Insulation voltage-resistant installation structure of high-voltage power device
By combining the T-shaped inverted design of insulating particles with thermally conductive insulating ceramic pads, the problem of insufficient insulation withstand voltage between power devices and heat sinks is solved, enhancing safety and reliability and reducing manufacturing difficulty.
Patent Information
- Application Number
- CN202423226363.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2034-12-26
AI Technical Summary
In existing technologies, insufficient insulation withstand voltage between power devices and heat sinks leads to insufficient creepage distance, causing safety incidents.
The insulating particles are arranged in an inverted T-shape. The combination of horizontal bosses and vertical sleeves increases the creepage distance and blocks electrical creepage through physical contact between the insulating particles and the thermally conductive insulating ceramic gasket.
This effectively increases the creepage distance between power devices and heat sinks, improves product safety and reliability, and reduces the stringent requirements of manufacturing processes.
Smart Images
Figure CN223728773U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to high -voltage power device installation technical field especially relates to a kind of insulation pressure-resistant mounting structure of high-voltage power device. BACKGROUND
[0002] With the development of power electronics industry, many electronic products use semiconductor power devices to realize power conversion;These power tubes will generate a lot of heat when working, and need to install a heat sink for power devices to reduce their temperature;Make power devices run at a lower temperature, which is considered an important basis for reliability determination.
[0003] Most power electronic products need shell design for appearance, product function implementation, fixed components, insulation protection and other functions;Usually the heat sink of power device will be compatible with the shell design, which can ensure the weight and material cost of the product;Since the power supply of most electronic products is AC power grid, and the main power device is generally on the primary side, it is the same electrical network as the AC power grid;In order to better ensure the heat dissipation, vibration and other requirements of power devices, attaching power devices to the heat sink is the best choice;At this time, if the insulation level between power device and shell is insufficient, electric shock and other safety events will occur.
[0004] The power tube package of plug-in type has a hole position, and the power device is attached to the heat sink through the hole position with screws, which has the advantage of reliably installing the power device on the heat sink, and using screws for fixation is a better choice for vibration, contact state and production convenience.
[0005] Figure 1 The structure diagram of the power device attached to the heat sink in the prior art, Figure 3 , Figure 4 The cross-sectional view of the power device attached to the heat sink in the prior art;The overall structure includes screw 100, insulating particles 200, heat-conducting insulating pad (heat-conducting insulating cloth, heat-conducting insulating ceramic gasket) 300, power device 400 (SIC, IGBT, MOSFET, GaN, power triode, power diode, etc.) and heat sink 500. The power device, insulating particles, heat-conducting insulating pad and heat sink are assembled together using screws, and the power device transmits heat to the heat sink through the back heat dissipation surface, finally achieving the purpose of power device heat dissipation. Figure 2 The rear view of the existing power device, the power device is designed with a tubular plastic tube 401 at the hole position for preventing the creepage distance of insulation pressure, and the tube opening of the plastic tube 401 is surrounded by metal cooling fins 402. The manufacturer often provides the creepage distance under the basic insulation protection level when designing.
[0006] The traditional heat conduction mode solves the heat dissipation problem, but meanwhile introduces the insulation withstand voltage problem between the power device and the heat sink. The insulation particles and the insulation heat-conductive pad are used as parts of the insulation system, and due to the dimensional tolerance of the height H (as shown in Figure 3 ) of the actual insulation particle tubular part, the general tolerance is ±0.3mm, the dimensional tolerance of the overall thickness L (as shown in Figure 3 ) of the power device exists, the general tolerance is ±0.3mm, when the total tolerance of the insulation particles and the power device assembled on the heat sink is large, the creepage distance between the screw and the power device is insufficient, and finally the safety event occurs. For example: Figure 3 From the metal heat sink of the power device, through the surface of the plastic tube of the power device, to the screw through the lower end face of the insulation particle, and finally to the heat sink, forming a current return path 600 (the black thick line in Figure 3 ), causing a safety event; Figure 4 From the metal heat sink of the power device, through the lower end face of the plastic tube of the power device, to the screw through the vertical face of the insulation pad, and finally to the heat sink, forming a current return path 600 (the black thick line in Figure 4 ), causing a safety event. Practical new type content
[0007] The utility model aims at providing an insulation withstand voltage mounting structure of high-voltage power device, to solve the problem that when the total tolerance of the insulation particles and the power device assembled on the heat sink is large, the creepage distance between the screw and the power device is insufficient, and finally the safety event occurs.
[0008] The technical scheme of the utility model is: an insulation withstand voltage mounting structure of high-voltage power device, including heat sink, power device, heat-conductive insulation ceramic pad, insulation particle, screw, the heat-conductive insulation ceramic pad is arranged between the power device and the heat sink;The screw is penetrated through the heat-conductive insulation ceramic pad and the power device after the insulation particle is sleeved, so that the power device is locked on the heat sink;
[0009] The power device includes a shell, the shell has a through hole formed by a plastic tube for the screw and the insulation particle to pass through, and the shell is provided with a metal heat sink around the pipe opening of the plastic tube on the side in contact with the heat-conductive insulation ceramic pad;
[0010] The insulation particle is in the shape of T upside down as a whole, and the structure includes a ring-shaped horizontal boss and a tubular vertical sleeve connected;The horizontal boss is contained in the interior of the heat-conductive insulation ceramic pad or the heat sink, and the vertical sleeve is penetrated in the heat-conductive insulation ceramic pad and the plastic tube.
[0011] Preferably, when the horizontal boss is accommodated in the interior of the heat sink, the heat sink is internally recessed on the side in contact with the heat-conducting insulating ceramic gasket, and a groove with a circular cross section is formed in the recess; a threaded hole for mounting a screw is formed in the bottom of the groove.
[0012] Preferably, when the horizontal boss is accommodated in the heat-conducting insulating ceramic gasket, a first hole and a second hole are sequentially formed in the heat-conducting insulating ceramic gasket from top to bottom, the diameter of the first hole is smaller than that of the second hole; the vertical sleeve passes through the first hole, and the horizontal boss is accommodated in the second hole.
[0013] The bottom surface of the horizontal boss abuts against the heat sink, and the top surface of the horizontal boss is in interference fit or bonded with the body of the heat-conducting insulating ceramic gasket forming the first hole.
[0014] The heat sink is provided with a threaded hole for mounting a screw.
[0015] Preferably, the inner diameter of the plastic tube is greater than the outer diameter of the vertical sleeve.
[0016] Preferably, the end surface of the insulating particle on the side where the vertical sleeve is located is accommodated in the interior of the power device.
[0017] Preferably, the heat-conducting insulating ceramic gasket is provided with a first through hole for the vertical sleeve of the screw and the insulating particle to pass through, the hole diameter of the first through hole is greater than or equal to the inner diameter of the plastic tube and smaller than the outer diameter of the plastic tube.
[0018] Preferably, the hole diameter of the first hole is greater than or equal to the inner diameter of the plastic tube and smaller than the outer diameter of the plastic tube.
[0019] Preferably, the height of the horizontal boss is equal to or smaller than the depth of the groove, and the outer diameter of the horizontal boss is smaller than the diameter of the groove.
[0020] Compared with the prior art, the utility model has the advantages that:
[0021] (1) The utility model discloses a high voltage power device's insulation voltage resistance mounting structure of example one, including radiator, power device, heat insulation ceramic gasket, insulating particle, screw, and insulating particle whole is T shape upside down, when horizontal boss is contained in the inside of radiator, the recess that one side of radiator and heat insulation ceramic gasket contact is recessed and is set up the groove of circular section, and horizontal boss is contained in the recess, and example one installs insulating particle upside down on radiator, and this can increase the creepage distance between power device and radiator through the size of horizontal boss of insulating particle, and the size tolerance of power device and insulating particle will not affect electrical creep path, and the size tolerance of whole structure's assembly is also reduced, and this can strengthen the product's safety regulation reliability, and need not very strict production manufacturing process ability.
[0022] (2) The utility model discloses a high voltage power device's insulation voltage resistance mounting structure of example two, including radiator, power device, heat insulation ceramic gasket, insulating particle, screw, and insulating particle whole is T shape upside down, when horizontal boss is contained in the inside of heat insulation ceramic gasket, the first hole and the second hole are set up in turn on heat insulation ceramic gasket and go through, and the diameter of first hole is less than the diameter of second hole, and first hole is passed through vertical sleeve, and second hole contains horizontal boss, and example two is blocked through the physical contact of horizontal boss of insulating particle and heat insulation ceramic gasket on the electrical creep phenomenon, and becomes physical insulation, and when the total tolerance of insulating particle and power device is assembled on the radiator in prior art, the problem that the insufficient creepage distance between screw and power device leads to the safety regulation event is solved. BRIEF DESCRIPTION OF DRAWINGS
[0023] The utility model will be further described in connection with the drawings and examples:
[0024] Figure 1 It is the structure diagram of power device locking in prior art on radiator,
[0025] Figure 2 It is the back view of power device in prior art,
[0026] Figure 3 , Figure 4 It is the sectional view of power device locking in prior art on radiator,
[0027] Figure 5 It is the sectional view of high voltage power device's insulation voltage resistance mounting structure of example one,
[0028] Figure 6 It is the sectional view of high voltage power device's insulation voltage resistance mounting structure of example two,
[0029] Figure 7A cross-sectional view of an insulating withstand voltage mounting structure for a high-voltage power device, wherein an insulating tube is provided on a thermally conductive insulating ceramic pad to replace the overall T-shaped inverted insulating particles.
[0030] Among them: 1. Screw, 2. Insulating particle, 21. Horizontal boss, 22. Vertical sleeve, 3. Thermally conductive insulating ceramic gasket, 31. First hole, 32. Second hole, 33. Insulating tube section, 4. Power device, 41. Plastic tube, 42. Metal heat sink, 5. Heat sink, 51. Groove, 6. Current return path. Detailed Implementation
[0031] The present invention will be further described in detail below with reference to specific embodiments:
[0032] In the description of the utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.
[0033] Example 1
[0034] like Figure 5 As shown, an insulation withstand voltage mounting structure for a high-voltage power device includes a heat sink 5, a power device 4, a thermally conductive insulating ceramic gasket 3, insulating particles 2, and a screw 1. The thermally conductive insulating ceramic gasket 3 is placed between the power device 4 and the heat sink 5. After the screw 1 is fitted with the insulating particles 2, it passes through the thermally conductive insulating ceramic gasket 3 and the power device 4, securing the power device 4 to the heat sink 5. The power device 4 includes a housing with a through hole formed by a plastic tube 41 for the screw 1 and the insulating particles 2 to pass through. The housing is connected to the thermally conductive insulating ceramic gasket 3. A metal heat sink 42 is provided around the opening of the plastic tube 41 on the side of the gasket 3 that is in contact with it. The insulating particle 2 is T-shaped and inverted, and its structure includes a connected annular horizontal boss 21 and a tubular vertical sleeve 22. The inner diameter of the plastic tube 41 is larger than the outer diameter of the vertical sleeve 22, so that the vertical sleeve 22 of the insulating particle 2 can pass through the plastic tube 41. The horizontal boss 21 is accommodated inside the thermally conductive insulating ceramic gasket 3 or the heat sink 5, and the vertical sleeve 22 passes through the thermally conductive insulating ceramic gasket 3 and the plastic tube 41. In this embodiment, the thermally conductive insulating ceramic gasket 3 can be replaced by thermally conductive insulating cloth.
[0035] When the horizontal boss 21 is accommodated inside the heat sink 5, a circular groove 51 is recessed on the side of the heat sink 5 that contacts the thermally conductive insulating ceramic pad 3, and the horizontal boss 21 is accommodated in the groove 51. The specific structure for accommodating the horizontal boss 21 in the groove 51 is as follows: the height of the horizontal boss 21 is equal to or less than the depth of the groove 51, and the outer diameter of the horizontal boss 21 is smaller than the diameter of the groove 51. A threaded hole for mounting screws 1 is provided on the bottom surface of the groove 51. The end face of the insulating particle 2, on the side where the vertical sleeve 22 is located, is accommodated inside the power device 4.
[0036] The thermally conductive and insulating ceramic gasket 3 has a first through hole through which the screw 1 and the vertical sleeve 22 of the insulating particle 2 pass. The diameter of the first through hole is greater than or equal to the inner diameter of the plastic tube 41 and less than the outer diameter of the plastic tube 41. Preferably, the diameter of the first through hole is equal to the inner diameter of the plastic tube 41, thereby increasing the creepage distance.
[0037] In this embodiment, the electrical creepage path is as follows: from the metal heat sink 42 of the power device 4, through the lower end face of the plastic tube 41 of the power device 4, from the surface of the vertical sleeve 22 of the insulating particle 2 to the surface of the horizontal boss 21 of the insulating particle 2, and finally to the heat sink 5, forming a current return path 6. Figure 5 The bold black line indicates that the length of the current return path 6 is greater than the safe creepage distance between the power device 4 and the heat sink 5. In this embodiment, by inverting the insulating particle 2 and installing it on the heat sink 5, the creepage distance between the power device 4 and the heat sink 5 can be increased by the size of the horizontal boss 21 of the insulating particle 2. The tolerance of the overall thickness of the power device 4 and the tolerance of the vertical sleeve 22 of the insulating particle 2 are reflected in the vertical distance N between the end face of the vertical sleeve 22 away from the horizontal boss 21 and the top surface of the power device 4 (e.g., ...). Figure 5 As shown above; therefore, in this embodiment, the dimensional tolerances of the power device 4 and the insulating particle 2 will not affect the electrical creepage path. For individual parts, high dimensional tolerances are not required, and the assembly tolerance of the entire structure is also reduced. This can enhance the safety and reliability of the product without requiring very strict manufacturing process capabilities.
[0038] Example 2
[0039] like Figure 6As shown, an insulation pressure mounting structure of a high-voltage power device includes a heat sink 5, a power device 4, a heat-conducting insulation ceramic gasket 3, an insulation particle 2, and a screw 1. The heat-conducting insulation ceramic gasket 3 is arranged between the power device 4 and the heat sink 5. The screw 1, after being coated with the insulation particle 2, penetrates the heat-conducting insulation ceramic gasket 3 and the power device 4 to lock the power device 4 on the heat sink 5. The power device 4 includes a shell having a through hole formed by a plastic tube 41 for the screw 1 and the insulation particle 2 to pass through. A surface of the shell, which is in contact with the heat-conducting insulation ceramic gasket 3, is provided with a metal fin 42 around a tube opening of the plastic tube 41. The insulation particle 2 is in a T-shaped inverted shape as a whole, and includes a ring-shaped horizontal boss 21 and a tubular vertical sleeve 22 connected to each other. An inner diameter of the plastic tube 41 is greater than an outer diameter of the vertical sleeve 22, so that the vertical sleeve 22 of the insulation particle 2 penetrates the plastic tube 41. The horizontal boss 21 is accommodated in an interior of the heat-conducting insulation ceramic gasket 3 or the heat sink 5, and the vertical sleeve 22 penetrates the heat-conducting insulation ceramic gasket 3 and the plastic tube 41. The heat sink 5 is provided with a threaded hole for mounting the screw 1.
[0040] When the horizontal boss 21 is accommodated in the interior of the heat-conducting insulation ceramic gasket 3, a first hole 31 and a second hole 32 are sequentially provided in the heat-conducting insulation ceramic gasket 3 in a penetrating manner from top to bottom. A diameter of the first hole 31 is smaller than a diameter of the second hole 32. The first hole 31 is for the vertical sleeve 22 to penetrate, and the second hole 32 is for the horizontal boss 21 to be accommodated. A bottom surface of the horizontal boss 21 abuts against the heat sink 5, and a top surface of the horizontal boss 21 is in interference fit or bonded with a body of the heat-conducting insulation ceramic gasket 3 forming the first hole 31. Figure 6 An end surface of the insulation particle 2, in which the vertical sleeve 22 is located, is accommodated in the interior of the power device 4. A hole diameter of the first hole 31 is greater than or equal to an inner diameter of the plastic tube 41, and is smaller than an outer diameter of the plastic tube 41.
[0041] In the embodiment, the bottom surface of the horizontal boss 21 abuts against the heat sink 5, and the top surface of the horizontal boss 21 is in interference fit or bonded with the body of the heat-conducting insulation ceramic gasket 3 forming the first hole 31. Through the physical contact between the horizontal boss 21 of the insulation particle 2 and the heat-conducting insulation ceramic gasket 3, the electrical creep phenomenon is blocked, and becomes physical insulation. The problem that when the insulation particle and the power device are assembled on the heat sink, the total tolerance is large, the creep distance between the screw and the power device is insufficient, and finally an electrical safety event occurs is solved. In the mounting structure of the embodiment, a high dimensional tolerance is not required for a single part, and the assembly tolerance of the whole structure is also reduced. Therefore, the electrical safety reliability of the product is strengthened, and a very strict production and manufacturing process capability is not required.
[0042] In addition, as shown in FIG. 2, the heat-conducting insulation ceramic gasket 3 is provided with a plurality of through holes 33 for the screw 1 to penetrate. Figure 7As shown, the heat-conducting insulating ceramic gasket 3 can be provided with an insulating tube part 33 to replace the whole T-shaped inverted insulating particle 2, which also blocks the electrical creep phenomenon and becomes physical insulation, solving the problem in the prior art that when the insulating particle and the power device are assembled on the heat sink, the total tolerance is large, which leads to insufficient creep distance between the screw and the power device, and finally causes an electrical safety event.
[0043] The above embodiments are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application, therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.
Claims
1. An insulation withstand mounting structure of a high voltage power device, characterized by: The heat sink, the power device, the heat-conducting and insulating ceramic gasket, the insulating particles and the screw are included, the heat-conducting and insulating ceramic gasket is arranged between the power device and the heat sink, and the screw is sleeved with the insulating particles and penetrates through the heat-conducting and insulating ceramic gasket and the power device, so that the power device is locked on the heat sink. The power device includes a shell, the shell has a through hole formed by a plastic tube for the screw and the insulating particles to pass through, and a surface of the shell, which is in contact with the heat-conducting and insulating ceramic gasket, is provided with a metal fin around a tube opening of the plastic tube. The insulating particles are in the shape of a T-shaped inverted body, and the structure includes a ring-shaped horizontal boss and a tubular vertical sleeve connected to each other, the horizontal boss is accommodated in the heat-conducting and insulating ceramic gasket or the heat sink, and the vertical sleeve is arranged in the heat-conducting and insulating ceramic gasket and the plastic tube.
2. The insulation pressure mounting structure of a high voltage power device according to claim 1, characterized by: When the horizontal boss is accommodated in the heat sink, a surface of the heat sink, which is in contact with the heat-conducting and insulating ceramic gasket, is concave and provided with a groove with a circular cross section, and the horizontal boss is accommodated in the groove, and a threaded hole for mounting the screw is formed in the bottom of the groove.
3. The insulation pressure mounting structure of a high voltage power device according to claim 1, wherein: When the horizontal boss is accommodated in the heat-conducting and insulating ceramic gasket, a first hole and a second hole are sequentially formed in the heat-conducting and insulating ceramic gasket, the diameter of the first hole is smaller than that of the second hole, the vertical sleeve passes through the first hole, and the horizontal boss is accommodated in the second hole. The bottom surface of the horizontal boss is in abutment with the heat sink, and the top surface of the horizontal boss is in interference fit or adhesion with the body of the heat-conducting and insulating ceramic gasket forming the first hole. The heat sink is provided with a threaded hole for mounting the screw.
4. An insulation pressure mounting structure for a high voltage power device according to claim 2 or 3, characterized in that: The inner diameter of the plastic tube is greater than the outer diameter of the vertical sleeve.
5. The insulation pressure mounting structure of a high voltage power device according to claim 2 or 3, wherein: The end surface of the insulating particles on the side where the vertical sleeve is located is accommodated in the power device.
6. The high voltage power device insulation pressure mounting structure according to claim 2, wherein: The heat-conducting and insulating ceramic gasket is provided with a first through hole for the screw and the vertical sleeve of the insulating particles to pass through, the diameter of the first through hole is greater than or equal to the inner diameter of the plastic tube and smaller than the outer diameter of the plastic tube.
7. The high voltage power device insulation pressure mounting structure according to claim 3, wherein: The diameter of the first hole is greater than or equal to the inner diameter of the plastic tube and smaller than the outer diameter of the plastic tube.
8. The high voltage power device insulation pressure mounting structure according to claim 2, wherein: The height of the horizontal boss is equal to or smaller than the depth of the groove, and the outer diameter of the horizontal boss is smaller than the diameter of the groove.