Metal base plate heat dissipation structure and photovoltaic power optimizer

Abstract

The application provides a metal substrate heat dissipation structure and a photovoltaic power optimizer. The metal substrate heat dissipation structure comprises a printed circuit board (PCB), a multilayer metal plate and a power device. The multilayer metal plate comprises a first metal layer, a second metal layer, a first insulating layer and a second insulating layer. The power device is arranged on the first metal layer to realize power interconnection between the power devices. The PCB is electrically connected with the first metal layer to realize control of the controller on the PCB on the power device on the first metal layer. The first metal layer is electrically connected with the second metal layer to realize an electromagnetic shielding function. The first insulating layer and the second insulating layer respectively realize functional insulation and reinforced insulation. The metal substrate heat dissipation structure fully utilizes the strong heat dissipation characteristics of the metal substrate, effectively simplifies the heat dissipation structure, reduces the production difficulty and material cost of the heat dissipation structure, reduces the interface thermal resistance and improves the heat dissipation efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat dissipation, and in particular to a metal substrate heat dissipation structure and a photovoltaic power optimizer. BACKGROUND

[0002] The Buck circuit inside the photovoltaic power optimizer generally involves power devices such as Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), referred to as MOS tubes, and diodes. In the working state, the switching loss of these power devices is mostly in the form of heat dissipation, which easily leads to an increase in the temperature of the power devices. The power devices have certain limits on the temperature they can withstand, and if the heat generated by the power devices cannot be conducted away in time, their working capacity and performance will deteriorate sharply, seriously affecting their working stability and reducing their working efficiency. At the same time, the service life of the power devices is closely related to their working temperature, and a lower working temperature is conducive to prolonging the service life of the power devices. In addition, under a long working state, the power devices with a high temperature will also cause high-temperature baking of the controller devices on the Printed circuit board (PCB) with a low temperature, seriously affecting the working stability of the controller devices. Therefore, it is particularly important to conduct away the heat generated by the semiconductor power devices in time. SUMMARY

[0003] The metal substrate heat dissipation structure provided by the embodiments of the present application can solve the problems of low heat dissipation efficiency, complex structure, and high material cost of the heat dissipation structure in the existing photovoltaic power optimizer.

[0004] In a first aspect, the embodiments of the present application provide a metal substrate heat dissipation structure, which comprises a PCB, a multi-layer metal plate, and a power device. The multi-layer metal plate comprises a first metal layer, a first insulating layer, a second metal layer (equivalent to the metal substrate layer 403 in Embodiment Three), and a second insulating layer which are sequentially stacked. The power device is arranged on the surface of the first metal layer away from the first insulating layer. The PCB is electrically connected with the first metal layer to realize the control of the controller device on the PCB over the power device on the first metal layer. The static point on the first metal layer is electrically connected with the second metal layer to realize electromagnetic shielding.

[0005] According to the above technical solution, the metal substrate heat dissipation structure makes full use of the advantage that the PCB can flexibly arrange the wiring, arranges the complex control circuit and control device on the PCB, and sets the power device with large heat on the first metal layer of the multi-layer metal plate. Through the electrical interconnection between the PCB and the first metal layer, the control device on the PCB controls the power device on the first metal layer, and the structure is simple and easy to implement.

[0006] In addition, for the multi-layer metal plate, the setting of the first metal layer in the multi-layer metal plate can not only realize the power interconnection between the power devices, but also facilitate the electrical connection between the PCB and the power device, and realize the control of the control device on the PCB on the power device on the first metal layer. The setting of the first insulating layer in the multi-layer metal plate can realize functional insulation. The second metal layer in the multi-layer metal plate can be connected to the static point on the first metal layer through side wall soldering / plating tin or via hole, thereby playing a shielding effect of noise reflux. At the same time, the second metal layer has strong heat dissipation capacity and can also play a role in strengthening heat dissipation. The second insulating layer in the multi-layer metal plate can have a thickness of more than 10 mil, thereby playing a regulatory insulation effect. The multi-layer metal plate makes full use of the characteristics of the second metal layer with strong heat dissipation capacity, and by pressing the first insulating layer, the second insulating layer, the first metal layer and the second metal layer, the structure is simplified, the interface thermal resistance is reduced, the heat dissipation efficiency is improved, the number of MOS tubes is reduced, and the material cost is reduced.

[0007] In a possible implementation manner, the multi-layer metal plate further includes a third metal layer (equivalent to the metal substrate layer 205 in the implementation one or the second embodiment), which is arranged below the second insulating layer. That is, the multi-layer metal plate includes the first metal layer, the first insulating layer, the second metal layer, the second insulating layer and the third metal layer which are stacked in sequence. Among them, the second metal layer is connected to the static point on the first metal layer through side wall soldering / plating tin or via hole, thereby realizing the function of electromagnetic shielding. The third metal layer has strong heat dissipation capacity and can realize rapid heat dissipation of the multi-layer metal plate, and at the same time, the third metal layer can also play a certain supporting role, thereby stabilizing the structure of the multi-layer metal plate.

[0008] In a possible implementation, the projection area of the first metal layer and the first insulating layer in the stacking direction of the multilayer metal plate is less than or equal to the projection area of the second metal layer and the second insulating layer in the stacking direction of the multilayer metal plate. That is, the first metal layer (corresponding to the metal layer 401 in Embodiment Three), the first insulating layer (corresponding to the insulating layer 403 in Embodiment Three), the second metal layer (corresponding to the metal substrate layer 403 in Embodiment Three), and the second insulating layer (corresponding to the insulating layer 404 in Embodiment Three) are all spaced apart from each other by a certain distance, which facilitates the implementation of the side wall soldering / tinning or via hole.

[0009] In a possible implementation, the projection area of the first metal layer, the first insulating layer, and the second metal layer in the stacking direction of the multilayer metal plate is less than the projection area of the second insulating layer and the third metal layer in the stacking direction of the multilayer metal plate. That is, the first metal layer (corresponding to the metal layer 201 in Embodiment One or Two), the first insulating layer (corresponding to the insulating layer 202 in Embodiment One or Two), and the second metal layer (corresponding to the metal layer 203 in Embodiment One or Two) are all spaced apart from each other by a certain distance, which facilitates the implementation of better safety regulation insulation.

[0010] In a possible implementation, the thickness of the second insulating layer is greater than the thickness of the first insulating layer, which facilitates the implementation of better safety regulation insulation.

[0011] In a possible implementation, when the volume or area of the PCB is small, the first metal layer of the multilayer metal plate can be used to accommodate not only the power device such as the MOS tube but also the entire PCB. By using the first metal layer to accommodate the entire PCB, the volume of the metal substrate heat dissipation structure can be reduced, the manufacturing process can be simplified, and the material cost can be saved. Meanwhile, because the area of the multilayer metal plate is large, the heat dissipation effect of the corresponding metal substrate heat dissipation structure is also good.

[0012] In addition, when the area or volume of the multilayer metal plate is small, the middle part of the PCB can be processed to have a hole in the stacking direction, and the edge of the hole of the PCB can be fixed on the surface of the first metal layer away from the first insulating layer, which is simple in structure and easy to implement.

[0013] In addition, when the volume or area of the PCB is large, the PCB can be erected in the stacking direction of the multi-layer metal plate and above the first metal layer, that is, the PCB has a certain spacing with the first metal layer in the stacking direction of the multi-layer metal plate. Specifically, a metal column or a metal frame can be arranged on the first metal layer of the multi-layer metal plate, and the PCB is erected in the stacking direction of the multi-layer metal plate through the support of the metal column or the metal frame. The metal column can realize electrical interconnection between the PCB and the first metal layer in addition to the support function. By erecting the PCB in the stacking direction of the multi-layer metal plate, the high-temperature baking of the high-heat power device (such as a MOS tube) on the first metal layer on the low-heat controller on the PCB can be alleviated, and the working stability of the controller is improved.

[0014] In a possible implementation, the metal substrate heat dissipation structure further comprises a heat sink or a metal shell connected with the multi-layer metal plate. The heat sink is provided with a plurality of heat dissipation fins, which can increase the heat exchange area and improve the heat exchange efficiency.

[0015] In a possible implementation, the metal substrate heat dissipation structure is in direct contact with the heat sink or the metal shell, that is, the metal substrate heat dissipation structure is fixed on the heat sink or the metal shell by screws. In addition, the metal substrate heat dissipation structure can also be in indirect contact with the heat sink, that is, the metal substrate heat dissipation structure is adhered to the heat sink or the metal shell by silicone grease, gel or heat-cured glue, so as to ensure the close contact between the metal substrate heat dissipation structure and the heat sink or the metal shell, increase the heat exchange area, and avoid the influence of air on the heat dissipation efficiency as much as possible.

[0016] In a possible implementation, the contact part of the heat sink and the multi-layer metal plate is a protruding structure, which is an integral structure or a separate structure (the protruding structure and the heat sink are connected by welding, riveting, adhesion or the like). Through the arrangement of the protruding structure, the safety distance can be increased, and the personal safety can be better ensured.

[0017] In a possible implementation, an insulating layer is arranged around the protruding structure to enhance insulation.

[0018] In a second aspect, the embodiments of the present application further provide a photovoltaic power optimizer, which comprises the metal substrate heat dissipation structure of any one of the first aspect and a photovoltaic power optimizer shell, and the metal substrate heat dissipation structure is located in the accommodating space surrounded by the photovoltaic optimizer shell.

[0019] In a first possible implementation manner of the second aspect, a gap between the metal substrate heat dissipation structure and the photovoltaic power optimizer shell is filled with potting glue to strengthen the heat dissipation capability of the metal substrate heat dissipation structure and shorten the required safety distance of the metal substrate heat dissipation structure. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 Fig. 1 is a schematic diagram of a cross section of a common metal substrate heat dissipation structure;

[0021] Figure 2 Fig. 2 is a schematic diagram of a cross section of another common metal substrate heat dissipation structure;

[0022] Figure 3 Fig. 3 is a schematic diagram of a cross section of a metal substrate heat dissipation structure 100 provided by an embodiment of the present application;

[0023] Figure 4 Fig. 4 is a schematic diagram of a cross section of a metal substrate heat dissipation structure 200 provided by an embodiment of the present application;

[0024] Figure 5 (a) Fig. 5 is a schematic diagram of a cross section of a first metal substrate heat dissipation structure provided by an embodiment of the present application;

[0025] Figure 5 (b) Fig. 6 is a schematic diagram of a cross section of a second metal substrate heat dissipation structure provided by an embodiment of the present application;

[0026] Figure 5 (c) Fig. 7 is a schematic diagram of a cross section of a third metal substrate heat dissipation structure provided by an embodiment of the present application;

[0027] Figure 6 Fig. 8 is a schematic diagram of a cross section of a metal substrate heat dissipation structure 300 provided by an embodiment of the present application;

[0028] Figure 7 Fig. 9 is a top view of the metal substrate heat dissipation structure 300 provided by an embodiment of the present application;

[0029] Figure 8 (a) Fig. 10 is a schematic diagram of a cross section of a fourth metal substrate heat dissipation structure provided by an embodiment of the present application;

[0030] Figure 8 (b) Fig. 11 is a schematic diagram of a cross section of a fifth metal substrate heat dissipation structure provided by an embodiment of the present application;

[0031] Figure 8 (c) Fig. 12 is a schematic diagram of a cross section of a sixth metal substrate heat dissipation structure provided by an embodiment of the present application; DETAILED DESCRIPTION

[0032] The photovoltaic power optimizer can track the maximum power point of a single photovoltaic module in real time by using a unique software algorithm and circuit topology, so as to solve the problem of reduced power generation of a photovoltaic system caused by shading and orientation difference of a photovoltaic module, realize maximum power output of a single photovoltaic module, and improve the power generation efficiency of the photovoltaic system.

[0033] With the increasing requirements of low energy consumption, high efficiency and high reliability of photovoltaic power optimizers in the industry, the heat dissipation problem of power devices inside the photovoltaic power optimizer has attracted more and more attention. However, the heat dissipation structure in the existing photovoltaic power optimizer is composed of different discrete layers, and there are many bonding interfaces between the layers, resulting in large interface thermal resistance, low heat dissipation efficiency, more MOS usage, and increased cost.

[0034] Figure 1 is a common cross-sectional schematic diagram of a metal substrate heat dissipation structure. The power devices (such as MOS tubes and diodes) are arranged on the PCB and realize one-way heat dissipation downward through the high-density via on the PCB. The bottom of the PCB is sequentially provided with a heat spreading aluminum substrate and a ceramic substrate to respectively realize the effects of strengthening heat dissipation and safety regulation insulation. The gaps between the PCB, the heat spreading aluminum substrate and the ceramic substrate can be filled with a heat conducting medium (such as heat conducting silicone grease or gel) to reduce the cavities between the upper and lower layers, thereby achieving better heat conduction effect. In addition, the connection and fixation between the ceramic substrate and the aluminum heat sink are achieved by using a heat-cured glue. In addition, a copper sheet or metal block for grounding can be added between the MOS and the shell to shield the noise return. Although this technology can achieve a certain heat dissipation effect, the total thermal resistance of this metal substrate heat dissipation structure is large due to the contact thermal resistance between the multiple discrete layers, the number of power devices increases (in order to avoid high temperature of the power devices and improve the working stability of the power devices, more power devices are connected in parallel to reduce the temperature of a single power device), and the cost increases. At the same time, the bonding and curing of the ceramic sheet for insulation effect needs to be baked, and the assembly processing between the layers is also troublesome.

[0035] Figure 2 is another common cross-sectional schematic diagram of a metal substrate heat dissipation structure. The power devices are arranged below the PCB, and the power devices include two heat dissipation surfaces, which can realize bidirectional heat dissipation through the upward and downward heat transfer paths. In the downward heat transfer path of the power devices, the structure is sequentially provided with a heat spreading aluminum block and an insulating film to respectively realize the functions of strengthening heat dissipation and safety regulation insulation. A heat conducting medium (such as heat conducting silicone grease or gel) is also used to fill the gaps between the power devices, the heat spreading aluminum block and the insulating film to reduce the interface thermal resistance and improve the heat transfer efficiency. Compared with the structure of Figure 1The described structure has a slightly lower thermal resistance, but the power devices within it, such as MOSFETs, are double-sided, requiring advanced technology. Furthermore, the structure involves the stacking of multiple discrete layers, making its mounting complex and potentially reducing its reliability.

[0036] To address the above issues, this application provides a metal substrate heat dissipation structure that is simpler, significantly reduces interfacial thermal resistance, and improves heat dissipation efficiency. Furthermore, this structure simplifies the manufacturing process, enhances reliability, and reduces material costs.

[0037] Example 1:

[0038] Embodiment 1 of this application provides a metal substrate heat dissipation structure 100, which can solve the heat dissipation problem of photovoltaic power optimizers while simplifying the manufacturing process, reducing material costs, and improving reliability.

[0039] Figure 3 This is a cross-sectional schematic diagram of a "castle-style" metal substrate heat dissipation structure 100 provided in an embodiment of this application. Figure 3 As shown, the metal substrate heat dissipation structure 100 includes: a heat sink (metal casing) 104, a multilayer metal plate 103 disposed on the heat sink 104, power devices 106 (such as MOSFETs or diodes requiring heat dissipation) disposed on the multilayer metal plate 103, and a PCB 101 disposed on the multilayer metal plate 103, supported by metal conductor pillars 105, a metal frame, etc., and connected or soldered with PINs (Pin Headers) (such as reflow soldering or wave soldering). The PCB 101 and the heat sink 104 can be fixedly connected by screws 102 or clips. The multilayer metal plate 103 and the heat sink 104 at its bottom can be in direct or indirect contact. Direct contact refers to the multilayer metal plate 103 being fixed to the heat sink 104 by screws 207, clips, pins, rivets, spring clips, etc., achieving a tight fit between the two to reduce voids between the multilayer metal plate 103 and the heat sink 104, thereby improving heat dissipation efficiency. Indirect contact refers to the application of thermally conductive materials such as silicone grease or gel between the multilayer metal plate 103 and the heat sink 104 to reduce voids between them, thereby achieving better heat conduction than air. The heat sink 104 is equipped with multiple heat dissipation fins, which can increase the heat exchange area and improve heat exchange efficiency. Its material can be metals or alloys with high thermal conductivity, such as copper or aluminum. Understandably, the spatial relationship between the heat sink 104, the multilayer metal plate 103, and the PCB 101 gives the metal substrate heat dissipation structure 100 a "castle-like" structure. The multilayer metal plate 103 provides the first round of heat dissipation, while the heat sink 104 provides the second round of enhanced heat dissipation.

[0040] Specifically, the multi-layer metal plate 103 is sequentially provided with a metal layer 201, an insulating layer 202, a metal layer 203, an insulating layer 204 and a metal substrate layer 205 from top to bottom along the height direction of the multi-layer metal plate 103, and the layers can be formed by compression molding. The metal layer 201 and the metal layer 203 can be made of copper or aluminum, the metal substrate layer 205 can be made of copper, aluminum or aluminum-copper alloy, and the insulating layers 202 and 204 can be made of high-thermal-conductivity PP material. In this embodiment, the materials of the metal layer, the insulating layer and the metal substrate layer 205 are not specifically limited.

[0041] The metal layer 201 is mainly used for power interconnection between the power devices 106 and electrical interconnection between the control devices on the PCB 101 and the power devices 106, and the metal layer 203 is mainly used for electromagnetic shielding. Optionally, the thickness of the metal layer 201 is less than the thickness of the metal layer 203. In addition, in order to achieve the electromagnetic shielding function of the metal layer 203, the metal layer 203 can be connected to the static point on the metal layer 201 through side wall soldering / tinning or via 206. The static point refers to a point in the circuit where the potential does not change abruptly. By connecting to the static point, the metal layer 203 can achieve a similar effect to grounding the metal shell of the photovoltaic power optimizer. In addition, the insulating layer 202 is arranged between the metal layer 201 and the metal layer 203 to achieve the effect of functional insulation. The insulating layer 204 arranged below the metal layer 203 can have a thickness of more than 10 mil to achieve the effect of reinforced insulation. At the same time, in order to better achieve the regulatory function, the projection area of the metal layer 201, the insulating layer 202 and the metal layer 203 in the stacking direction of the multi-layer metal plate 103 is less than the projection area of the metal layer 203 and the metal substrate layer 205 in the stacking direction of the multi-layer metal plate 103, i.e., there is a certain regulatory distance 301 between the edges of the metal layer 201, the insulating layer 202, the metal layer 203 and the insulating layer 204 and the metal substrate layer 205. The regulatory distance 301 refers to the shortest distance that can achieve insulation through air while ensuring the stability and safety of the electrical performance of the multi-layer metal plate 103. In order to shorten the regulatory distance 301 and improve the heat dissipation efficiency of the metal substrate heat dissipation structure 100, the gap between the PCB 101 and the heat sink 104 can also be filled with glue. In addition, the metal substrate layer 205 has strong heat dissipation efficiency and can strengthen heat dissipation, and the metal substrate layer 205 can also support the multiple metal layers and insulating layers in the vertical direction.

[0042] In addition, due to the material and structural limitations of the multi-layer metal plate 103, the surface and interior of the multi-layer metal plate 103 are difficult to arrange and process complex circuits, and therefore, the metal substrate heat dissipation structure 100 is arranged by the metal conductor column 105 or PIN welding (more economical) to place the PCB 101 above the multi-layer metal plate 103, arrange the complex control circuit and the corresponding device on the PCB 101, and arrange the power device 106 on the multi-layer metal plate 103, which is convenient for processing and easy to realize. In addition to the supporting effect, the metal conductor column 105 or PIN welding can also realize the electrical interconnection between the PCB 101 and the power device 106. At the same time, it is worth noting that the power device 106 has a higher temperature specification than the PCB 101, that is, the temperature of the power device 106 during operation is higher than that of the PCB 101. If the power device 106 is in direct contact with the PCB 101 for a long time, the power device 106 will bake the PCB 101, thereby causing the performance and reliability of the corresponding device on the PCB 101 to decrease. Therefore, the metal substrate heat dissipation structure 100 can also alleviate the baking of the power device 106 on the PCB 101 and improve the performance stability and reliability of the device.

[0043] It should be noted that in the metal substrate heat dissipation structure 100, the heat sink 104 and the connecting member (such as the screw 102 and the screw 207) between the heat sink 104 and the PCB 101 and the multi-layer metal plate 103 are optional. Through the arrangement of the heat sink 104, the multi-layer metal plate 103 can play a first round of heat dissipation effect, and then continue to play a second round of heat dissipation effect.

[0044] In summary, the "castle type" metal substrate heat dissipation structure 100 fully utilizes the advantages of flexible wiring of the PCB 101 and strong heat dissipation capacity of the metal substrate layer 205 in the multi-layer metal plate 103, and has a simple structure and is easy to process and form. In addition, the multi-layer metal plate 103 also omits the ceramic sheet and the aluminum block in the common metal substrate heat dissipation structure, simplifies the structure, and reduces the material cost. Moreover, the simple structure of the multi-layer metal plate 103 also shortens the heat transfer path, reduces the total interface thermal resistance, improves the heat dissipation efficiency, and can reduce the number of power devices used.

[0045] Embodiment two:

[0046] The embodiment two of the present application provides a metal substrate heat dissipation structure 200, which can solve the problem of heat dissipation of the photovoltaic power optimizer, simplify the preparation process, reduce the material cost, and improve the reliability.

[0047] Figure 4is a sectional view of still another metal substrate heat dissipation structure 200 provided by Embodiment Two of the present application. The main difference between Embodiment Two and Embodiment One is the relative size of the PCB 101 and the multi-layer metal plate 103 and the positional relationship between the PCB 101 and the multi-layer metal plate 103. As shown in Figure 4 the metal substrate heat dissipation structure 200 includes a heat sink (metal housing) 104, a multi-layer metal plate 103 arranged on the heat sink 104, a power device 106 (MOS tube or diode device requiring heat dissipation, etc.) arranged on the multi-layer metal plate 103, and a PCB 101 arranged on the multi-layer metal plate 103. The multi-layer metal plate 103 and the PCB 101 can be connected by PIN connection, welding, riveting or clamping, etc. In Embodiment Two, when the volume or area of the PCB 101 is small, the PCB 101 can be designed as a small plate and directly arranged on the metal layer 201 of the multi-layer metal plate 103. By arranging the PCB 101 and the power device 106 directly on the metal layer 201 of the multi-layer metal plate 103, the height of the metal substrate heat dissipation structure 200 in the stacking direction can be reduced, thereby reducing the volume of the metal substrate heat dissipation structure 200, simplifying the preparation process and saving material costs. At the same time, since the area of the multi-layer metal plate 103 is large, the heat dissipation effect of the metal substrate heat dissipation structure 200 will also be high. The multi-layer metal plate 103 and the heat sink 104 at the bottom thereof can be in direct contact or indirect contact. Direct contact means that the multi-layer metal plate 103 is fixed on the heat sink 104 by screws 207, clamping, pins, riveting, spring clamps, etc., to achieve close contact between the two, so as to reduce the voids between the multi-layer metal plate 103 and the heat sink 104, thereby improving the heat dissipation efficiency, while indirect contact means that a heat-conducting material such as silicone grease or gel is applied between the multi-layer metal plate 103 and the heat sink 104 to reduce the voids between the multi-layer metal plate 103 and the heat sink 104, thereby achieving better heat conduction effect than air. The heat sink 104 is provided with a plurality of heat dissipation fins, which can increase the heat exchange area and improve the heat exchange efficiency, and the material thereof can be copper or aluminum or other metal or alloy with high thermal conductivity.

[0048] Specifically, the multi-layer metal plate 103 is sequentially provided with a metal layer 201, an insulating layer 202, a metal layer 203, an insulating layer 204 and a metal substrate layer 205 from top to bottom along the height direction thereof, and the above layers are formed by compression molding. The metal layer 201 and the metal layer 203 can be copper or aluminum, the metal substrate layer 205 can be copper, aluminum or aluminum-copper alloy, and the insulating layers 202 and 204 can be high-thermal-conductivity PP material. Herein, the materials of the above metal layers, insulating layers and metal substrate layer 205 are not specifically limited.

[0049] The metal layer 201 is mainly used to realize power interconnection between the plurality of power devices 106 and electrical interconnection between the control devices on the PCB 101 and the plurality of power devices 106, and the metal layer 203 is mainly used to realize electromagnetic shielding function, therefore, the thickness of the metal layer 201 is less than the thickness of the metal layer 203. Meanwhile, in order to realize the electromagnetic shielding function of the metal layer 203, the metal layer 203 is connected to the static points of the metal layer 201 through the sidewall soldering / tinning or via 206. In addition, the insulating layer 202 is arranged between the metal layer 201 and the metal layer 203 to realize the safety regulation insulation function. The insulating layer 204 arranged below the metal layer 203 can have a thickness of more than 10 mil to realize the function of strengthening insulation. Meanwhile, in order to better realize the safety regulation function, the projection area of the metal layer 201, the insulating layer 202 and the metal layer 203 in the stacking direction of the multi-layer metal plate 103 is less than the projection area of the metal layer 203 and the metal substrate layer 205 in the stacking direction of the multi-layer metal plate 103, that is, there is a certain safety regulation distance 301 between the edges of the metal layer 201, the insulating layer 202, the metal layer 203 and the insulating layer 204 and the metal substrate layer 205. The safety regulation distance 301 refers to the shortest distance that can realize insulation through air while ensuring the stability and safety of the electrical performance of the multi-layer metal plate 103. In addition, the metal substrate layer 205 can also play the role of supporting the top multi-layer structure.

[0050] In addition, due to the material and structural limitations of the multi-layer metal plate 103, it is difficult to arrange and process complex lines on the surface and inside of the multi-layer metal plate 103, therefore, the embodiment two also arranges the complex lines on the PCB 101, and arranges the power devices 106 on the multi-layer metal plate 103. Different from the embodiment one, the PCB in the embodiment two is more integrated and smaller in size, and can be directly fixed on the multi-layer metal plate 103, therefore, the metal conductor column 105 and the screw 102 in the embodiment one can be omitted, which simplifies the process and saves material cost.

[0051] It should be noted that in the metal substrate heat dissipation structure 200, the heat sink 104 and the connecting member (such as the screw 207) between the heat sink 104 and the multi-layer metal plate 103 are optional. Through the arrangement of the heat sink 104, the heat sink 104 can continue to play the role of the second round of heat dissipation after playing the role of the first round of heat dissipation of the multi-layer metal plate 103.

[0052] In addition, referring to Figure 5 , in the embodiment one, the position and size relationship between the PCB 101 and the multi-layer metal plate 103 is shown in Figure 5 (a), in the embodiment two, the position and size relationship between the PCB 101 and the multi-layer metal plate 103 is shown in Figure 5(b) shows, in addition to the positional and dimensional relationship between the PCB 101 and the multi-layer metal plate 103, the positional and dimensional relationship between the PCB 101 and the metal conductor column 105. Figure 5 (c) shows. In (c), the PCB 101 is perforated at the middle part in the stacking direction, and the perforated edge of the PCB 101 is connected to the surface of the metal layer 201 away from the insulating layer 202. The perforated edge of the perforated PCB 101 and the metal layer 201 of the multi-layer metal plate 103 can be connected by welding 207, riveting or clamping, etc. The structure is simple and easy to implement.

[0053] In general, the metal substrate heat dissipation structure 200 in Embodiment Two fully utilizes the advantages of flexible wiring of the PCB 101 and strong heat dissipation capacity of the metal substrate layer 205 in the multi-layer metal plate 103, and the multi-layer metal plate 103 also omits the ceramic sheet and the heat spreading aluminum block in the common metal substrate heat dissipation structure and the metal conductor column 105 in Embodiment One, thereby reducing the material cost. Moreover, the simple structure of the multi-layer metal plate 103 also shortens the heat transfer path, reduces the total interfacial thermal resistance, and improves the heat dissipation efficiency.

[0054] Embodiment Three:

[0055] Embodiment Three of the present application provides still another multi-layer metal plate heat dissipation structure 300, which can solve the problem of heat dissipation of the photovoltaic power optimizer, simplify the preparation process, reduce the material cost, and improve the reliability.

[0056] Figure 6 is a cross-sectional schematic view of still another metal substrate heat dissipation structure 300 provided by the embodiments of the present application. Embodiment Three is mainly different from Embodiments One and Two in the structure, composition of the multi-layer metal plate 103 and the positional relationship between the PCB 101 and the multi-layer metal plate 103. As shown in Figure 6 the metal substrate heat dissipation structure 300 includes the heat sink 104, the multi-layer metal plate 103 arranged on the heat sink 104, the power device 106 arranged on the metal layer 401 of the multi-layer metal plate 103, and the perforated PCB 101 arranged on the metal layer 401 of the multi-layer metal plate 103. In the metal substrate heat dissipation structure 300, the PCB 101 is perforated at the middle part in the stacking direction, and the perforated edge of the PCB 101 is connected to the surface of the metal layer 401 away from the insulating layer 402. The perforated edge of the PCB 101 and the metal layer 401 of the multi-layer metal plate 103 can be connected by welding 207, riveting or clamping, etc. The multi-layer metal plate 103 and the heat sink 104 can be connected by a heat-conducting material such as silicone grease, gel or heat-curing glue, or by welding, etc. to reduce the interfacial thermal resistance and improve the heat transfer efficiency of the metal substrate heat dissipation structure 300.

[0057] Specifically, the multi-layer metal plate 103 is sequentially provided with a metal layer 401, an insulating layer 402, a metal substrate layer 403, and an insulating layer 404 from top to bottom along the height direction of the multi-layer metal plate 103, and the layers are formed by compression molding. The metal layer 401 can be made of copper or aluminum, the metal substrate layer 403 can be made of copper, aluminum, or aluminum-copper alloy, and the insulating layers 402 and 404 can be made of high-thermal-conductivity PP material. In this embodiment, the materials of the metal layer 401, the insulating layer 402, the metal substrate layer 403, and the insulating layer 404 are not specifically limited.

[0058] The metal layer 401 is mainly used to realize power interconnection between the plurality of power devices 106 and electrical interconnection between the control devices on the PCB 101 and the power devices 106 on the multi-layer metal plate 103. Different from the first and second embodiments, the metal substrate layer 403 of the multi-layer metal plate 103 of the third embodiment can be connected to the static points on the metal layer 401 by side wall soldering / tinning or via 206, thereby realizing the function of electromagnetic shielding. In addition to the function of electromagnetic shielding, the metal substrate layer 403 can also have the effect of strengthening heat dissipation due to its strong heat dissipation capacity. The insulating layer 402 is arranged between the metal substrate layer 403 and the metal layer 401 to realize the function of insulation. The insulating layer 404 arranged below the metal substrate layer 403 can have a thickness of more than 10 mil to realize the function of strengthening insulation. Meanwhile, the projection area of the metal layer 401 and the insulating layer 402 in the stacking direction of the multi-layer metal plate 103 can be less than or equal to the projection area of the metal substrate layer 403 and the insulating layer 404 in the stacking direction of the multi-layer metal plate 103. That is, the edges of the metal layer 401 and the insulating layer 402 and the edges of the metal substrate layer 403 and the insulating layer 404 can have a certain distance, which can facilitate the realization of side wall soldering / tinning or via 206. In addition, the edges of the metal layer 401 and the insulating layer 402 and the edges of the metal substrate layer 403 and the insulating layer 404 can also not have a certain distance, and the electrical interconnection between the metal layer 401 and the metal substrate layer 403 can be realized by means of interlayer via. In order to ensure sufficient safety distance 301, a protruding structure 107 is arranged on the side of the heat sink 104 connected to the multi-layer metal plate 103, and the protruding structure 107 is connected to the multi-layer metal plate 103. The protruding structure 107 can be integrally formed with the heat sink 104 or fixed by welding, riveting, or clamping. In addition, the safety of the multi-layer metal plate heat dissipation structure 300 can be improved by arranging the insulating layer 303 on both sides of the protruding structure 107. The insulating layer 303 can be fixed to the heat sink 104 by means of bonding, riveting, or clamping. In addition, in order to shorten the safety distance 301, the insulating layer 303 can be filled with glue 302 between the PCB 101 and the insulating layer 303.

[0059] In addition, due to the material and structural limitations of the multilayer metal board 103, it is difficult to arrange and process complex circuits on the surface and inside of the multilayer metal board 103. Therefore, in this embodiment, complex wiring is also arranged on the PCB 101, while power devices 106 are arranged on the multilayer metal board 103. Figure 7 for Figure 6 The diagram shows a top view of the heat dissipation structure 300 on the metal substrate. Figure 7 As shown, by making holes in PCB101 and fixing the remaining PCB101 directly onto the multilayer metal plate 103, the metal conductor post 105 in Embodiment 1 can be eliminated, saving material costs and simplifying the structure.

[0060] It should be noted that in the metal substrate heat dissipation structure 300, the heat sink 104 is optional. By setting the heat sink 104, after the multi-layer metal plate 103 has achieved the first round of heat dissipation, it can continue to play the role of the second round of heat dissipation.

[0061] Additionally, refer to Figure 8 In Embodiment 3, the positional and size relationship between PCB101 and multilayer metal plate 103 is as follows: Figure 8 As shown in (b), the positional and size relationship between PCB101 and multilayer metal board 103 can also be... Figure 8 (a) and Figure 8 As shown in (c). Specifically, in Figure 8 In (a), the volume and area of ​​PCB101 are relatively small. PCB101 can be fixed to the metal layer 401 of the multilayer metal plate 103 by means of pin connection, soldering, riveting, or snap-fit, thereby reducing the height of the metal substrate heat dissipation structure 300 in the stacking direction and reducing the volume of the metal substrate heat dissipation structure 300. Figure 8 In (c), the area and volume of PCB101 are relatively large. PCB101 can be mounted on top of multilayer metal plate 103 by setting metal conductor pillars 105 or PIN soldering, which alleviates the high temperature baking of control devices on PCB101 by power devices 106 in the working state.

[0062] In summary, the metal substrate heat dissipation structure 300 in this embodiment fully utilizes the advantages of flexible PCB 101 routing and strong heat dissipation capacity of the multilayer metal plate 103, and its structure is simple and easy to process and form. Furthermore, the multilayer metal plate 403 omits the ceramic sheet and heat-spreading aluminum block of common metal substrate heat dissipation structures, as well as the metal conductor pillar 105 or metal frame of Embodiment 1, and the metal layer 203 of Embodiment 1 or Embodiment 2, simplifying the structure and reducing material costs. Moreover, the simple multilayer metal plate 103 structure in this embodiment also shortens the heat transfer path, reducing the total interfacial thermal resistance and improving heat dissipation efficiency.

[0063] Embodiment four

[0064] Embodiment four of the present application provides a photovoltaic power optimizer, which comprises the metal substrate heat dissipation structure according to any one of the above embodiments one to three and a photovoltaic power optimizer shell. The metal substrate heat dissipation structure according to any one of the above embodiments one to three is placed in the accommodating space surrounded by the photovoltaic power optimizer shell.

[0065] It is easy to understand that, on the basis of several embodiments provided by the present application, the skilled in the art can combine, split, recombine, etc. to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0066] The above specific embodiments further detail the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the present application shall be included in the protection scope of the present application.

Claims

1. A metal base plate heat dissipating structure, characterized by comprising: The metal substrate heat dissipation structure comprises: A printed circuit board (PCB), a multi-layer metal plate, and a power device, the multi-layer metal plate comprising a first metal layer, a first insulating layer, a second metal layer, and a second insulating layer stacked in sequence; The first metal layer is electrically connected with the second metal layer to achieve electromagnetic shielding; The power device is arranged on a surface of the first metal layer away from the first insulating layer; The PCB is provided with a control device for controlling the power device, and the PCB is electrically connected with the first metal layer and arranged on a side of the first metal layer away from the first insulating layer.

2. The metal base plate heat dissipating structure according to claim 1, wherein ； The multi-layer metal plate further comprises a third metal layer arranged below the second insulating layer.

3. The metal base plate heat dissipating structure according to claim 1, wherein ； The projection area of the first metal layer and the first insulating layer in the stacking direction of the multi-layer metal plate is less than or equal to the projection area of the second metal layer and the second insulating layer in the stacking direction of the multi-layer metal plate.

4. The metal base plate heat dissipating structure according to claim 2, wherein ； The projection area of the first metal layer, the first insulating layer, and the second metal layer in the stacking direction of the multi-layer metal plate is less than the projection area of the second insulating layer and the third metal layer in the stacking direction of the multi-layer metal plate.

5. The metal base plate heat dissipating structure according to any one of claims 1 to 4, wherein ； The thickness of the second insulating layer is greater than the thickness of the first insulating layer.

6. The metal substrate heat dissipation structure according to any one of claims 1-5, wherein: The PCB is arranged on the first metal layer of the multi-layer metal plate as a whole; or The PCB is provided with a hole in the stacking direction, and the hole edge of the PCB is connected with the surface of the first metal layer away from the first insulating layer; or The PCB is arranged on the multi-layer metal plate in the stacking direction and above the first metal layer.

7. The metal substrate heat dissipation structure according to any one of claims 1-6, wherein: The metal substrate heat dissipation structure further comprises a heat sink connected with the multi-layer metal plate.

8. The metal substrate heat dissipation structure according to claim 7, wherein: The metal substrate heat dissipation structure is fixed on the heat sink by screws, silicone grease, gel, or heat-cured glue. The contact part of the heat sink with the multi-layer metal plate is a convex structure, and the convex structure is an integral structure or a separate structure with the heat sink.

9. The metal base plate heat dissipating structure according to claim 8, wherein ； An insulating layer is arranged around the convex structure.

10. The metal base plate heat dissipating structure according to claim 9, wherein ； The photovoltaic power optimizer comprises the metal substrate heat dissipation structure according to any one of claims 1-10 and a housing of the photovoltaic power optimizer; 11. A photovoltaic power optimizer, comprising: The metal substrate heat dissipation structure is arranged in a containing space surrounded by the housing of the photovoltaic power optimizer.

12. The photovoltaic power optimizer according to claim 11, wherein: The gap between the metal substrate heat dissipation structure and the housing of the photovoltaic power optimizer is filled with potting glue. ​

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