Pressure balancing clamp for crimping type IGBT (Insulated Gate Bipolar Translator) device

Abstract

The utility model belongs to the field of pressure fixtures, and particularly discloses a pressure balancing fixture for a crimping type IGBT (Insulated Gate Bipolar Translator) device. According to the application, the universal ball is additionally arranged between the top pressing plate and the displacement compensation assembly, the ball body of the universal ball is matched with the groove in the lower surface of the top pressing plate / the groove in the upper surface of the displacement compensation assembly and forms point contact, and when the top pressing plate is subjected to uneven mechanical pressure, the uneven mechanical pressure is reduced through the point contact of the universal ball and the groove; when the IGBT chip is clamped by the clamp, pressure is applied to the displacement compensation assembly, so that when the clamp clamps the IGBT chip, the pressure is uniformly applied to the parallel chips, and the IGBT chip is prevented from being damaged and faulted due to unbalanced mechanical pressure. Pressure sensors are additionally arranged on the universal ball and the displacement compensation assembly, the pressure sensors are fixedly connected with the upper assembly and the lower assembly, it can be ensured that the pressure sensors are located at the geometric center position of the crimping clamp, meanwhile, the mechanical pressure applied to the crimping IGBT chip can be displayed in real time, and a basis is provided for guaranteeing pressure saturation of a device.

Description

Technical Field

[0001] The present application belongs to the field of pressure fixtures, and more specifically, relates to a pressure equalization fixture for press-fit IGBT devices. Background Art

[0002] High-voltage, high-capacity flexible direct current transmission systems (HVDCs) supporting large-scale renewable energy transmission are key technologies for building a new power system dominated by renewable energy. Press-fit IGBTs are core components of HVDC converter valves. Press-fit IGBTs use mechanical pressure to press-fit the IGBT chip, molybdenum sheet, silver gasket, copper block, and gate spring pins, achieving electrical connections and heat dissipation. Contact thermal resistance accounts for 50% of the total thermal resistance of press-fit IGBTs. Uneven pressure can lead to uneven current distribution and temperature variations among parallel chips, as well as IGBT chip damage, easily causing press-fit IGBT failures. Pressure balance is crucial for ensuring reliable operation of press-fit IGBTs. Currently, press-fit IGBTs with double-sided heat dissipation use a rigid press-fit package. Even slight thickness variations between the individual package components of parallel chips can lead to device failure, necessitating balanced pressure application across the IGBT device. Furthermore, press-fit fixtures for IGBT devices lack real-time pressure sensing, preventing them from understanding the mechanical stress being applied to the chip. A press-fit fixture with real-time pressure sensing is urgently needed. Utility Model Content

[0003] In view of the defects of the prior art, the purpose of this application is to provide a pressure equalization clamp for press-fit IGBT devices, aiming to solve the problems of uneven pressure and inability to perceive real-time pressure in existing press-fit clamps.

[0004] To achieve the above objectives, in a first aspect, the present application provides a pressure equalization fixture for a press-fit IGBT device, comprising: a top pressure plate and a bottom plate, the top pressure plate and the bottom plate being arranged longitudinally corresponding to each other, and the opposing surfaces thereof being connected by a top pressure guide rod;

[0005] The top plate and the bottom plate are coaxially arranged in sequence: a universal ball, a displacement compensation component and a heat dissipation component;

[0006] The universal ball comprises a sphere and a base, and the sphere is located in the center of the fixture;

[0007] The sphere matches the groove on the lower surface of the top pressure plate and forms a point contact, and the base is tightly connected to the upper surface of the displacement compensation component, or the sphere matches the groove on the upper surface of the displacement compensation component and forms a point contact, and the base is tightly connected to the lower surface of the top pressure plate;

[0008] The heat dissipation assembly is used to clamp and fix the press-fit type IGBT device.

[0009] To achieve the above-mentioned purpose, in a second aspect, the present application provides a pressure equalization fixture for a press-fit type IGBT device, comprising: a top pressure plate and a bottom plate, wherein the top pressure plate and the bottom plate are arranged longitudinally corresponding to each other, and the opposite surfaces are connected by a top pressure guide rod;

[0010] The top plate and the bottom plate are coaxially arranged in sequence: a universal ball, a pressure sensor, a displacement compensation component and a heat dissipation component;

[0011] The universal ball comprises a sphere and a base, and the sphere is located in the center of the fixture;

[0012] The sphere matches the groove on the lower surface of the top pressure plate and forms point contact, the base is tightly connected to the upper surface of the pressure sensor, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly, or the sphere matches the groove on the upper surface of the pressure sensor and forms point contact, the base is tightly connected to the lower surface of the top pressure plate, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly;

[0013] The heat dissipation assembly is used to clamp and fix the press-fit type IGBT device.

[0014] Preferably, another universal ball is provided between the pressure sensor and the displacement compensation assembly. The ball of the universal ball is located in the center of the fixture and matches the groove on the upper surface of the displacement compensation assembly to form point contact. The base is firmly connected to the lower surface of the pressure sensor.

[0015] Preferably, the depth of the universal ball embedded in the groove does not exceed 1 / 3 of the ball.

[0016] Preferably, the hardness of the sphere is not less than HRB40.

[0017] Preferably, a displacement compensation component is further provided between the heat dissipation component and the base plate.

[0018] Preferably, the displacement compensation assembly comprises: a disc spring upper flat washer, a plurality of disc springs, a disc spring lower flat washer and an insulating plate provided with a guide rod;

[0019] The disc spring upper flat washer, a plurality of disc springs and the disc spring lower flat washer are concentrically assembled on the guide rod on the insulating plate.

[0020] Preferably, the displacement compensation assembly further comprises: a supporting fixing plate for axially supporting and fixing the flat washer on the disc spring.

[0021] Preferably, the heat dissipation assembly is three parallel water-cooling plates, which are used to perform water cooling on the clamped and fixed press-fit IGBT devices and provide electrical connection ports.

[0022] Preferably, the pressing guide rod is a screw made of epoxy resin material.

[0023] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies:

[0024] (1) The present application provides a pressure-equalizing fixture for press-fit IGBT devices, in which a universal ball is added between a top pressure plate and a displacement compensation assembly. The sphere of the universal ball matches the groove on the lower surface of the top pressure plate / the upper surface of the displacement compensation assembly and forms a point contact. When the top pressure plate is subjected to uneven mechanical pressure, the uneven mechanical pressure is applied to the displacement compensation assembly through the point contact between the universal ball and the groove. Then, when the fixture is clamped, pressure is evenly applied to each parallel chip, ensuring that the IGBT chip will not be damaged or malfunctioned due to uneven mechanical pressure.

[0025] (2) The present application provides a pressure equalization fixture for press-fit IGBT devices. By adding a pressure sensor to the universal ball and displacement compensation assembly, the pressure sensor is tightly connected to the upper and lower assemblies, which can ensure that the pressure applied to the pressure sensor is at the geometric center position of the press-fit fixture. At the same time, the mechanical pressure applied to the press-fit IGBT chip can be displayed in real time, providing a basis for ensuring the pressure saturation of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an exploded view of a pressure equalization fixture for a press-fit IGBT device provided in an embodiment of the present application.

[0027] Figure 2 This is an exploded view of another pressure equalization fixture for press-fit IGBT devices provided in an embodiment of the present application.

[0028] Figure 3 This is a schematic diagram of the universal ball pressure equalization principle provided in an embodiment of the present application.

[0029] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0030] 1-top pressure plate, 2-bottom plate, 3-universal ball, 4-displacement compensation assembly, 5-heat dissipation assembly, 6-pressure sensor, 301-sphere, 302-base, 401-support fixing plate, 402-disc spring upper flat washer, 403-disc spring, 404-disc spring lower flat washer, 405-insulation plate, 501-water cooling plate. DETAILED DESCRIPTION

[0031] For ease of understanding, the English abbreviations and related technical terms involved in the embodiments of this application are explained and described below.

[0032] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0033] like Figure 1 As shown, the present application provides a pressure equalization fixture for a press-fit type IGBT device, comprising: a top pressure plate 1 and a bottom plate 2, wherein the top pressure plate and the bottom plate are arranged correspondingly in the longitudinal direction, and the opposite surfaces are connected by a top pressure guide rod (not shown);

[0034] The top plate 1 and the bottom plate 2 are coaxially arranged in sequence: a universal ball 3, a displacement compensation component 4 and a heat dissipation component 5;

[0035] The universal ball 3 includes a sphere 301 and a base 302, and the sphere is located in the center of the fixture;

[0036] The sphere 301 matches the groove on the lower surface of the top pressure plate 1 and forms a point contact, and the base 302 is fastened to the upper surface of the displacement compensation component 4. Alternatively, the sphere 301 matches the groove on the upper surface of the displacement compensation component 4 and forms a point contact, and the base 302 is fastened to the lower surface of the top pressure plate 1;

[0037] The heat dissipation assembly 4 is used to clamp and fix the press-fit type IGBT device.

[0038] It should be noted that the top pressure plate 1 and the bottom plate 2 are made of a material with a lower density, such as aluminum alloy, to reduce the overall weight of the IGBT clamp. At the same time, the material has a high hardness and will not be damaged.

[0039] It should be noted that the surface of the steel ball is smooth and can easily deviate from the geometric center of the press-fit IGBT device during installation, making it easy for it to slip out of the press-fit assembly. Therefore, a universal ball is preferred in this application. A universal ball is a sphere embedded in the inner cavity of the raceway seat, allowing it to roll freely in the raceway without popping out. Its upper surface is a spherical structure, and the lower surface of the roller seat is a flat structure. It can withstand large loads and torques, has the advantages of flexible rolling, and can play the role of support, connection, and rotation.

[0040] A small diameter "ball bowl" shaped groove is machined in the geometric center of the top pressure plate. When installing and pressing the IGBT device, this groove will cooperate with the universal ball, so that the universal ball is in the center of the clamp, ensuring that the pressure applied after pressing is applied from the center of the clamp to the surface of the device. In one embodiment, there are three top pressure guide rods, evenly distributed on the circle where the outer diameter of the IGBT device is located. Mechanical pressure is applied by tightening the nuts on the top pressure guide rods. Figure 2As shown, since the nuts are at the vertices of the triangle, when the three nuts are tightened separately, the top pressure plate will deviate in different directions, and the top pressure plate will be subjected to uneven mechanical pressure. However, the uneven mechanical pressure will be applied to the lower component through the point contact between the universal ball and the groove of the top pressure plate. Due to the existence of the universal ball, the lower component will be subjected to uniform mechanical pressure. Therefore, the mechanical pressure on the crimped IGBT device is balanced.

[0041] On the other hand, Figure 3 As shown, the present application provides a pressure equalization fixture for a press-fit type IGBT device, comprising: a top pressure plate 1 and a bottom plate 2, wherein the top pressure plate 1 and the bottom plate 2 are arranged longitudinally corresponding to each other, and the opposite surfaces are connected by a top pressure guide rod (not shown);

[0042] The top plate and the bottom plate are coaxially arranged in sequence: a universal ball 3, a pressure sensor 6, a displacement compensation component 4 and a heat dissipation component 5;

[0043] The universal ball comprises a sphere and a base, and the sphere is located in the center of the fixture;

[0044] The sphere matches the groove on the lower surface of the top pressure plate and forms point contact, the base is tightly connected to the upper surface of the pressure sensor, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly, or the sphere matches the groove on the upper surface of the pressure sensor and forms point contact, the base is tightly connected to the lower surface of the top pressure plate, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly;

[0045] The heat dissipation assembly is used to clamp and fix the press-fit type IGBT device.

[0046] Specifically, the pressure sensor consists of a force sensor and a control instrument. The force sensor uses the piezoelectric effect to measure pressure. When external pressure acts on the device, the piezoelectric material generates an electric charge. The pressure is measured by measuring the amount of charge generated. The control instrument requires a 220V power supply, and the instrument displays the specific pressure value in real time through a four-digit digital tube. The upper and lower surfaces of the pressure sensor are both flat. The lower surface of the pressure sensor is fastened to the upper surface of the displacement compensation component (for example, by screws and internal threads). The upper surface of the pressure sensor is fastened to the lower surface of the universal ball to ensure that the pressure applied to the sensor is at the geometric center of the crimping fixture.

[0047] Preferably, another universal ball is provided between the pressure sensor 6 and the displacement compensation component 4. The ball 301 of the universal ball is located in the center of the fixture and matches the groove on the upper surface of the displacement compensation component 4 to form point contact. The base 302 is firmly connected to the lower surface of the pressure sensor 6.

[0048] Preferably, the depth of the universal ball embedded in the groove does not exceed 1 / 3 of the ball.

[0049] It should be noted that the embedding depth will affect the area of ​​point contact. The greater the embedding depth, the larger the contact area of ​​the sphere, which may result in non-point contact between the universal ball and the top pressure plate. Therefore, this application preferably does not exceed 1 / 3.

[0050] Preferably, the hardness of the sphere is not less than HRB40.

[0051] It should be noted that, because the pressure applied during the crimping process is relatively large (above 10kN), the point contact causes the sphere to be subjected to a very large pressure. If the hardness is not enough, the sphere will be cracked or even crushed. Therefore, the preferred hardness of this application is not lower than HRB40.

[0052] Preferably, a displacement compensation component 4 is further provided between the heat dissipation component 5 and the base plate 2 .

[0053] Preferably, the displacement compensation assembly 4 includes: a disc spring upper flat washer 402, a plurality of disc springs 403, a disc spring lower flat washer 404 and an insulating plate 405 provided with a guide rod;

[0054] The disc spring upper flat washer, a plurality of disc springs and the disc spring lower flat washer are concentrically assembled on the guide rod on the insulating plate.

[0055] It should be noted that the clamp applies pressure via disc springs on the upper and lower sides. This compresses the disc springs, creating deformation that applies axial static loads at their upper inner and lower outer edges. Nuts secure the deformed disc springs to the module interior to store energy. The disc springs can be stacked to achieve a higher load on the crimped IGBT device under the same deformation.

[0056] It should be noted that the upper flat washer 402 of the disc spring and the lower flat washer 404 of the disc spring can increase the contact area between the disc spring and other plates, prevent the material surface from being deformed or damaged due to excessive force, and fill the gap between the disc spring and other plates, thereby playing a role in adjusting the distance.

[0057] Preferably, the displacement compensation assembly 4 further includes: a supporting fixing plate 401 for axially supporting and fixing the flat washer 402 on the disc spring.

[0058] It should be noted that the support fixing plate and the pressure sensor are in planar contact. To ensure that the center position does not shift during installation, screws and internal threads are used to fasten the support fixing plate and the pressure sensor.

[0059] Preferably, the heat dissipation assembly 5 is three parallel water-cooling plates 501, which are used to perform water cooling on the clamped and fixed press-fit IGBT devices and provide electrical connection ports.

[0060] The heat dissipation assembly can also be of other types such as air cooling, and can also be fin-shaped. In this application, flat water cooling is preferred. The press-fit IGBT device is placed between water cooling plates for double-sided heat dissipation. The upper bridge press-fit IGBT device is placed between the two upper water cooling plates, and the lower bridge IGBT device is placed between the two lower water cooling plates. The middle water cooling plate is shared by the two press-fit IGBT devices.

[0061] Preferably, the pressing guide rod is a screw made of epoxy resin material.

[0062] It should be noted that the screw connects the entire crimped IGBT fixture longitudinally, and the nut tightens on the screw to flexibly apply clamping force to the IGBT device. At the same time, the collector and emitter potentials of the crimped IGBT are relatively high, and this potential changes with the device's switching frequency. Therefore, the installation of the screw requires consideration of insulation from the high potential of the device. Using epoxy resin materials with a high insulation grade to manufacture the screw can increase the breakdown voltage level between the screw and the device, thereby enhancing safety.

[0063] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0064] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0065] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0066] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0067] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A pressure equalization fixture for a press-fit IGBT device, characterized in that: include: A top pressure plate and a bottom plate, the top pressure plate and the bottom plate are arranged longitudinally corresponding to each other, and the opposite surfaces are connected by a top pressure guide rod; The top plate and the bottom plate are coaxially arranged in sequence: a universal ball, a displacement compensation component and a heat dissipation component; The universal ball comprises a sphere and a base, and the sphere is located in the center of the fixture; The sphere matches the groove on the lower surface of the top pressure plate and forms a point contact, and the base is tightly connected to the upper surface of the displacement compensation component, or the sphere matches the groove on the upper surface of the displacement compensation component and forms a point contact, and the base is tightly connected to the lower surface of the top pressure plate; The heat dissipation assembly is used to clamp and fix the press-fit type IGBT device.

2. A pressure equalization fixture for press-fit IGBT devices, characterized in that: include: A top pressure plate and a bottom plate, the top pressure plate and the bottom plate are arranged longitudinally corresponding to each other, and the opposite surfaces are connected by a top pressure guide rod; The top plate and the bottom plate are coaxially arranged in sequence: a universal ball, a pressure sensor, a displacement compensation component and a heat dissipation component; The universal ball comprises a sphere and a base, and the sphere is located in the center of the fixture; The sphere matches the groove on the lower surface of the top pressure plate and forms point contact, the base is tightly connected to the upper surface of the pressure sensor, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly, or the sphere matches the groove on the upper surface of the pressure sensor and forms point contact, the base is tightly connected to the lower surface of the top pressure plate, and the lower surface of the pressure sensor is tightly connected to the upper surface of the displacement compensation assembly; The heat dissipation assembly is used to clamp and fix the press-fit type IGBT device.

3. The pressure equalizing fixture according to claim 2, wherein: Another universal ball is provided between the pressure sensor and the displacement compensation assembly. The ball of the universal ball is located in the center of the fixture and matches the groove on the upper surface of the displacement compensation assembly to form point contact. The base is firmly connected to the lower surface of the pressure sensor.

4. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: The depth of the universal ball embedded in the groove does not exceed 1 / 3 of the ball.

5. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: The hardness of the sphere is not less than HRB40.

6. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: A displacement compensation component is also provided between the heat dissipation component and the base plate.

7. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: The displacement compensation assembly includes: a disc spring upper flat washer, a plurality of disc springs, a disc spring lower flat washer and an insulating plate provided with a guide rod; The disc spring upper flat washer, a plurality of disc springs and the disc spring lower flat washer are concentrically assembled on the guide rod on the insulating plate.

8. The pressure equalizing fixture according to claim 7, wherein: The displacement compensation assembly also includes: a supporting fixing plate, which is used to axially support and fix the flat washer on the disc spring.

9. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: The heat dissipation assembly is three parallel water-cooling plates, which are used to perform water cooling on the clamped and fixed press-fit IGBT devices and provide electrical connection ports.

10. The pressure equalizing fixture according to any one of claims 1 to 3, characterized in that: The top pressure guide rod is a screw made of epoxy resin material.

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