between the first metal belt 30 and the second metal belt 32, and in a restrained state. A cooling process is performed so as to reach a predetermined temperature. Since the continuum 50 is gradually cooled while being constrained by the first metal belt 30 and the second metal belt 32, it is possible to prevent lead frame width warpage and lead level differences that are likely to occur during the cooling process. The

  Further, the cooled continuous body 50 is guided by the grip roller 13 provided beside the second drive roller 20 and conveyed outside the apparatus.

  Next, the pressure roller 40 and the support roller 42 for sandwiching the first and second metal belts 30 and 32 of the heating and cooling processing apparatus 1 of the present embodiment will be described in more detail. Before describing the pressure roller 40 and the support roller 42 of the present embodiment, problems of the pressure roller and the support roller of the comparative example will be described. FIG. 4 is a perspective view showing a state in the vicinity of the pressure roller and the support roller in the heating and cooling processing apparatus of the comparative example.

  As shown in FIG. 4, in the comparative example, a lead frame continuum 500 is disposed between the first metal belt 300 and the second metal belt 320. The first and second metal belts 300 and 320 are pinched by the pressure roller 400 and the support roller 420.

  The pressure roller 400 and the support roller 420 rotate in conjunction with the rotation of the first and second metal belts 300 and 320, and the continuum 500 is conveyed while being pressurized. The pressure roller 400 and the support roller 420 are formed of an elongated cylindrical body, and the rotation curved surfaces of the pressure roller 400 and the support roller 420 are the same continuous surface throughout.

  In the comparative example, since the pressure roller 400 is formed of a straight cylindrical body, the continuous body 500 is locally pressed in the linear portion in the width direction by the pressure roller 400. Since the lead frame continuum 500 is formed of a relatively soft metal such as copper, the surface of the lead frame may be damaged by the pressure between the pressure roller 400 and the support roller 420, resulting in a decrease in manufacturing yield.

  By adopting the pressure roller according to this embodiment described below, such a problem can be solved. FIG. 5 is a perspective view showing a state in the vicinity of the pressure roller and the support roller in the heating and cooling processing apparatus according to the embodiment of the present invention. FIG. 5 corresponds to a perspective view of the region indicated by D of the heating and cooling processing apparatus 1 of FIG.

  In the heating / cooling processing apparatus 1 according to the present embodiment, a lead frame continuous body 50 is disposed between the first metal belt 30 and the second metal belt 32. A plurality of pressure rollers 40 are arranged side by side in the longitudinal direction above the first metal belt 30, and a plurality of support rollers 42 are arranged in the longitudinal direction below the second metal belt 32.

  The individual pressure rollers 40 and the support rollers 42 are arranged in the width direction of the metal belts 30 and 32, respectively. The individual pressure rollers 40 are arranged at positions corresponding to the respective support rollers 42.

  The continuous body 50 is pinched by the pressure roller 40 and the support roller 42 via the first and second metal belts 30 and 32. The pressure roller 40 and the support roller 42 rotate in conjunction with the rotation of the first and second metal belts 30 and 32, and the continuum 50 is conveyed while being pinched by the pressure roller 40 and the support roller 42.

  The pressure roller 40 according to the present embodiment is devised so as to contact and press only the both end portions in the width direction of the first metal belt 30. The pressure roller 40 includes a shaft portion 40b made of an elongated cylindrical body, and a large-diameter portion 40a made of a cylindrical body connected to both ends thereof and having a diameter larger than that of the shaft portion 40b.

  Such a pressure roller 40 is obtained by forming a step by processing the central portion of the rotating curved surface of a straight elongated cylindrical member. The continuous body 50 of the lead frame is set to have a width narrower than the width of the shaft portion 40b of the pressure roller 40, and is disposed and clamped at the center portion in the width direction of the first and second metal belts 30 and 32. .

  As a result, only the large diameter portions 40 a at both ends of the pressure roller 40 come into contact with both ends of the first metal belt 30 to press the continuous body 50, and at the center in the width direction of the first metal belt 30. The pressure roller 40 does not come into contact. Therefore, unlike the comparative example described above, the continuous body 50 is not pressed linearly in the width direction, so that the surface of the continuous body 50 is prevented from being damaged.

  Further, the support roller 42 is formed of a straight cylindrical body whose rotational curved surface is the same surface throughout, and the rotational curved surface of the support roller 42 comes into contact with the entire width direction of the lower surface of the second metal belt 32 from the pressure roll 40. It is designed to support the applied pressure.

  As shown in FIG. 6, both ends of the support roller 42 are rotatably connected to the base 70. Further, both ends of the pressure roller 40 are rotatably connected to the support member 80. A plurality of (for example, two) pressure rollers 40 are supported by one support member 80. The pressure roller 40 is pressed toward the first metal belt 30 by the pressure from the support member 80. With this pressing force, the continuous body 50 is clamped by the first metal belt 30 and the second metal belt 32.

  As described above, in the present embodiment, the large-diameter portions 40a at both ends of the pressure roller 40 partially pressurize both ends of the first metal belt 30, and the continuous body 50 of the first metal belt 30 is disposed. The central part is not directly pressurized.

  Therefore, the surface of the continuous body 50 is prevented from being damaged during the heating / cooling process of the heating / cooling processing apparatus 1, and the lead frame can be manufactured with high reliability and high yield. Since the first metal belt 30 has a certain degree of rigidity, the continuous body 50 is appropriately pressed toward the second metal belt 32 only by pressurizing both ends of the first metal belt 30, so that the heating and cooling process is stable. Done.

  The pressure roller 40 that presses only both ends of the first metal belt 30 may be employed in both the heating region A and the cooling region B, or may be employed in either one of the heating regions A and the cooling region B.

  In the heating / cooling processing apparatus 1 of the present embodiment, the second metal belt 32 may overlap the lower side of the first metal belt 30 and can travel in the same direction, and the pair of rollers described in FIG. In addition to the belt driving method, various belt driving methods can be employed.

FIG. 1 is a cross-sectional view showing a heating / cooling apparatus according to an embodiment of the present invention. FIG. 2 is a partial plan view showing a continuum of lead frames processed by the heating / cooling apparatus according to the embodiment of the present invention. FIG. 3 is a partial plan view showing a state where the connecting portion of the inner lead is removed after the lead frame continuous body is processed by the heating and cooling processing apparatus of the embodiment of the present invention. FIG. 4 is a perspective view showing a state in the vicinity of the pressure roller and the support roller in the heating and cooling processing apparatus of the comparative example related to the present invention. FIG. 5 is a perspective view showing a state in the vicinity of the pressure roller and the support roller in the heating and cooling processing apparatus according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing each connection state of a pair of pressure rollers and support rollers in the heating and cooling processing apparatus of the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heating / cooling processing apparatus, 10 ... 1st drive roller, 12 ... 1st driven roller, 13 ... Grip roller, 14a, 14b ... Cylinder apparatus, 16 ... Supply port, 18 ... Guide, 20 ... 2nd drive roller, 22 2nd driven roller, 24 ... auxiliary heating roller, 30 ... 1st metal belt, 32 ... 2nd metal belt, 40 ... pressure roller, 40a ... large diameter part, 40b ... shaft part, 42 ... support roller, 50 ... Lead frame continuum, 60 ... die pad, 62 ... inner lead, 64 ... connecting portion, 70 ... base, 80 ... support member, A ... heating region, B ... cooling region, C ... preheating portion.

Claims (6)

A first metal belt traveling in one direction;
A second metal belt disposed under the first metal belt and running in the same direction as the first metal belt;
A plurality of pressure rollers disposed on and in contact with the first metal belt to partially press both ends in the width direction of the first metal belt;
A plurality of support rollers disposed under and in contact with the second metal belt, and a heating region and a cooling region are provided in a region where the first metal belt and the second metal belt overlap. Use heating and cooling processing equipment,
A continuum of pressed lead frames having a width narrower than that of the first and second metal belts is in contact with the first metal belt and the second metal belt. Supplying to the center part of the width direction between a metal belt and the said 2nd metal belt, the both ends outside the center part of the said 1st, 2nd metal belt are pinched by the said pressure roller and the said support roller. In this state, by passing the heating region and the cooling region by running the metal belt, including removing residual strain of the continuum,
Between the pair of rollers comprising the second drive roller and the second driven roller under the first metal belt which is wound around a pair of rollers comprising the first drive roller and the first driven roller and rotates. A method of manufacturing a lead frame continuum, wherein the second metal belt that is wound and rotated is disposed, and the second metal belt is disposed under the first metal belt. .   The pressure roller is composed of a rotating body connected to a shaft portion and both ends thereof and having a large diameter portion having a diameter larger than the shaft portion, and the large diameter portion is formed at both end portions of the first metal belt. The method for producing a continuous body of lead frames according to claim 1, wherein the pressure is contacted and pressurized.   The width of the continuous body of the lead frame is set to be narrower than the width of the shaft portion of the pressure roller, and is arranged at the center in the width direction of the metal belt. A method for producing a continuous body of lead frames. A first metal belt traveling in one direction;
A second metal belt disposed under the first metal belt and running in the same direction as the first metal belt;
A plurality of pressure rollers arranged on and in contact with the first metal belt to partially press both ends in the width direction of the first metal belt;
A plurality of support rollers disposed under and in contact with the second metal belt, and a heating region and a cooling region are provided in a region where the first metal belt and the second metal belt overlap,
A continuum of pressed lead frames having a width narrower than that of the first and second metal belts is in contact with the first metal belt and the second metal belt. Supply to the center in the width direction between the metal belt and the second metal belt, and both ends outside the center in the width direction of the first and second metal belts with the pressure roller and the support roller Including passing the heating region and the cooling region by running the metal belt in a clamped state,
Between the pair of rollers comprising the second drive roller and the second driven roller under the first metal belt which is wound around a pair of rollers comprising the first drive roller and the first driven roller and rotates. An apparatus for heating and cooling, wherein the second metal belt that is wound and rotated is disposed, and the second metal belt is disposed under the first metal belt.   The pressure roller is composed of a rotating body connected to a shaft portion and both ends thereof and having a large diameter portion having a diameter larger than the shaft portion, and the large diameter portion is formed at both end portions of the first metal belt. The heating / cooling processing apparatus according to claim 4, wherein the heating / cooling processing apparatus is configured to contact and pressurize.   The width of the continuous body of the lead frame is set to be narrower than the width of the shaft portion of the pressure roller, and is disposed at a central portion in the width direction of the metal belt. Heating and cooling processing equipment.

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