Manufacturing method for progressive die of LQFP144pin high-precision lead frame

Abstract

The invention provides an LQFP144pin high-precision lead frame progressive die manufacturing method, which belongs to the technical field of die manufacturing, and comprises the following steps: S1, processing an upper die holder and a lower die holder; s2, an upper die plate and a lower die plate are machined; s3, a male die is machined; s4, machining a female die; s5, a small discharging plate is machined; and S6, the mold is assembled. The manufacturing method has the beneficial effects that through a series of process improvements, the manufacturing difficulty of a high-precision multi-pin LQFP144 lead frame mold is overcome, and the processing and manufacturing precision is ensured; the pins in the die are firstly punched into short pins and then punched into long pins, so that the pins are prevented from being twisted and deformed in the punching process; the inner pins are punched in 16 stations, the pins in the step pitch direction are punched firstly, then the pins in the material width direction are punched, and the pin deviation phenomenon caused by step pitch accumulation in the punching process is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of mold manufacturing, and relates to a manufacturing method for a high-precision progressive mold for an LQFP144pin lead frame. Background Art

[0002] With the rapid progress of information technology, multiple fields such as automotive electronics, household appliances, and industrial equipment are accelerating their transformation towards digitalization and intelligentization. In these fields, the application of high-performance microprocessors is becoming increasingly widespread, and their demand is showing a continuous and rapid growth trend. Especially in products such as new energy vehicles, smart home appliances, and new industrial equipment, the usage of high-performance microprocessors has increased significantly.

[0003] As an essential key component in microprocessors, the lead frame undertakes important functions such as supporting the chip, connecting external circuits, and heat dissipation. In the current trend of continuously increasing circuit integration, the technical requirements for lead frames are becoming increasingly stringent, and they are developing towards high density, fine pitch, and multi-pin. In recent years, China has made certain progress in the technical field related to lead frames, especially achieving important breakthroughs in the research and development of high-precision progressive molds for multiple series of products such as lead frame discrete devices and surface mounting.

[0004] However, in the research and development and manufacturing technology of LQFP144 lead frame molds, China still faces severe challenges. At present, the processing and manufacturing accuracy of high-precision multi-pin LQFP144 lead frame molds is insufficient, the manufacturing is difficult, and there is a large room for improvement. Summary of the Invention

[0005] The purpose of the present invention is to address the above problems existing in the prior art and propose a manufacturing method for a high-precision progressive mold for an LQFP144pin lead frame.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A manufacturing method for a high-precision progressive mold for an LQFP144pin lead frame, including the steps of:

[0007] S1: Machine the upper die base and the lower die base, use a precision machining center to perform rough boring and chamfering of threaded holes, counterbore holes, and guide pillar holes, and use a precision surface grinder to finely grind the working surfaces of the upper die base and the lower die base so that the working surfaces reach specific flatness and parallelism, and grind the guide pillar holes and pin holes by coordinate grinding to reach a specific diameter tolerance range and relative position tolerance range;

[0008] S2: Machine the upper template and the lower template. Use a precision machining center to machine the threaded holes, counterbore holes, and wire threading holes. Precision surface grind the working surfaces of the upper template and the lower template on a precision surface grinder to make the working surfaces reach specific flatness and parallelism. Use a slow wire cutting machine to machine the cavity holes of the upper template and the lower template, leaving machining allowances. Precision surface grind the working surfaces of the upper template and the lower template again on a precision surface grinder to make the working surfaces reach specific flatness and parallelism. Machine the guide pillar holes and dowel pin holes by a jig grinder to reach a specific diameter tolerance range and relative position tolerance range. Finish machine the special-shaped cavity holes by slow wire cutting. Detect the diameters and position dimensions of the guide bushing holes and dowel pin holes of the upper template and the lower template, and detect the flatness of the upper template and the lower template.

[0009] S3: Machine the punch, using a hand grinder and a surface grinder for finishing.

[0010] S4: Machine the die, using a slow wire cutting machine to cut the cavity.

[0011] S5: Machine the small stripper plate, using a combination of hard alloy and steel part for edge positioning.

[0012] S6: Assemble the die.

[0013] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S1, after precision surface grinding the working surfaces of the upper die base and the lower die base on a precision surface grinder and before grinding the guide pillar holes and dowel pin holes by a jig grinder, chrome plate the outer shapes of the upper die base and the lower die base to reach specific thickness and uniformity.

[0014] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S1, after grinding the guide pillar holes and dowel pin holes by a jig grinder, detect the diameters and position dimensions of the guide bushing holes and dowel pin holes of the upper die base and the lower die base, and detect the flatness of the upper die base and the lower die base.

[0015] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S2, after machining the threaded holes, counterbore holes, and wire threading holes of the upper template and the lower template using a precision machining center and before machining the cavity holes of the upper template and the lower template using a slow wire cutting machine, release the internal residual stress of the material through secondary ultra-deep cryogenic treatment.

[0016] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S2, after machining the cavity holes of the upper template and the lower template using a slow wire cutting machine and before precision surface grinding the working surfaces of the upper template and the lower template on a precision surface grinder, release the internal residual stress of the material processing through low-temperature tempering treatment.

[0017] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S3, when machining the punch, the external shape of the punch is machined by hand grinding to ensure the machining accuracy, roughing and material removal are carried out for the profiling grinding of the special-shaped curved surface, and a profiling support is used when machining the special-shaped curved surface edge of the punch by profiling grinding.

[0018] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, when machining the external shape of the same type of punch, a batch clamping and one-time forming machining technology is adopted to ensure the consistency of the machining dimensions of the punch.

[0019] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S4, when machining the die, specific galvanized wire is used for machining, and the four sides of the die are precisely trimmed by hand grinding to remove the material from the edge. The machining method is a slow wire cutting and one-time trimming and six-oil cutting machining mode to make the die cavity reach a specific surface finish. A preformed avoidance pit is machined on the reverse side of the die cavity, and an anti-jump waste card slot is machined according to the shape rules of the die cavity.

[0020] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S5, the pin of the steel part stripper plate is precisely positioned with the stripper plate seat, and the carbide stripper plate is machined into a side positioning structure to make the small stripper plate reach a specific length and width dimension accuracy. A deep preformed pit is machined on the reverse side of the small stripper plate cavity, and the cavity positioning is reserved.

[0021] In the above manufacturing method of the LQFP144pin high-precision lead frame progressive die, in step S6, chamfering, deburring and cleaning are carried out on the upper template and the lower template before assembling the die; when assembling the die, the guide pillar and the guide sleeve adopt a freezing assembly process.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. By improving a series of processes such as machining the upper die base and the lower die base, machining the upper template and the lower template, machining the punch, machining the die, machining the small stripper plate and assembling the die, the manufacturing difficulty of the high-precision multi-pin LQFP144 lead frame die is overcome, and the machining and manufacturing accuracy is ensured.

[0024] 2. The short pins in the die are punched first, and then the long pins are punched to prevent the pins from being distorted and deformed during the punching process; the inner pins are punched and completed in 16 stations. The pins in the step direction are punched first, and then the pins in the material width direction are punched to reduce the pin deviation phenomenon caused by the cumulative step during the punching process.

[0025] 3. Before machining the upper template and the lower template using a precision machining center for the machining of threaded holes, counterbore holes, and wire threading holes, and before machining the cavity holes of the upper template and the lower template using a slow wire cutting machine, release the internal residual stress of the material through secondary ultra-deep cryogenic treatment.

[0026] 4. After machining the cavity holes of the upper template and the lower template using a slow wire cutting machine and before precision surface grinding the working surfaces of the upper template and the lower template using a precision surface grinding machine, release the internal residual stress generated during material processing through low-temperature tempering treatment.

[0027] 5. The punch is machined using a hand grinder and a profile grinder. The outer shape of the punch is machined by the hand grinder, and its machining accuracy is controlled within ±0.002 mm, which is used to rough and remove material for the profile grinding of the special-shaped curved surface. When machining the special-shaped curved surface edge of the punch using the profile grinder, a template support is used to prevent problems such as chipping, fracture, deformation, and chatter during the machining of the punch. Brief Description of the Drawings

[0028] Figure 1 It is a process flow chart of the manufacturing method of the LQFP144pin high-precision lead frame progressive die of the present invention. Detailed Embodiments

[0029] The following are specific embodiments of the present invention in combination with the drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0031] In addition, in the present invention, descriptions such as "first", "second", and "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0032] In the present invention, unless otherwise clearly specified and defined, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

[0035] As Figure 1 shown, a manufacturing method for a LQFP144pin high-precision lead frame progressive die includes the steps:

[0036] S1: Process the upper die base and the lower die base, use a precision machining center to perform rough boring and chamfering of threaded holes, counterbore holes, and guide pillar holes, and use a precision surface grinder to finely grind the working surfaces of the upper die base and the lower die base so that the working surfaces reach specific flatness and parallelism, and grind the guide pillar holes and pin holes by a coordinate grinder to reach a specific diameter tolerance range and relative position tolerance range.

[0037] Specifically, use a precision surface grinder to finely grind the working surfaces of the upper die base and the lower die base so that the flatness and parallelism of the working surfaces are less than 0.005 mm.

[0038] Specifically, grind the guide pillar holes and pin holes by a coordinate grinder so that the diameter tolerance of the guide pillar holes is controlled within (-0.01 mm / -0.015 mm), the tolerance of the pin holes is controlled within (+0.008 mm / +0.005 mm), and the relative position tolerance of all pin holes and guide pillar holes is controlled within 0.002 mm.

[0039] S2: Machine the upper template and the lower template. Use a precision machining center to machine the threaded holes, counterbore holes, and wire threading holes. Use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template so that the working surfaces reach specific flatness and parallelism. Use a slow wire cutting machine to machine the cavity holes of the upper template and the lower template, leaving a machining allowance. Use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template again so that the working surfaces reach specific flatness and parallelism. Machine the guide pillar holes and dowel pin holes by a jig grinder to achieve a specific diameter tolerance range and relative position tolerance range. Finish machining the special-shaped cavity holes by slow wire cutting. Detect the diameters and position dimensions of the guide bushing holes and dowel pin holes of the upper template and the lower template, and detect the flatness of the upper template and the lower template.

[0040] Specifically, use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template, ensuring that the flatness and parallelism of the two major surfaces are less than 0.01 mm, and leaving a thickness allowance of 0.05 mm.

[0041] Specifically, use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template so that the flatness and parallelism of the working surfaces are less than 0.005 mm, and leaving a thickness allowance of 0.05 mm.

[0042] Specifically, use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template again so that the working surfaces reach specific flatness and parallelism less than 0.003 mm, ensuring that the parallelism of the entire set of molds after assembly is less than 0.015 mm.

[0043] Specifically, grind the guide pillar holes and dowel pin holes by a jig grinder so that the diameter tolerance of the guide pillar holes is controlled within (-0.01 mm / -0.015 mm), the tolerance of the dowel pin holes is controlled within (+0.008 mm / +0.005 mm), and the relative position tolerance of all dowel pin holes and guide pillar holes is controlled within 0.002 mm.

[0044] Specifically, finish machining the special-shaped cavity holes by slow wire cutting, taking the coordinates from the center of the reference hole by a jig grinder.

[0045] S3: Machine the punch, using a hand grinder and a surface grinder for finishing.

[0046] S4: Machine the die, using a slow wire cutting machine to cut the cavity.

[0047] S5: Machine the small stripper plate, using a combination of hard alloy and steel block for edge positioning.

[0048] S6: Assemble the mold.

[0049] In this embodiment, through a series of process improvements including machining the upper die base and the lower die base, machining the upper template and the lower template, machining the punch, machining the die, machining the small stripper plate, and assembling the die, the manufacturing difficulties of the high-precision multi-pin LQFP144 lead frame die are overcome, ensuring the machining accuracy.

[0050] In addition, the die adopts a layout station design of punching the outer pins first and then the inner pins, which is more conducive to the stress release of the material and fully reduces the risk of product deformation.

[0051] In this embodiment, the inner pins of the die are punched with short pins first and then long pins to prevent the pins from being distorted and deformed during the blanking process; the inner pins are punched in 16 stations. The pins in the step distance direction are punched first, and then the pins in the material width direction are punched to reduce the pin deviation phenomenon caused by the cumulative step distance during the blanking process.

[0052] As Figure 1 shown, on the basis of the above embodiment, in step S1, after machining the working surfaces of the upper die base and the lower die base on a precision surface grinder and before grinding the guide pin holes and dowel pin holes by a jig grinder, chrome plating is applied to the outer shapes of the upper die base and the lower die base to achieve a specific thickness and uniformity.

[0053] In this embodiment, chrome plating is applied to the outer shapes of the upper die base and the lower die base. The coating thickness is controlled to be greater than 0.03 mm, and the coating thickness uniformity is controlled within 0.005 mm, which helps the performance of the die base to ensure a better machining effect.

[0054] As Figure 1 shown, on the basis of the above embodiment, in step S1, after grinding the guide pin holes and dowel pin holes by a jig grinder, the diameters and position dimensions of the guide bushing holes and dowel pin holes of the upper die base and the lower die base are detected, and the flatness of the upper die base and the lower die base is detected.

[0055] As Figure 1 shown, on the basis of the above embodiment, in step S2, after machining the threaded holes, counterbore holes, and wire threading holes of the upper template and the lower template using a precision machining center and before machining the cavity holes of the upper template and the lower template by a slow wire cutting machine, the internal residual stress of the material is released through secondary ultra-deep cryogenic treatment.

[0056] As Figure 1 shown, on the basis of the above embodiment, in step S2, after machining the cavity holes of the upper template and the lower template by a slow wire cutting machine and before precision surface grinding the working surfaces of the upper template and the lower template, the internal residual stress of the material during machining is released through low-temperature tempering treatment.

[0057] As Figure 1As shown, on the basis of the above-mentioned embodiment, in step S3, when machining the punch, the shape of the punch is machined by a hand grinder to ensure the machining accuracy, roughing and material removal for the machining of the special-shaped curved surface of the optical curve grinder, and a template support is used when machining the special-shaped curved surface edge of the optical curve grinder.

[0058] It should be noted here that the width of the narrow part of the edge of the inner pin punch is less than 0.1 mm, the length of the edge of the punch is 8 mm, the effective edge height of the punch is 6.5 mm, the entire edge of the punch is as thin as a cicada's wing, and the edge of the punch is an irregular special-shaped curved surface. During the machining process, the punch is prone to chipping, fracture, deformation, chatter, etc.

[0059] In this embodiment, to solve the above machining problems, the punch machining adopts a machining mode of hand grinder plus optical curve grinder. The hand grinder is used to machine the shape of the punch, and its machining accuracy is controlled within ±0.002 mm. Roughing and material removal are carried out for the machining of the special-shaped curved surface of the optical curve grinder, and a template support is used when machining the special-shaped curved surface edge of the optical curve grinder, preventing problems such as chipping, fracture, deformation, and chatter during the punch machining process.

[0060] As Figure 1 shown, on the basis of the above-mentioned embodiment, when machining the shape of the same type of punch, a batch clamping and one-time forming machining technology is adopted to ensure the consistency of the machining dimensions of the punch.

[0061] In this embodiment, the number of the same type of outer pin punches is relatively large. To improve the machining quality of the punch and improve the production efficiency, a batch clamping and one-time forming machining technology is adopted when machining the shape of the same type of punch, ensuring the consistency of the machining dimensions of the punch and also improving the production efficiency.

[0062] As Figure 1 shown, on the basis of the above-mentioned embodiment, in step S4, when machining the die, specific galvanized wire is used for machining, and the process of using a hand grinder to remove material from the edge and finely trim the four-side dimensions of the die. The machining method is a slow wire cutting and one repair and six oil cutting machining mode to make the die cavity reach a specific surface finish. A preformed method is used to machine a relief pit on the reverse side of the die cavity, and anti-jump waste material card slots are machined according to the shape rules of the die cavity.

[0063] It should be noted here that the die is a side positioning structure, and extremely high requirements are imposed on the perpendicularity of the four sides of the die and the relative position accuracy of the die cavity.

[0064] In this embodiment, the concave die is processed by wire cut EDM for the cavity, and the four sides of the concave die are finely trimmed by hand grinding to measure the dimensions. The minimum gap of the concave die cavity is 0.11 mm. During the processing, a galvanized wire with a diameter of ￠0.05 mm is selected for processing, and the processing method is wire cut EDM with one roughing and six finishings. The surface finish of the concave die cavity is less than Ra0.1 um. The higher the surface finish of the concave die, the less likely the waste material is to be blocked. To prevent the waste material from blocking the concave die cavity, a preformed concave pit is processed on the reverse side of the concave die cavity. The anti-jump waste material card slots are processed according to the shape rules of the cavity, which can fully inhibit the upward jump of the waste material.

[0065] As Figure 1 shown, on the basis of the above embodiment, in step S5, the steel part stripper plate is processed with pins for precise positioning with the stripper plate seat, and the carbide stripper plate is processed into an edge positioning structure so that the small stripper plate reaches specific length and width dimension accuracy. A deep preformed concave pit is processed on the reverse side of the small stripper plate cavity, and cavity positioning is reserved.

[0066] In this embodiment, the small stripper plate adopts a combined structure of carbide and steel part edge positioning. The steel part stripper plate is processed with pins for precise positioning with the stripper plate seat, and the carbide stripper plate is processed into an edge positioning structure. During the processing, the length and width dimension accuracy of the stripper plate is controlled within ±0.001 mm, which fully reduces the cumulative error caused by assembly. A 4.3 mm deep preformed concave pit is processed on the reverse side of the small stripper plate cavity, and 4.2 mm cavity positioning is reserved, which can increase the positioning length of the punch and the effective cutting edge strength of the punch.

[0067] In addition, the small stripper plate is designed with a strong pressure structure, which effectively solves the deformation factors such as distortion and warping generated during the blanking process of fine pins.

[0068] In addition, the concave die and the small stripper plate adopt an edge positioning structure, which is convenient for adjusting the gap between the punch and the concave die.

[0069] As Figure 1 shown, on the basis of the above embodiment, in step S6, before assembling the mold, chamfering, deburring and cleaning are carried out on the upper template and the lower template; when assembling the mold, the guide pillars and guide sleeves adopt a cryogenic assembly process.

[0070] In this embodiment, before assembling the mold, chamfering, deburring and cleaning are carried out on the upper template and the lower template; when assembling the mold, the guide pillars and guide sleeves adopt a cryogenic assembly process, which can better ensure the perpendicularity of the guide pillars after assembly.

Claims

1. A manufacturing method for a high-precision lead frame progressive die with 144 pins of LQFP, characterized in that, Including the steps: S1: Process the upper die base and the lower die base. Use a precision machining center to rough-bore and chamfer the threaded holes, counterbore holes, and guide pillar holes, and use a precision surface grinder to precisely grind the working surfaces of the upper die base and the lower die base so that the working surfaces reach specific flatness and parallelism. Grind the guide pillar holes and pin holes by a coordinate grinder to reach a specific diameter tolerance range and relative position tolerance range. S2: Process the upper template and the lower template. Use a precision machining center to machine the threaded holes, counterbore holes, and wire threading holes. Use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template so that the working surfaces reach specific flatness and parallelism. Use a slow wire cutting machine to machine the cavity holes of the upper template and the lower template, leaving machining allowances. Use a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template again so that the working surfaces reach specific flatness and parallelism. Machine the guide pillar holes and pin holes by a coordinate grinder to reach a specific diameter tolerance range and relative position tolerance range. Finish-machine the special-shaped cavity holes by a slow wire cutting machine. Detect the diameters and position dimensions of the guide bushing holes and pin holes of the upper template and the lower template, and detect the flatness of the upper template and the lower template. S3: Process the punch, using a hand grinder and a profiling grinder for machining. S4: Process the die, using a slow wire cutting machine to cut the cavity. S5: Process the small stripper plate, using a combination of hard alloy and steel block edge positioning. S6: Assemble the die.

2. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, characterized in that: In step S1, after precisely grinding the working surfaces of the upper die base and the lower die base on the precision surface grinder and before grinding the guide pillar holes and pin holes by a coordinate grinder, chrome-plate the outer shapes of the upper die base and the lower die base to reach a specific thickness and uniformity.

3. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 2, wherein: In step S1, after grinding the guide pillar holes and pin holes by a coordinate grinder, detect the diameters and position dimensions of the guide bushing holes and pin holes of the upper die base and the lower die base, and detect the flatness of the upper die base and the lower die base.

4. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, characterized in that: In step S2, after using a precision machining center to machine the threaded holes, counterbore holes, and wire threading holes when processing the upper template and the lower template and before using a slow wire cutting machine to machine the cavity holes of the upper template and the lower template, release the internal residual stress of the material through secondary ultra-deep cryogenic treatment.

5. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 4, characterized in that: In step S2, after using a slow wire cutting machine to machine the cavity holes of the upper template and the lower template and before using a precision surface grinder to precisely grind the working surfaces of the upper template and the lower template, release the internal residual stress of the material processing through low-temperature tempering treatment.

6. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, characterized in that: In step S3, when processing the punch, use a hand grinder to machine the outer shape of the punch, ensure the machining accuracy, rough and remove material for the profiling grinder to machine the special-shaped curved surface, and use a profiling support when the profiling grinder machines the special-shaped curved surface edge.

7. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1 or 6, characterized in that: When processing the outer shapes of the same type of punches, adopt the batch clamping and one-time forming processing technology to ensure the consistency of the punch machining dimensions.

8. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, characterized in that: In step S4, when processing the die, use a specific galvanized wire for machining, and use a hand grinder to remove material and precisely trim the four-side dimensions of the die. The processing method is the slow wire cutting and one-repair-six-oil cutting processing mode so that the die cavity reaches a specific surface finish. Use a pre-forming method to machine a relief pit on the reverse side of the die cavity, and machine anti-jump waste material clamping grooves on the die cavity according to the cavity shape rules.

9. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, wherein: In step S5, the machining pin of the steel part stripper plate is precisely positioned with the stripper plate seat, and the carbide stripper plate is machined into a side positioning structure to enable the small stripper plate to achieve specific length and width dimensional accuracy. A deep preformed pit is machined on the reverse side of the small stripper plate cavity, and cavity positioning is reserved.

10. The manufacturing method of the LQFP144pin high-precision lead frame progressive die according to claim 1, characterized in that: In step S6, chamfering, deburring, and cleaning are performed on the upper template and the lower template before assembling the mold; when assembling the mold, the guide pillars and guide sleeves adopt a cryogenic assembly process.

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