MOS tube fixing structure

Abstract

The utility model provides an MOS tube fixing structure. The MOS tube fixing structure comprises an MOS tube; a fixing hole is formed in the heat dissipation substrate in the vertical direction; the insulating heat-conducting gasket is arranged between the MOS tube and the heat dissipation substrate, a through hole is formed in the insulating heat-conducting gasket in the vertical direction, and the through hole and the fixing hole are correspondingly and coaxially formed; the fastening piece comprises a connecting column part and a connecting piece part, the connecting piece part is pressed on the side, away from the insulating heat-conducting gasket, of the MOS tube, and the connecting column part sequentially penetrates through the through hole and the fixing hole to sequentially press the MOS tube and the insulating heat-conducting gasket on the heat dissipation substrate. Through the above structure, the MOS tube can be fixed without installing an external fixing device, the installation space is saved, the creepage distance between the MOS tube and the heat dissipation substrate is increased, and the installation reliability is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of electronic equipment installation, and in particular to a MOS tube fixing structure. Background Art

[0002] With the development of the automobile industry, new energy vehicles have gradually become an important development direction of the automobile industry. Among them, the DCDC (direct current / direct current) converter is one of the important components of new energy vehicles. It mainly converts the input DC voltage into an AC voltage that meets the system requirements through the switching action of the MOS tube. Since the overlap between the drain voltage and the working current in the switching state of the MOS tube generates heat loss and causes the temperature to rise, the temperature of the MOS tube needs to be controlled, otherwise it will cause damage and affect the service life of the equipment. In order to meet the heat dissipation requirements, the MOS tube needs to be attached to the radiator. Since the MOS tube itself carries voltage, insulation treatment needs to be done between the MOS tube and the heat dissipation substrate. The usual practice is to place a thermally conductive insulating gasket between the MOS tube and the heat dissipation plate. Correspondingly, a device for fixing the MOS tube is required to ensure that the MOS and the thermally conductive insulating gasket fit tightly on the radiator.

[0003] In the prior art, the MOS tube is installed on the heat sink through the self-provided screw mounting holes, but the creepage distance or electrical clearance between the screw and the MOS tube is insufficient, and the requirement of the input high voltage on the insulation distance cannot be met.

[0004] Therefore, how to provide a MOS tube installation structure for a high-voltage DCDC converter to improve the reliability of MOS tube installation has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present disclosure is to provide a MOS tube fixing structure to solve the problem of insufficient creepage distance during MOS tube installation.

[0006] The present disclosure provides a MOS tube fixing structure, comprising: a MOS tube; a heat dissipation substrate, wherein a fixing hole is formed in the vertical direction of the heat dissipation substrate; an insulating thermally conductive gasket, which is arranged between the MOS tube and the heat dissipation substrate, wherein a through hole is formed in the vertical direction of the insulating thermally conductive gasket, and wherein the through hole is coaxially arranged corresponding to the fixing hole; a fastener, comprising a connecting column part and a connecting part part, wherein the connecting part part is pressed on a side of the MOS tube away from the insulating thermally conductive gasket, and wherein the connecting column part passes through the through hole and the fixing hole in sequence, and the MOS tube and the insulating thermally conductive gasket are pressed on the heat dissipation substrate in sequence.

[0007] In one embodiment of the present disclosure, a groove is provided on each of the left and right sides of the top of the fixing hole of the heat dissipation substrate, and the grooves are respectively abutted against the surfaces of the insulating thermal conductive gasket and the connecting column part of the fastener, and the grooves are filled with insulating thermal conductive material.

[0008] In an embodiment of the present disclosure, the groove has a shape of any one of a triangle, a quadrilateral, a polygon, and a circle.

[0009] In an embodiment of the present disclosure, the fastener is a screw, wherein the connecting column part is a stud, and the connecting part part is a nut; the through hole and the fixing hole are both threaded holes.

[0010] In an embodiment of the present disclosure, the screw is made of metal.

[0011] In one embodiment of the present disclosure, the screw is covered with an insulating protective cover.

[0012] In one embodiment of the present disclosure, the insulating protective cover includes an integrally formed top insulating pad and a lower sleeve, wherein the insulating pad is arranged between a side of the MOS tube away from the insulating thermally conductive gasket and the nut of the screw; the sleeve passes through the through hole and the fixing hole in sequence, and contacts the surfaces of the grooves on the left and right sides of the fixing hole.

[0013] In an embodiment of the present disclosure, the MOS tube includes a metal plate stacked on the insulating thermally conductive gasket, and also includes an insulating shell that completely encapsulates the metal plate except for a region in contact with the insulating thermally conductive gasket.

[0014] In an embodiment of the present disclosure, an end portion of the insulating thermally conductive gasket exceeds the insulating shell of the MOS tube.

[0015] In an embodiment of the present disclosure, there are a plurality of MOS tubes, and the connecting part of the fastener simultaneously presses the plurality of MOS tubes onto the insulating thermally conductive gasket.

[0016] As described above, the MOS tube fixing structure provided in the embodiment of the present disclosure increases the creepage distance of the high-voltage MOS tube by filling the heat-conducting insulating material in the groove of the heat-dissipating substrate. In addition, only one screw with insulating particles is needed to fix the MOS tube on the heat-dissipating substrate, and no external fixing device needs to be installed, which improves the reliability of the product, saves installation space, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the fixing structure of a MOS tube in the prior art is shown.

[0018] Figure 2A schematic diagram of a MOS tube fixing structure in an embodiment of the present disclosure is shown.

[0019] Figure 3a A schematic diagram showing the fixed creepage distance of a MOS tube in an embodiment of the present disclosure is shown.

[0020] Figure 3b A schematic diagram showing the fixed creepage distance of a MOS tube in the prior art.

[0021] Figure 4 A schematic diagram of a MOS tube fixing structure in another embodiment of the present disclosure is shown.

[0022] Component number description

[0023] 1 MOS tube

[0024] 11. Metal Plate

[0025] 12 Insulation shell

[0026] 2 Heat dissipation substrate

[0027] 3 Insulation thermal pad

[0028] 31 Insulation ceramic sheet

[0029] 4 Fasteners

[0030] 41 Connecting column part

[0031] 42 Connector Part

[0032] 6 Countersunk Hole

[0033] 61 First cylindrical hole

[0034] 62 Second cylindrical hole

[0035] 63 Third cylindrical hole

[0036] 71 Insulation pad

[0037] 72 Casing

[0038] 81 Through hole

[0039] 82 fixing holes

[0040] 9 Grooves

[0041] 10 Press plate DETAILED DESCRIPTION

[0042] The following is an explanation of the embodiments of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the information disclosed by the present disclosure. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in the present disclosure can also be modified or changed in various ways according to different viewpoints and application modules without departing from the spirit of the present disclosure. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0043] The following is a detailed description of the embodiments of the present disclosure with reference to the accompanying drawings so that those skilled in the art can easily implement the present disclosure. The present disclosure can be embodied in many different forms and is not limited to the embodiments described herein.

[0044] In the representations of the present disclosure, the reference terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or a group of embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples represented in the present disclosure and the features of different embodiments or examples, unless they are mutually contradictory.

[0045] In order to clearly describe the present disclosure, components not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0046] Throughout the specification, when a device is said to be "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. In addition, when a device is said to "include" a certain component, unless otherwise stated, it does not exclude other components, but means that other components may be included.

[0047] Although the terms first, second, etc. are used to represent various elements in this article in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, modules, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or a group of other features, steps, operations, elements, modules, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0048] The technical terms used herein are only used to refer to specific embodiments and are not intended to limit the present disclosure. The singular form used herein also includes the plural form unless the sentence clearly indicates the contrary meaning. The meaning of "including" used in the specification is to specify specific characteristics, regions, integers, steps, operations, elements and / or components, and does not exclude the existence or addition of other characteristics, regions, integers, steps, operations, elements and / or components.

[0049] Although not defined differently, all terms, including technical and scientific terms used herein, have the same meaning as those generally understood by those skilled in the art to which the present disclosure belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with relevant technical literature and the message of the present disclosure, and shall not be overly interpreted as ideal or very formal meanings unless defined.

[0050] Since the MOS tube itself is small in size, the process of drilling the mounting hole on it is high, so there is also a method in the prior art of using an additional pressing plate 10, drilling the mounting hole on the pressing plate 10 and then fixing the MOS tube with screws. Figure 1As shown, an insulating ceramic sheet 31 is placed between the MOS tube and the heat dissipation substrate, and a pressing plate 10 is placed above the side of the MOS tube 1 away from the insulating ceramic sheet 31, and is used to press the MOS tube 1 onto the insulating ceramic sheet 31. A countersunk hole 6 is opened on the top of the pressing plate 10, and the countersunk hole includes a first cylindrical hole 61 at the top and a second cylindrical hole 62 at the bottom, and the aperture of the first cylindrical hole 61 is larger than the aperture 62 of the second cylindrical hole; a third cylindrical hole 63 is opened on the heat dissipation substrate 2, and the aperture of the third cylindrical hole 63 is the same as that of the second cylindrical hole 62 at the bottom of the countersunk hole and is coaxially arranged accordingly. During installation, the screws pass through the countersunk hole 6 of the pressing plate 10 and the third cylindrical hole 63 of the heat dissipation substrate 2 in turn to fix the MOS tube 1 on the insulating ceramic sheet 31. It can be seen from this installation structure that the space occupied is large, and an additional pressing plate 10 is required, and the installation cost is high.

[0051] In view of this, some embodiments of the present disclosure may provide a MOS tube fixing structure to solve the above technical problems. Figure 2 As shown, a MOS tube installation structure is shown, including: a MOS tube 1, a heat dissipation substrate 2, an insulating thermal conductive gasket 3, and a fastener 4.

[0052] In some embodiments, the MOS tube 1 is divided into two parts, including a metal plate 11 stacked on the insulating thermally conductive gasket 3 , and an insulating shell 12 that completely encapsulates the metal plate 11 except for the area in contact with the insulating thermally conductive gasket 3 .

[0053] The heat dissipation substrate 2 has a fixing hole 82 formed in a vertical direction.

[0054] The insulating thermally conductive gasket 3 is disposed between the MOS tube 1 and the heat dissipation substrate 2 . The insulating thermally conductive gasket 3 has a through hole 81 formed in a vertical direction. The through hole 81 is coaxially disposed with the fixing hole 82 .

[0055] Specifically, because the MOS tube itself carries voltage, insulation treatment needs to be done between the MOS tube and the heat dissipation substrate. Furthermore, the insulating thermally conductive gasket 3 can be a ceramic sheet. In order to avoid displacement of the insulating thermally conductive gasket 3, a groove for placing the insulating thermally conductive gasket 3 can be provided on the top of the heat dissipation substrate 2, and a first thermally conductive silicone grease layer and a second thermally conductive silicone grease layer are respectively provided on the surface of the groove and the insulating thermally conductive gasket 3, so that the MOS tube 1 pressed on the insulating thermally conductive gasket 3 can quickly transfer heat to the heat dissipation substrate 2, and avoid the voltage of the MOS tube 1 from being transferred to the heat dissipation substrate 2.

[0056] In some embodiments, a groove 9 is provided on the left and right sides of the top of the fixing hole 82 of the heat dissipation substrate 2, and the groove 9 abuts against the surface of the insulating thermally conductive gasket 3 and the connecting column part of the fastener 4, respectively, and the groove 9 is filled with an insulating thermally conductive material. The shape of the groove 9 is any one of a triangle, a quadrilateral, a polygon, and a circle.

[0057] Specifically, the groove 9 filled with insulating heat-conducting material is opened on the top of the heat dissipation substrate 2 to increase the creepage distance, and the depth of the groove 9 is positively correlated with the creepage distance.

[0058] Take the groove 9 as a quadrilateral as an example. Figure 3a As shown, the end of the insulating thermal pad 3 exceeds the insulating shell 12 of the MOS tube 1, and the creepage distance between the MOS tube 1 and the heat dissipation substrate 2 is a broken line AB. Figure 3b Among them, the creeping distance between the MOS tube 1 and the heat dissipation substrate 2 is a straight line CD. Therefore, by adding a groove 9 filled with insulating particles in the heat dissipation substrate 2, the electrical gap between the MOS tube 1 and the heat dissipation substrate 2 can be increased, meeting the requirements of the high voltage transmission on the insulation distance, and improving the reliability of the MOS tube installation.

[0059] The fastener 4 includes a connecting column part 41 and a connecting part 42. The connecting part 42 is pressed on the side of the MOS tube 1 away from the insulating thermally conductive gasket 3. The connecting column 41 part passes through the through hole 81 and the fixing hole 82 in sequence, and presses the MOS tube 1 and the insulating thermally conductive gasket 3 onto the heat dissipation substrate 2 in sequence.

[0060] In some embodiments, the connector portion 42 of the fastener 4 simultaneously presses a plurality of MOS tubes 1 onto the insulating thermally conductive gasket 3 .

[0061] Compared with the prior art, the connector part 42 of the fastener 4 can be pressed on multiple MOS tubes 1 at the same time, reducing the number of fasteners 4 required. Accordingly, since it is necessary to open a through hole 81 and a fixing hole 82 on the heat dissipation substrate 2 and the insulating thermal pad 3 to facilitate the installation of the fastener 4, the number of fasteners 4 is reduced, and the number of holes to be opened is naturally reduced, thereby simplifying the manufacturing process.

[0062] In some embodiments, the fastener 4 is a screw, the connecting column portion 41 is a stud, and the connecting member portion 42 is a nut; the through hole 81 and the fixing hole 82 are both threaded holes. Specifically, the screw is made of metal.

[0063] In order to prevent the metal screws from causing the MOS tube to be short-circuited, further, in some embodiments, the screws are covered with an insulating protective sleeve.

[0064] For example, Figure 4 As shown, the insulating protective cover includes an integrally formed top insulating pad 71 and a lower sleeve 72, wherein the insulating pad 71 is arranged between the side of the MOS tube 1 away from the insulating thermal pad 3 and the nut of the screw; the sleeve 72 passes through the through hole 81 and the fixing hole 82 in sequence, and contacts the surfaces of the grooves 9 on the left and right sides of the fixing hole 82.

[0065] In the above embodiment, the insulating protective cover is designed as an integrated unit, which is convenient for processing and manufacturing, and also convenient for assembly of the MOS tube in production line.

[0066] Furthermore, the inner hole edge of the lower sleeve 72 of the insulating protective sleeve abuts against the stud, avoiding insulation failure caused by the shrinkage of the insulating protective sleeve, effectively increasing the electrical distance between the MOS tube and the heat dissipation substrate, and solving the problem of the insulation withstand voltage failure of the MOS tube after installation.

[0067] Of course, in actual situations, the fastener 4 can also include screws and anti-loosening parts. The anti-loosening parts are passed through the studs. The anti-loosening parts can be anti-loosening gaskets, such as spring gaskets. Of course, the anti-loosening parts can also include an ordinary gasket and a spring gasket. The ordinary gasket and the spring gasket are both passed through the screw body, wherein the spring gasket is abutted against the side of the insulating thermally conductive gasket 3 facing away from the heat dissipation substrate 2.

[0068] In summary, the embodiments of the present disclosure provide a MOS tube fixing structure, which increases the creepage distance between the MOS tube and the heat dissipation substrate by opening a groove filled with an insulating material on the heat dissipation substrate, thereby improving the reliability of the MOS tube installation. In addition, by opening holes in the heat dissipation substrate and the insulating thermal conductive gasket, only one screw with an insulating protective sleeve is needed to fix the MOS tube, and no external fixing device needs to be installed, which saves installation space, reduces costs, avoids drilling holes in the MOS tube itself, and simplifies the manufacturing process.

[0069] The above embodiments are merely illustrative of the principles and effects of the present disclosure, and are not intended to limit the present disclosure. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present disclosure. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present disclosure shall still be covered by the claims of the present disclosure.

Claims

1. A MOS tube fixing structure, characterized in that: include: MOS tube; A heat dissipation substrate, wherein a fixing hole is formed in a vertical direction of the heat dissipation substrate; wherein a groove is formed on the left and right sides of the top of the fixing hole of the heat dissipation substrate, respectively, and the groove abuts against the surface of the insulating thermal conductive gasket and the connecting column part of the fastener, and the groove is filled with an insulating thermal conductive material; The insulating thermally conductive gasket is arranged between the MOS tube and the heat dissipation substrate, and the insulating thermally conductive gasket has a through hole in the vertical direction, and the through hole is coaxially arranged with the fixing hole; The fastener includes a connecting column part and a connecting member part. The connecting member part is pressed on a side of the MOS tube away from the insulating thermally conductive gasket. The connecting column part passes through the through hole and the fixing hole in sequence to press the MOS tube and the insulating thermally conductive gasket onto the heat dissipation substrate in sequence.

2. The MOS tube fixing structure according to claim 1, characterized in that: The groove has a shape of any one of a triangle, a quadrilateral and a circle.

3. The MOS tube fixing structure according to claim 1, characterized in that: The fastener is a screw, wherein the connecting column part is a stud and the connecting part part is a nut; the through hole and the fixing hole are both threaded holes.

4. The MOS tube fixing structure according to claim 3, characterized in that: The screw is made of metal.

5. The MOS tube fixing structure according to claim 4, characterized in that: The screw is covered with an insulating protective sleeve.

6. The MOS tube fixing structure according to claim 5, characterized in that: The insulating protective sleeve comprises an integrally formed top insulating pad and a lower sleeve, wherein: The insulating pad is arranged between a side of the MOS tube away from the insulating thermally conductive pad and the nut of the screw; The sleeve passes through the through hole and the fixing hole in sequence, and contacts the surfaces of the grooves on the left and right sides of the fixing hole.

7. The MOS tube fixing structure according to claim 1, characterized in that: The MOS tube includes a metal plate stacked on the insulating thermally conductive pad, and also includes an insulating shell that completely encapsulates the metal plate except for the area in contact with the insulating thermally conductive pad.

8. The MOS tube fixing structure according to claim 7, characterized in that: The end of the insulating thermally conductive gasket exceeds the insulating shell of the MOS tube.

9. The MOS tube fixing structure according to claim 1, characterized in that: There are multiple MOS tubes, and the connecting part of the fastener simultaneously presses the multiple MOS tubes onto the insulating thermally conductive gasket.

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