Production method of lead frame

Abstract

The invention provides a production method of a lead frame, and relates to the field of lead frame production, and the scheme is that the production method comprises the following steps: S01, designing an etched lead frame, and reserving a set stamping allowance on a single side of a pin of the etched frame; s02, carrying out etching processing; s03, removing stamping allowance after etching of the pins through a stamping process; s04, carrying out plastic packaging; and S05, forming and processing the pins. According to the invention, the excessive glue on the side surface of the frame line pin can be efficiently removed.

Description

Technical Field

[0001] This invention relates to the field of lead frame manufacturing, and more particularly to a method for manufacturing lead frames. Background Technology

[0002] Leadframes, as chip carriers for integrated circuits, are an important structural material in semiconductor packaging. They mainly serve as a bridge connecting the internal circuitry of the chip with external wires. Their structure consists of two main parts: chip pads and leads. Leadframes can be manufactured using stamping or etching processes. Etching processes use etching solutions to slowly corrode the copper plate, avoiding significant stress concentration and thus minimizing deformation during subsequent molding. Etching processes have a wide range of applications.

[0003] In the prior art, the etched cross section of the lead frame, especially the pins, is not a flat cross section, but a concave cross section. This concavity increases the gap with the injection mold, causing the molding compound to fill into the concave surface during molding, resulting in excess glue on the side of the pins. Once excess glue appears on the side of the pins, it will affect the quality of subsequent electroplating and pin forming, and thus affect the quality of the packaged product. It needs to be removed by manual physical wiping.

[0004] However, with the above technical solutions, due to the large amount of excess adhesive on the side of the pins, the operating space in this area is small, making it difficult to manually remove the excess adhesive. If chemical solution soaking is used, the lead frame needs to be immersed in the soaking tank for 30 minutes to 1 hour or longer. After soaking, it needs to be taken out and then put into the water tank for cleaning. It then needs to be taken out and placed in the high-pressure water jet spraying area. The entire process of removing excess adhesive is completed by high-pressure water jet spraying, air knife drying, electric heating drying and material collection. The whole process has many steps and low efficiency. Summary of the Invention

[0005] To address the technical problem of difficulty in removing excess adhesive from the sides of etched lead frames in the prior art, this invention provides a method for manufacturing lead frames that can efficiently remove excess adhesive from the sides of the lead frames.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a method for producing a lead frame, comprising the following steps: S01: Design the etched lead frame, and reserve a set stamping allowance on one side of the pins of the etched frame; S02: Etching process; S03: Plastic sealing; S04: Excess adhesive on the side of the pin is removed by stamping using a lead frame excess adhesive removal device; S05: Lead forming process.

[0007] This invention removes excess adhesive from both sides of the leads using a lead frame adhesive removal device by stamping. This method can replace manual adhesive removal, is not limited by operating space, has a high level of automation, and lower labor intensity. Compared with the chemical solution soaking method, it has fewer steps and faster processing efficiency.

[0008] Furthermore, the lead frame adhesive removal device includes a stamping machine body, on which a lower die assembly and an upper die assembly are provided. The upper die assembly is movably mounted on the stamping machine body and includes a cutter mounting plate and an upper fixing plate. A stamping cutter is provided on the cutter mounting plate, and a comb-tooth structure for stamping the pin areas on both sides of the lead frame is provided at the lower part of the stamping cutter. The lower die assembly includes a lower fixing plate, on which a support block is provided. The support block is opposite to the corresponding stamping cutter, and the support block is provided with a comb-tooth structure for supporting the lead frame pins. Receiving grooves are provided at corresponding positions on the lower fixing plate and the upper fixing plate. The support block and the stamping cutter are provided with the edges of the corresponding receiving grooves and are arranged according to the pin layout of the lead frame. The receiving grooves are used to receive the encapsulant in the middle area of ​​the lead frame.

[0009] This invention provides support and protection for the pins using a support block, without damaging the pin structure.

[0010] Furthermore, the upper mold assembly also includes an upper fixing plate, which is disposed below the tool mounting plate. The lower surface of the upper fixing plate is provided with the receiving groove. The tool mounting plate can move up and down relative to the upper fixing plate. The upper fixing plate is provided with a guide hole at the edge of the receiving groove. The stamping tool can extend out from the guide hole. A tool guide block is provided in the guide hole. The tool guide block can be in contact with the stamping tool.

[0011] This invention, by setting an upper fixed plate, a tool guide block, and a tool mounting plate that can move up and down relative to the upper fixed plate, can separate the stamping action of the stamping tool from the mold closing process, and provides a good guiding effect, avoiding the stamping tool from being impacted during the mold closing process, thus affecting its service life.

[0012] Furthermore, the upper mold assembly also includes a cover plate, which is screwed to the tool mounting plate and disposed on the upper part of the tool mounting plate. The upper fixed plate is provided with a guide rod, which can move up and down through the tool mounting plate. A limit seat is provided at the upper end of the guide rod, and the limit seat is disposed up and down inside the cover plate. A return spring is provided between the upper fixed plate and the tool mounting plate, and a limit post is provided on the upper surface of the upper fixed plate.

[0013] This invention achieves a floating connection between the tool mounting plate and the upper fixing plate through a guide rod and a return spring, which can meet the needs of simultaneous movement and independent movement of the tool fixing plate.

[0014] Furthermore, the lower part of the tool guide block is provided with a comb structure, and the comb structure of the tool guide block and the corresponding comb structure of the support block are arranged vertically opposite each other. The comb structure of the stamping knife can penetrate the comb structure of the tool guide block and reach the comb structure of the support block.

[0015] The present invention provides a comb-tooth structure at the lower part of the tool guide block, which on the one hand can extend the guiding distance of the stamping tool, and on the other hand can cooperate with the comb-tooth structure on the support block to better press the lead structure and prevent the lead from deforming during stamping, thus affecting the manufacturing accuracy of the lead frame.

[0016] Furthermore, the lower fixing plate is provided with a support mounting hole at the edge of the receiving groove, and the support block is provided in the support mounting hole. The lower part of the support block is connected to a pressure plate and the pressure plate is connected to the lower fixing plate. Multiple support blocks share one pressure plate. A chip flow groove is provided on the pressure plate at a position corresponding to the receiving groove, and the chip flow groove communicates with the support mounting hole.

[0017] Furthermore, in S03, a stamping machine is used for stamping, and the stroke of the stamping tool of the stamping machine is greater than the thickness of the lead frame.

[0018] Furthermore, in S01, a set stamping allowance is reserved on one side of the pins of the etched frame.

[0019] This invention, by setting stamping allowances on both sides of the pin, can retain a certain stamping processing allowance after etching. During stamping, a portion of the pin material is removed, so that the force of the stamping tool acts on the pin rather than just on the excess glue. The removal process does not result in excess glue sticking, and the removal of excess glue is more thorough.

[0020] As can be seen from the above technical solutions, the present invention has the following advantages: This invention provides a method for manufacturing lead frames. An adhesive removal device removes excess adhesive from both sides of the leads by stamping, replacing manual adhesive removal. It is not limited by operating space, has a high level of automation, and lowers labor intensity. Compared to chemical solution immersion methods, it has fewer steps and faster processing efficiency. Support blocks provide support and protection for the leads, preventing damage to the lead structure. The upper fixed plate, tool guide block, and tool mounting plate can move up and down relative to the upper fixed plate, separating the stamping action of the stamping tool from the mold closing process and providing good guidance, preventing the stamping tool from being impacted during mold closing and affecting its service life. Guide rods and... The return spring enables a floating connection between the tool mounting plate and the upper fixed plate, meeting the needs of simultaneous movement and independent movement of the tool fixing plate. A comb-like structure is installed at the bottom of the tool guide block, extending the guiding distance for the stamping tool and cooperating with the comb-like structure on the support block to better clamp the pin structure, preventing pin deformation during stamping and ensuring the lead frame's manufacturing accuracy. Stamping allowances are provided on both sides of the pin, retaining a certain amount of stamping allowance after etching. During stamping, a portion of the pin material is removed, ensuring the stamping force acts on the pin rather than just on excess adhesive. This process eliminates excess adhesive adhesion and achieves more thorough removal. Attached Figure Description

[0021] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating a specific embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram illustrating the processing principle of a specific embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram of the lead frame adhesive removal device in a specific embodiment of the present invention.

[0025] Figure 4 This is a structural diagram of the upper mold assembly and the lower mold assembly in the mold separation state in a specific embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of the support plate, upper mold assembly, and lower mold assembly in the mold-closed state in a specific embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the upper mold assembly and the lower mold assembly in the mold-closed state in a specific embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram of the lower mold assembly in a specific embodiment of the present invention.

[0029] Figure 8 This is a schematic diagram of the pressure plate in a specific embodiment of the present invention.

[0030] Figure 9 A schematic diagram of the upper mold assembly in a specific embodiment of the present invention.

[0031] Figure 10 This is a schematic diagram of the stamping knife in a specific embodiment of the present invention.

[0032] Figure 11 This is a schematic diagram of the tool guide block in a specific embodiment of the present invention.

[0033] Figure 12 This is a schematic diagram of the support block in a specific embodiment of the present invention.

[0034] Figure 13 This is a schematic diagram of the assembly structure of the stamping knife, the tool guide block, and the support block in the stamping state according to a specific embodiment of the present invention.

[0035] In the diagram, 1 is the bearing plate; 3 is the hanging rod; 4 is the lower mold assembly; 401 is the lower fixing plate; 402 is the pressure plate; 403 is the support block; 404 is the positioning pin; 405 is the guide sleeve; 406 is the guide part; 407 is the collecting part; 5 is the upper mold assembly; 501 is the cover plate; 502 is the tool mounting plate; 503 is the upper fixing plate; 504 is the limiting post; 506 is the guide rod; 507 is the limiting seat; 508 is the guide post; 510 is the tool guide block; 511 is the stamping knife; 8 is the lifting drive assembly; 9 is the return spring; and 11 is the receiving groove. Detailed Implementation

[0036] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0037] like Figure 1 As shown in the figure, this specific embodiment provides a method for manufacturing a lead frame, including the following steps: S01: Design and etch the lead frame; S02: Etching process; S03: Plastic sealing; S04: Excess adhesive on the side of the pin is removed by stamping using a lead frame excess adhesive removal device; S05: Lead forming process.

[0038] This specific embodiment uses a lead frame excess adhesive removal device to remove excess adhesive from both sides of the leads by stamping. It can replace manual adhesive removal, is not limited by operating space, has a high level of automation, and has low labor intensity. Compared with the chemical solution soaking method, it has fewer steps and faster processing efficiency.

[0039] Because the excess adhesive has a certain degree of elasticity after curing and adheres to the pins, in order to completely remove the excess adhesive and prevent it from affecting the stamping tool 511, such as... Figure 2 As shown in this specific embodiment, in S01, a set stamping allowance is reserved on one side of the pin of the etching frame. The set stamping allowance is denoted as a along the width direction of the pin, and 90μm≤a≤110μm. By setting a stamping allowance of 90μm~110μm on both sides of the pin, a certain stamping processing allowance can be retained after etching. The excess glue adheres to the recessed surface on both sides of the stamping allowance. During stamping, the stamping knife can act on the metal material instead of just on the excess glue. There is no elastic deformation of excess glue or adhesion of the stamping knife 511 during the removal process, and the removal of excess glue is more thorough.

[0040] like Figures 3 to 6As shown, in this specific embodiment, the lead frame adhesive removal device includes a stamping machine body, a lower die assembly 4, and an upper die assembly 5. The stamping machine body includes a support plate 1 and a worktable. The support plate 1 is connected to a lifting drive assembly 8, which adopts a motor + lead screw configuration. The support plate 1 can move up and down reciprocally. The upper die assembly 5 is detachably connected to the support plate 1. The upper die assembly 5 includes a tool mounting plate 502, on which a stamping tool 511 is provided. The lower part of the stamping tool 511 is provided with a comb-tooth structure for stamping the pin areas on both sides of the lead frame. The support plate 1 can drive the stamping tool 511 to move up and down to remove the adhesive overflow on both sides of the pins. The lower die assembly 4 includes a lower fixed plate 401, on which a support block 403 is provided. The support block 403 is positioned opposite to the corresponding stamping cutter 511. The upper side of the support block 403 has a protruding comb structure for supporting the lead frame pins. The lower fixing plate 401 and the upper mold assembly 5 are provided with corresponding receiving grooves 11 at their contact surfaces. The receiving grooves 11 are used to receive the plastic encapsulation body in the middle area of ​​the lead frame. The support block 403 and the stamping cutter 511 are provided with the edges of the corresponding receiving grooves 11 and are arranged according to the pin layout of the lead frame. In this specific embodiment, a row of pins is provided around the lead frame. Correspondingly, the support block 403 and the stamping cutter 511 are arranged around the receiving grooves 11. The number of teeth of the comb structure of the stamping cutter 511 is one more than the number of pins in each row, and the number of teeth of the comb structure of the support block 403 is the same as the number of pins in each row.

[0041] This specific embodiment uses the cooperation of the stamping machine body, the upper die assembly 5 and the lower die assembly 4 to remove excess glue (including some metal material on both sides of the pin) from both sides of the pin by stamping. The pin is supported and protected by the comb structure of the support block 403, which will not damage the pin structure. It has a high level of automation, low labor intensity and fast processing efficiency.

[0042] like Figures 5 to 7 as well as Figure 10 and Figure 12As shown, since multiple stamping cutters 511 and support blocks 403 are provided according to the pin arrangement, in order to replace the corresponding parts after the stamping cutter 511 or support block 403 is damaged, and to avoid the need to replace other intact parts, in this specific embodiment, both the stamping cutter 511 and support block 403 are designed to be detachable. Specifically, the upper die assembly 5 also includes a cover plate 501, which is bolted to the upper part of the tool mounting plate 502. A positioning block protrudes from one side of the upper part of the stamping cutter 511, and the tool mounting plate 502 is provided with a tool mounting hole. A boss is provided on the upper part of the inner wall of the tool mounting hole. A fixing block is provided in the tool mounting hole that can move up and down. The fixing block is provided with a screw hole. A tool bolt is screwed onto the cover plate 501. The tool bolt passes through the positioning block and connects to the fixing block. The fixing block is located below the boss and can abut against the lower surface of the boss. A support mounting hole is provided on the lower fixing plate 401 at the edge of the receiving groove 11. The support mounting hole communicates with the receiving groove 11. A support block 403 is provided in the support mounting hole. A pressure plate 402 is screwed to the lower part of the support block 403. The pressure plate 402 is screwed to the lower fixing plate 401.

[0043] like Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9As shown, due to the small size of the pins in the prior art, the corresponding tooth size of the comb structure of the stamping cutter 511 is narrow and the strength is low. To avoid the adverse effects of stamping on the stamping cutter 511, in this specific embodiment, the upper die assembly 5 also includes an upper fixing plate 503. The upper fixing plate 503 is disposed below the cutter mounting plate 502. The upper fixing plate 503 and the lower fixing plate 401 are in contact during stamping. The lower surface of the upper fixing plate 503 is provided with a receiving groove 11. Furthermore, the cutter mounting plate 502 can move up and down relative to the upper fixing plate 503. The upper fixing plate 503 is located at... The receiving groove 11 has guide holes at its edge, through which the stamping cutter 511 can extend. The upper fixed plate 503 has a cutter guide block 510 that can contact the stamping cutter 511. The cutter mounting plate 502 and the upper fixed plate 503 are configured to move relative to each other. During mold closing (the process of the upper mold assembly 5 and the lower mold assembly 4 fitting together), the stamping cutter 511 can be controlled to remain inside the upper fixed plate 503 and not extend. After mold closing, the stamping cutter 511 extends to perform the stamping operation. This avoids impact on the stamping cutter 511 during mold closing and prevents it from being damaged. The deformation of the pressing knife 511 extends its service life. Simultaneously, the tool guide block 510 guides the pressing knife 511, preventing deformation during the stamping process. To enable the tool mounting plate 502 to move vertically relative to the upper fixed plate 503, a guide rod 506 is screwed onto the upper fixed plate 503. The guide rod 506 moves vertically through the guide hole of the tool mounting plate 502. A guide sleeve is installed inside the guide hole of the tool mounting plate 502, allowing relative movement between the guide sleeve and the guide rod 506. A limit seat 507 is provided at the upper end of the guide rod 506; the two together form a T-shaped structure. The structure includes a limiting sleeve inside the cover plate 501, a limiting seat 507 inside the limiting sleeve, and a stepped hole inside the limiting sleeve that can abut against the lower surface of the limiting seat 507 to achieve limiting. The limiting seat 507 and the guide rod 506 are movably mounted inside the limiting sleeve of the cover plate 501. A return spring 9 is provided between the limiting seat 507 and the bearing plate 1. A limiting post 504 is provided on the upper surface of the upper fixed plate 503. Through the action of the return spring 9, the guide rod 506 and the limiting seat 507, a floating connection between the tool mounting plate 502 and the upper fixed plate 503 is achieved.When the support plate 1 moves the upper mold assembly 5 downward, the upper fixed plate 503 and the lower fixed plate 401 come into close contact to close the mold. After the mold is closed, the support plate 1 continues to move the tool mounting plate 502 downward, while the upper fixed plate 503 remains stationary. The return spring 9 is continuously compressed, and the tool mounting plate 502 moves downward along the guide rod 506. The stamping knife 511 moves downward relative to the tool guide block 510 and extends to perform stamping until the tool mounting plate 502 abuts against the limiting post 504. At this point, the stamping knife 511 has moved into position and the stamping is complete. The support plate 1 moves upward, moving the tool mounting plate 502 upward along the guide rod 506. The stamping knife 511 returns to its original position, and the length of the return spring 9 increases. As the support plate 1 continues to move upward, the limiting seat 507 falls back into the limiting sleeve and gradually abuts against the limiting sleeve under the gravity of the upper fixed plate 503. When the support plate 1 continues to move upward, it can move the upper fixed plate 503 upward to open the mold.

[0044] like Figure 11 and Figure 13 As shown in this specific embodiment, a comb-tooth structure protrudes from one side of the lower part of the tool guide block 510. The comb-tooth structure of the tool guide block 510 and the comb-tooth structure of the corresponding support block 403 are arranged vertically opposite each other. The comb-tooth structure of the stamping knife 511 can penetrate the comb-tooth structure of the tool guide block 510 and reach the comb-tooth structure of the support block 403. By setting the comb-tooth structure at the lower part of the tool guide block 510, the guiding distance of the stamping knife 511 can be extended on the one hand, and it can cooperate with the comb-tooth structure on the support block 403 to better press the pin structure and prevent the pin from deforming during stamping, which would affect the manufacturing accuracy of the lead frame.

[0045] In this specific embodiment, a step is provided in the guide hole of the upper fixing plate 503, and a limiting block is provided on one side of the upper part of the tool guide block 510. The lower surface of the limiting block can contact the upper surface of the step. A baffle is screwed onto the upper fixing plate 503, and the baffle can contact the upper surface of the limiting block. The tool guide block 510 can be detached and installed through the cooperation of the step, the limiting block and the baffle. The corresponding tool guide block 510 can be replaced after the tool guide block 510 is deformed or damaged, without the need to replace other parts, thus reducing maintenance costs.

[0046] like Figure 8 As shown, in order to facilitate chip collection, multiple support blocks 403 share a pressure plate 402. A chip flow channel is provided on the pressure plate 402 at a position corresponding to the receiving groove 11. The chip flow channel is connected to the support mounting hole. The chip flow channel includes a guide part 406 and a collection part 407 that are connected. The guide part 406 has a trapezoidal structure and the wide end faces upward. By providing the guide part 406, it is easy to collect chips.

[0047] In this specific embodiment, the lower mold assembly 4 is mounted on the worktable by a fixture.

[0048] like Figures 4 to 6 As shown, in order to accurately position the tool, the tool mounting plate 502 is provided with a guide post 508, which extends from the upper fixing plate 503. The lower fixing plate 401 is provided with a guide sleeve 405, and the lower fixing plate 401 is also provided with a positioning pin 404. The upper fixing plate 503 is provided with a positioning hole.

[0049] like Figure 3 As shown, in this specific embodiment, the edge of the upper fixing plate 503 protrudes from the tool mounting plate 502 and the cover plate 501. The edge of the upper fixing plate 503 is located inside the hanging rod 3. Limiting plates are also provided on the other two sides of the bearing plate 1. The limiting plates abut against the corresponding sides of the upper mold assembly 5.

[0050] To facilitate chip movement, in S03, the stroke of the punch 511 is greater than the thickness of the lead frame.

[0051] As can be seen from the above specific embodiments, the present invention has the following beneficial effects: 1. The lead frame adhesive removal device removes excess adhesive from both sides of the leads by stamping, which can replace manual adhesive removal. It is not limited by the operating space, has a high level of automation, and has low labor intensity. Compared with the chemical solution soaking method, it has fewer steps and faster processing efficiency. 2. The pins are supported and protected by the support block 403, without damaging the pin structure; 3. By setting the upper fixed plate 503, the tool guide block 510 and the tool mounting plate 502, which can move up and down relative to the upper fixed plate 503, the stamping action of the stamping knife 511 can be separated from the mold closing process, and a good guiding effect is provided to avoid the stamping knife 511 being impacted during the mold closing process, thus affecting its service life. 4. The floating connection between the tool mounting plate 502 and the upper fixed plate 503 is achieved through the guide rod 506 and the return spring 9, which can meet the need for independent movement of the tool mounting plate 502; 5. By setting a comb structure at the lower part of the tool guide block 510, the guiding distance of the punching tool 511 can be extended on the one hand, and it can cooperate with the comb structure on the support block 403 to better press the pin structure and prevent the pin from deforming during punching, which would affect the manufacturing accuracy of the lead frame. 6. By setting a stamping allowance on both sides of the pin, a certain stamping processing allowance can be retained after etching. During stamping, a portion of the pin material is removed, so that the force of the stamping knife 511 acts on the pin rather than just on the excess glue. There is no excess glue sticking during the removal process, and the removal of excess glue is more thorough.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the 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 other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for producing a lead frame, characterized in that, Includes the following steps: S01: Design and etch the lead frame; S02: Etching process; S03: Plastic sealing; S04: Excess adhesive on the side of the pin is removed by stamping using a lead frame excess adhesive removal device; S05: Lead forming process.

2. The method for producing the lead frame as described in claim 1, characterized in that, In S04, the lead frame adhesive removal device includes a stamping machine body. The stamping machine body is equipped with a lower die assembly (4) and an upper die assembly (5). The upper die assembly (5) is movably mounted on the stamping machine body. The upper die assembly (5) includes a stamping cutter (511). The lower part of the stamping cutter (511) is provided with a comb-like structure for stamping the pin areas on both sides of the lead frame. The lower die assembly (4) includes a lower fixing plate (401). A support block (403) is provided on the lower fixing plate (401). The support block (403) is positioned opposite to the corresponding stamping cutter (511). The upper side of the support block (403) is provided with a comb structure for supporting the lead frame pins. The surfaces of the lower fixing plate (401) and the upper mold assembly (5) that are in contact with each other are provided with receiving grooves (11). The receiving grooves (11) are used to accommodate the plastic sealant in the middle area of ​​the lead frame. The support block (403) and the stamping cutter (511) are provided with the edges of the corresponding receiving grooves (11) and are arranged according to the pin layout of the lead frame.

3. The method for producing the lead frame as described in claim 2, characterized in that, The upper mold assembly (5) also includes an upper fixing plate (503), which is located below the tool mounting plate (502). The lower surface of the upper fixing plate (503) is provided with a receiving groove (11). The tool mounting plate (502) can move up and down relative to the upper fixing plate (503). The upper fixing plate (503) is provided with a guide hole at the edge of the receiving groove (11). The stamping tool (511) can extend out from the guide hole. The upper fixing plate (503) is provided with a tool guide block (510), which can be in contact with the stamping tool (511).

4. The method for producing the lead frame as described in claim 3, characterized in that, The upper mold assembly (5) also includes a cover plate (501), which is screwed to the tool mounting plate (502) and is located on the upper part of the tool mounting plate (502). The upper fixed plate (503) is provided with a guide rod (506), which can move up and down through the tool mounting plate (502). The upper end of the guide rod (506) is provided with a limit seat (507), which can move up and down inside the cover plate (501). A reset spring (9) is provided between the upper fixed plate (503) and the bearing plate (1). A limit post (504) is provided on the upper surface of the upper fixed plate (503).

5. The method for producing the lead frame as described in claim 4, characterized in that, The lower part of the tool guide block (510) is provided with a comb structure. The comb structure of the tool guide block (510) and the comb structure of the corresponding support block (403) are arranged opposite each other. The comb structure of the stamping knife (511) can penetrate the comb structure of the tool guide block (510) and reach the comb structure of the support block (403).

6. The method for producing the lead frame as described in claim 5, characterized in that, The lower fixed plate (401) is provided with a support mounting hole at the edge of the receiving groove (11). A support block (403) is provided in the support mounting hole. A pressure plate (402) is connected to the lower part of the support block (403) and the pressure plate (402) is connected to the lower fixed plate (401). Multiple support blocks (403) share a pressure plate (402). A chip flow groove is provided on the pressure plate (402) at the position corresponding to the receiving groove (11). The chip flow groove is connected to the support mounting hole.

7. The method for producing a lead frame as described in claim 1, characterized in that, In S05, when the lead frame excess adhesive is removed by punching using the lead frame excess adhesive removal device, the stroke of the punching knife (511) of the lead frame excess adhesive removal device is greater than the thickness of the lead frame pin.

8. The method for producing a lead frame as described in claim 1, characterized in that, In S01, a set stamping allowance is reserved on one side of the pins of the etched frame.

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