Wedge-shaped welding chopper

Abstract

The utility model relates to a wedge-shaped welding chopper, which comprises a chopper body and a chopper head, the chopper head is bonded at the end part of the chopper body, a wedge-shaped groove is arranged at one end of the chopper head at the chopper body, and the wedge-shaped groove is used for clamping a metal bonding wire to be processed. The wedge-shaped welding chopper has the advantages that the surface smoothness of a welding spot and the number of burrs are ensured, and the width of the welding spot is reduced; the width of the welding spot is 1.1-1.4 times of the wire diameter, meanwhile, the service life of the wedge-shaped welding chopper is prolonged by 64%, the problem that the space layout is affected by the width of the welding spot is finally solved, the occurrence rate of insulation failure is reduced, and the service life of the wedge-shaped welding chopper is prolonged.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor packaging bonding, and particularly relates to a wedge welding capillary. Background Art

[0002] With the rapid development of the new energy vehicle industry, the demand for automotive-grade power modules is increasing day by day, and SiC (silicon carbide) power modules have received more and more attention due to their excellent electrical performance advantages. In order to ensure the full play of the high-efficiency, high-frequency, and high-temperature characteristics of SiC modules, the current-carrying and heat dissipation characteristics of the products are particularly important, and metal bonding wires are also required to have better performance to meet the conduction, current-carrying, and heat dissipation characteristics of the circuit.

[0003] The bonding wire is a core material used in semiconductor packaging and is a conducting wire used to connect an electronic chip to a wire or between chips. The wedge welding capillary (Bondwedge) is a tool used for bonding, which is composed of a metal semi-cylindrical blade body and a blade tip, usually made entirely of metal, and can fix the metal bonding wire on the chip or the frame.

[0004] However, in the actual production process using traditional technologies, the following problems exist: the width of the first solder joint of the product is relatively large, which increases the distance between solder joints, affects the solder joint layout on the limited bonding area, and has great spatial limitations; during the ultrasonic welding process, some burrs will fall off from the solder joints to form metal debris, and these metal debris will disperse to all corners of the product. When such metal debris falls into the insulation groove, it will cause insulation failure during product testing, reduce the product yield, and significantly reduce the life of the wedge welding capillary, increasing production costs. It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0005] In view of the deficiencies of the prior art, the utility model discloses a wedge welding capillary.

[0006] The technical solution adopted by the utility model is as follows:

[0007] A wedge welding capillary includes a blade body and a blade tip. The blade tip is bonded to the end of the blade body. A wedge-shaped groove is formed at one end of the blade body where the blade tip is located, and the wedge-shaped groove holds the metal bonding wire to be processed.

[0008] Further, the chamfer range of the wedge-shaped groove is 65° to 70°.

[0009] Further, in the vertical direction, the height at which the metal bonding wire exposes from the wedge-shaped groove is set as the exposed height of the metal bonding wire.

[0010] Further, in the case where the metal wire is not deformed, the ratio range of the exposed height of the metal wire to the diameter of the metal bonding wire is 25-40%.

[0011] Further, the vertical cross-sectional shape of the tool tip is trapezoidal, and the width of the tool tip gradually decreases from top to bottom.

[0012] Further, a titanium nitride coating is provided on the surface of the tool tip.

[0013] Further, the thickness range of the titanium nitride coating is 4-8 mm.

[0014] Further, the tool body is semi-cylindrical.

[0015] Further, the tool tip is a ceramic tool tip.

[0016] The beneficial effects of the present utility model are as follows:

[0017] 1. A wedge-shaped groove is provided at the end of the tool tip, which accommodates the metal bonding wire, reduces the solder joint width, reduces the number of burrs and the length of burrs, controls the solder joint width within 1.1-1.4 times the wire diameter, and finally solves the problem that the wide solder joint affects the space layout; the incidence rate of insulation failure is reduced from the original 0.4% to less than 0.05%; the incidence rate of insulation failure is reduced, and the life of the wedge welding split tool is increased by 64%.

[0018] 2. Strictly control the chamfer range of the wedge-shaped groove, so that the contact surface height between the tool tip and the metal bonding wire is closer to the welding surface. In this way, ultrasonic energy can be transmitted faster with less loss and act on the bonding surface, improving the utilization rate of ultrasonic energy.

[0019] 3. Strictly control the exposed height of the metal bonding wire to ensure that the metal bonding wire will not be thrown out of the wedge-shaped groove during the welding process, and ensure that the wedge-shaped groove tool tip will not touch the welding surface during the welding process, avoiding direct damage to the welding surface. 4. The tool tip is plated with a titanium nitride coating. Titanium nitride is characterized by high wear resistance and small friction coefficient, which can prevent the metal bonding wire from sticking to the wedge-shaped groove tool tip. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a front view schematic diagram of a wedge welding split tool structure.

[0021] Figure 2 is Figure 1 a partial enlarged structural schematic diagram at A in

[0022] Figure 3 is a side view schematic diagram of a wedge welding split tool structure.

[0023] Figure 4It is a top - view schematic diagram of a wedge - type welding split - blade structure. In the figure: 1, blade body; 2, blade tip; 3, wedge - shaped groove; 4, exposed height of metal bonding wire. Detailed implementation manners

[0024] The following combines with the attached drawings to illustrate the detailed implementation manners of the present utility model.

[0025] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following further details the device proposed by the present utility model in combination with the attached drawings and specific implementation manners. According to the following description, the advantages and features of the present utility model will be clearer. It should be noted that the attached drawings are in a very simplified form and all use non - precise scales, only for conveniently and clearly assisting in explaining the purpose of the implementation manners of the present utility model. In order to make the purpose, features and advantages of the present utility model more obvious and understandable, please refer to the attached drawings. It should be known that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed by the present utility model.

[0026] Embodiment:

[0027] A wedge - type welding split - blade, as Figure 1 shown, includes a blade body 1 and a blade tip 2. The blade tip 2 is bonded to the end of the blade body 1. The blade body 1 and the blade tip 2 are bonded into one body. The blade body 1 is fixed on the transducer of the equipment, and the blade tip 2 holds the metal bonding wire to be processed. The bonding between the blade body 1 and the blade tip 2 should be firm, without breakage and without affecting the impedance output of the transducer.

[0028] As Figure 1 and Figure 2 shown, the vertical cross - sectional shape of the blade tip 2 is trapezoidal, and the width of the blade tip 2 gradually decreases from top to bottom. A wedge - shaped groove 3 is opened at one end of the blade tip 2 away from the blade body 1. The wedge - shaped groove 3 holds the metal bonding wire to be processed. The chamfer and depth of the wedge - shaped groove 3 are related to the wire diameter of the bonding wire. The chamfer angle range of the wedge - shaped groove 3 is 65 - 70°, so that the contact surface height between the blade tip 2 and the metal bonding wire is closer to the welding surface. In this way, ultrasonic energy can be transmitted faster with less loss to act on the bonding surface, improving the utilization rate of ultrasonic energy.

[0029] As Figure 1 and Figure 2As shown, in the vertical direction, the height at which the metal bonding wire exposes from the wedge-shaped groove 3 is set as the exposed height 4 of the metal bonding wire, and the ratio range of the exposed height of the metal wire to the diameter of the metal bonding wire is 25 - 40%. This ensures that the metal bonding wire will not be thrown out of the wedge-shaped groove 3 during the welding process, and at the same time, it can ensure that the cutting head 2 of the wedge-shaped groove 3 will not touch the welding surface during the welding process, avoiding direct damage to the welding surface.

[0030] As Figure 1 and Figure 2 shown, the cutting head 2 is a ceramic cutting head 2. The ceramic itself has high hardness, avoiding the situation that the cutting head 2 is easily damaged, which is beneficial to extending the service life. The surface of the cutting head 2 is provided with a titanium nitride coating, and the thickness range of the titanium nitride coating is 4 - 8 mm. The characteristics of the titanium nitride coating are high wear resistance and small friction coefficient, preventing the metal bonding wire from bonding with the cutting head 2 of the wedge-shaped groove 3.

[0031] As Figure 3 and Figure 4 shown, the tool body 1 is in a semi-cylindrical shape. The tool body 1 is fixed to the transducer of the equipment by screws. The width of the flat section of the tool body 1 is greater than or equal to the diameter of the round surface of the screw head.

[0032] Specific working process:

[0033] During work, by applying a certain pressure, the bonding metal wire is brought into contact with the welding surface using the cutting head 2, and the bonding metal wire is deformed to a certain extent. At the same time, the ultrasonic generator of the transducer transmits ultrasonic energy to the bonding metal wire and the welding surface through the tool body 1, causing the bonding metal wire to bond with the welding surface.

[0034] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification. The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the utility model patent should be subject to the appended claims.

Claims

1. A wedge-shaped welding cutter, characterized in that: It includes a blade body and a tool tip. The tool tip is adhesively bonded to the end of the blade body. A wedge-shaped groove is formed at one end of the blade body for clamping the metal bonding wire to be processed. The chamfer range of the wedge-shaped groove is 65° to 70°. In the vertical direction, the height of the metal bonding wire protruding from the wedge-shaped groove is set as the exposed height of the metal bonding wire. Without deformation of the metal wire, the ratio range of the exposed height of the metal wire to the diameter of the metal bonding wire is 25% to 40%.

2. The wedge-shaped soldering split blade according to claim 1, characterized in that: The vertical cross-sectional shape of the tool tip is trapezoidal, and the width of the tool tip gradually decreases from top to bottom.

3. A wedge-shaped welding split tool according to claim 1, characterized in that: A titanium nitride coating is provided on the surface of the tool tip.

4. A wedge-shaped welding split blade according to claim 3, characterized in that: The thickness range of the titanium nitride coating is 4 mm to 8 mm.

5. A wedge-shaped welding split tool according to claim 1, characterized in that: The blade body is semi-cylindrical.

6. A wedge-shaped welding split tool according to claim 1, characterized in that: The tool tip is a ceramic tool tip.

Images