Ultrasonic bonding terminal and power module with crimping function

Abstract

The utility model discloses an ultrasonic bonding terminal and a power module with a crimping function. The terminal is of an integrated punch forming structure and comprises a connecting part used for being connected and pressed with a PCB; the composite part is connected to the lower end of the crimping part; the ultrasonic bonding part is connected with the lower end of the composite part, and the ultrasonic bonding part at least comprises a bend; the crimping part is made of a first material, the ultrasonic bonding part is made of a second material, and the hardness of the first material is greater than that of the second material; the composite part is a composite area formed by combining the first material and the second material through an atomic level interface. According to the ultrasonic bonding terminal, the crimping part and the ultrasonic bonding part are firmly combined through the composite part, so that the stability and reliability of the product structure are ensured. The terminal provided by the utility model has the advantages of excellent conductivity, design flexibility, excellent corrosion resistance and excellent physical performance; the terminal can be designed according to the application of the first material and the second material, the forming thickness of the terminal can be flexibly adjusted, and the processing cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of power modules, in particular to an ultrasonic bonding terminal and a power module with a crimping function. Background Art

[0002] At present, the ultrasonic bonding terminals on the market are generally divided into two parts, including a crimping part and an ultrasonic bonding part. Ultrasonic bonding terminals are mainly used in power modules to connect PCB boards and DBC boards to transmit drive signals or conduct electricity. When installing the PCB board on the power module, the crimping part of the crimped PIN is deformed by force, so it is free from manual secondary spot welding, so the crimping part needs to have a higher hardness. The ultrasonic welding part is connected to the DBC. In order to achieve the ultrasonic welding effect, the material hardness of the ultrasonic bonding part needs to be lower.

[0003] In addition, there are still some ultrasonic bonding terminals on the market that have no crimping part, which requires secondary welding to form the crimping part in order to connect the terminal to the PCB board. The production efficiency of such secondary welded ultrasonic bonding terminals is low. The ultrasonic bonding terminals with crimping part structures are generally manufactured by separately processing and forming the ultrasonic bonding part and the crimping part that constitute the ultrasonic bonding terminal, and then connecting the ultrasonic bonding part and the crimping part together by mechanical riveting or welding to form an ultrasonic bonding terminal. Therefore, the existing ultrasonic bonding terminals not only have complex manufacturing processes, high processing difficulty, low processing efficiency, and low yield, but also have product reliability problems caused by riveting or welding.

[0004] At the same time, the thickness of various regions (ultrasonic bonding part and crimping part) of ultrasonic bonding terminals currently on the market are mostly consistent. Even those with inconsistent thickness are obtained through complex die-casting, machining and other expensive methods. Utility Model Content

[0005] The purpose of the utility model is to provide an ultrasonic bonding terminal to address the problems of low reliability, complex manufacturing process, high processing difficulty, low processing efficiency and low yield rate faced by existing terminals, thereby solving the problems faced by existing terminals such as complex terminal processing, high processing difficulty, low yield rate and poor reliability caused by mechanical riveting or welding.

[0006] In order to achieve the above object, the utility model is realized by the following technical solutions:

[0007] The utility model designs an ultrasonic bonding terminal, which is a terminal with a crimping function and is an integrated stamping structure, comprising:

[0008] A crimping portion, which is used to connect with a PCB board;

[0009] a composite portion connected to the lower end of the crimping portion;

[0010] and an ultrasonic bonding portion connected to the lower end of the composite portion, wherein the ultrasonic bonding portion comprises at least one bending portion;

[0011] The material of the crimping portion is a first material, the material of the ultrasonic bonding portion is a second material, and the hardness of the first material is greater than that of the second material;

[0012] The composite portion is a composite region formed by the first material and the second material being bonded at the atomic level interface.

[0013] Furthermore, in an ultrasonic bonding terminal, the crimping portion and the PCB board are interference fit.

[0014] Furthermore, an ultrasonic bonding terminal: the ultrasonic bonding portion is configured as a "Z"-shaped structure or an "L"-shaped structure.

[0015] Furthermore, in an ultrasonic bonding terminal, the thicknesses of the crimping portion, the composite portion and the ultrasonic bonding portion are set to be different.

[0016] The utility model also provides a power module with a crimping function, and the power module comprises the ultrasonic bonding terminal with a crimping function.

[0017] Furthermore, a power module with a crimping function is provided, the power module comprising:

[0018] Module base plate;

[0019] A plurality of DBC boards are respectively arranged on the module bottom plates;

[0020] A plurality of semiconductor chips, at least one semiconductor chip is disposed on each DBC board;

[0021] A plurality of bonding wires, one end of which is electrically connected to the semiconductor chip, and the other end of which is electrically connected to the DBC board or another semiconductor chip;

[0022] A plurality of ultrasonic bonding terminals, whose ultrasonic bonding parts are connected to the DBC board;

[0023] An insulating filling layer, which is disposed on the module bottom plate and is used to cover the DBC board, the semiconductor chip and the bonding wire;

[0024] A plastic-encapsulated shell is provided with connection holes for connecting to a heat sink, the module base plate is assembled on the plastic-encapsulated shell, and the DBC board, semiconductor chip, bonding wire, ultrasonic bonding terminal and insulating filling layer are arranged inside the plastic-encapsulated shell, and the crimping portion extends through the plastic-encapsulated shell to the outside.

[0025] Furthermore, a power module with a crimping function: a bushing is arranged in the connecting hole; and an elastic sealing member is also arranged between the plastic-encapsulated shell and the module bottom plate.

[0026] Specifically, the elastic sealing member is used to disperse the pressure exerted by the plastic package housing on the module bottom plate.

[0027] Beneficial effects of the utility model:

[0028] (1) The ultrasonic bonding terminal of the utility model has a simple structural design and adopts integrated stamping molding. The crimping part and the ultrasonic bonding part are firmly combined through the composite part, which ensures the stability and reliability of the product structure. The ultrasonic bonding terminal of the utility model realizes the excellent comprehensive performance of the overall material through design. The terminal has excellent conductivity, design flexibility, excellent corrosion resistance and excellent physical properties. At the same time, the terminal can be designed according to the application of the first material and the second material, and its molding thickness can be flexibly adjusted. There is no need for subsequent die-casting or machining to achieve the difference in thickness between the crimping part and the ultrasonic bonding part, and the processing cost is low.

[0029] (2) The ultrasonic bonding terminal of the utility model is formed by integrated stamping, and does not require mechanical riveting or welding, which greatly simplifies the manufacturing process of the terminal, significantly reduces the processing difficulty, reduces the processing cost, and improves the yield. The terminal of the utility model avoids the connection between the crimping part and the ultrasonic bonding part by riveting or welding, and the obtained terminal has higher reliability and lower manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of the structure of an ultrasonic bonding terminal designed for Example 1 of the utility model, wherein the ultrasonic bonding portion of the terminal is a "Z"-shaped structure;

[0032] Figure 2 This is a schematic diagram of the assembly of the ultrasonic bonding terminal and the PCB board in Example 1 of the utility model;

[0033] Figure 3 This is a schematic diagram of the structure of another ultrasonic bonding terminal provided by the utility model, in which the ultrasonic bonding portion of the terminal is an "L"-shaped structure;

[0034] Figures 4 to 10 This is a schematic diagram of the manufacturing process of the ultrasonic bonding terminal of Example 2 of the utility model;

[0035] Fig.11 This is a cross-sectional schematic diagram of a power module with a crimping function provided in Example 3 of the utility model.

[0036] Markings in the figure: 1-ultrasonic bonding terminal, 2-PCB board, 3-first plate material, 4-second plate material, 5-first embedded groove, 6-composite area, 7-second embedded groove, 8-composite plate material, 11-crimping part, 12-composite part, 13-ultrasonic bonding part, 10-module base plate, 20-DBC board, 30-semiconductor chip, 40-bonding wire, 50-insulating filling layer, 60-plastic package shell, 61-connecting hole, 62-bushing, 70-elastic seal, 80-solder, 90-screw. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the utility model and its application or use. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0038] In the description of the present utility model, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom" and the like indicate positions or positional relationships, which are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Moreover, the terms "first", "second" and the like are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein.

[0039] Example 1

[0040] like Figures 1 to 3 As shown, this embodiment 1 designs an ultrasonic bonding terminal. The ultrasonic bonding terminal 1 is a terminal with a crimping function and is an integrated stamping structure. Its structure is as shown in FIG. Figure 1 As shown, it includes:

[0041] The crimping portion 11 is used to connect with the PCB board 2 (the crimping portion 11 and the PCB board 2 adopt an interference fit), such as Figure 2 As shown;

[0042] a composite portion 12, which is electrically connected to the lower end of the crimping portion 11;

[0043] And an ultrasonic bonding portion 13, which is electrically connected to the lower end of the composite portion 12, and the ultrasonic bonding portion 13 presents a "Z"-shaped structure; in another embodiment, the ultrasonic bonding portion 13 may also present an "L"-shaped structure, such as Figure 3 As shown;

[0044] The material of the crimping portion 11 is a first material, and the material of the ultrasonic bonding portion 13 is a second material, and the hardness of the first material is greater than that of the second material;

[0045] The composite part 12 is a composite region 7 formed by the interface bonding of the first material and the second material at the atomic level; the thicknesses of the crimping part 11, the composite part 12 and the ultrasonic bonding part 13 are set to be different.

[0046] like Figures 4 to 10 As shown, a manufacturing method is provided for the ultrasonic bonding terminal of the above-mentioned embodiment 1, and the method comprises the following specific steps:

[0047] S1, providing a first plate 3 formed of a first material and a second plate 4 formed of a second material, and cleaning their surfaces;

[0048] S2, a first embedded groove 5 is opened on the front side of the first plate 3, and then the second plate 4 is filled into the first embedded groove 5, as shown in FIG. Figure 4 and Figure 5 As shown;

[0049] S3, hot rolling deformation and heat treatment are performed after filling to promote atomic transition and diffusion at the atomic level between the first plate 3 and the second plate 4, thereby forming an effective metallurgical bond at the interface and forming the composite region 6, such as Figure 6 As shown;

[0050] S4, a second embedded groove 7 is opened on the side of the first plate 3 opposite to the first embedded groove 5, and the second embedded groove 7 is connected to the first embedded groove 5 and a part of the composite area 6 at the bottom of the first embedded groove 5 is removed, and then the second plate 4 is filled into the second embedded groove 7. Figure 7 and Figure 8 As shown;

[0051] After filling, hot rolling deformation and heat treatment are continued to complete the firm combination of the first plate 3 and the second plate 4 to obtain a composite plate 8. Fig. 9 As shown;

[0052] S5, the composite sheet 8 is integrally stamped to obtain an ultrasonic bonding terminal blank. Specifically, the composite sheet 8 can be cut and then stamped. Fig.10 As shown;

[0053] S6. Bend the blank according to design requirements to obtain an ultrasonic bonding terminal 1.

[0054] Example 3

[0055] like Fig.11 As shown, this embodiment 3 provides a power module with a crimping function, and the power module includes:

[0056] Module base plate 10;

[0057] A plurality of DBC boards 20, which are respectively soldered to the module bottom plate 10 by solder 80;

[0058] A plurality of semiconductor chips 30, at least one semiconductor chip 30 is disposed on each DBC board 20 (the semiconductor chip 30 may also be soldered to the DBC board 20 by solder);

[0059] A plurality of bonding wires 40, one end of which is electrically connected to the semiconductor chip 30, and the other end of which is electrically connected to the DBC board 20 or another semiconductor chip 30;

[0060] A plurality of ultrasonic bonding terminals 1, wherein the ultrasonic bonding portion 13 is connected to the DBC board 20, and the crimping portion 11 extends in a direction away from the DBC board 20;

[0061] An insulating filling layer 50 is disposed on the module bottom plate 10. The insulating filling layer 50 is used to cover the DBC board 20, the semiconductor chip 30 and the bonding wire 40. The insulating filling layer 50 does not cover the crimping portion 11.

[0062] A plastic-encapsulated housing 60 is provided with a connection hole 61, a bushing 62 is provided in the connection hole 61, and the plastic-encapsulated housing 60 can be connected to the heat sink by inserting a screw 90 into the connection hole 61, and the module bottom plate 10 is in contact with the heat sink;

[0063] The module base plate 10 is assembled on the plastic shell 60, and an elastic sealing member 70 is also arranged between the plastic shell 60 and the module base plate 10, which can disperse the pressure of the plastic shell 60 on the module base plate 10. The DBC board 20, the semiconductor chip 30, the bonding wire 40, the ultrasonic bonding terminal 1 and the insulating filling layer 50 are all arranged inside the plastic shell 60, and the crimping portion 11 passes through the plastic shell 60 and extends to the outside thereof.

[0064] The above preferred embodiments of the utility model are only used to explain the utility model, and are not used to limit the utility model. Any obvious changes or modifications derived from the technical solution of the utility model are still within the protection scope of the utility model.

Claims

1. An ultrasonic bonding terminal, characterized in that: The ultrasonic bonding terminal (1) is a terminal with a crimping function and is an integrated stamping structure, comprising: A crimping portion (11) used for connecting to a PCB board (2); A composite portion (12) connected to the lower end of the crimping portion (11); and an ultrasonic bonding portion (13), which is connected to the lower end of the composite portion (12), and the ultrasonic bonding portion (13) includes at least one bending portion; The material of the crimping portion (11) is a first material, the material of the ultrasonic bonding portion (13) is a second material, and the hardness of the first material is greater than that of the second material; The composite part (12) is a composite area formed by the first material and the second material being bonded at the atomic level interface.

2. The ultrasonic bonding terminal according to claim 1, characterized in that: The crimping portion (11) and the PCB board (2) are in interference fit.

3. The ultrasonic bonding terminal according to claim 1, characterized in that: The ultrasonic bonding portion (13) is configured as a "Z"-shaped structure or an "L"-shaped structure.

4. The ultrasonic bonding terminal according to claim 1, characterized in that: The thicknesses of the crimping portion (11), the composite portion (12) and the ultrasonic bonding portion (13) are set to be different.

5. A power module with crimping function, characterized in that: The power module comprises the ultrasonic bonding terminal with crimping function as claimed in any one of claims 1 to 4.

6. A power module with crimping function according to claim 5, characterized in that: The power module comprises: Module base plate (10); A plurality of DBC boards (20) are respectively arranged on the module bottom plate (10); A plurality of semiconductor chips (30), with at least one semiconductor chip (30) being disposed on each DBC board (20); a plurality of bonding wires (40), one end of which is electrically connected to the semiconductor chip (30), and the other end of which is electrically connected to the DBC board (20) or another semiconductor chip (30); A plurality of ultrasonic bonding terminals (1), wherein the ultrasonic bonding portions (13) of the terminals are connected to the DBC board (20); An insulating filling layer (50) is disposed on the module base plate (10) and is used to cover the DBC plate (20), the semiconductor chip (30) and the bonding wire (40); A plastic-encapsulated shell (60) is provided with a connection hole (61) for connecting to a heat sink, the module base plate (10) is assembled on the plastic-encapsulated shell (60), and the DBC board (10), the semiconductor chip (30), the bonding wire (40), the ultrasonic bonding terminal (1) and the insulating filling layer (50) are arranged inside the plastic-encapsulated shell (60), and the crimping portion (11) passes through the plastic-encapsulated shell (60) and extends to the outside thereof.

7. A power module with crimping function according to claim 6, characterized in that: A bushing (62) is provided in the connecting hole (61); An elastic sealing member (70) is also provided between the plastic-encapsulated housing (60) and the module bottom plate (10).

Images