Bonding chopper for silicon carbide material packaging copper wire

Abstract

The utility model relates to a bonding chopper for packaging a copper wire by a silicon carbide material, which comprises a chopper handle and a chopper head, the chopper head is made of a cubic boron nitride material, the chopper head is arranged at one end of the chopper handle, and the chopper head is brazed on the chopper handle through vacuum. According to the utility model, the cutter handle is made of the tungsten steel material, only the cutter head is made of the CBN (cubic boron nitride) material, the CBN material is harder than the tungsten steel material, the hardness of the cutter head is improved, and the CBN material has thermal conductivity, thermal stability and chemical stability, can keep inertia and hardness in a high-temperature environment, and is not easy to chemically react with other elements; the thermal conductivity is favorable for reducing the temperature of a cutting area so as to reduce diffusion abrasion, and the service life of the tool bit is prolonged by two times.

Description

Technical Field

[0001] The utility model relates to the field of copper wire bonding, and particularly to a bonding split blade for encapsulating copper wire with silicon carbide material. Background Technique

[0002] Aluminum wire bonding is a connection technology widely used in IC packaging. It fixes aluminum wire on a chip or a substrate through thermosonic welding. The advantages of this technology are that the aluminum wire has good electrical conductivity and low cost, and is suitable for mass production. However, with the improvement of the performance requirements of power modules for new energy vehicles, the traditional aluminum wire bonding technology faces some challenges.

[0003] Due to its excellent thermal conductivity, copper wire is increasingly used in the bonding of high-power modules, especially in power modules with a silicon nitride (Si3N4) matrix. Silicon nitride is a material with high thermal conductivity, high electrical insulation and good mechanical properties, and is very suitable for applications in high-power and high-temperature environments.

[0004] However, when using copper wire for bonding, the traditional tungsten steel split blade may encounter wear problems. Although tungsten steel has high hardness and good wear resistance, when it comes into contact with copper wire, due to the relatively high hardness of copper, the split blade may wear faster, affecting the quality and reliability of bonding. In addition, the friction between the copper wire and the split blade may also generate metal particles, which may contaminate the chip or the substrate, further affecting the performance and stability of the product.

[0005] To solve these problems, a new type of split blade needs to be developed. Summary of the Utility Model

[0006] To solve the above problems, the utility model provides a bonding split blade for encapsulating copper wire with silicon carbide material.

[0007] To achieve the above purpose, the technical solution adopted by the utility model is as follows: The utility model relates to a bonding split blade for encapsulating copper wire with silicon carbide material, which includes a tool shank and a tool tip. The tool tip is made of cubic boron nitride material, the tool shank is made of tungsten steel material, and the tool tip is vacuum brazed to one end of the tool shank.

[0008] Preferably, the end of the tool shank is provided with a tool shank mounting surface for connecting with the tool tip; the bottom of the tool tip is provided with a tool tip mounting surface matching the tool shank, and the tool tip mounting surface is connected with the tool shank mounting surface, and the tool tip and the tool shank are formed into one body through vacuum brazing.

[0009] Preferably, the periphery of the tool shank mounting surface is provided with a first inclined surface, a second inclined surface, a third inclined surface and a fourth inclined surface. The first inclined surface and the second inclined surface are opposite surfaces, and the third inclined surface and the fourth inclined surface are opposite surfaces. The periphery of the tool tip mounting surface is provided with a first connecting surface, a second connecting surface, a third connecting surface and a fourth connecting surface. The first connecting surface and the second connecting surface are opposite surfaces, and the third connecting surface and the fourth connecting surface are opposite surfaces.

[0010] Preferably, when the tool tip is mounted on the tool shank, the first connecting surface is connected to the first inclined surface and spliced into a first plane, the second connecting surface is connected to the second inclined surface and spliced into a second plane, the third connecting surface is connected to the third inclined surface and spliced into a third plane, and the fourth connecting surface is connected to the fourth inclined surface 14 and spliced into a fourth plane.

[0011] Preferably, a groove is provided at the top of the tool tip. The bottom of the groove forms a working area, and the working area includes a first chamfering portion, a connecting portion, and a second chamfering portion that are sequentially connected along the length direction of the working area. Among them, the first chamfering portion is connected to the first connecting surface, and the second chamfering portion is connected to the second connecting surface.

[0012] Preferably, the groove is a V-shaped groove.

[0013] Preferably, the first chamfering portion and the second chamfering portion are arc-shaped structures, and the length of the first chamfering portion is longer than that of the second chamfering portion.

[0014] Preferably, a first arc edge is formed between the first chamfering portion and the first connecting surface; a second arc edge is formed between the second chamfering portion and the second connecting surface, and the arc length of the first arc edge is longer than that of the second arc edge.

[0015] The beneficial effect of the present utility model lies in that: The present utility model relates to a bonding splitting tool for encapsulating copper wires in silicon carbide materials, which includes a tool shank and a tool tip. The tool tip is provided at one end of the tool shank, and the tool tip is vacuum brazed to the tool shank. In the present utility model, the tool shank is made of tungsten steel material, and only the tool tip is made of CBN (cubic boron nitride) material. The CBN (cubic boron nitride) material is harder than the tungsten steel material, which improves the hardness of the tool tip. The CBN (cubic boron nitride) material has thermal conductivity, thermal stability, and chemical stability, can remain inert and hard in a high-temperature environment, and is not easy to chemically react with other elements. The thermal conductivity is beneficial to reducing the temperature in the cutting area and reducing diffusion wear, and doubles the service life of the tool tip. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the present utility model.

[0017] Figure 2 is a schematic diagram of the split structure of the present utility model.

[0018] Figure 3 It is a schematic diagram of the end face structure of the present utility model.

[0019] Figure 4 It is a schematic diagram of the tool shank structure of the present utility model.

[0020] Figure 5 It is a schematic diagram of the tool tip structure of the present utility model.

[0021] Figure 6 It is a schematic diagram of the bottom structure of the tool tip of the present utility model.

[0022] Reference numerals

[0023] 1. Tool shank; 11. First inclined surface; 12. Second inclined surface; 13. Third inclined surface; 14. Fourth inclined surface; 15. Tool shank mounting surface

[0024] 2. Tool tip; 21. First connecting surface; 22. Second connecting surface; 23. Third connecting surface; 24. Fourth connecting surface; 25. Tool tip mounting surface; 26. Groove; 261. First chamfered part; 2611. First arc edge; 262. Connecting part; 263. Second chamfered part; 2631. Second arc edge; 31. First plane; 32. Second plane; 33. Third plane; 34. Fourth plane. Specific embodiments

[0025] Please refer to Figure 1-6 As shown, the present utility model relates to a bonding split knife for encapsulating copper wires in silicon carbide materials, which includes a tool shank 1 and a tool tip 2. The tool tip 2 is arranged at one end of the tool shank 1, and the tool tip 2 is vacuum brazed to the tool shank 1.

[0026] In this embodiment, the tool shank 1 is made of tungsten steel and is in the shape of a slender cylinder. Among them, the end of the tool shank 1 is provided with a tool shank mounting surface 15 for connecting with the tool tip 2. The periphery of the tool shank mounting surface 15 is provided with a first inclined surface 11, a second inclined surface 12, a third inclined surface 13 and a fourth inclined surface 14 to prevent the tool tip 2 from being misaligned during installation. Among them, the first inclined surface 11 and the second inclined surface 12 are opposite surfaces, and the third inclined surface 13 and the fourth inclined surface 14 are opposite surfaces.

[0027] In this embodiment, the tool bit 2 is used for operating on copper wires. The heat conduction block of the copper wire is applicable to high-power silicon nitride power device modules. When traditional tungsten steel is used to weld copper wires, it is prone to wear, resulting in poor product stability. Therefore, the tool bit 2 of the present utility model preferably adopts CBN (cubic boron nitride) material (as disclosed in patent document CN112771190A). CBN (cubic boron nitride) is a newly synthesized material composed of nitrogen atoms and boron atoms. CBN (cubic boron nitride) is harder than tungsten steel and also has good thermal conductivity, thermal stability, and chemical stability. It can maintain inertness and hardness at a temperature of up to 1000°C and is not prone to chemical reactions with other elements. The thermal conductivity of CBN (cubic boron nitride) is beneficial to reducing the temperature in the cutting area and reducing diffusion wear, thereby doubling the service life of the tool bit.

[0028] In this embodiment, the tool bit 2 is wedge-shaped. Among them, a tool bit mounting surface 25 matching the tool handle 1 is provided at the bottom of the tool bit 2. The tool bit mounting surface 25 is connected to the tool handle mounting surface 15, and the tool bit 2 and the tool handle 1 are integrated by vacuum brazing.

[0029] Furthermore, a first connection surface 21, a second connection surface 22, a third connection surface 23, and a fourth connection surface 24 are provided around the tool bit mounting surface 25. The first connection surface 21 and the second connection surface 22 are opposite surfaces, and the third connection surface 23 and the fourth connection surface 24 are opposite surfaces. When the tool bit 2 is installed on the tool handle 1, the first connection surface 21 is connected to the first inclined surface 11 and spliced into a first plane 31, the second connection surface 22 is connected to the second inclined surface 12 and spliced into a second plane 32, the third connection surface 23 is connected to the third inclined surface 13 and spliced into a third plane 33, and the fourth connection surface 24 is connected to the fourth inclined surface 14 and spliced into a fourth plane 34, so that the tool bit 2 is installed at the installation position of the tool bit 2, avoiding misalignment installation of the tool bit 2 and the tool handle 1 and affecting the positioning of the tool bit 2.

[0030] Further, a groove 26 is provided at the top of the tool bit 2. The groove 26 is a V-shaped groove, and the bottom of the groove 26 forms a working area. The working area includes a first chamfered portion 261, a connecting portion 262, and a second chamfered portion 263 that are sequentially connected along the length direction of the working area. In this embodiment, the first chamfered portion 261 and the second chamfered portion 263 are arc-shaped structures. Among them, the length of the first chamfered portion 261 is longer than that of the second chamfered portion 263. The first chamfered portion 261 is connected to the first connecting surface 21, and a first arc edge 2611 is formed between the first chamfered portion 261 and the first connecting surface 21; the second chamfered portion 263 is connected to the second connecting surface 22, and a second arc edge 2631 is formed between the second chamfered portion 263 and the second connecting surface 22. The arc length of the first arc edge 2611 is longer than that of the second arc edge 2631. When the bonding split tool presses out a cutting edge on the copper wire, the first chamfered portion 261 contacts and squeezes the copper wire. Since the first chamfered portion 261 is arc-shaped and the first arc edge 2611 is longer than the second arc edge 2631, the overall shape of the first chamfered portion 261 is smoother. When the first chamfered portion 261 squeezes the copper wire, the force-bearing area on the first chamfered portion 261 is larger, thereby reducing the wear rate of the first chamfered portion 261.

[0031] The utility model relates to a bonding split tool for encapsulating copper wires with silicon carbide materials, which includes a tool shank 1 and a tool bit 2. The tool bit 2 is arranged at one end of the tool shank 1. The tool bit 2 is vacuum brazed to the tool shank 1. In the utility model, the tool shank 1 is made of tungsten steel, and only the tool bit 2 is made of CBN (cubic boron nitride). The CBN (cubic boron nitride) material is harder than the tungsten steel material, which improves the hardness of the tool bit 2. The CBN (cubic boron nitride) material has thermal conductivity, thermal stability, and chemical stability, can remain inert and hard in a high-temperature environment, and is not prone to chemical reactions with other elements. The thermal conductivity is beneficial to reducing the temperature in the cutting area and reducing diffusion wear, doubling the service life of the tool bit 2.

[0032] The above embodiments are only descriptions of the preferred embodiments of the utility model, and do not limit the scope of the utility model. Without departing from the design spirit of the utility model, various deformations and improvements made by those of ordinary engineering and technical personnel in the art to the technical solutions of the utility model shall fall within the protection scope determined by the claims of the utility model.

Claims

1. A bonding tool for copper wire packaging of silicon carbide materials, characterized by: The utility model comprises a knife handle and a knife head, wherein the knife head is made of cubic boron nitride material, the knife handle is made of tungsten steel material, and the knife head is vacuum brazed to one end of the knife handle. The periphery of the tool handle mounting surface is provided with a first bevel, a second bevel, a third bevel and a fourth bevel, the first bevel and the second bevel are opposite surfaces, and the third bevel and the fourth bevel are opposite surfaces; The cutter head mounting surface is surrounded by a first connecting surface, a second connecting surface, a third connecting surface and a fourth connecting surface. The first connecting surface is opposite to the second connecting surface, and the third connecting surface is opposite to the fourth connecting surface.

2. A bonding tool for silicon carbide material packaging copper wire according to claim 1, characterized in that: The end of the knife handle is provided with a knife handle mounting surface for connecting with the knife head, and the bottom of the knife head is provided with a knife head mounting surface matching the knife handle. The knife head mounting surface is connected to the knife handle mounting surface, and the knife head and the knife handle are integrated by vacuum brazing.

3. A bonding tool for silicon carbide material packaging copper wire according to claim 1, characterized in that: When the cutter head is installed on the cutter handle, the first connecting surface is connected to the first inclined surface and spliced ​​into a first plane, the second connecting surface is connected to the second inclined surface and spliced ​​into a second plane, the third connecting surface is connected to the third inclined surface and spliced ​​into a third plane, and the fourth connecting surface is connected to the fourth inclined surface and spliced ​​into a fourth plane.

4. A bonding tool for silicon carbide material packaging copper wire according to claim 3, characterized in that: A groove is provided at the top of the cutter head, and a working area is formed at the bottom of the groove. The working area includes a first chamfered portion, a connecting portion, and a second chamfered portion which are connected in sequence along the length direction of the working area, wherein the first chamfered portion is connected to the first connecting surface, and the second chamfered portion is connected to the second connecting surface.

5. A bonding tool for silicon carbide material packaging copper wire according to claim 4, characterized in that: The groove is a V-shaped groove.

6. A bonding tool for silicon carbide material packaging copper wire according to claim 4, characterized in that: The first chamfered portion and the second chamfered portion are arc-shaped structures, and the length of the first chamfered portion is longer than that of the second chamfered portion.

7. A bonding tool for silicon carbide material packaging copper wire according to claim 6, characterized in that: A first curved side is formed between the first chamfered portion and the first connecting surface; a second curved side is formed between the second chamfered portion and the second connecting surface, and the arc length of the first curved side is longer than that of the second curved side.

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