A tool for welding the base plate and the terminal to the DBC at the same time

Abstract

The utility model relates to the technical field of semiconductor products, and is a tool for welding a bottom plate and a terminal to a DBC at the same time, comprising a bottom plate, a top surface of which is provided with a screw hole and a first positioning hole; a positioning hollow is provided in the middle of a frame, the frame has a positioning pin corresponding to the position of the first positioning hole, and a screw corresponding to the position of the screw hole; a positioning sheet is installed in the positioning hollow, and the positioning sheet has a second positioning hole for positioning the terminal; a positioning plate has a third positioning hole for positioning the terminal, and the positioning plate also has a fourth positioning hole corresponding to the position of the positioning pin, and the positioning plate covers the upper end of the frame, and the positioning pin is inserted into the fourth positioning hole. The tool solves the original method of requiring two weldings, and can improve production efficiency, reduce the types of solder, and improve the production performance of power modules.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor products, and is a tool for welding a bottom plate and a terminal to a DBC at the same time. Background Art

[0002] In the current processing of power modules with base plates, welding process is the main processing process; its quality directly affects the yield rate of power modules and the performance of finished products; and welding tooling is the basis that directly affects the welding position and welding process. Some existing power modules with base plates are usually welded together by DBC components, base plates and power terminals.

[0003] The commonly used method for welding power modules now is to weld the terminals and DBC components once through the tooling, and then weld the welded parts again through the tooling and weld them to the bottom plate for the second time. This method involves two welding processes. In order to ensure that the solder used for the first welding will not melt during the second welding, thereby causing the terminals that have been welded once to shift, the solder welding temperature during the second welding is usually about 30 degrees lower than the melting temperature of the first solder; and the DBC component itself needs to weld devices such as chips, so there is at least one welding process. This means that at least 3 types of solder must be used when welding this type of power module, and the melting temperature difference of the solder is up to 60 degrees.

[0004] The use of the secondary soldering method prolongs the processing time of the power module, affecting production efficiency. At the same time, multiple clamping also affects the position accuracy of the power module components. The large number of solder types will affect the minimum melting temperature of the power module, which also affects the performance of the power module. Utility Model Content

[0005] To solve the above problems, the utility model proposes a tool for welding the bottom plate and the terminal to the DBC at the same time, which solves the original method that requires two weldings, can improve production efficiency, reduce the types of solder, and improve the production performance of the power module.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A tool for welding a base plate and a terminal to a DBC at the same time, comprising:

[0008] A bottom plate, the top surface of which is provided with screw holes and a first positioning hole;

[0009] A frame, wherein the center thereof has a positioning hollow, and the frame has a positioning pin corresponding to the position of the first positioning hole, and a screw corresponding to the position of the screw hole;

[0010] A positioning piece, installed in the positioning hollow, the positioning piece having a second positioning hole for positioning the terminal;

[0011] The positioning plate has a terminal hole for positioning the terminal. The positioning plate also has a third positioning hole corresponding to the position of the positioning pin. The positioning plate covers the upper end of the frame, and the positioning pin is inserted into the third positioning hole.

[0012] Preferably, the screw is a countersunk screw, and the top end of the screw hole is chamfered.

[0013] Preferably, the positioning sheet is a graphite sheet with a Teflon layer on its surface.

[0014] Preferably, the assembly of the frame and the positioning plate is a cubic member, three of the four corners around the cubic member are rounded and the other corner is beveled.

[0015] Preferably, the frame has four locating pins, which are respectively located at the four corners of the top surface of the frame, and two diagonal locating pins in one group of the four locating pins are cylindrical pins, and two diagonal locating pins in another group are diamond pins.

[0016] Preferably, one of the corners in the positioning hollowing is a bevel.

[0017] Preferably, the positioning plate comprises an intermediate plate and a positioning needle plate, and opposite side edges of the intermediate plate have recesses for easy taking.

[0018] Preferably, the intermediate plate has a terminal hole for placing the terminal, and the front side of the terminal hole has a first chamfer.

[0019] Preferably, the positioning needle plate has a terminal hole for the positioning terminal, and the terminal hole has a second chamfer on a side facing the frame, and the second chamfer is larger than the first chamfer.

[0020] Preferably, the four corners of the intermediate plate and the positioning needle plate have mounting holes, the inner diameter of which is 0.1mm to 0.15mm larger than the diameter of the support column on the frame; the inner diameter of the terminal hole on the positioning needle plate is 0.05mm to 0.1mm larger than the terminal diameter.

[0021] The beneficial effects of using the utility model are:

[0022] Through the coordination of the base plate, frame, positioning piece and positioning plate, this tooling can simultaneously weld the base plate and the terminal to the DBC, thereby improving welding efficiency, saving production time, reducing the types of solder, increasing the melting temperature of the product's lowest temperature solder, and improving production performance. At the same time, the base plate and the terminal are welded, and the clamping and welding are performed in one time, which can improve the relative position of the three and improve the product position accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of the exploded view of the tooling for welding the base plate and the terminal to the DBC at the same time.

[0024] Figure 2 This is a schematic diagram of welding tooling assembly.

[0025] Figure 3 Exploded diagram for welding tooling use.

[0026] Figure 4 Use exploded views for welding fixtures.

[0027] Figure 5 This is a schematic diagram of the base plate and terminals after being welded to the DBC.

[0028] Reference numerals include:

[0029] 1-base plate; 2-soldering piece; 3-DBC assembly; 4-terminal soldering piece; 5-terminal; 6-frame; 7-locating pin; 8-countersunk screw; 9-locating piece; 10-middle plate; 11-locating needle plate. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.

[0031] In order to solve the problems that the secondary welding method is used in the prior art, the processing time of the power module becomes longer, and the position accuracy of the power module components is affected, such as Figure 1-Figure 5 As shown, this embodiment proposes a tool for welding a base plate and a terminal to a DBC at the same time, including a base plate 1, a frame 6, a positioning piece 9, a countersunk screw 8, an intermediate plate 10 and a positioning pin plate 11.

[0032] A screw hole and a first positioning hole are provided on the top surface of the base plate 1; a positioning hollow is provided in the middle of the frame 6, and the frame 6 has a positioning pin 7 corresponding to the position of the first positioning hole, and a screw corresponding to the position of the screw hole; a positioning piece 9 is installed in the positioning hollow, and the positioning piece 9 has a second positioning hole for positioning the terminal 5; the positioning plate includes an intermediate plate 10 and a positioning needle plate 11, and the intermediate plate 10 and the positioning needle plate 11 both have a third positioning hole for positioning the terminal 5, and the intermediate plate 10 and the positioning needle plate 11 also have a fourth positioning hole corresponding to the position of the positioning pin 7, and the intermediate plate 10 and the positioning needle plate 11 cover the upper end of the frame 6, and the positioning pin 7 is inserted into the fourth positioning hole.

[0033] When in use, place the base plate 1 on a flat table, then place the frame 6 on the frame 6, use four positioning pins 7 to locate the relative position of the frame 6 and the base plate 1, and then use two countersunk screws 8 to fix the two. Place the welding piece 2 in the positioning hollow in the frame 6, and then place the DBC component 3 on the welding piece 2. Place the positioning piece 9 above the DBC component 3, and then place the terminal welding piece 4 in the corresponding position of the positioning piece 9 in turn. Place the middle plate 10 on the frame 6 and use four positioning columns for positioning. Place the terminals 5 in the corresponding holes on the middle plate 10 in sequence. Then place the positioning pin plate 11 above the middle plate 10 and position it through the four positioning columns on the frame 6 to accurately locate the position of the terminal 5. Then place the entire assembly in a formic acid furnace and weld it using a conventional heating welding method. This tooling can simultaneously weld the base plate 1 and the terminal 5 to the DBC component 3, which improves welding efficiency and saves production time. It can reduce the types of solder, increase the melting temperature of the lowest temperature solder of the product, improve the performance in production, and weld the base plate 1 and the terminal 5 at the same time. The one-time clamping and welding can improve the relative position of the three and improve the product position accuracy.

[0034] Preferably, the screw is a countersunk screw 8, the top of the screw hole is chamfered, and the frame 6 and the base plate 1 are connected using the countersunk screw 8, which can better ensure the relative accuracy of the two.

[0035] As a preferred embodiment, the positioning sheet 9 is a graphite sheet with a Teflon layer on the surface. The positioning sheet 9 is made of graphite, which has small thermal deformation and ensures accuracy, and the surface is sprayed with Teflon to prevent powder from falling.

[0036] Preferably, the assembly of the frame 6 and the positioning plate is a cubic member, of which three of the four corners are rounded and the other is beveled, so as to avoid the difficulty in identifying the angle and orientation of the assembly after installation.

[0037] The frame 6 has four positioning pins 7, which are respectively located at the four corners of the top surface of the frame 6. Among the four positioning pins 7, two positioning pins 7 in a group of diagonal positions are cylindrical pins, and two positioning pins 7 in another group of diagonal positions are diamond pins. The cylindrical pins and diamond pins can play a fool-proof effect, and are easy to assemble when the positioning requirements are met.

[0038] Preferably, one of the corners in the positioning hollow is beveled, which also has an anti-mistake effect.

[0039] Preferably, the positioning plate comprises an intermediate plate 10 and a positioning needle plate 11 , and opposite side edges of the intermediate plate 10 are provided with depressions, which facilitate the taking of the positioning needle plate 11 .

[0040] Preferably, the middle plate 10 is provided with a terminal hole for placing the terminal 5, and the front side of the terminal hole has a first chamfer. The positioning pin plate 11 has a terminal hole for positioning the terminal 5, and the side of the terminal hole facing the frame 6 has a second chamfer, and the second chamfer is larger than the first chamfer.

[0041] In addition, there is no tooling device under the bottom plate 1, so the conduction efficiency is higher when heating the solder, the thermal resistance is small, and welding is easy.

[0042] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.

Claims

1. A tool for welding a base plate and a terminal to a DBC at the same time, characterized in that: include A bottom plate, the top surface of which is provided with screw holes and a first positioning hole; A frame, wherein the center thereof has a positioning hollow, and the frame has a positioning pin corresponding to the position of the first positioning hole, and a screw corresponding to the position of the screw hole; A positioning piece, installed in the positioning hollow, the positioning piece having a second positioning hole for positioning the terminal; The positioning plate has a third positioning hole for positioning the terminal. The positioning plate also has a fourth positioning hole corresponding to the position of the positioning pin. The positioning plate covers the upper end of the frame, and the positioning pin is inserted into the fourth positioning hole.

2. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: The screw is a countersunk screw, and the top end of the screw hole is chamfered.

3. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: The positioning sheet is a graphite sheet with a Teflon layer on the surface.

4. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: The assembly of the frame and the positioning plate is a cubic member, three of the four corners around the cubic member are rounded and the other corner is a bevel.

5. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: The frame is provided with four positioning pins, which are respectively located at the four corners of the top surface of the frame. Two positioning pins in a group of diagonal positions among the four positioning pins are cylindrical pins, and two positioning pins in another group of diagonal positions are diamond pins.

6. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: One of the corners in the positioning hollowing is a bevel.

7. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 1, characterized in that: The positioning plate comprises a middle plate and a positioning needle plate, and the opposite side edges of the middle plate are provided with recesses for easy taking.

8. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 7, characterized in that: The intermediate plate has a terminal hole for placing the terminal, and the front side of the terminal hole has a first chamfer.

9. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 8, characterized in that: The positioning needle plate has a terminal hole for positioning the terminal, and the terminal hole has a second chamfer on one side facing the frame, and the second chamfer is larger than the first chamfer.

10. The tooling for welding the bottom plate and the terminal to the DBC at the same time according to claim 7, characterized in that: The four corners of the middle plate and the positioning needle plate are provided with mounting holes, the inner diameter of which is 0.1mm to 0.15mm larger than the diameter of the support column on the frame; the inner diameter of the terminal hole on the positioning needle plate is 0.05mm to 0.1mm larger than the terminal diameter.

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