Wire bonding machine small claw single column windowing presser plate

Abstract

The utility model provides a kind of small claw single column windowing pressboard of wire bonding machine, it is related to the field of semiconductor device packaging equipment, it includes pressboard fixed seat, intermediate pressboard and cover plate, the pressboard fixed seat is equipped with ladder window, intermediate pressboard is located in the ladder window, cover plate can be fixed in the top of the intermediate pressboard by screw press fit, and elastic wave piece is arranged between intermediate pressboard and cover plate, the both sides of intermediate pressboard are equipped with at least three strip grooves, each groove is equipped with elastic wave piece, in natural state, the trough of the elastic wave piece is contacted with the bottom of groove, the crest of elastic wave piece is higher than the upper edge of groove, the utility model solves the technical problem in prior art that wave-shaped metal long strip piece is penetrated through groove along the length direction of intermediate pressboard, fatigue deformation is likely to be generated due to local stress concentration after long-term stress, leading to overall elastic force attenuation, and then affecting the press fit stability of cover plate.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor device packaging equipment, and in particular to a single-row windowed pressure plate for a wire bonding machine's small claw. Background Technology

[0002] Wire bonding machines are mainly used for internal lead bonding in the semiconductor device packaging process. During wire bonding, the die to be bonded is placed on the lead frame and conveyed to the heating block of the wire bonding machine by a conveyor belt. The pressure plate presses the lead frame and the heating block together, so that the lead frame is in a stable state during the wire bonding process, thereby ensuring that the solder joint is subjected to uniform and stable force.

[0003] In existing technologies, most pressure plates are subject to deformation due to materials, carriers, and the pressure plate itself after prolonged use, resulting in insufficient tightness between the pressure plate and the heating block and thus unqualified sealing. In contrast, Chinese utility model patent CN218135868U discloses a pressure plate for a wire bonding machine, which includes a pressure plate fixing seat with a stepped window. An intermediate pressure plate is inserted into the stepped window, and the size and shape of the intermediate pressure plate matches the stepped window. The intermediate pressure plate has a wire bonding window in the middle, and grooves are formed on both sides of the wire bonding window. Elastic elements are set in the grooves. The elastic elements are wavy elastic structures and abut against the cover plate and the stepped window.

[0004] The above-mentioned prior art has at least the following defects: the wavy metal strip, which runs through the groove along the length of the middle pressure plate, is prone to fatigue deformation due to local stress concentration after long-term stress, resulting in the overall elasticity reduction, which in turn affects the stability of the cover plate pressing. Utility Model Content

[0005] This application provides a single-row windowed pressure plate for a wire bonding machine's small claw, which solves the technical problem in the prior art where a wavy metal strip penetrates the groove along the length of the middle pressure plate, and after long-term stress, fatigue deformation is easily caused by local stress concentration, resulting in overall elasticity reduction and thus affecting the stability of the cover plate pressing.

[0006] To solve the above technical problems, this utility model adopts the following technical solution: a single-row windowed pressure plate for a wire bonding machine's small claw, comprising a pressure plate fixing seat, a middle pressure plate, and a cover plate. The pressure plate fixing seat has a stepped window extending through its thickness direction. The outline of the stepped window is adapted to the outer outline of the middle pressure plate. The middle pressure plate is embedded in the stepped window. The cover plate is pressed onto the middle pressure plate and fixed to the fixing seat by screws. At least three strip-shaped grooves are provided at intervals along the length direction on both sides of the middle pressure plate. Each groove extends along the length direction of the middle pressure plate, and each groove is independently provided with an elastic corrugated sheet. Under natural unloaded conditions, the trough of the elastic corrugated sheet is in contact with the bottom of the groove, while the crest of the elastic corrugated sheet is higher than the upper edge of the groove.

[0007] In use, the wire die to be bonded is fed onto the heating block of the wire bonding machine along with the lead frame. The intermediate pressure plate presses the lead frame and the heating block together under the elastic force of the elastic corrugated sheet. The wire bonding equipment completes the bonding through the bonding window and the cover plate window. Since the intermediate pressure plate has at least three strip-shaped grooves on both sides, and each groove has an elastic corrugated sheet, the existing through-type overall elastic structure is divided into multiple independent elastic corrugated sheets. Even if individual elastic corrugated sheets are fatigued and deformed due to long-term stress, the overall elastic force will not be significantly reduced, and other elastic corrugated sheets can still maintain a stable elastic force output. Therefore, this invention can ensure the pressing stability of the intermediate pressure plate on the lead frame, thereby reducing the problem of unqualified packaging caused by unstable pressing.

[0008] As a further improvement to the above solution, the width of the elastic wave sheet is the same as the width of the groove, and the length of the elastic wave sheet is less than the length of the groove. Since the width of the elastic wave sheet is the same as the width of the groove, it can be ensured that the elastic wave sheet does not wobble in the width direction within the groove and can transmit elastic force evenly when subjected to force. At the same time, the length of the elastic wave sheet is less than the length of the groove, which can reserve deformation space for the elastic wave sheet and avoid it from being damaged by rigid collision with the two ends of the groove during deformation under force.

[0009] As a further improvement to the above solution, each groove has a limiting boss integrally formed at both ends along its length direction. The limiting boss extends along the length direction of the groove, and each end of the elastic corrugated sheet is provided with a corresponding slot. The slot can engage with the limiting boss, and the inner wall of the slot fits against the outer wall of the limiting boss. The cooperation between the slot and the limiting boss can accurately limit the elastic corrugated sheet, effectively preventing the elastic corrugated sheet from shifting or falling off along the length direction of the groove during repeated stress deformation. Therefore, the positional stability of the elastic corrugated sheet during operation is guaranteed, ensuring that it can always provide stable elastic support for the cover plate and the intermediate pressure plate.

[0010] As a further improvement to the above solution, an elastic rubber pad is attached and fixed to the bottom of each groove, and the upper surface of the elastic rubber pad is in contact with the trough of the elastic corrugated sheet.

[0011] As a further improvement to the above solution, a buffer pad is attached to the lower surface of the cover plate at the position corresponding to the crest of the elastic corrugated sheet, and the area of ​​the buffer pad is not less than the projected area of ​​the elastic corrugated sheet on the cover plate.

[0012] As a further improvement to the above solution, the upper surface of the pressure plate fixing seat is also provided with positioning pins. There are four positioning pins, which are symmetrically distributed in pairs on both sides of the stepped window. Positioning holes are opened through the thickness direction of the cover plate. The number of positioning holes is the same as the number of positioning pins and their positions correspond one-to-one. The diameter of the positioning holes is adapted to the outer diameter of the positioning pins. During the process of fixing or disassembling the cover plate by screws, the positioning pins can accurately cooperate with the positioning holes to achieve guiding positioning and avoid the cover plate from shifting or misaligning. Therefore, the alignment and assembly of the cover plate and the intermediate pressure plate can be completed quickly, reducing the time of repeated debugging and improving the assembly efficiency.

[0013] As a further improvement to the above solution, a welding wire window is provided through the intermediate pressure plate, and a cover plate window is provided through the cover plate. The upper edges of both the welding wire window and the cover plate window are chamfered to form a slope. The slope extends upward and outward from the inner wall of the welding wire window and the cover plate window. Thus, when the welding torch of the welding equipment performs welding operations through the window, the slope can prevent the welding torch from rigidly colliding with the edge of the window, reducing the wear of the welding torch and the edge of the window.

[0014] As a further improvement to the above solution, a slag collection groove is provided on both sides of the welding window on the upper surface of the intermediate pressure plate. Both slag collection grooves extend along the length of the intermediate pressure plate, and the distance between the two slag collection grooves is smaller than the width of the cover plate window. The welding slag, debris and other impurities generated during the welding process will be effectively intercepted and collected by the slag collection grooves, preventing impurities from entering the stepped window or groove and adhering to the surface of the elastic corrugated sheet, thereby preventing the elastic corrugated sheet from losing elasticity due to impurities.

[0015] As can be seen from the above technical solutions, this utility model has at least the following technical effects or advantages:

[0016] In use, the wire die to be bonded is fed onto the heating block of the wire bonding machine along with the lead frame. The intermediate pressure plate presses the lead frame and the heating block together under the elastic force of the elastic corrugated sheet. The wire bonding equipment completes the bonding through the bonding window and the cover plate window. Since the intermediate pressure plate has at least three strip-shaped grooves on both sides, and each groove has an elastic corrugated sheet, the existing through-type overall elastic structure is divided into multiple independent elastic corrugated sheets. Even if individual elastic corrugated sheets are fatigued and deformed due to long-term stress, the overall elastic force will not be significantly reduced, and other elastic corrugated sheets can still maintain a stable elastic force output. Therefore, this invention can ensure the pressing stability of the intermediate pressure plate on the lead frame, thereby reducing the problem of unqualified packaging caused by unstable pressing. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is an exploded view of the present invention;

[0019] Figure 2 This is a schematic diagram showing the installation of the elastic corrugated sheet on the intermediate pressure plate.

[0020] Figure 3 for Figure 2 A magnified view of a portion of point A in the middle;

[0021] Figure 4 This is an assembly diagram illustrating the usage habits of this product.

[0022] Explanation of reference numerals in the attached drawings: 1. Pressure plate fixing seat; 101. Stepped window; 2. Intermediate pressure plate; 201. Welding window; 3. Cover plate; 301. Cover plate window; 4. Groove; 401. Limiting boss; 5. Elastic corrugated sheet; 6. Slot; 7. Elastic rubber pad; 8. Positioning pin; 9. Positioning hole; 10. Slag collection trough. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this patent, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this patent.

[0024] like Figures 1 to 4 As shown, this utility model discloses a single-row windowed pressure plate for a wire bonding machine, which includes a pressure plate fixing seat 1, an intermediate pressure plate 2, and a cover plate 3. The three are assembled to form a complete pressing structure, which is used for the stable pressing of lead frames during the semiconductor device packaging process.

[0025] The pressure plate fixing seat 1 is an integral metal base with a stepped window 101 in the center of its surface. The size of the stepped window 101 is adapted to the intermediate pressure plate 2, so that the intermediate pressure plate 2 can be fitted into the stepped window 101 to meet the pressing action requirements. The two side walls of the intermediate pressure plate 2 are symmetrically provided with grooves 4 along the length direction, and each side has at least three grooves 4, each groove 4 having a rectangular cross-section. Each groove 4 is independently fitted with an elastic corrugated sheet 5, which is made of 65Mn spring steel. In its natural state, the troughs of the elastic corrugated sheet 5 are in close contact with the bottom of the groove 4, while the crests are higher than the upper edge of the groove 4, ensuring that the cover plate 3 can effectively resist and generate elastic deformation when pressed.

[0026] As a further optimization, the width of the elastic corrugated sheet 5 is the same as the width of the groove 4, while its length is less than the length of the groove 4. This avoids rigid collisions between the elastic corrugated sheet 5 and the two ends of the groove 4 during deformation. At the same time, each end of the groove 4 is integrally formed with a limiting boss 401. Correspondingly, the two ends of the elastic corrugated sheet 5 are stamped to form a groove 6 that matches the limiting boss 401. During assembly, the groove 6 and the limiting boss 401 are tightly engaged, which can effectively prevent the elastic corrugated sheet 5 from shifting or falling off after being subjected to force.

[0027] To enhance the cushioning effect and protect the elastic corrugated sheet 5, a layer of elastic rubber pad 7 is adhered to the bottom of each groove 4 using high-temperature resistant adhesive. The elastic rubber pad 7 is made of silicone rubber, which can absorb some vibration energy and prevent rigid contact between the elastic corrugated sheet 5 and the bottom of the groove 4. Correspondingly, a buffer pad is also adhered to the area on the lower surface of the cover plate 3 that contacts the elastic corrugated sheet 5. The buffer pad is made of polytetrafluoroethylene, which can reduce frictional wear between the elastic corrugated sheet 5 and the cover plate 3.

[0028] The cover plate 3 is fixedly connected to the intermediate pressure plate 2 by screws 11. To ensure assembly accuracy, the surface of the pressure plate fixing seat 1 is also provided with four positioning pins 8, two of which are symmetrically distributed on the left side of the stepped window 101 and the other two are symmetrically distributed on the right side. Four positioning holes 9 are opened at corresponding positions on the cover plate 3, and the positioning holes 9 and the positioning pins 8 are fitted with clearance. When the cover plate needs to be frequently disassembled and reassembled, the positioning pins 8 can guide the cover plate 3 to quickly reset, avoiding repeated adjustment and alignment, and improving work efficiency.

[0029] A rectangular wire bonding window 201 is provided in the middle of the intermediate pressure plate 2, and a cover plate window 301 is provided at the corresponding position on the cover plate 3. Both provide an operating channel for the welding torch of the wire bonding equipment. The upper edge of the wire bonding window 201 and the upper edge of the cover plate window 301 are both machined with slopes, which can effectively avoid rigid collision between the welding torch and the edge of the window.

[0030] Furthermore, due to the potential generation of welding slag, flux residue, or oil during the wire bonding process, these impurities may enter the groove 4 through the gap between the intermediate pressure plate 2 and the stepped window 101, adhering to the surface of the elastic corrugated sheet 5. Long-term accumulation can lead to jamming or loss of elasticity in the elastic element. Therefore, the intermediate pressure plate 2 is equipped with two slag collection grooves 10 on both sides of the wire bonding window 201. The slag collection grooves 10 are elongated grooves, their length matching the length of the intermediate pressure plate 2, and the distance between the two slag collection grooves 10 is less than the width of the wire bonding window 201. The slag collection grooves 10 efficiently collect welding slag, debris, and other impurities generated during the wire bonding process, preventing them from entering the stepped window 101 or the groove 4 and affecting equipment operation.

[0031] The working process of this embodiment is as follows: During wire bonding, the wire grains to be bonded are conveyed to the heating block of the wire bonding machine by the lead frame. The intermediate pressure plate 2 presses the lead frame and the heating block tightly together under the elastic force of the elastic corrugated sheet 5. The wire bonding equipment completes the inner lead bonding through the wire bonding window 201 and the cover plate window 301.

[0032] In this invention, the groove is changed from a through-type to a segmented type, with each segment accommodating only one elastic corrugated sheet. This breaks down the integral elastic corrugated sheet 5 that runs through the groove 22 into multiple independent segments of shorter elastic corrugated sheets 5. Thus, if a single segment of the elastic corrugated sheet 5 fails due to localized stress concentration, it only affects the pressing force in the corresponding area, while other segments maintain stable elasticity. This avoids overall elasticity attenuation and improves the stability of the cover plate pressing.

[0033] In the description of this utility model, the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for describing this utility model and do not require that this utility model be constructed or operated in a specific orientation, and therefore should not be construed as limiting this utility model. The terms "connected" and "linked" in this utility model should be interpreted broadly. For example, they can refer to a connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0034] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in its embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A small jaw single-row windowing presser plate for a wire bonding machine, comprising a presser plate fixing seat (1), an intermediate presser plate (2) and a cover plate (3), a stepped window (101) is provided through the thickness direction of the presser plate fixing seat (1), the profile of the stepped window (101) is matched with the outer profile of the intermediate presser plate (2), the intermediate presser plate (2) is embedded in the stepped window (101), and the cover plate (3) is pressed on the top of the intermediate presser plate (2) and is fixed with the fixing seat (1) by a screw (11), characterized in that, At least three strip-shaped grooves (4) are provided at intervals along the length direction on both sides of the intermediate pressure plate (2). Each groove (4) extends along the length direction of the intermediate pressure plate (2), and each groove (4) is independently provided with an elastic wave sheet (5). Under natural stress, the trough part of the elastic wave sheet (5) is in contact with the bottom of the groove (4), while the crest part of the elastic wave sheet (5) is higher than the upper edge of the groove (4).

2. The wire bonding machine small claw single-row windowed pressure plate according to claim 1, characterized in that, The width of the elastic wave plate (5) is the same as the width of the groove (4), and the length of the elastic wave plate (5) is less than the length of the groove (4).

3. The wire bonding machine small claw single-row windowed pressure plate according to claim 2, characterized in that, Each groove (4) has a limiting boss (401) integrally formed at both ends along its length direction. The limiting boss (401) extends along the length direction of the groove (4). Each elastic wave sheet (5) has a corresponding slot (6) at both ends. The slot (6) can engage with the limiting boss (401), and the inner wall of the slot (6) is in contact with the outer wall of the limiting boss (401).

4. A single-row windowed pressure plate for a wire bonding machine's small claw according to claim 1, characterized in that, An elastic rubber pad (7) is attached to the bottom of each groove (4), and the upper surface of the elastic rubber pad (7) is in contact with the trough of the elastic corrugated sheet (5).

5. A single-row windowed pressure plate for a wire bonding machine's small claw according to claim 4, characterized in that, On the lower surface of the cover plate (3), a buffer pad is attached to the part corresponding to the crest of the elastic wave sheet (5), and the area of ​​the buffer pad is not less than the projected area of ​​the elastic wave sheet (5) on the cover plate (3).

6. A single-row windowed pressure plate for a wire bonding machine's small claw according to claim 1, characterized in that, The upper surface of the pressure plate fixing seat (1) is also provided with positioning pins (8). There are four positioning pins (8), and the four positioning pins (8) are symmetrically distributed in pairs on both sides of the stepped window (101). The cover plate (3) is provided with positioning holes (9) through its thickness direction. The number of positioning holes (9) is the same as the number of positioning pins (8) and their positions correspond one-to-one. The diameter of the positioning holes (9) is adapted to the outer diameter of the positioning pins (8).

7. A single-row windowed pressure plate for a wire bonding machine's small claw according to claim 6, characterized in that, A welding wire window (201) is provided through the middle pressure plate (2), and a cover plate window (301) is provided through the cover plate (3). The upper edge of the welding wire window (201) and the upper edge of the cover plate window (301) are both chamfered to form a slope. The slope extends upward and outward from the inner wall of the welding wire window (201) and the cover plate window (301).

8. A single-row windowed pressure plate for a wire bonding machine's small claw according to claim 7, characterized in that, On the upper surface of the intermediate pressure plate (2), a slag collection groove (10) is provided on both sides of the welding window (201). Both slag collection grooves (10) extend along the length of the intermediate pressure plate (2), and the distance between the two slag collection grooves (10) is smaller than the width of the cover window (301).

Images