CN107993942B - Manufacturing process of lead frame - Google Patents

Abstract

The invention relates to a lead frame manufacturing process which comprises a stamping process, wherein the stamping process comprises the steps of processing a metal plate into a frame body, processing a plurality of pin parts in the frame body side by side, connecting a supporting part with the tail ends of the pin parts, processing at least two supporting feet on the supporting part, connecting one end of each supporting foot with the supporting part, and connecting the other end of each supporting foot with the frame body. By applying the invention, the lead part can be effectively supported in the subsequent process, and the product reject ratio caused by the deformation of the lead part is greatly reduced.

Description

Manufacturing process of lead frame

【Technical field】

The present invention relates to a lead frame manufacturing process.

【Background technique】

As the chip carrier of integrated circuits, the lead frame is a key structural part that realizes the electrical connection between the lead-out end of the chip's internal circuit and the outer lead by means of bonding materials (gold wire, aluminum wire, copper wire) to form an electrical circuit. When it comes to the bridge function of connecting with external wires, most semiconductor integrated blocks need to use lead frames, which are important basic materials in the electronic information industry.

In the prior art, the manufacturing method of the lead frame is generally a mold stamping method or a chemical etching method, and a plurality of pins are arranged in some lead frames, and the pins are generally elongated and easily deformed. Due to gravity and other effects, if no preventive measures are taken, it is easy to cause a high defect rate of the final product in the subsequent stamping process.

【Content of invention】

In order to solve the problem in the prior art that the pin portion of the lead frame is easily deformed and cause a relatively high defect rate in the product manufacturing process, the present invention ensures the coplanarity of the lead frame by optimizing the stamping process in the manufacturing process, which can greatly reduce the Product defect rate due to deformation of the lead portion.

The present invention is achieved through the following technical solutions:

The manufacturing process of the lead frame includes a stamping process, the stamping process includes processing the metal sheet into a frame body, processing a plurality of pins side by side in the frame body, and connecting the support portion to the ends of the multiple pins , and at least two supporting feet are processed on the supporting part, and one end of the supporting feet is connected to the supporting part, and the other end is connected to the frame body.

According to the above-mentioned manufacturing process of the lead frame, the stamping process further includes: processing two of the supporting legs, and respectively processing the two ends of the supporting part.

In the above-mentioned manufacturing process of the lead frame, when performing the punching process, the supporting leg is punched into an L-shape with two ends connected to the frame body and the supporting portion respectively.

In the manufacturing process of the above lead frame, when performing the stamping process, it includes processing the connecting portion between the two supporting legs.

In the above-mentioned manufacturing process of the lead frame, when processing the connecting portion, the connecting portion is processed into a rectangular piece whose two ends are respectively connected to the two supporting legs.

According to the above-mentioned manufacturing process of the lead frame, the metal sheet is a copper strip.

In the above-mentioned manufacturing process of the lead frame, the subsequent processes of the stamping process include a heat treatment process, an electroplating process, a tape attachment process, a leg cutting process, a cutting process and a packaging process.

According to the above-mentioned manufacturing process of the lead frame, the leg cutting step includes cutting off the support portion.

In the above-mentioned manufacturing process of the lead frame, the plating layer in the electroplating process is at least one of the group consisting of nickel, palladium, gold, silver or alloys thereof.

Compared with prior art, the present invention has following advantage:

The present invention provides a manufacturing process of a lead frame. In the stamping process, a plurality of the lead parts are processed side by side in the frame body, and the support part is connected to the ends of the plurality of lead parts. , and at least two supporting feet are processed on the supporting part, and one end of the supporting feet is connected to the supporting part, and the other end is connected to the frame body. The lead part can be effectively supported in the subsequent process, the coplanarity of the lead frame can be ensured, and the defective rate of the product caused by the deformation of the lead part can be greatly reduced.

【Description of drawings】

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the workpiece diagram after described stamping process in the preferred embodiment of the present invention;

Fig. 2 is a finished drawing of the lead frame according to the preferred embodiment of the present invention.

【Detailed ways】

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The present invention provides a manufacturing process of a lead frame, as shown in Fig. 2 , the finished lead frame manufactured by the lead frame manufacturing process of the present invention, the manufacturing process includes a stamping process, a heat treatment process, an electroplating process, a tape-attaching process, and foot cutting process, cutting process and packing process;

Figure 1 is a workpiece diagram after the stamping process in a preferred embodiment of the present invention, the stamping process includes processing the metal sheet into a frame body 1, specifically, the metal sheet is a copper strip, and a plurality of leads The feet 12 are processed side by side in the frame body 1, a gap is provided between two adjacent pins 12, the support 13 is connected to the ends of a plurality of the pins 12, and the support At least two supporting legs 131 are processed on the part 13, and one end of the supporting legs 131 is connected to the supporting part 13, and the other end is connected to the frame body 1. The pin portion 12 has a slender structure, and the above-mentioned processing technology can enable the pin portion 12 to be effectively supported in the subsequent process, ensuring the coplanarity of the lead frame, that is, a plurality of the pin portions 12 can be guaranteed to be in the same plane as the entire frame body 1 to the greatest extent, greatly reducing the product defect rate caused by the deformation of the pin portion 12 .

In this embodiment, in the stamping process, two support feet 131 are processed, which are respectively processed at both ends of the support portion 13 . In addition, when performing the stamping process, the supporting legs 131 are punched into an L-shape whose two ends are respectively connected to the frame body 1 and the supporting portion 13. The L-shaped supporting legs 131 have better cutting performance and reduce the cutting edge. Difficulty in making the mouth; and process the connecting portion between the two supporting feet 131. When processing the connecting portion, the connecting portion is processed into a rectangular sheet whose two ends are respectively connected to the two supporting feet 131, further Strengthen the supporting strength of the supporting feet 131 .

The heat treatment process uses an annealing furnace for annealing to reduce hardness and improve machinability; eliminate residual stress, stabilize dimensions, reduce deformation and crack tendency; refine grains, adjust structure, and eliminate structure defects.

In the electroplating process, the plating layer is at least one of the group consisting of nickel, palladium, gold, silver or alloys thereof. After electroplating, the chip loading and bonding performance of the lead frame in the packaging process can be guaranteed, so that chips and welding wires can form good diffusion welding with the lead frame.

The tape attaching process includes attaching the protective tape to the workpiece in the previous process, so as to protect the surface of the workpiece and ensure the surface quality.

The leg cutting process includes cutting off the support portion 13 . Since the support part 13 is to improve the product process performance, reduce the deformation rate of the workpiece in the previous process, and improve the final pass rate of the product, the support part 13 needs to be cut off in the corner cutting process to form the final product shape.

The subsequent process of the leg cutting process is the cutting process of cutting the plurality of lead frames obtained by continuous stamping into independent monomers, followed by the packaging process of packaging the finished lead frames.

To sum up, the present invention provides a lead frame manufacturing process. In the stamping process, a plurality of the pin portions 12 are processed side by side in the frame body 1, and the support portion 13 and the plurality of The ends of the pin parts 12 are connected, and at least two supporting feet 131 are processed on the supporting part 13, and one end of the supporting feet 131 is connected to the supporting part 13, and the other end is connected to the frame body 1. This enables the pin portion 12 to be effectively supported in subsequent processes, greatly reducing the defective rate of products caused by the deformation of the pin portion 12 .

The foregoing is one or more implementation modes provided in conjunction with specific content, and it is not considered that the specific implementation of the present invention is limited to these descriptions. Any approach or similarity to the method and structure of the present invention, or some technical deduction or replacement based on the concept of the present invention should be regarded as the scope of protection of the present invention.

Claims (8)

1. The manufacturing process of the lead frame is characterized by comprising a stamping process, wherein the stamping process comprises the steps of processing a metal plate into a frame body (1), processing a plurality of pin parts (12) in the frame body (1) side by side, connecting a supporting part (13) with the tail ends of the plurality of pin parts (12), processing at least two supporting legs (131) on the supporting part (13), connecting one end of each supporting leg (131) with the supporting part (13), and connecting the other end of each supporting leg (131) with the frame body (1);

and in the stamping process, the supporting legs (131) are punched into an L shape with two ends respectively connected with the frame body (1) and the supporting part (13).

2. The lead frame manufacturing process according to claim 1, wherein the stamping process further comprises machining two supporting legs (131) at two ends of the supporting portion (13).

3. The lead frame manufacturing process according to claim 1, wherein the punching process includes machining a connecting portion between the two support legs (131).

4. The manufacturing process of the lead frame according to claim 3, wherein the connecting portion is formed into a rectangular sheet shape having two ends respectively connected to the two supporting legs (131).

5. The process for manufacturing lead frames according to claim 1, wherein the metal plate material is a copper strip.

6. The lead frame manufacturing process according to any one of claims 1 to 5, wherein the punching process is followed by a heat treatment process, a plating process, a taping process, a pin cutting process, a cutting process, and a packaging process.

7. The process for manufacturing lead frames according to claim 6, wherein the step of cutting the legs comprises cutting away the support (13).

8. The process for manufacturing lead frames according to claim 7, wherein the plating layer of the plating process is at least one of the group consisting of nickel, palladium, gold, silver or alloys thereof.