Insulation cooling fin for heat dissipation of power tube and power tube device comprising insulation cooling fin

Abstract

The invention discloses an insulation cooling fin for heat dissipation of a power tube and a power tube device comprising the insulation cooling fin, the insulation cooling fin comprises an insulation pressing plate and a heat conduction assembly embedded on the insulation pressing plate, the heat conduction assembly is used for connecting the power tube, and the insulation pressing plate is used for pressing the heat conduction assembly on a radiator; the heat conduction assembly comprises a non-metal insulation heat conduction block, and the non-metal insulation heat conduction block is configured to conduct heat of the power tube to the radiator and electrically isolate the power tube from the radiator. As the insulating pressing plate is only used for pressing each heat conduction assembly on the radiator, the insulating pressing plate occupying a large area does not need to have good heat conduction performance and can be made of a low-price material, the use amount of the insulating heat conduction material can be reduced, and the material cost is saved; in addition, the metal heat conduction block is embedded in the back face of the non-metal insulation heat conduction block, and the heat conduction capacity of the heat conduction assembly can be further improved on the premise that the high-voltage insulation capacity is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of power tubes, and in particular to an insulating heat sink for heat dissipation of a power tube and a power tube device containing the insulating heat sink. Background Art

[0002] Power tubes are a type of semiconductor device used to control and process higher power electrical energy. In high-power applications, power tubes generate heat when working. If the heat dissipation is poor, the device performance will be reduced or even damaged. Therefore, a thermally conductive insulating sheet is usually set between the power tube and the heat sink. It has thermal conductivity and electrical insulation properties, and can provide the necessary electrical isolation while ensuring heat dissipation efficiency.

[0003] Traditional thermal insulation sheets use ceramic gaskets. Small ceramic gaskets are sandwiched between each power tube and the heat sink. The power tube, ceramic gasket, and heat sink are provided with relatively aligned screw holes. The screws are screwed into the screw holes to tighten the power tube, ceramic gasket, and heat sink together, thereby achieving the functions of power tube insulation and heat dissipation. However, this thermal insulation method has poor insulation ability, and the long-term withstand voltage of the power tube is about 1000V. Obviously, as various types of power electronic converters develop towards higher power and higher voltage, this withstand voltage capability can no longer meet the demand.

[0004] To this end, the applicant proposed that each power tube share a large ceramic gasket. Since the use area of ​​the ceramic gasket is greatly increased, the insulation capacity of the power tube is greatly improved, and the long-term withstand voltage can reach 5000V to 10000V. When fully loaded at room temperature, the shell temperature of the power tube can reach about 90°C, and the heat dissipation capacity is strong. However, the use of a large area of ​​ceramic gaskets also greatly increases the material cost. For example, the cost of a ceramic gasket with an area of ​​228*80mm increases by about 200 yuan.

[0005] Therefore, the prior art lacks a low-cost thermally conductive insulating sheet that can improve the voltage resistance of the power tube. Summary of the invention

[0006] The embodiments of the present application solve the technical problem of high cost of thermally conductive insulating sheets capable of adapting to higher voltage resistance in the prior art by providing an insulating heat sink for power tube heat dissipation and a power tube device containing the same.

[0007] To solve the above technical problems, in a first aspect, an embodiment of the present application provides an insulating heat sink for heat dissipation of a power tube, comprising an insulating pressing plate and a heat conducting component embedded in the insulating pressing plate, wherein the heat conducting component is used to connect the power tube, and the insulating pressing plate is used to press the heat conducting component onto the heat sink;

[0008] The heat conduction assembly includes a non-metallic insulating heat conduction block, which is configured to conduct the heat of the power tube to the heat sink and electrically isolate the power tube from the heat sink.

[0009] Furthermore, the front side of the non-metallic insulating heat-conducting block is used to connect the power tube, and the back side of the non-metallic insulating heat-conducting block is embedded with a metal heat-conducting block.

[0010] Furthermore, the insulating pressing plate is provided with a window penetrating along the thickness direction thereof, and the insulating pressing plate is provided with a pressing edge extending into the window;

[0011] When the insulating pressing plate is pressed against the heat sink, the pressing edge simultaneously presses the heat conducting component against the heat sink.

[0012] Furthermore, the back side of the non-metallic insulating thermally conductive block is recessed toward itself to form a groove with a bottom, and the groove is used to install the metal thermally conductive block. After the metal thermally conductive block is embedded in the groove, the metal thermally conductive block is flush with the back side of the non-metallic insulating thermally conductive block.

[0013] Furthermore, one side of the embedding groove extends to the edge of the back side of the non-metallic insulating heat-conducting block to form a side opening.

[0014] Furthermore, a temperature measuring hole is provided on the insulating pressing plate, the temperature measuring hole is connected to the window, the temperature measuring hole is used to place a temperature measuring head, and the temperature measuring head detects the temperature of the metal heat conductive block.

[0015] Furthermore, the insulating pressing plate is provided with a first connection hole for connecting to the heat sink, and the heat conducting component is provided with a second connection hole for connecting to the power tube;

[0016] The insulating pressing plate is fixedly connected to the heat sink by a first screw, and the heat conducting component is pressed tightly onto the heat sink;

[0017] The power tube is fixedly connected to the heat conducting component via a second screw.

[0018] Furthermore, the first connection hole is a plain through hole, the first screw passes through the first connection hole and is threadedly connected to the heat sink, and the insulating pressing plate is pressed onto the heat sink by the first screw.

[0019] Furthermore, the second connection hole is a blind hole, and the second connection hole is a threaded hole, and the second screw passes through the power tube and is screwed into the second connection hole, so as to tighten the power tube onto the insulating heat sink.

[0020] In a second aspect, an embodiment of the present application provides a power tube device, comprising a heat sink, a power tube, and an insulating heat sink as described in any one of the first aspects, and the insulating heat sink is arranged between the heat sink and the power tube.

[0021] In the embodiment of the present application, the insulating heat sink is assembled by an insulating pressure plate and a thermally conductive component, wherein the insulating heat sink transfers the heat of the power tube to the heat sink through the thermally conductive component and provides an electrical isolation function, and the insulating pressure plate is only used to press each thermally conductive component onto the heat sink. Therefore, the insulating pressure plate that occupies a large area is not required to have good thermal conductivity and can be made of inexpensive materials, which can reduce the use of insulating thermally conductive materials and thus save material costs. In addition, by embedding a metal thermally conductive block on the back of the non-metallic insulating thermally conductive block, since the thermal conductivity of the metal is more than 10 times that of the non-metal, while ensuring the high voltage insulation capacity, the thermal conductivity of the thermally conductive component is further improved, and a high-voltage and high-power power supply system can be reliably realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 is a schematic diagram of the structure of a power tube device in an embodiment of the present application;

[0024] Figure 2 It is a front view schematic diagram of an insulating heat sink in an embodiment of the present application;

[0025] Figure 3 It is a schematic diagram of the back side of the insulating heat sink in an embodiment of the present application;

[0026] Figure 4 It is a front view schematic diagram of a non-thermal conductive insulating pressing plate in an embodiment of the present application;

[0027] Figure 5 It is a schematic diagram of the back side of the non-thermal conductive insulating pressing plate in an embodiment of the present application;

[0028] Figure 6 It is a front view schematic diagram of a heat conducting component in an embodiment of the present application;

[0029] Figure 7 It is a schematic diagram of the back side of the heat conducting component in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The embodiments of the present application solve the technical problem of high cost of thermally conductive insulating sheets capable of adapting to higher voltage resistance in the prior art by providing an insulating heat sink for power tube heat dissipation and a power tube device containing the same.

[0031] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] Figure 1 is a schematic diagram of the structure of a power tube device in an embodiment of the present application, such as Figure 1 The power tube 300 device includes a heat sink 100, a power tube 300, and an insulating heat sink 200 disposed between the heat sink 100 and the power tube 300. The power tube 300 may be a MOS tube, an IGBT tube, etc. The heat sink 100 is used to dissipate heat from the power tube 300 and is generally a metal heat sink, such as an aluminum heat sink. The insulating heat sink 200 improves the efficiency of heat transfer from the power tube 300 to the heat sink 100 on the one hand, and provides electrical isolation on the other hand.

[0033] Figure 2 is a front view of an insulating heat sink 200 in an embodiment of the present application. Figure 3 is a schematic diagram of the back side of the insulating heat sink 200 in an embodiment of the present application, such as Figures 2-3 As shown, the insulating heat sink 200 includes an insulating plate 210 and a heat-conducting component 220 embedded in the insulating plate 210. When a plurality of heat-conducting components 220 are arranged on the insulating plate 210, each heat-conducting component 220 is arranged at intervals on the insulating plate 210. The insulating plate 210 is provided with a first connection hole 212 for connecting with the heat sink 100, and the heat-conducting component 220 is provided with a second connection hole 223 for connecting with the power tubes 300 one by one.

[0034] The first connecting hole 212 is a through hole, and the first connecting hole 212 is an unthreaded hole (bright hole). The radiator 100 is provided with a third connecting hole corresponding to the first connecting hole 212, and the third connecting hole is a threaded hole. The first screw 400 passes through the first connecting hole 212 and is then threadedly connected to the third connecting hole of the radiator 100. The insulating pressing plate 210 is pressed onto the radiator 100 by the head of the first screw 400. Since the first connecting hole 212 is an unthreaded hole, the first screw 400 passes through the first connecting hole 212 and is directly threadedly connected to the radiator 100, which makes installation simpler and more convenient.

[0035] The second connection hole 223 is a blind hole, and the second connection hole 223 is a threaded hole. The second screw passes through the power tube 300 and is screwed into the second connection hole 223, so that the power tube 300 is tightened on the insulating heat sink 200. Since the second connection hole 223 is a blind hole, the second screw cannot penetrate the insulating heat sink 200, thereby achieving better heat dissipation and insulation effects.

[0036] In addition, since the heat sink 100, the power tube 300 and the insulating heat sink 200 are not connected by the same screw, a large voltage difference will not be generated between the semiconductor part of the power tube 300 and the heat sink 100, and the power tube 300 will not be directly grounded due to the grounding of the heat sink 100.

[0037] In addition, since the insulating pressure plate 210 is only used to press each thermal conductive component 220 onto the heat sink 100, the insulating heat sink 200 transfers the heat of the power tube 300 thereon to the heat sink 100 through the thermal conductive component 220 and provides an electrical isolation function. Therefore, the insulating pressure plate 210 occupying a larger area is not required to have good thermal conductivity (but requires insulation), and can be made of low-cost insulating materials to reduce the use of insulating thermal conductive materials, thereby saving material costs.

[0038] Specifically, the insulating plate 210 can be made of hard, low-cost, non-thermal conductive insulating materials, such as epoxy resin boards (such as FR-4 epoxy boards), plastics, etc. Taking the FR-4 epoxy board as an example, based on the use area of ​​228*80mm, the cost can be reduced by about 100 yuan compared with the ceramic gasket of the same area in the prior art. Even if the cost of the thermal conductive component 220 is included, the cost can be reduced by about 90 yuan due to the small amount of use of the thermal conductive component 220 and the low cost.

[0039] Figure 4 is a front view of the insulating pressing plate 210 in an embodiment of the present application, Figure 5 is a schematic diagram of the back side of the insulating pressing plate 210 in an embodiment of the present application, such as Figures 4-5 As shown, the insulating pressure plate 210 is in the form of a sheet, and is provided with one or more rectangular windows 211 extending through the insulating pressure plate 210 along its thickness direction, and a pressing edge 213 extending into the window 211 is provided on the front side of the insulating pressure plate 210. When the insulating pressure plate 210 is screwed onto the heat sink 100 by the first screw 400, the pressing edge 213 simultaneously presses the heat conducting component 220 onto the heat sink 100.

[0040] Figure 6 is a front view of a heat conducting component 220 in an embodiment of the present application. Figure 7 is a schematic diagram of the back side of the heat conducting component 220 in an embodiment of the present application. Figures 6-7As shown, the heat-conducting component 220 includes a non-metallic insulating heat-conducting block 221 and a metal heat-conducting block 222 embedded on the back side of the non-metallic insulating heat-conducting block 221, and the second connecting hole 223 is staggered with the metal heat-conducting block 222 and arranged on the front side of the non-metallic insulating heat-conducting block 221.

[0041] The non-metallic insulating heat-conducting block 221 can be in the shape of a thin block such as a rectangle or a square that is easy to process, and the material can be alumina ceramics, zirconium oxide ceramics, aluminum nitride ceramics, silicon nitride ceramics, zirconium nitride ceramics, silicon carbide ceramics, etc. The non-metallic insulating heat-conducting block 221 can also be in the shape of a thin block such as a rectangle or a square that is easy to process, and the material can be copper, aluminum, etc.

[0042] Of course, in some embodiments of the present application, the non-metallic insulating heat conductive block 221 may not be provided with a metal heat conductive block 222. It has been verified that the non-metallic insulating heat conductive block 221 on the heat conductive assembly 220 can achieve a long-term withstand voltage of 5000V to 10000V without a metal heat conductive block 222. When the room temperature is fully loaded, the power tube shell temperature can reach about 90°C, and the heat dissipation capacity is relatively strong. When a metal heat conductive block 222 is provided on the non-metallic insulating heat conductive block 221, the insulation capacity can reach a long-term withstand voltage of 5000V to 10000V, and when the room temperature is fully loaded, the power tube shell temperature can reach about 80°C, and the heat dissipation capacity is very strong.

[0043] It can be seen that by embedding the metal heat-conducting block 222 on the back of the non-metallic insulating heat-conducting block 221, since the thermal conductivity of metal is more than 10 times that of non-metal, the thermal conductivity of the heat-conducting component 220 is further improved under the premise of ensuring high voltage insulation capacity, and a high-voltage and high-power power supply system can be reliably realized. At the same time, in the entire insulating heat sink 200, the non-metallic insulating heat-conducting block 221 has the highest cost, but because the use area is small and the size can be adjusted according to different insulation voltage requirements, the production cost can be reduced while ensuring that the insulation voltage requirements are met.

[0044] like Figures 6-7 As shown, the back portion of the non-metallic insulating heat conductive block 221 is recessed inward to form a groove with a bottom. After the metal heat conductive block 222 is embedded in the groove, the metal heat conductive block 222 is flush with the back of the non-metallic insulating heat conductive block 221, so as to facilitate good contact between the heat conductive component 220 and the heat sink 100, and the groove is not penetrated, so that the non-metallic insulating heat conductive block 221 isolates the power tube and the metal heat conductive block 222. Of course, the back of the metal heat conductive block 222 and the non-metallic insulating heat conductive block 221 may not be flush, and the gap is eliminated by applying a thermal conductive silicone grease coating (see below for details).

[0045] In addition, in order to facilitate the embedding of the metal heat conductive block 222 into the embedding groove, a portion of the back surface of the non-metallic insulating heat conductive block 221 can be dug out along one side edge of the back surface toward the middle of the back surface to form an embedding groove with a side opening. In this way, the metal heat conductive block 222 can be embedded into the embedding groove with the cooperation of the side opening and the embedding groove notch, which is more convenient and efficient. Of course, the side opening may not be provided, and this is not limited here.

[0046] In one embodiment of the present application, Figures 1 to 5 As shown, the insulating pressure plate 210 is also provided with a temperature measuring hole 214 which penetrates along its own thickness direction, the temperature measuring hole 214 is connected to the rectangular window 211, and the temperature measuring hole 214 is adjacent to the metal heat-conducting block 222 of the heat-conducting component 220 in the window 211, and the temperature measuring hole 214 is used to place a temperature measuring head, and the temperature measuring head is used to detect the temperature of the metal heat-conducting block 222, so as to indirectly obtain the temperature of the power tube 300. Since the metal heat-conducting block has fast heat transfer, the timeliness and sensitivity of indirectly obtaining the temperature of the power tube 300 by detecting the temperature of the metal heat-conducting block 222 are better.

[0047] In one embodiment of the present application, thermal interface materials are filled between the heat sink 100 and the insulating heat sink 200, between the thermal conductive component 220 and the power tube 300, and between the non-metallic insulating thermal conductive block 221 and the metal thermal conductive block 222. The thermal interface materials can eliminate gaps, thereby further improving the insulation and heat dissipation effects to better meet the high-voltage insulation requirements above 2000V.

[0048] The thermal interface material is a thermally conductive silicone grease coating applied on the radiator 100, the insulating heat sink 200, and the power tube 300. Thermally conductive silicone grease is also called heat dissipation paste or thermal conductive paste. It is a thermally conductive silicone grease-like compound made of organic silicone as the main raw material and added with materials with excellent heat resistance and thermal conductivity. It is mainly used for heat conduction and heat dissipation of electronic components, such as power amplifiers, transistors, electron tubes, CPUs, etc., so as to ensure the stability of the electrical performance of electronic instruments and meters.

[0049] It should be understood that although the terms "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are used only to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit without departing from the scope of the exemplary embodiments.

[0050] The directional terms such as outer, middle, inner, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0051] The above is only a preferred embodiment of the present application, and is not any formal or substantial limitation to the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present application, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the substantial technology of the present application are still within the scope of the technical solution of the present application.

Claims

1. An insulating heat sink for power tube heat dissipation, characterized in that: It comprises an insulating pressing plate (210) and a heat-conducting component (220) embedded in the insulating pressing plate (210), wherein the heat-conducting component (220) is used to connect a power tube (300), and the insulating pressing plate (210) is used to press the heat-conducting component (220) onto the heat sink (100); The heat conduction component (220) comprises a non-metallic insulating heat conduction block (221), and the non-metallic insulating heat conduction block (221) is configured to conduct the heat of the power tube (300) to the heat sink (100) and electrically isolate the power tube (300) and the heat sink (100).

2. The insulating heat sink for heat dissipation of a power tube as claimed in claim 1, characterized in that: The front side of the non-metallic insulating heat-conducting block (221) is used for connecting the power tube (300), and a metal heat-conducting block (222) is embedded on the back side of the non-metallic insulating heat-conducting block (221).

3. The insulating heat sink for heat dissipation of a power tube as claimed in claim 1, characterized in that: The insulating pressing plate (210) is provided with a window (211) penetrating along the thickness direction thereof, and the insulating pressing plate (210) is provided with a pressing edge (213) extending into the window (211); When the insulating pressing plate (210) is pressed onto the heat sink (100), the pressing edge (213) simultaneously presses the heat conducting component (220) onto the heat sink (100).

4. The insulating heat sink for heat dissipation of a power tube as claimed in claim 2, characterized in that: The back side of the non-metallic insulating heat-conducting block (221) is recessed toward itself to form an embedding groove with a bottom, and the embedding groove is used to install the metal heat-conducting block (222).

5. The insulating heat sink for heat dissipation of a power tube as claimed in claim 4, characterized in that: One side of the embedding groove extends to the edge of the back side of the non-metallic insulating heat-conducting block (221) to form a side opening.

6. The insulating heat sink for heat dissipation of a power tube as claimed in claim 3, characterized in that: The insulating pressing plate (210) is also provided with a temperature measuring hole (214), the temperature measuring hole (214) being in communication with the window (211), and the temperature measuring hole (214) being used to place a temperature measuring head, the temperature measuring head detecting the temperature of the metal heat conducting block (222).

7. The insulating heat sink for heat dissipation of a power tube as claimed in claim 1, characterized in that: The insulating pressing plate (210) is provided with a first connection hole (212) for connecting to the heat sink (100), and the heat conducting component (220) is provided with a second connection hole (223) for connecting to the power tube (300); The insulating pressing plate (210) is fixedly connected to the heat sink (100) by means of a first screw (400), and the heat conduction component (220) is pressed against the heat sink (100); the power tube (300) is fixedly connected to the heat conduction component (220) by means of a second screw.

8. The insulating heat sink for heat dissipation of a power tube as claimed in claim 7, characterized in that: The first connection hole (212) is a plain through hole, the first screw (400) passes through the first connection hole (212) and is threadedly connected to the heat sink (100), and the insulating pressing plate (210) is pressed onto the heat sink (100) by the first screw (400).

9. The insulating heat sink for heat dissipation of a power tube as claimed in claim 8, characterized in that: The second connection hole (223) is a blind hole, and the second connection hole (223) is a threaded hole, and the second screw passes through the power tube (300) and is screwed into the second connection hole (223), thereby tightening the power tube (300) onto the insulating heat sink (200).

10. A power tube device, characterized in that: It comprises a heat sink (100), a power tube (300), and an insulating heat sink (200) according to any one of claims 1 to 9, wherein the insulating heat sink (200) is arranged between the heat sink (100) and the power tube (300).

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