Power electronic equipment

Abstract

The utility model discloses power electronic equipment, and belongs to the technical field of power devices. The power electronic equipment comprises a machine shell and a functional assembly, the machine shell comprises a heat conduction shell layer and an insulation shell layer, a containing cavity is formed in the heat conduction shell layer, the insulation shell layer wraps the outer surface of the heat conduction shell layer, the heat conductivity coefficient of the insulation shell layer is smaller than that of the heat conduction shell layer, and the functional assembly is contained in the containing cavity. The power electronic equipment disclosed by the utility model is low in manufacturing cost, good in thermal link reliability and good in heat dissipation effect.

Description

Technical Field

[0001] The present application relates to the technical field of power devices, and in particular to a power electronic device. Background Art

[0002] Power electronic equipment generally refers to equipment with power electronic devices as the main functional components, which are mainly used for the conversion and control of high-power electric energy. Power electronic equipment is widely used in various fields. Taking the photovoltaic field as an example, common power electronic equipment includes micro inverters, photovoltaic power optimizers, etc.

[0003] Most power electronic devices rely on natural heat dissipation. In the related art, the casing architecture of power electronic devices based on natural heat dissipation is mainly divided into the following three types: full metal casing, semi-metal casing (such as a plastic cover spliced ​​with a metal base) and full plastic casing. Among them, the heat dissipation capacity of full metal casing and semi-metal casing is relatively strong, but the cost is relatively high, and because additional insulating materials need to be arranged between the metal casing and the internal high-voltage devices, the thermal link reliability risk is high; the full plastic casing is low in cost and does not require additional insulating materials, but the heat dissipation capacity is very limited. Utility Model Content

[0004] The embodiment of the present application provides a power electronic device with low manufacturing cost, good thermal link reliability and good heat dissipation effect. The technical solution is as follows:

[0005] A power electronic device, comprising a housing and a functional component;

[0006] The housing comprises a heat-conducting shell layer and an insulating shell layer, wherein a receiving cavity is formed inside the heat-conducting shell layer; the insulating shell layer covers the outer surface of the heat-conducting shell layer, and the thermal conductivity of the insulating shell layer is smaller than the thermal conductivity of the heat-conducting shell layer;

[0007] The functional component is accommodated in the accommodating cavity.

[0008] Based on the above scheme, the casing of the power electronic device adopts a stacked structure with at least two layers, the inner layer of the casing is a heat-conducting shell layer, and the functional component is located in the accommodating cavity formed inside the heat-conducting shell layer. When the functional component generates heat, the heat on the functional component can be quickly distributed and discharged through the heat-conducting shell layer, thereby meeting the heat dissipation requirements of the power electronic device; the outer layer of the casing is an insulating shell layer, which can effectively isolate the charged functional components from the outside world, meet the insulation requirements of the power electronic device, and ensure safety performance; in addition, precisely because the casing itself has an insulating shell layer, there is no need to arrange additional insulating material inside the casing of the power electronic device, which reduces the risk of thermal link reliability, reduces the complexity of the manufacturing process, and is relatively low in cost.

[0009] In a possible implementation, the heat-conducting shell layer is a metal layer or a heat-conducting plastic layer; and / or the insulating shell layer is an insulating plastic layer.

[0010] Based on the above possible implementations, the heat-conducting shell layer can be made of metal material or heat-conducting plastic with a large thermal conductivity coefficient to ensure that the heat generated by the functional components when working is quickly evenly distributed and transferred to the insulating shell layer for dissipation, thereby improving the heat dissipation efficiency of the functional components and maintaining the temperature of the working environment within the normal operating temperature range. The insulating shell layer can be made of relatively low-cost insulating plastic, which can ensure the insulation performance on the one hand and reduce the manufacturing cost of the casing on the other hand, achieving cost advantages.

[0011] In a possible implementation, a heat transfer structure is disposed on the heat conductive shell layer, and the heat transfer structure protrudes from the inner surface of the heat conductive shell layer toward the functional component.

[0012] Based on the above possible implementation methods, by arranging a heat transfer structure on the heat conductive shell layer and making the heat transfer structure protrude toward the functional component, on the one hand, the heat conductive area of ​​the heat conductive shell layer is increased, and on the other hand, the distance between the heat conductive shell layer and the functional component is shortened, which helps to improve the heat conductive efficiency of the heat conductive shell layer, thereby improving the heat dissipation effect of the casing on the functional component.

[0013] In one possible implementation, the functional component includes at least one functional element;

[0014] The heat transfer structure includes a first heat transfer protrusion, a first spacer is provided between the first heat transfer protrusion and at least one of the functional elements, and a thermal conductivity of the first spacer is greater than or equal to a thermal conductivity of air.

[0015] Based on the above possible implementation, the functional component includes at least one functional element, and the functional element is easy to generate heat when working. In order to dissipate the heat generated by the functional element as quickly as possible, the heat transfer structure includes a first heat transfer protrusion, which extends in a direction close to the corresponding functional element and is in thermal contact with the corresponding functional element through a first spacer. Since the thermal conductivity of the first spacer is greater than or equal to the thermal conductivity of air, a better heat conduction effect can be achieved.

[0016] In a possible implementation, the first spacer is any one of a thermally conductive gel, a thermally conductive pad, and a potting glue filled in the accommodation cavity.

[0017] In a possible implementation, the functional component includes at least one functional element and a circuit board for carrying the at least one functional element, wherein a heat dissipation hole is provided in a setting area of ​​at least one functional element on the circuit board, and the heat dissipation hole penetrates the circuit board along a thickness direction of the circuit board;

[0018] The heat transfer structure includes a second heat transfer protrusion, a second spacer is provided between the second heat transfer protrusion and the area on the circuit board where the heat dissipation holes are provided, and the thermal conductivity of the second spacer is greater than or equal to the thermal conductivity of the first spacer.

[0019] Based on the above possible implementations, for some functional elements with large heat dissipation requirements, their heat dissipation paths can be optimized. Specifically, the heat generated by the functional element can be dissipated to the outside world through the first spacer, the heat-conducting shell layer and the insulating shell layer in sequence, and can also be dissipated to the outside world through the heat dissipation holes on the circuit board, the second spacer, the second heat transfer protrusion, the heat-conducting shell layer and the insulating shell layer in sequence. Therefore, by optimizing the heat dissipation path of the functional element, the heat dissipation efficiency is improved, and the heat dissipation requirements of the functional element with large heat generation are met.

[0020] In a possible implementation, the second spacer is any one of a thermally conductive gel, a thermally conductive pad, and a potting glue filled in the accommodation cavity.

[0021] In a possible implementation, the functional component includes a circuit board, the circuit board has a high-low voltage isolation line, and the high-low voltage isolation line is used to isolate a high-voltage area and a low-voltage area of ​​the circuit board;

[0022] The housing is provided with an insulating structure, and the insulating structure is configured to prevent the current in the high-voltage area from creeping to the low-voltage area through the heat-conducting shell layer.

[0023] Based on the above possible implementation methods, in order to prevent the current in the high-voltage area of ​​the circuit board from creeping to the low-voltage area through the thermally conductive shell and to ensure the safety performance of the casing, an insulating structure is provided on the casing. The insulating structure can either isolate the high-voltage area from the thermally conductive shell to prevent the current leaking from the high-voltage area from creeping to the thermally conductive shell; or can isolate the low-voltage area from the thermally conductive shell to prevent the current creeping to the thermally conductive shell from continuing to creep to the low-voltage area; or can isolate the thermally conductive shell into two parts that are not electrically connected to each other to prevent the thermally conductive shell from acting as an effective conductive medium between the high-voltage area and the low-voltage area.

[0024] In a possible implementation manner, the high and low voltage isolation lines are located within an orthographic projection of the insulation structure on the board surface of the circuit board.

[0025] Based on the above possible implementation methods, the setting position of the insulation structure is opposite to the position of the high and low voltage isolation lines on the circuit board, so as to isolate the thermally conductive shell into two parts that are electrically isolated from each other and correspond to the high voltage area and low voltage area of ​​the circuit board respectively. In this way, the current in the high voltage area of ​​the circuit board is prevented from leaking to the part of the thermally conductive shell corresponding to the low voltage area, thereby improving the insulation reliability and ensuring the safety performance of the casing.

[0026] In a possible implementation, the insulation structure includes at least one of the following:

[0027] A recessed portion, the recessed portion comprising an escape opening disposed on the heat-conducting shell layer, the escape opening penetrating the heat-conducting shell layer along a thickness direction;

[0028] An insulating protrusion is connected to the insulating shell layer and extends into the accommodating cavity through a via hole on the heat-conducting shell layer.

[0029] Based on the above possible implementation manner, the insulating structure includes at least one of a recessed portion and an insulating protrusion formed on the inner wall of the housing.

[0030] As for the recessed portion, it includes an avoidance opening arranged on the thermally conductive shell layer. The position of the avoidance opening is opposite to the position of the high and low voltage isolation lines on the circuit board, and separates the thermally conductive shell layer into two independent parts. When the current in the high-voltage area of ​​the circuit board leaks, the current will only flow to the part of the thermally conductive shell layer close to the high-voltage area, and cannot flow to the part of the thermally conductive shell layer close to the low-voltage area, thereby avoiding the failure and damage of functional components caused by the current creeping from the high-voltage area to the low-voltage area.

[0031] As for the insulating protrusion, a part of it extends through the via hole on the thermally conductive shell layer to the interior of the accommodating cavity. When the current in the high-voltage area leaks into the thermally conductive shell layer, the current will be blocked by the insulating protrusion and cannot approach the low-voltage area of ​​the circuit board, thereby avoiding the failure and damage of functional components caused by the current creeping from the high-voltage area to the low-voltage area.

[0032] In a possible implementation, the housing is a contoured structure that is similar in shape to the outer contour of the functional component.

[0033] Based on the above possible implementation methods, the distance between each part of the casing and the functional components is shortened. On the one hand, the local size of the casing is reduced, which helps to achieve miniaturization of the equipment and reduce the material cost of manufacturing power electronic equipment; on the other hand, the distance between the heat-conducting shell on the casing and the functional components is also shortened, which further improves the thermal conductivity of the heat-conducting shell, thereby enhancing the heat dissipation performance of the equipment.

[0034] In a possible implementation, the power electronic device is a micro photovoltaic inverter or a photovoltaic power optimizer.

[0035] Based on the implementations provided in the above aspects, this application can also be further combined to provide more implementations. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1is a schematic diagram of a cross-sectional structure of a first power electronic device provided in an embodiment of the present application;

[0037] Figure 2 is a partial cross-sectional schematic diagram of a second power electronic device provided in an embodiment of the present application;

[0038] Figure 3 is a partial cross-sectional schematic diagram of a third power electronic device provided in an embodiment of the present application;

[0039] Figure 4 is a partial cross-sectional schematic diagram of a fourth power electronic device provided in an embodiment of the present application;

[0040] Figure 5 is a partial cross-sectional schematic diagram of a fifth power electronic device provided in an embodiment of the present application;

[0041] Figure 6 is a partial cross-sectional schematic diagram of a sixth power electronic device provided in an embodiment of the present application;

[0042] Figure 7 is a partial cross-sectional schematic diagram of a seventh power electronic device provided in an embodiment of the present application;

[0043] Figure 8 It is a partial cross-sectional schematic diagram of an eighth power electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0045] Power electronic equipment generally refers to electronic equipment with power electronic devices (such as resistors, capacitors, transformers, etc.) as the main functional components, mainly used for the conversion and control of high-power electric energy. Power electronic equipment has a wide range of applications in various fields. Taking the photovoltaic field as an example, common power electronic equipment includes micro inverters, photovoltaic power optimizers, photovoltaic junction boxes, etc.

[0046] Functional components in power electronic equipment will generate heat when working, causing the temperature of the working environment to rise. High temperature environment can easily cause functional components to fail or cause other safety accidents. In order to ensure the normal operation of functional components and improve the safety of power electronic equipment, it is necessary to dissipate the heat accumulated inside the equipment in time.

[0047] Most power electronic devices dissipate heat mainly through natural heat dissipation. In the natural heat dissipation process, the housing of the power electronic device is an important heat transfer link that receives the heat inside the device and dissipates it to the surrounding environment. Especially for some power electronic devices with a closed structure, the design of the housing is particularly important.

[0048] In the related art, the casing architecture of power electronic equipment based on natural heat dissipation is mainly divided into the following three types: full metal casing, semi-metal casing and full plastic casing. The following is a brief introduction to these three casing architectures in the related art.

[0049] An all-metal case refers to a case whose entire body is made of the same or different metal materials. Since metal has a high thermal conductivity, the heat dissipation capacity of an all-metal case is relatively strong. However, in order to prevent large currents from leaking into the all-metal case during the operation of power electronic equipment and causing electric shock to the human body, it is usually necessary to arrange an insulating material layer inside the all-metal case to isolate the functional components from the metal case. However, this will lengthen the thermal link and increase the risk of thermal link reliability. For example, thermal contact failure is prone to occur between the insulating material layer and the metal case. In addition, the price of metal raw materials is relatively high, so the manufacturing cost of an all-metal case is very expensive.

[0050] A semi-metal casing refers to a casing in which one part is made of metal material and the other part is made of non-metal material, such as a casing structure with a plastic cover spliced ​​with a metal base, or a casing structure with a metal cover spliced ​​with a plastic base. Since the semi-metal casing is made of metal, its heat dissipation performance is second only to that of a full-metal casing. However, similar to a full-metal casing, in order to ensure the safety of power electronic equipment, it is also necessary to arrange an insulating material layer inside the semi-metal casing to isolate the functional components from the metal casing. Therefore, the semi-metal casing also has the problems of long thermal links, high reliability risks and high manufacturing costs.

[0051] An all-plastic casing refers to a casing whose entire body is made of the same or different types of plastic materials. Since the cost of plastic is much lower than that of metal and it has its own insulation properties, the manufacturing cost of the all-plastic casing is relatively low and does not require an additional insulation structure. However, the thermal conductivity of plastic materials is usually relatively low, and the heat dissipation capacity of a closed all-plastic casing is very limited. It is difficult to meet the heat dissipation requirements of functional components, and a heat spreader needs to be arranged inside the casing to enhance heat dissipation. However, the arrangement of a heat spreader will increase the complexity of the assembly process of power electronic equipment, and will increase the thickness, weight and overall manufacturing cost of the power electronic equipment. In addition, the introduction of a heat spreader will increase the number of dimensional chains on the thermal link and increase the reliability risk of the thermal link.

[0052] The embodiment of the present application relates to a power electronic device. For example, the power electronic device can be any one of a micro photovoltaic inverter, a power optimizer, and a photovoltaic junction box. Compared with the power electronic devices using the above three housing architectures, the power electronic devices of the embodiment of the present application have the advantages of small structure, low manufacturing cost, and good heat dissipation effect. Next, the implementation method and related structural features of the power electronic device provided by the present application will be further described in detail in conjunction with the accompanying drawings.

[0053] Figure 1 is a schematic cross-sectional structure diagram of a power electronic device provided by an exemplary embodiment of the present application. Figure 1 The power electronic device comprises a functional component 2 and a casing 1 , wherein the functional component 2 is located inside the casing 1 .

[0054] Functional component 2 is a component used to realize the core functions of power electronic equipment. Figure 1 As shown, the functional component 2 may include a circuit board 22 and at least one functional element 21 disposed on the circuit board 22. Exemplarily, the functional element 21 may be a capacitor, an inductor, a transformer, a relay, or the like.

[0055] Next, continue to see Figure 1 The housing 1 is in the shape of a closed box, and its shell adopts a stacked structure, including a heat-conducting shell layer 11 and an insulating shell layer 12 stacked in sequence from the inside to the outside. Among them, the interior of the heat-conducting shell layer 11 is hollow to form a housing cavity 111, and the housing cavity 111 is used to accommodate the functional component 2 and other components of the power electronic equipment. The insulating shell layer 12 is attached to the heat-conducting shell layer 11 and at least wraps the outer surface 112 of the heat-conducting shell layer 11, for example, it can only wrap the outer surface 112 of the heat-conducting shell layer 11, or it can wrap the outer surface 112 and at least a part of the inner surface 113 of the heat-conducting shell layer 11. The insulating shell layer 12 plays a protective role for the heat-conducting shell layer 11 on the one hand, and plays an insulating protection role on the other hand to ensure the safety of the housing 1. In some examples, the housing 1 includes an upper cover and a base that are independently formed, and the base is a cavity structure and has an opening. The upper cover covers or covers the opening of the base and is tightly connected to the base. The upper cover and the base are both laminated structures, each comprising a heat-conducting shell layer 11 and an insulating shell layer 12 stacked sequentially from the inside to the outside.

[0056] It should be noted that in the embodiment of the present application, there is no specific limitation on the connection method between the insulating shell 12 and the heat-conducting shell 11, as long as it can be ensured that the insulating shell 12 is attached to the heat-conducting shell 11 and the two maintain thermal contact. For example, the insulating shell 12 can be injection molded on the heat-conducting shell 11, or bonded to the heat-conducting shell 11 by a heat-conducting adhesive.

[0057] In addition, in this embodiment, the thermal conductivity of the heat-conducting shell 11 is greater than the thermal conductivity of the insulating shell 12, that is, the thermal resistance of the heat-conducting shell 11 is smaller than the thermal resistance of the insulating shell 12. In this way, the heat generated by the functional component 2 located in the accommodating cavity 111 can be quickly distributed and conducted to the insulating shell 12 through the heat-conducting shell 11 which is closer and has a larger thermal conductivity, and then dissipated to the external environment through the insulating shell 12, thereby avoiding excessive temperature rise in the surrounding environment of the functional component 2.

[0058] Optionally, the insulating shell 12 is an insulating plastic layer. The insulating plastic layer can be made of, for example, polycarbonate, ABS engineering plastics, etc., which has the characteristics of low raw material cost and good insulation performance.

[0059] Optionally, the heat-conducting shell layer 11 may be a heat-conducting plastic layer, which may be made of, for example, high-thermal-conducting plastic.

[0060] In one example, the high thermal conductivity plastic is anisotropic, and its lateral thermal conductivity is greater than its normal thermal conductivity. Therefore, when heat is transferred to the thermal conductive plastic layer, it is quickly distributed horizontally, avoiding local high temperatures caused by local heat accumulation. After the heat is distributed, it is more efficient to transfer it vertically, thus achieving better heat dissipation effect.

[0061] Optionally, the heat-conducting shell layer 11 may be a metal layer. The metal layer may be made of, for example, copper and its copper alloys, aluminum and its alloys. It should be noted that, compared with the semi-metallic shell structure in the related art, the metal layer and the insulating shell layer 12 in the shell 1 provided in this embodiment are stacked from the inside to the outside, so the heat conduction is more uniform and the heat dissipation efficiency is faster.

[0062] Optionally, when the heat-conducting shell layer 11 is a metal layer, the thickness of the metal layer is smaller than the thickness of the insulating shell layer 12. In this way, the material cost of the housing 1 is reduced.

[0063] In some examples, such as Figure 2 As shown, a heat transfer structure 13 is disposed on the heat conductive shell 11 , and the heat transfer structure 13 protrudes from an inner surface 113 of the heat conductive shell 11 toward the functional component 2 .

[0064] The heat transfer structure 13 is used to increase the heat transfer area of ​​the heat-conducting shell 11 and reduce the thermal resistance of the thermal link between the functional component 2 and the heat-conducting shell 11. The arrangement position of the heat transfer structure 13 on the heat-conducting shell 11 is designed according to the actual heat dissipation requirements, and can be protruded toward the position where the large current passes on the circuit board 22, or toward at least one functional element 21. The heat transfer structure 13 and the circuit board 22 can be indirectly in contact through a spacer including air, and similarly, the heat transfer structure 13 and the functional element 21 can also be indirectly in contact through a spacer including air.

[0065] Optionally, the spacer is made of an interface thermal conductive material, such as thermal grease, thermal conductive adhesive, thermal conductive rubber, thermal conductive tape, and phase change material, to ensure the reliability of the thermal link.

[0066] In this embodiment, the material of the heat transfer structure 13 can be selected according to actual needs, and can be the same as the heat conductive shell 11, or different from the heat conductive structure, as long as it has good thermal conductivity. In one example, the material of the heat transfer structure 13 is the same as the material of the heat conductive shell 11, and the heat transfer structure 13 and the heat conductive shell 11 are an integrally formed structure.

[0067] For some functional elements 21 with low heat dissipation requirements, single-sided heat dissipation can be performed. Figure 2 As shown, in some examples, the heat transfer structure 13 includes a first heat transfer protrusion 131, which is located on a side of the functional element 21 away from the circuit board 22, and the first heat transfer protrusion 131 protrudes from the inner surface 113 of the heat conductive shell 11 toward the functional element 21.

[0068] Alternatively, if Figure 2 As shown, the first heat transfer protrusion 131 includes a plurality of heat dissipation teeth, which are spaced apart on the inner surface 113 of the heat-conducting shell 11 and are located opposite to at least one functional element 21 to absorb the heat generated by at least one functional element 21. The plurality of heat dissipation teeth may be distributed at equal intervals or at unequal intervals, and the interval may be greater than or less than the width of each heat dissipation tooth. For example, the intervals between the plurality of heat dissipation teeth corresponding to the portion of the functional element 21 that generates relatively more heat are smaller.

[0069] Alternatively, if Figure 2 As shown, the first heat transfer protrusion 131 includes at least one heat dissipation boss, and the setting position of the heat dissipation boss is directly opposite to at least one functional element 21 to absorb the heat generated by at least one functional element 21. The shape and size of the heat dissipation boss can be selected and designed according to actual needs. For example, the shape of the heat dissipation boss is the same as the shape of the outer contour of the functional element 21, and the area of ​​the top surface of the heat dissipation boss is the same as the area of ​​the top surface of the functional element 21, and the top surface of the heat dissipation boss is directly opposite to the top surface of the functional element 21.

[0070] In some examples, a first spacer 14 is disposed between the first heat transfer protrusion 131 and the at least one functional element 21 , and a thermal conductivity of the first spacer 14 is greater than or equal to a thermal conductivity of air.

[0071] Optionally, the first spacer 14 is generally a solid spacer made of a thermally conductive interface material, and the thermal conductivity of the thermally conductive interface material is greater than the thermal conductivity of air.

[0072] For example, in some power electronic devices, such as micro inverters, the accommodating cavity 111 is filled with a potting compound 141, which serves to fix, protect and insulate the functional component 2. At least one first heat transfer protrusion 131 and the corresponding functional element 21 are in indirect contact through the potting compound 141, that is, the first spacer 14 is the potting compound 141.

[0073] Exemplarily, the first spacer 14 is a first thermally conductive gel 142 or a thermally conductive pad. The thermal conductivity of the first thermally conductive gel 142 and the thermally conductive pad are both higher than the thermal conductivity of the potting glue 141 , which can achieve a better heat dissipation effect.

[0074] For some functional components 21 with higher heat dissipation requirements, double-sided heat dissipation can be performed to achieve higher heat dissipation efficiency. Figure 1 and Figure 2 In some examples, a heat dissipation hole 221 is provided in the area where at least one functional element 21 is provided on the circuit board 22. The heat dissipation hole 221 is also called a PCB via, and penetrates the circuit board 22 along the thickness direction of the circuit board 22. In this case, a part of the heat generated by the functional element 21 can be transferred to the heat-conducting shell 11 on the first side of the circuit board 22 through the first heat transfer protrusion 131, and another part of the heat can be transferred to the second side of the circuit board 22 through the heat dissipation hole 221, and then transferred to the heat-conducting shell 11 on the second side of the circuit board 22, so as to achieve double-sided heat dissipation. Among them, the first side of the circuit board 22 is the side where the functional element 21 is provided, and the second side of the circuit board 22 is the side of the circuit board 22 away from the functional element 21.

[0075] Optionally, a metal coating (not shown) is provided on the hole wall of the heat dissipation hole 221 to improve the heat conduction efficiency of heat transferred to the second side of the circuit board 22 through the heat dissipation hole 221. Exemplarily, the metal coating may be a copper coating.

[0076] To further improve the heat dissipation effect, in some examples, such as Figure 2 As shown, in addition to the above-mentioned first heat transfer protrusion 131, the heat transfer structure 13 also includes a second heat transfer protrusion 132, which is located on the second side of the circuit board 22, and the second heat transfer protrusion 132 protrudes from the inner surface 113 of the heat conductive shell 11 toward the direction close to the heat dissipation hole 221 on the circuit board 22.

[0077] Alternatively, if Figure 2As shown, the second heat transfer protrusion 132 includes at least one heat dissipation boss, and the setting position of the heat dissipation boss is opposite to the setting area of ​​the heat dissipation hole 221 on the circuit board 22 to absorb the heat transferred through the heat dissipation hole 221. The shape and size of the heat dissipation boss can be selected and designed according to actual needs. For example, the shape of the top surface of the heat dissipation boss is the same as the shape of the setting area of ​​the heat dissipation hole 221 on the circuit board 22, and the area of ​​the top surface of the heat dissipation boss is the same as the area of ​​the setting area, and the top surface of the heat dissipation boss is opposite to the setting area.

[0078] In some examples, a second spacer 15 is provided between the second heat transfer protrusion 132 and the area on the circuit board 22 where the heat dissipation holes 221 are provided. The thermal conductivity of the second spacer 15 is generally greater than or equal to the thermal conductivity of air.

[0079] Optionally, the second spacer 15 is a solid spacer made of a thermally conductive interface material, the thermal conductivity of the thermally conductive interface material being greater than the thermal conductivity of air. Exemplarily, the second spacer 15 is a potting glue, a second thermally conductive gel 151 or a thermally conductive pad.

[0080] In some examples, such as Figures 3 to 5 As shown, the circuit board 22 has a high-voltage area 223 and a low-voltage area 224, wherein the high-voltage area 223 is used to arrange the high-voltage circuit, and the low-voltage area 224 is used to arrange the low-voltage circuit. The electronic components in the high-voltage circuit and the electronic components in the low-voltage circuit need to be arranged separately to avoid mutual influence and cause functional component failure or damage. The circuit board 22 also has a high-low voltage isolation line 222, which is used to isolate the high-voltage area 223 from the low-voltage area 224. In some cases, the current in the high-voltage area 223 may creep to the heat-conducting shell 11, making the heat-conducting shell 11 charged, and then creep to the low-voltage area 224 through the heat-conducting shell 11. In this example, an insulating structure 16 can be set on the housing 1, and the insulating structure 16 is configured to prevent the current in the high-voltage area from creeping to the low-voltage area 224 through the heat-conducting shell 11 to meet safety requirements.

[0081] In some examples, the high-low voltage isolation line 222 is located within the positive projection of the insulating structure 16 on the board surface of the circuit board 22, wherein the board surface of the circuit board 22 refers to the surface with the largest area on the circuit board 22. The high-low voltage isolation line 222 is arranged opposite to the insulating structure 16, and the area of ​​the positive projection of the insulating structure 16 on the board surface of the circuit board 22 should be greater than or equal to the layout area of ​​the high-low voltage isolation line 222 on the circuit board 22, thereby preventing the current in the high-voltage area 223 from directly or indirectly creeping to the low-voltage area 224, thereby improving the insulation reliability.

[0082] Optionally, the insulating structure 16 may include Figure 3 or Figure 4 The recessed portion 161 is shown, and Figure 5 At least one of the insulating protrusions 162 is shown.

[0083] In some examples, the depth of the recessed portion 161 is equal to the thickness of the heat-conducting shell 11, that is, Figure 3 As shown, the recessed portion 161 is an escape opening 1611 provided on the heat-conducting shell 11, and the escape opening 1611 penetrates the heat-conducting shell 11 along the thickness direction, thereby separating the heat-conducting shell 11 into two parts that are independent of each other and spaced from each other, and the two parts are electrically disconnected. The direction of the recessed depth is parallel to the thickness direction of the heat-conducting shell 11 at that position.

[0084] In other examples, the depth of the recessed portion 161 is greater than the thickness of the heat-conducting shell layer 11, that is, Figure 4 As shown, the recessed portion 161 includes an escape opening 1611 disposed on the heat-conducting shell layer 11 and an escape groove 1612 disposed on the inner surface 121 of the insulating shell layer 12 . The escape opening 1611 penetrates the heat-conducting shell layer 11 along the thickness direction, and the open end of the escape groove 1612 is connected to the escape opening 1611 .

[0085] In other examples, such as Figure 5 As shown, the insulating protrusion 162 is formed on the inner surface 121 of the insulating shell 12, and one end of the insulating protrusion 162 away from the inner surface 121 of the insulating shell 12 passes through the via hole 114 on the heat-conducting shell 11, extends to the inside of the accommodating cavity 111, and is accommodated in the accommodating cavity 111. The via hole 114 and the insulating protrusion 162 separate the heat-conducting shell 11 into two independent parts, and the two parts are electrically isolated.

[0086] In this embodiment, the material of the insulating protrusion 162 can be selected according to actual needs, and can be the same as the insulating shell 12 or different from the insulating structure 16, as long as the insulation effect can be achieved. In one example, the material of the insulating protrusion 162 is the same as the material of the insulating shell 12, and the insulating protrusion 162 and the insulating shell 12 are an integrally formed structure.

[0087] In the related art, the full metal casing or semi-metal casing of the power electronic equipment usually adopts a flat box-shaped structure. When filling the potting glue, a large amount of potting glue is used, which leads to a large weight of the whole machine and high cost.

[0088] To solve this problem, in some examples of the present application, the housing 1 is a contoured structure similar to the outer contour of the functional component 2. That is, the housing 1 is adapted to the shape and height of the internal functional component 2 and is made into an uneven shape, thereby reducing the amount of potting glue 141 in the accommodating cavity 111 and reducing the weight and manufacturing cost of the whole machine. In addition, the contoured housing 1 can shorten the distance between the heat-conducting shell 11 and the functional component 2, reduce thermal resistance, and improve heat dissipation efficiency.

[0089] The following uses a micro inverter as an example of a power electronic device, and further describes the embodiments of the present application in combination with a specific scenario. It should be understood that the advantages of the embodiments of the present application will be partially described in the following description, and some are obvious from the description, or can be learned through the implementation of the embodiments of the present application.

[0090] In low heat dissipation demand scenarios: See Figure 6 and Figure 7 The housing 1 of the power electronic device adopts a double-layer contoured structure, including an insulating shell 12 located on the outside and a heat-conducting shell 11 located on the inside. The inner surface 113 of the heat-conducting shell 11 is smooth and featureless. The functional component 2 of the power electronic device is accommodated inside the heat-conducting shell 11. The functional component 2 includes a circuit board 22 and two functional elements 21 arranged on the circuit board 22. If the thermal coupling between the two functional elements 21 is weak, such as Figure 6 As shown, the two functional elements 21 can be arranged on the same side of the circuit board 22, and a heat dissipation hole 221 is provided through the arrangement area of ​​one of the functional elements 21 on the circuit board 22 along the thickness direction; if the thermal coupling between the two functional elements 21 is strong, such as Figure 7 As shown, the two functional elements 21 can be arranged on opposite sides of the circuit board 22, and a heat dissipation hole 221 is provided through the arrangement area of ​​one of the functional elements 21 on the circuit board 22 along the thickness direction. The rest of the interior of the heat-conducting shell 11 is filled with a potting compound 141 to fix and protect the functional component 2.

[0091] When the power electronic device is working, the functional element 21 generates heat. Figure 6 and Figure 7 The functional element 21 on the left side mainly transfers heat to the contoured housing 1 through the potting glue 141 for dissipation; Figure 6 and Figure 7 On the one hand, the functional element 21 located on the right side can directly transfer part of the heat to the contoured housing 1 through the potting glue 141 for dissipation. On the other hand, the heat can also be transferred to the potting glue 141 on the side of the circuit board 22 away from the functional element 21 through the heat dissipation holes 221 on the circuit board 22, and then transferred to the contoured housing 1 on this side for dissipation, so as to achieve a stronger heat dissipation effect.

[0092] like Figure 6 As shown, when the thermal coupling between the two functional elements 21 on the circuit board 22 is weak, since the two functional elements 21 are arranged on the same side, the distance d1 between the circuit board 22 and the bottom wall of the casing 1 is relatively small, and the height of the casing 1 is relatively small, which makes it easier to miniaturize the device.

[0093] like Figure 7 As shown, when the thermal coupling between the two functional elements 21 on the circuit board 22 is strong, since the two functional elements 21 are arranged on opposite sides, the distance d2 between the circuit board 22 and the bottom wall of the housing 1 is relatively large, that is, d2>d1, and the height of the housing 1 is relatively large. However, compared with the height of the all-plastic housing that requires an additional temperature plate in the related art, and the height of the all-metal housing and semi-metal housing that require an additional insulating partition and cannot be contoured, the height of the housing 1 of the power electronic device provided in the embodiment of the present application is obviously significantly smaller.

[0094] In scenarios with high heat dissipation requirements: Figure 8 As shown, the housing 1 of the power electronic device adopts a double-layer contoured structure, including an insulating shell layer 12 located on the outside and a heat-conducting shell layer 11 located on the inside. The inner surface 113 of the heat-conducting shell layer 11 can be provided with a first heat transfer protrusion 131 and / or a second heat transfer protrusion 132 to increase the heat transfer area of ​​the heat-conducting shell layer 11, wherein the first heat transfer protrusion 131 and the second heat transfer protrusion 132 are an integrally formed structure with the heat-conducting shell layer 11. The functional component 2 of the power electronic device is accommodated inside the heat-conducting shell layer 11, and the functional component 2 includes a circuit board 22, and three functional elements 21 arranged on the circuit board 22, one of the three functional elements 21 is arranged in the high-voltage area 223 of the circuit board 22, and the other two are arranged in the low-voltage area 224 of the circuit board, wherein one of the functional elements 21 located in the low-voltage area 224 (i.e. Figure 8 The functional element 21 on the right side is in thermal contact with the first heat transfer protrusion 131 through the first heat conductive gel 142, and the setting area of ​​the functional element 21 is penetrated by a heat dissipation hole 221 along the thickness direction, and the setting area of ​​the heat dissipation hole 221 on the circuit board 22 is in indirect contact with the second heat transfer protrusion 132 through the second heat conductive gel 151, wherein the second heat conductive gel 151 is in thermal contact with the metal plating in the heat dissipation hole 221; the functional element 21 located in the high voltage area 223 (i.e. Figure 8 and another functional element 21 located in the low pressure area 224 (i.e. Figure 8 The functional component located on the far left in the figure) is in indirect contact with another first heat transfer protrusion 131 through a potting glue 141 poured into the inside of the heat conductive shell 11, and the potting glue 141 is used to fix, protect and insulate the functional component 2.

[0095] When the power electronic device is working, the functional element 21 generates heat. Figure 8 The functional element 21 at the far left and the functional element 21 at the middle position mainly transfer heat to the first heat transfer protrusion 131 through the potting glue 141, and then transfer heat to the contoured housing 1 for dissipation; Figure 8 The functional element 21 located on the far right can, on the one hand, directly transfer part of the heat to the first heat transfer protrusion 131 through the first heat conductive gel 142, and then transfer it to the contoured housing 1 for dissipation; on the other hand, it can transfer the heat to the second heat conductive gel 151 on the side of the circuit board 22 away from the functional element 21 through the heat dissipation holes 221 on the circuit board 22, and then dissipate the heat through the second heat transfer protrusion 132 and the contoured housing 1 on this side in turn, so as to achieve a stronger heat dissipation effect.

[0096] In the high voltage and high current scenario: the insulating shell 12 of the housing 1 can meet the general insulation requirements. However, when there are high voltage areas 223 and low voltage areas 224 on the circuit board 22, the current in the high voltage area 223 may creep through the heat conductive shell 11 to the low voltage area 224, and the resistance between the two areas cannot be cut off. Figure 8 The inner wall of the casing 1 of the power electronic device is partially hollowed out to form a recessed portion 161, and / or an insulating protrusion 162 is protruding from the inner wall of the casing 1 of the power electronic device, and the recessed portion 161 and the insulating protrusion 162 are directly opposite to the position of the high and low voltage isolation line 222.

[0097] When the power electronic device is working, a large current passes through the high-voltage area 223 of the circuit board 22. Since the recessed portion 161 and the insulating protrusion 162 separate the heat-conducting shell 11 into two parts that are electrically isolated from each other, the current in the high-voltage area 223 on the circuit board 22 is prevented from creeping toward the low-voltage area 224 through the heat-conducting shell 11. Therefore, the safety requirements are met, the insulation performance of the housing 1 is guaranteed, and the safety of the power electronic device is improved.

[0098] It should be noted that this application is attached Figure 1-8 The patterns are intended to represent different parts of the structure of the power electronic device. Different structures are distinguished by patterns of different styles. Patterns such as shadows in the accompanying drawings may have reduced clarity or distortion due to document printing or scanning, but do not affect the structure of the power electronic device, that is, do not affect the essential content of this solution.

[0099] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" means one or more, and "plurality" means two or more. The words "first", "second", etc. do not limit the quantity and execution order, and the words "first", "second", etc. do not limit them to be different.

[0100] In this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the words "exemplary" or "for example" is intended to present the related concepts in a concrete way.

[0101] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present disclosure, and will not be described in detail here.

[0102] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A power electronic device, characterized in that: The power electronic device comprises a housing (1) and a functional component (2); The housing (1) comprises a heat-conducting shell layer (11) and an insulating shell layer (12); a receiving cavity (111) is formed inside the heat-conducting shell layer (11); the insulating shell layer (12) covers an outer surface (112) of the heat-conducting shell layer (11); and the thermal conductivity of the insulating shell layer (12) is smaller than the thermal conductivity of the heat-conducting shell layer (11); The functional component (2) is accommodated in the accommodating cavity (111).

2. The power electronic device according to claim 1, characterized in that: The heat-conducting shell layer (11) is a metal layer or a heat-conducting plastic layer; and / or, The insulating shell layer (12) is an insulating plastic layer.

3. The power electronic device according to claim 1 or 2, characterized in that: A heat transfer structure (13) is provided on the heat-conducting shell layer (11), and the heat transfer structure (13) protrudes from the inner surface (113) of the heat-conducting shell layer (11) in a direction close to the functional component (2).

4. The power electronic device according to claim 3, characterized in that: The functional component (2) comprises at least one functional element (21); The heat transfer structure (13) comprises a first heat transfer protrusion (131), a first spacer (14) is provided between the first heat transfer protrusion (131) and at least one of the functional elements (21), and the thermal conductivity of the first spacer (14) is greater than or equal to the thermal conductivity of air.

5. The power electronic device according to claim 4, characterized in that: The first spacer (14) is any one of a thermally conductive gel, a thermally conductive pad, and a potting glue filled in the accommodating cavity (111).

6. The power electronic device according to claim 3, characterized in that: The functional component (2) comprises at least one functional element (21) and a circuit board (22) for carrying the at least one functional element (21), wherein a heat dissipation hole (221) is provided in a region of the circuit board (22) where the at least one functional element (21) is provided, and the heat dissipation hole (221) penetrates the circuit board (22) along a thickness direction of the circuit board (22); The heat transfer structure (13) comprises a second heat transfer protrusion (132), a second spacer (15) is provided between the second heat transfer protrusion (132) and a setting area on the circuit board (22) where the heat dissipation hole (221) is provided, and the thermal conductivity of the second spacer (15) is greater than or equal to the thermal conductivity of air.

7. The power electronic device according to claim 6, characterized in that: The second spacer (15) is any one of a thermally conductive gel, a thermally conductive pad, and a potting glue filled in the accommodating cavity (111).

8. The power electronic device according to claim 1 or 2, characterized in that: The functional component (2) comprises a circuit board (22), the circuit board (22) having a high-low voltage isolation line (222), the high-low voltage isolation line (222) being used to isolate a high-voltage area (223) and a low-voltage area (224) of the circuit board (22); An insulating structure (16) is provided on the casing (1), and the insulating structure (16) is configured to prevent the current in the high-voltage area (223) from creeping to the low-voltage area (224) through the heat-conducting casing layer (11).

9. The power electronic device according to claim 8, characterized in that: The high and low voltage isolation lines (222) are located within the orthographic projection of the insulating structure (16) on the board surface of the circuit board (22).

10. The power electronic device according to claim 9, characterized in that: The insulating structure (16) includes at least one of the following: A recessed portion (161), the recessed portion (161) comprising an avoidance opening (1611) arranged on the heat-conducting shell layer (11), the avoidance opening (1611) penetrating the heat-conducting shell layer (11) along a thickness direction; An insulating protrusion (162), one end of the insulating protrusion (162) being connected to the insulating shell layer (12), and the other end of the insulating protrusion (162) being accommodated in the accommodation cavity (111) via a through hole (114) on the heat-conducting shell layer (11).

11. The power electronic device according to claim 1, characterized in that: The housing (1) is a contoured structure having a shape similar to the outer contour of the functional component (2).

12. The power electronic device according to claim 1, characterized in that: The power electronic device is any one of a micro photovoltaic inverter, a photovoltaic power optimizer and a photovoltaic junction box.

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