Stamping die for lead frame production

Abstract

The utility model relates to the technical field of lead frame stamping, and discloses a stamping die for lead frame production, which comprises an upper die and a lower die, a driving part is arranged between a lower die base and an upper die base, a plurality of stamping heads are arranged at the bottom of the upper die side by side, the heights of the plurality of stamping heads are sequentially reduced from the middle to the outside, and the stamping heads are arranged on the lower die base. Two positioning pieces used for flexibly fixing the lead frame are symmetrically arranged at the two ends of the bottom of the upper die, the driving piece comprises a base, and the lower die base is fixedly arranged on the base. The stamping head at the bottom of the upper die base is changed into a form that the middle is high and the two sides are gradually reduced, so that the influence of deformation of the die on the local pressure height of the upper die in the stamping process is counteracted, and the local pressure borne by pins of each row of products during stamping is improved from the original small middle pressure and large two-side pressure to the same middle pressure and two-side pressure; therefore, the lead frame stamping quality is improved.

Description

Technical Field

[0001] The present application relates to the technical field of lead frame stamping, and in particular to a stamping die for producing a lead frame. Background Art

[0002] There are two main manufacturing processes for lead frames used in semiconductor packaging: etching and stamping. The etching process is characterized by low mold costs, but the manufacturing process is complicated, resulting in a high unit price, which is suitable for multi-variety and small-batch products. The stamping process is characterized by high mold costs, but the manufacturing process is simple, resulting in a low unit price, which is suitable for small-variety and large-scale production.

[0003] In the prior art, for lead frames formed by stamping, in order to improve production efficiency, the design density of the lead frames has been continuously increased, from the initial 1-row product design, gradually increased to 2-row, 3-row... 5-row product design, and the increasing trend is still continuing. The multi-row product design doubles the production efficiency per unit time.

[0004] With regard to the above-mentioned related technologies, the inventor believes that while production efficiency is improved, new quality problems also arise. The most important new problem is that the local pressure of the die unloading plate on the multiple rows of products produced in each stroke during the stamping process is not the same, such as Figure 4 As shown, the pins subjected to small local pressure are deformed or twisted during the stamping process, thereby causing defects in the lead frame after stamping.

[0005] The above information disclosed in the background technology is only used to increase the understanding of the background technology of the present application, and therefore, it may include information that does not constitute the prior art known to ordinary technicians in the field. Utility Model Content

[0006] In order to solve the problem that the local pressures of the die unloading plate on the multi-row products produced by the stroke are not the same during the stamping process, which causes the pins with small local pressure to deform or twist during the stamping process, this solution changes the original side-by-side punching heads with the same height to a design with low ends and high middle, so as to offset the influence of the deformation of the die on the local pressure height of the upper die during the stamping process, thereby improving the stamping quality.

[0007] The present application provides a stamping die for producing a lead frame, which adopts the following technical solution: a stamping die for producing a lead frame, comprising an upper die and a lower die, and a driving part is arranged between the lower die and the upper die, a plurality of stamping heads are arranged side by side at the bottom of the upper die, and the heights of the plurality of stamping heads decrease successively from the middle to the outside, and two positioning parts for flexibly fixing the lead frame are symmetrically arranged at both ends of the bottom of the upper die.

[0008] Preferably, the driving member comprises a base, the lower mold is fixedly arranged on the base, two stamping cylinders are symmetrically arranged on the base, the output shaft of the stamping cylinder is connected to an upper cover plate, and the upper cover plate is fixedly connected to the upper mold.

[0009] Preferably, four guide columns are fixedly provided on the upper part of the base, and the upper ends of the guide columns are movably plugged into the upper cover plate.

[0010] Preferably, the positioning member comprises a rubber seat, a plurality of grooves are formed inside the rubber seat, and a spring 1 is arranged in the groove.

[0011] Preferably, an active cavity is provided inside the lower mold, and a plurality of stamping grooves matching the stamping head are provided on the upper surface of the lower mold, the stamping grooves are connected to the active cavity, and a support member is provided in the active cavity for supporting the stamped area on the lead frame during stamping.

[0012] Preferably, the support member includes a telescopic rod fixedly arranged in the movable cavity, a spring 2 is sleeved on the surface of the telescopic rod, and a slide plate movably arranged in the movable cavity is fixedly arranged on the top end of the telescopic rod, and a plurality of supporting feet movably engaged with the stamping grooves are arranged on the upper part of the slide plate.

[0013] In summary, this application includes the following beneficial technical effects:

[0014] 1. By changing the punch head at the bottom of the upper die to a form that is high in the middle and gradually lower on both sides, the influence of the die deformation on the local pressure height of the upper die during the stamping process is offset, so that the local pressure on each row of product pins during stamping is improved from the original small pressure in the middle and large pressure on both sides to the same pressure in the middle and on both sides, thereby improving the stamping quality of the lead frame;

[0015] 2. A support member is provided in the lower die, and the support member is used to provide a stable upward supporting force for the stamping position on the lead frame when the upper stamping head applies pressure to the stamping position of the lead frame, so that the end face of the stamping position of the lead frame is smoother and will not be deformed, thereby further improving the stamping quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the external structure of an embodiment of the application;

[0017] Figure 2 is a schematic diagram of a front cross-sectional structure of an embodiment of the application;

[0018] Figure 3 is a schematic diagram of the external structure of the support member in the application embodiment;

[0019] Figure 4A schematic diagram of different distributions of local pressures of multiple rows of punch heads in the prior art;

[0020] Figure 5 Schematic diagram of local pressure distribution after changes in multiple rows of punch heads in this scheme.

[0021] Explanation of the reference numerals in the accompanying drawings: 1. upper mold; 101. punch head; 2. lower mold; 201. punching groove; 3. driving member; 301. base; 302. punching cylinder; 303. upper cover plate; 304. guide column; 4. positioning member; 401. rubber seat; 402. spring one; 5. supporting member; 501. telescopic rod; 502. spring two; 503. slide plate; 504. supporting foot. DETAILED DESCRIPTION

[0022] The following is combined with Figure 1-Figure 5 This application is described in further detail.

[0023] The present application embodiment discloses a stamping die for producing a lead frame. Figure 1-Figure 5 A stamping die for producing a lead frame comprises an upper die 1 and a lower die 2, and a driving member 3 is installed between the lower die and the upper die, a plurality of stamping heads 101 are installed side by side at the bottom of the upper die 1, and the heights of the plurality of stamping heads 101 decrease from the middle to the outside, and two positioning members 4 for flexibly fixing the lead frame are symmetrically installed at both ends of the bottom of the upper die 1.

[0024] By adopting the above technical solution, when the upper mold is pressed downward and deformation or distortion occurs, the punch head 101 at the bottom of the lower mold is changed to a form that is high in the middle and gradually lowered on both sides. This can offset the effect of the mold deformation during the stamping process on the local pressure height of the upper mold, so that the local pressure on each row of product pins during stamping is improved from the original small pressure in the middle and large pressure on both sides to the same pressure in the middle and on both sides.

[0025] Reference Figure 1-Figure 2 The driving member 3 includes a base 301, the lower mold is connected to the base 301 by bolts, two stamping cylinders 302 are symmetrically installed on the base 301, the output shaft of the stamping cylinder 302 is connected to the upper cover plate 303, the upper cover plate 303 is welded to the upper mold, and four guide columns 304 are also welded to the upper part of the base 301, and the upper ends of the guide columns 304 are movably plugged into the upper cover plate 303.

[0026] By adopting the above technical solution, the upper mold is driven by the stamping cylinder 302 to quickly reciprocate and press downward, and at the same time, the guide column 304 plays a stabilizing and guiding role for the upper mold.

[0027] Reference Figure 2 The positioning member 4 includes a rubber seat 401, a plurality of grooves are formed inside the rubber seat 401, and a spring 402 is installed in the groove.

[0028] By adopting the above technical solution, during the downward movement of the upper mold, the rubber seat 401 can contact and flexibly abut the lead frame on the lower mold, and the rubber seat 401 is compressed to fix the lead frame during stamping, thereby ensuring the stability of the lead frame during stamping.

[0029] Reference Figure 2-Figure 3 A movable cavity is provided inside the lower mold, and a plurality of stamping grooves 201 matching the stamping head 101 are provided on the upper surface of the lower mold. The stamping grooves 201 are communicated with the movable cavity. A support member 5 for supporting the stamped area on the lead frame during stamping is installed in the movable cavity. The support member 5 includes a telescopic rod 501 connected to the movable cavity by bolts. A spring 2 502 is sleeved on the surface of the telescopic rod 501. A slide plate 503 movably installed in the movable cavity is connected to the top of the telescopic rod 501 by bolts. A plurality of supporting feet 504 movably engaged with the stamping grooves 201 are installed on the upper part of the slide plate 503.

[0030] By adopting the above technical solution: the support foot 504 is embedded in the stamping groove 201 on the upper surface of the lower mold, and the upper end surface of the support foot 504 is flush with the upper end surface of the lower mold. When the punch head 101 presses down to punch the lead frame, the support frame is pushed downward, and as the spring 2 502 is compressed, it can provide a stable support for the stamped part of the lead frame, making the stamped cross-section of this part smoother.

[0031] The implementation principle of a stamping die for lead frame production in an embodiment of the present application is as follows: the lead frame is transported between the upper die and the lower die by an external transport device, the upper die is pressed downward, the rubber seat 401 abuts against the lead frame, and the stamping head 101 abuts against the lead frame for stamping. The bottom end surface of the stamped part of the lead frame is supported by the supporting feet 504. When the upper die is partially deformed or twisted, the stamping head 101 at the bottom of the lower die is changed to a form with a middle high and two sides gradually lowered, which can offset the influence of the deformation of the die during the stamping process on the local pressure height of the upper die, so that the local pressure on each row of product pins during stamping is improved from the original small pressure in the middle and large pressure on the two sides to the same pressure in the middle and on the two sides. Figure 5 shown.

[0032] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0033] Secondly: In the drawings of the embodiments disclosed in the present utility model, only the structures related to the embodiments disclosed in the present utility model are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present utility model can be combined with each other;

[0034] Finally: The above are only preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

[0035] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A stamping die for producing a lead frame, characterized in that: The invention comprises an upper mould (1) and a lower mould (2), wherein a driving member (3) is arranged between the lower mould and the upper mould, a plurality of punching heads (101) are arranged side by side at the bottom of the upper mould (1), the heights of the plurality of punching heads (101) decrease from the middle to the outside, and two positioning members (4) for flexibly fixing a lead frame are symmetrically arranged at both ends of the bottom of the upper mould (1).

2. A stamping die for producing a lead frame according to claim 1, characterized in that: The driving member (3) comprises a base (301), the lower mold is fixedly arranged on the base (301), two punching cylinders (302) are symmetrically arranged on the base (301), the output shaft of the punching cylinder (302) is connected to an upper cover plate (303), and the upper cover plate (303) is fixedly connected to the upper mold.

3. The stamping die for lead frame production according to claim 2, characterized in that: Four guide columns (304) are also fixedly arranged on the upper part of the base (301), and the upper ends of the guide columns (304) are movably plugged into the upper cover plate (303).

4. The stamping die for producing a lead frame according to claim 2, characterized in that: The positioning member (4) comprises a rubber seat (401), a plurality of grooves are provided inside the rubber seat (401), and a spring 1 (402) is arranged in the groove.

5. The stamping die for producing a lead frame according to claim 1, characterized in that: An active cavity is provided inside the lower mold, and a plurality of punching grooves (201) matching the punching head (101) are provided on the upper surface of the lower mold, the punching grooves (201) are connected to the active cavity, and a support member (5) is provided in the active cavity for supporting the punched area on the lead frame during punching.

6. The stamping die for producing a lead frame according to claim 5, characterized in that: The support member (5) comprises a telescopic rod (501) fixedly arranged in the movable cavity, a second spring (502) is sleeved on the surface of the telescopic rod (501), and a slide plate (503) movably arranged in the movable cavity is fixedly arranged at the top end of the telescopic rod (501), and a plurality of supporting feet (504) movably engaged with the stamping groove (201) are arranged on the upper part of the slide plate (503).

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