Heat dissipation structure and electronic equipment

Abstract

The embodiment of the invention discloses a heat dissipation structure and electronic equipment. The heat dissipation structure comprises a cooling device, a heat conduction layer, a first circuit board and a first power device, the first power device is fixedly arranged on the first board surface of the first circuit board to form a power assembly; the first circuit board is fixedly connected with the cooling device, and the second board surface of the first circuit board abuts against the connecting surface of the cooling device. An inner concave part is arranged on the connecting surface of the cooling device, the outer contour of the inner concave part is located in the area where the first circuit board abuts against the cooling device, and the semi-solid heat conduction material is arranged in the inner concave part to form a heat conduction layer. In the scheme, the semi-solid heat conduction material is controlled to slide relative to the plate surface through the concave part, so that heat can be effectively conducted to the cooling device; in addition, based on the high heat conductivity coefficient of the semi-solid heat conduction material, gaps are filled while heat conduction is conducted, the absolute heat resistance of the heat dissipation structure can be reduced, low-heat-resistance high-heat-conduction heat dissipation is achieved, and reliable through-flow connection between power devices can be achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of computer hardware, and in particular to a heat dissipation structure and an electronic device. Background Art

[0002] As the performance of electronic devices improves, the heat dissipation requirements of corresponding power devices also increase accordingly. Taking the switching power supply as an example, as a typical high-frequency power conversion device, with the rapid development of artificial intelligence (AI), fifth-generation mobile networks (5G) and cloud applications, the power consumption requirements of supercomputing centers, servers, and routers continue to increase; while the power density of power supplies continues to increase, it is necessary to adapt to the high-density miniaturization development trend of power supplies. The heat dissipation problem is one of the key bottlenecks restricting the high-density development of power supplies. Therefore, it is necessary to effectively improve the heat dissipation effect of high-power devices while the power of the devices continues to increase and the size does not shrink. Summary of the invention

[0003] The embodiments of the present application provide a heat dissipation structure and an electronic device. By optimizing the structure of the heat dissipation structure, the heat dissipation capacity can be effectively improved to meet the heat dissipation performance requirements of high-density miniaturized application scenarios.

[0004] The first aspect of the embodiment of the present application provides a heat dissipation structure, which includes a cooling device, a heat-conducting layer, a first circuit board and a first power device; wherein the first power device is fixedly arranged on the first board surface of the first circuit board to form a power component; the first circuit board is fixedly connected to the cooling device, and the second board surface of the first circuit board abuts against the connecting surface of the cooling device; an inner recess is arranged on the connecting surface of the cooling device, and the outer contour of the inner recess is located in the area where the first circuit board abuts against the cooling device, and a semi-solid heat-conducting material is placed in the inner recess to form a heat-conducting layer. In this way, based on the inner recess, the semi-solid heat-conducting material can be controlled to slip relative to the board surface, and the vertical flow of the semi-solid heat-conducting material can be avoided to affect the contact area of ​​the heat-conducting interface, thereby effectively conducting heat to the cooling device, providing technical guarantee for meeting the heat dissipation requirements of high power density product layout.

[0005] In addition, based on the high thermal conductivity of the semi-solid thermal conductive material, the gaps can be filled while conducting heat, which can reduce the absolute thermal resistance of the heat dissipation structure and achieve low thermal resistance and high thermal conductivity heat dissipation. At the same time, based on the good heat dissipation capability of the heat dissipation structure, the first power device can utilize the reliable flow connection between the first circuit board and other power devices. In addition, on the basis of improving the thermal conductivity and improving the heat dissipation effect, the semi-solid thermal conductive material is placed in the inner recess, and the abutting surface of the first circuit board and the cooling device are directly in contact with each other. The configuration of the semi-solid thermal conductive material will not increase the size in the thickness direction of the board surface, and can reasonably control the thickness size of the heat dissipation structure, which is in line with the design trend of product miniaturization.

[0006] In practical applications, the semi-solid heat-conducting material may be heat-conducting silicone grease, heat-conducting silica gel or heat-conducting gel. For example, a heat-conducting gel with a thermal conductivity of 6 W / (m·K) may be used.

[0007] Exemplarily, the first circuit board is a high density interconnect printed circuit board.

[0008] Based on the first aspect, the embodiment of the present application further provides a first implementation of the first aspect: the solder resist layer on one side of the second board surface of the first circuit board includes a solder resist window, at least part of the solder resist window overlaps with the inner recess, and a semi-solid thermal conductive material is placed in the inner recess and the solder resist window to form the thermal conductive layer. Based on the solder resist window, the semi-solid thermal conductive material is able to contact and exchange heat with the first circuit board substrate at the position of the solder resist window, which can further reduce thermal resistance.

[0009] In practical applications, the solder resist opening on one side of the first circuit board may be consistent with the outer contour of the inner recess on one side of the cooling device to form a heat-conducting layer with good heat-conducting performance.

[0010] Based on the first aspect, or the first implementation of the first aspect, the embodiment of the present application further provides a second implementation of the first aspect: the copper foil layer on the side of the first circuit board close to the cooling device is a copper foil layer without electrical connection. In this way, good electrical insulation between the first circuit board and the cooling device can be achieved to ensure large current interconnection of the first power device.

[0011] Based on the first aspect, or the first implementation of the first aspect, or the second implementation of the first aspect, the embodiment of the present application further provides a third implementation of the first aspect: the conductor layer of the first circuit board is located between the copper foil layer without electrical connection and the first board surface, and holes connecting the conductor layers and penetrating the first board surface are opened on the first circuit board, and the holes include blind holes, buried holes or stacked holes. In this way, part of the heat generated by the first power device can be transferred to the second surface of the first circuit board through the blind holes, buried holes or stacked holes in sequence, so as to further reduce the thermal resistance of the first circuit board.

[0012] Exemplarily, the two conductor layers close to the first board surface can be connected through a blind hole. Except for the conductor layer adjacent to the first board surface, other conductor layers can be connected through buried holes. Part of the heat generated by the first power device can be transferred to the second surface of the first circuit board through the blind holes and the buried holes in turn, which can improve the heat conduction efficiency and has low process costs.

[0013] In other exemplary embodiments, the conductor layers on the first circuit board are connected via stacked vias formed by connecting blind vias and buried vias. The heat conduction path established by the stacked vias is shortened, which can further improve the overall thermal conductivity.

[0014] Based on the first aspect, or the first embodiment of the first aspect, or the second embodiment of the first aspect, or the third embodiment of the first aspect, the embodiment of the present application also provides a fourth embodiment of the first aspect: a plurality of first power devices are arranged on the first board surface of the first circuit board, and the plurality of first power devices are the same first power devices or different first power devices.

[0015] Based on the first aspect, or the first embodiment of the first aspect, or the second embodiment of the first aspect, or the third embodiment of the first aspect, or the fourth embodiment of the first aspect, the embodiment of the present application also provides a fifth embodiment of the first aspect: a surface nut is provided on the first circuit board, and a through hole is correspondingly provided on the cooling device; one end of the surface nut extends out of the second board surface of the first circuit board and extends into the through hole of the cooling device, and the other end of the surface nut does not exceed the first board surface of the first circuit board; a screw adapted to the surface nut is inserted into the through hole from the cooling device side. In this arrangement, the surface nut extends toward one side of the cooling device, which can reduce the local board area and facilitate the high-density layout of the product; at the same time, the length of the screw can be reasonably controlled, and a shorter screw can be used to achieve reliable fixation.

[0016] In practical applications, the through holes are non-metallized through holes to form insulation inside the holes and avoid short circuits between surface nuts and screws and the cooling device.

[0017] Based on the first aspect, or the first implementation of the first aspect, or the second implementation of the first aspect, or the third implementation of the first aspect, or the fourth implementation of the first aspect, the embodiment of the present application also provides a sixth implementation of the first aspect: the cooling device includes two connection surfaces, the two connection surfaces are a first connection surface and a second connection surface that are arranged opposite to each other, and at least one power component is fixedly arranged on the first connection surface and the second connection surface, respectively. Overall, it has a good integration, and the space saved can be used to layout more devices, and a higher power density can be achieved.

[0018] Based on the sixth implementation of the first aspect, the embodiment of the present application also provides a seventh implementation of the first aspect: the power component arranged on the first connection surface is the first power component, and the power component arranged on the second connection surface is the second power component; a surface-mounted nut is arranged on the first circuit board of the first power component, and through holes are respectively provided on the first circuit board of the cooling device and the second power component; one end of the surface-mounted nut extends out of the second board surface of the first circuit board of the first power component and extends into the through hole of the cooling device, and the other end of the surface-mounted nut does not exceed the first board surface of the first circuit board of the first power component; a screw adapted to the surface-mounted nut is inserted into the through hole from the side of the second power component. In this way, the local board area can be reduced, which is conducive to the high-density layout of the product.

[0019] Based on the first aspect, or the first implementation of the first aspect, or the second implementation of the first aspect, or the third implementation of the first aspect, or the fourth implementation of the first aspect, or the fifth implementation of the first aspect, or the sixth implementation of the first aspect, or the seventh implementation of the first aspect, the embodiment of the present application also provides an eighth implementation of the first aspect: it also includes a second circuit board and a second power device arranged on the second circuit board, the second circuit board is arranged to intersect with the first circuit board, the first circuit board is inserted and fixed on the second circuit board, and the two are electrically connected. In this way, a flow connection between the first power device on the first circuit board and the second power device on the second circuit board can be achieved.

[0020] Based on the first aspect, or the first implementation of the first aspect, or the second implementation of the first aspect, or the third implementation of the first aspect, or the fourth implementation of the first aspect, or the fifth implementation of the first aspect, the embodiment of the present application further provides a ninth implementation of the first aspect: the cooling device includes a plurality of connection surfaces, and at least one power component is fixedly arranged on each connection surface. Such an arrangement can further improve the structural integration and achieve a high-density layout.

[0021] In practical applications, the actual number of arrangements can be determined as needed, and the number of power components arranged on each connection surface can be the same or different.

[0022] Based on the first aspect, or the first embodiment of the first aspect, or the second embodiment of the first aspect, or the third embodiment of the first aspect, or the fourth embodiment of the first aspect, or the fifth embodiment of the first aspect, or the sixth embodiment of the first aspect, or the seventh embodiment of the first aspect, or the eighth embodiment of the first aspect, or the ninth embodiment of the first aspect, the embodiment of the present application also provides a tenth embodiment of the first aspect: further comprising an auxiliary cooling device, the auxiliary cooling device abutting against the cooling device. The auxiliary cooling device can improve the heat dissipation performance of the entire heat dissipation structure.

[0023] For example, the cooling device is in a "T" shape, including a first section and a second section arranged to intersect each other; the connection surface for arranging the power component is located on the first section extending vertically, and the auxiliary cooling device is adapted to the surface of the second section facing away from the first section, and both are provided with an auxiliary heat-conducting layer. Therefore, by providing the auxiliary heat-conducting layer, the heat conduction efficiency between the cooling device and the auxiliary cooling device can be improved.

[0024] In practical applications, the auxiliary heat-conducting layer can be formed by using a semi-solid heat-conducting material.

[0025] In other specific implementations, the auxiliary heat-conducting layer may also be a heat-conducting pad or a ceramic sheet.

[0026] Based on the first aspect, or the first embodiment of the first aspect, or the second embodiment of the first aspect, or the third embodiment of the first aspect, or the fourth embodiment of the first aspect, or the fifth embodiment of the first aspect, or the sixth embodiment of the first aspect, or the seventh embodiment of the first aspect, or the eighth embodiment of the first aspect, or the ninth embodiment of the first aspect, or the tenth embodiment of the first aspect, the embodiment of the present application also provides an eleventh embodiment of the first aspect: a liquid cooling channel is provided in the auxiliary cooling device. With such a configuration, based on the heat exchange capacity of the liquid cooling system, the heat dissipation performance of the heat dissipation structure can be further improved.

[0027] The first aspect of the embodiment of the present application provides an electronic device, which includes the heat dissipation structure as described above. Based on the heat dissipation structure provided by the embodiment of the present application, the heat generated by the power device on the electronic device can be quickly dissipated to provide a good ambient temperature and ensure the stable and reliable operation of the electronic device.

[0028] Exemplarily, the electronic device may be a power supply, a mobile phone, an antenna, a battery, an in-vehicle electronic product, a server, or other device types. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of a heat dissipation structure provided by the related technology of this application;

[0030] Figure 2 A schematic diagram of another heat dissipation structure provided by the related technology of this application;

[0031] Figure 3 A schematic diagram of a heat dissipation structure provided in an embodiment of the present application;

[0032] Figure 4 for Figure 3 A-direction view in the figure;

[0033] Figure 5A schematic diagram of a first circuit board provided in an embodiment of the present application;

[0034] Figure 6 A schematic diagram of another first circuit board provided in an embodiment of the present application;

[0035] Figure 7 A schematic diagram of another heat dissipation structure provided in an embodiment of the present application;

[0036] Figure 8 A schematic diagram of a flow connection structure provided in an embodiment of the present application;

[0037] Fig. 9 A schematic diagram of another heat dissipation structure provided in an embodiment of the present application;

[0038] Fig.10 for Fig. 9 The heat dissipation structure shown is Figure 1 The thermal simulation cloud diagram of the comparative example 1 is shown;

[0039] Fig.11 A schematic diagram of the heat dissipation structure described in Comparative Example 3;

[0040] Fig.12 A schematic diagram of another heat dissipation structure provided in an embodiment of the present application;

[0041] Fig.13 A schematic diagram of another heat dissipation structure provided in an embodiment of the present application;

[0042] Fig.14 A schematic diagram of another heat dissipation structure provided in an embodiment of the present application;

[0043] Fig.15 A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The embodiment of the present application provides a heat dissipation structure, which can effectively improve the heat dissipation capacity through structural optimization and meet the heat dissipation performance requirements of high-density miniaturized application scenarios.

[0045] See also Figure 1, this figure is a schematic diagram of a heat dissipation structure 100' provided by the related technology of this application. The heat dissipation structure includes a cooling device 1', a field effect transistor 2' and a circuit board 3', the field effect transistor 2' is arranged on the circuit board 3', and is electrically connected to the circuit board 3', and a thermally conductive gel layer 4' is arranged between the cooling device 1' and the surface of the field effect transistor 2' away from the circuit board 3'. Thus, the heat generated by the field effect transistor 2' is dissipated through the thermally conductive gel layer 4' and the cooling device 1' in sequence. However, the cooling device 1' contacts the back shell side of the field effect transistor 2' for heat exchange, the shell thermal resistance is large, and the heat dissipation efficiency is low, which cannot be applied to higher power scenarios.

[0046] See also Figure 2 , which is a schematic diagram of another heat dissipation structure 100" provided by the related technology of the present application. The heat dissipation structure includes a cooling device 1", a field effect transistor 2", a first circuit board 3", a heat-conducting insulating film 4", and a second circuit board 5", the second circuit board 5" is vertically connected to the first circuit board 3", the field effect transistor 2" is arranged on the second circuit board 5", and is electrically connected to the first circuit board 3" through the second circuit board 5", and a heat-conducting layer is arranged between the vertically arranged part of the cooling device 1" and the surface of the second circuit board 5" away from the field effect transistor 2", in order to avoid the vertical flow problem of thermally conductive gel and thermally conductive silicone grease, and to ensure the electrical insulation of the second circuit board 5", the heat-conducting layer is formed by a heat-conducting insulating film 4", and the second circuit board "is fixed to the vertically arranged part of the cooling device 1" by screws. However, limited by the thermal conductivity of the heat-conducting insulating film 4", the absolute thermal resistance cannot be effectively reduced.

[0047] Based on this, an embodiment of the present application provides a heat dissipation structure, which includes a cooling device, a heat conductive layer, a first circuit board and at least one first power device; wherein the first power device is fixedly arranged on the first board surface of the first circuit board to form a power component; the first circuit board is fixedly connected to the cooling device, and the second board surface of the first circuit board is abutted against the connecting surface of the cooling device to establish a contact heat exchange connection relationship between the power component and the cooling device; the connecting surface of the cooling device is provided with an inner recess, the outer contour of the inner recess is located in the area where the first circuit board is abutted against the cooling device, and the semi-solid heat conductive material is placed in the inner recess to form a heat conductive layer.

[0048] With such an arrangement, after the first circuit board is abutted and fixed against the cooling device, the semi-solid thermal conductive material can be controlled to slide relative to the board surface based on the inner recess, thereby avoiding the vertical flow of the semi-solid thermal conductive material affecting the contact area of ​​the thermal conductive interface, thereby effectively conducting heat to the cooling device, providing technical guarantee for meeting the heat dissipation requirements of high power density product layout.

[0049] In addition, based on the higher thermal conductivity of the semi-solid thermal conductive material, filling the gaps while conducting heat can reduce the absolute thermal resistance of the heat dissipation structure, achieving low thermal resistance and high thermal conductivity heat dissipation. Here, "absolute thermal resistance" refers to the physical property used to measure the resistance of a material, component or system to heat conduction, specifically characterizing the amount by which the heat conductivity through the material, component, structure or system is hindered or weakened under a unit temperature difference. A lower thermal resistance value means that more heat can be conducted under a unit temperature difference, and a lower absolute thermal resistance value indicates better thermal conductivity performance. At the same time, based on the good heat dissipation capability of the heat dissipation structure, the first power device can utilize the reliable flow connection between the first circuit board and other power devices.

[0050] In addition, on the basis of improving the thermal conductivity and improving the heat dissipation effect, the semi-solid thermal conductive material is placed in the inner recessed portion, and the abutting surfaces of the first circuit board and the cooling device are in direct abutment with each other. The configuration of the semi-solid thermal conductive material will not increase the size of the board in the thickness direction. On the whole, the thickness size of the heat dissipation structure can be reasonably controlled, which is in line with the design trend of product miniaturization.

[0051] In order to better understand the technical solution and technical effects of the present application, without losing generality, the specific embodiments will be described in detail below in conjunction with the accompanying drawings. Figure 3 and Figure 4 ,in, Figure 3 A schematic diagram of a heat dissipation structure provided in an embodiment of the present application, Figure 4 for Figure 3 A view in the figure.

[0052] like Figure 3 As shown, the heat dissipation structure 100 provided in this embodiment includes a cooling device 1, a first circuit board 2, a first power device 31 and a heat conductive layer 4. The first power device 31 is arranged on the first board surface 21 of the first circuit board 2 to form a first power component 10; the second board surface 22 of the first circuit board 2 is in contact with the first connection surface 11 of the cooling device 1, and a contact heat exchange connection relationship between the first power component 10 and the cooling device 1 is established to transfer the working heat of the first power device 31 to the cooling device 1.

[0053] In a specific implementation, the first power device 31 can be a field effect transistor (Metal Oxide Semiconductor Field Effect Transistor, abbreviated as MOSFET or MOS) to be heat-dissipated, or it can be a heating device or heating component such as a diode, a transistor, a capacitor, a resistor, an inductor, a transformer, a chip or a battery that generates heat during operation.

[0054] In other possible implementations, the number of first power devices 31 configured on the first circuit board 2 can be determined according to the overall product design requirements. In the case where multiple first power devices 31 are arranged on the first circuit board 2, the types of the first power devices can be the same or different.

[0055] The heat conducting layer 4 formed by the semi-solid heat conducting material can improve the heat conduction efficiency between the first circuit board 2 and the cooling device 1. Specifically, an inner concave portion 12 is provided on one side of the first connecting surface 11 of the cooling device 1. The outer contour of the inner concave portion 12 ( Figure 4 The inner recess 12 (shown by the dotted line) is located in the area where the first circuit board 2 and the cooling device 1 are in contact. In other words, the outer contour of the inner recess 12 for accommodating the semi-solid thermal conductive material is located in the overlapping area of ​​the first circuit board 2 and the cooling device 1. In this way, after the first circuit board 2 and the cooling device 1 are fixed against each other, the semi-solid thermal conductive material is restricted from sliding relative to the board surface, which prevents the semi-solid thermal conductive material from overflowing from the accommodating cavity formed by the inner recess 12, and can form a stable and reliable thermal conductive layer, effectively avoiding the possible impact of the flow of the semi-solid thermal conductive material under the action of gravity. As shown in the figure, when the board surface of the first circuit board 2 is set vertically, the technical advantage is particularly significant.

[0056] Here, the semi-solid thermally conductive material refers to the physical state of the thermally conductive material having a certain viscosity, filling the gaps while conducting heat, and effectively improving the heat dissipation performance of the heat dissipation structure. In a specific implementation, the semi-solid thermally conductive material can be thermally conductive silicone grease, thermally conductive silica gel, or thermally conductive gel. For example, but not limited to, a thermally conductive gel with a thermal conductivity of 6W / (m·K) can be used. According to the overall design requirements of the actual application scenario, the thickness of the thermally conductive layer formed can be controlled by adjusting the depth size of the inner recess 12, which is not limited in the embodiment of the present application. For example, a 0.3mm thick thermally conductive gel layer can be formed.

[0057] In general, the heat conducting layer 4 formed by the semi-solid heat conducting material is embedded between the cooling device 1 and the first circuit board 2. Without loss of generality, taking the structure of the cooling device 1 and the first circuit board 2 shown in the figure as an example, the thickness P of the heat dissipation structure is the sum of the thickness P1 of the cooling device 1 and the thickness P2 of the first circuit board 2. Figure 3 As shown, the configuration of the heat conducting layer 4 does not increase the size of the board in the thickness direction.

[0058] Optionally, in order to further improve the heat conduction efficiency, a structure capable of accommodating semi-solid heat conducting material may be provided on the first circuit board 2. Figure 3As shown, in this embodiment, the solder resist layer on one side of the second board surface 22 of the first circuit board 2 includes a solder resist window 23, and the solder resist window 23 is consistent with the outer contour of the inner recess 12 on the cooling device 1 side, and together form a accommodating cavity that can limit the sliding of the semi-solid thermal conductive material; in this way, the thickness of the thermal conductive layer formed by the semi-solid thermal conductive material is the sum of the depth dimensions of the inner recess 12 and the solder resist window 23.

[0059] Based on the solder resist opening 23, the semi-solid thermal conductive material and the first circuit board 2 substrate at the position of the solder resist opening 23 achieve contact heat exchange, which can further reduce thermal resistance. Here, in a possible implementation, the solder resist opening 23 on the first circuit board 2 side can be selectively configured as needed.

[0060] In other specific implementations, the solder resist window 23 on the side of the first circuit board 2 is not limited to being completely consistent with the outer contour of the inner recess 12 on the side of the cooling device 1. As long as the outer contour of the solder resist window 23 is located in the area where the first circuit board 2 and the cooling device 1 are in contact, and partially overlaps with the inner recess 12, a thermal conductive layer that effectively reduces thermal resistance can also be formed.

[0061] In order to improve the reliability of electrical insulation and the large-current interconnection of power devices, further, in this embodiment, the copper foil layer on the side of the first circuit board 2 close to the cooling device 1 is a copper foil layer L1 without electrical connection, or a blank signal layer. Figure 5 , which is a schematic diagram of a first circuit board provided in an embodiment of the present application.

[0062] In this way, based on the configuration of the copper foil layer L1 without electrical connection and the insulating layer between it and the conductor layer L2, the electrical insulation between the first circuit board 2 and the cooling device 1 is reliably achieved, and the large-current interconnection of the first power device 31 is ensured. The other conductor layers L2, L3, L4, L5 and L6 of the first circuit board 2 are stacked in sequence. In a specific implementation, the copper foil layer L1 without electrical connection and the insulating layer between it and the conductor layer L2 can be made of a semi-cured sheet material, such as but not limited to polypropylene (PP) and a reinforcing material. For example, the reinforcing material can be glass fiber cloth, paper base and composite material.

[0063] Optionally, in order to further enhance the vertical heat dissipation of the first power device 31 to the cooling device 1 side, the first circuit board 2 can use a high-density interconnect (High Density Interconnector, HDI) printed circuit board, which can make the product module more miniaturized while meeting the high standard requirements of electrical performance and heat dissipation efficiency. Exemplarily, the thermal conductivity of the first circuit board 2 can be 1W / (m·K) or 3W / (m·K).

[0064] In other specific implementations, the substrate of the first circuit board 2 may be made of other materials, which are determined according to the overall design requirements of the actual product, such as but not limited to, an aluminum substrate or a ceramic board.

[0065] For example Figure 5 As shown, the conductor layer L5 is connected to the conductor layer L6 through a blind via 241, and the conductor layer L2, the conductor layer L3, the conductor layer L4 and the conductor layer L5 are connected through a buried via 242. Part of the heat generated by the first power device 31 can be transferred to the second surface of the first circuit board 2 through the blind via 241 and the buried via 242 in sequence to reduce the thermal resistance of the first circuit board 2, thereby improving the heat conduction efficiency and having a low process cost.

[0066] See also Figure 6 , which is a schematic diagram of another first circuit board provided in an embodiment of the present application. Figure 5 The differences and connections between the described embodiments, and the components or structures with the same functions are indicated in the figures with the same symbols.

[0067] like Figure 6 As shown, the conductor layers L2, L3, L4, L5 and L6 of the first circuit board 2a are connected by stacked vias 243, and the stacked vias 243 are formed by connecting blind vias and buried vias. Figure 5 The heat conduction path established by the blind via 241 and the buried via 242 is shown. Figure 6 The heat conduction path established by the stacked holes 243 is shortened, which can further improve the overall thermal conductivity.

[0068] In addition, in this embodiment, a through hole 13 is provided on the cooling device 1, and a surface-mounted nut 51 is provided on the first circuit board 2. Figure 3 As shown, one end of the surface nut 51 extends out of the second board surface 22 of the first circuit board 2 and extends into the through hole 13 of the cooling device 1 , and the other end of the surface nut 51 does not exceed the first board surface 21 of the first circuit board 2 .

[0069] During assembly, the screw 52 is inserted into the through hole 13 from the side of the cooling device 1 and is tightened with the surface nut 51 to fix the cooling device to the first circuit board 2. Here, the through hole 13 is a non-metallized through hole to form insulation inside the hole to avoid short circuit between the surface nut 51 and the screw 52 and the cooling device 1.

[0070] The surface nut 51 is extended toward one side of the cooling device 1, which can reduce the local board area and facilitate the high-density layout of the product; at the same time, the length of the screw 52 can be reasonably controlled, and the above-mentioned assembly relationship can be reliably fixed by using a shorter screw. It should be understood that the number of matching surface nuts 51, screws 52 and through holes 13 is not limited to the one shown in the figure, and can be determined according to needs. This embodiment of the application is not limited.

[0071] See also Figure 7 , which is a schematic diagram of another heat dissipation structure provided in an embodiment of the present application. Figure 5 The differences and connections between the described embodiments, and the components or structures with the same functions are indicated in the figures with the same symbols.

[0072] like Figure 7 As shown, the heat dissipation structure 100b includes a cooling device 1, a first circuit board 2, a first power device 31, a heat conductive layer 4, a surface mounted nut 51 and a screw 52, ​​wherein the first power device 31 is arranged on the first board surface 21 of the first circuit board 2 to form a first power component 10; the second board surface 22 of the first circuit board 2 is in contact with the first connecting surface 11 of the cooling device 1 to establish a contact heat exchange connection relationship between the first power component 10 and the cooling device; semi-solid heat conductive material is built into the inner recess 12 on the side of the cooling device 1 and the solder resist window 23 on the side of the first circuit board 2 to form a heat conductive layer 4 located between the cooling device 1 and the first circuit board 2 to reduce thermal resistance and improve heat conduction efficiency.

[0073] The heat dissipation structure 100b provided in this embodiment further includes a second power device 32 and a second circuit board 6, wherein the second circuit board 6 is arranged to intersect with the first circuit board 2, and the second power device 32 is arranged on the second circuit board 6. The first circuit board 2 is inserted and fixed on the second circuit board 6, and the two are electrically connected to achieve a through-current connection between the first power device 31 on the first circuit board 2 and the second power device 32 on the second circuit board 6.

[0074] In a specific implementation, the first circuit board 2 and the second circuit board 6 can be connected by solder fingers. Figure 8 , which is a schematic diagram of a flow connection structure provided in an embodiment of the present application.

[0075] As shown in the figure, a male solder finger 25 is provided on the insertion side plate of the first circuit board 2, and a female solder finger 61 is provided on the board surface of the second circuit board 6. During assembly, the male solder finger 25 on the first circuit board 2 is inserted into the female solder finger 61 on the second circuit board 6, and the connection is achieved by wave soldering to form a corresponding electrical connection.

[0076] Taking the first power device 31 and the second power device 32 as MOS as an example, the MOS current on the first circuit board 2 can be connected to the MOS on the second circuit board 6. For the application scenario of multiple MOS, each MOS can be arranged in parallel, which is not limited in the embodiment of the present application.

[0077] Of course, the second circuit board 6 can also be electrically connected to an external circuit and other electronic components (not shown in the figure).

[0078] In addition, in other specific implementations, the first circuit board 2 and the second circuit board 6 may also be assembled and fixed by means of crimping or bonding, etc. This embodiment of the present application is not limited thereto.

[0079] The foregoing Figure 3 and Figure 7 In the implementation scheme, the cooling device 1 provides one connection surface. In other possible implementations, the cooling device may provide two or more connection surfaces to respectively adapt to the heat dissipation requirements of multiple power components. Fig. 9 , which is a schematic diagram of another heat dissipation structure provided in an embodiment of the present application.

[0080] like Fig. 9 As shown, the heat dissipation structure 100c includes a cooling device 1c and two first circuit boards 2, wherein a first power device 31 is arranged on the first board surface 21 of one first circuit board 2 to form a first power component 10c1; and two first power devices 31 are arranged on the first board surface 21 of the other first circuit board 2 to form a second power component 10c2.

[0081] The cooling device 1c is in a "T" shape, and includes a first section 1c1 and a second section 1c2 arranged to intersect each other, and the vertically arranged first section 1c1 includes a first connecting surface 11 and a second connecting surface 14 arranged oppositely. As shown in the figure, the first power component 10c1 is in contact with the first connecting surface 11 through the first circuit board 2, and the second power component 10c2 is in contact with the second connecting surface 14 through the first circuit board 2.

[0082] Correspondingly, the first connection surface 11 and the second connection surface 14 are respectively provided with inner recesses 12 to accommodate the semi-solid heat-conducting material to form a heat-conducting layer 4, so as to achieve low thermal resistance and high thermal conductivity and heat dissipation between the power component and the cooling device 1c. Optionally, the solder resist layers on one side of the second board surface 22 of the two first circuit boards 2 may also include solder resist windows 23 to further reduce thermal resistance.

[0083] In this embodiment, the two first circuit boards 2 are fixed to the cooling device 1c by matching surface nuts 51 and screws 52. Specifically, the surface nuts 51 are arranged on the first circuit board 2 of the first power component 10c1 and do not extend beyond the first board surface 21 of the first circuit board 2; the first circuit board 2 of the second power component 10c2 and the cooling device 1c are both provided with screw through holes.

[0084] During assembly, the screw 52 is inserted into the through hole from the first circuit board 2 side of the second power component 10c2, and is tightened with the surface-mounted nut 51 to fix the first power component 10c1 and the second power component 10c2 to the cooling device 1c. Similarly, the through holes on the first circuit board 2 of the second power component 10c2 and the cooling device 1c are also non-metallized through holes.

[0085] In addition to the matching screws 52 and surface nuts 51, in other possible implementations, the first circuit board and the cooling device can also be fixed by welding. Specifically, a soldering pad (not shown in the figure) can be provided on the second board side of the first circuit board, and the soldering pad and the connecting surface of the cooling device can be fixed by welding.

[0086] Here, the heat dissipation structure 100c further includes a second power device 32 and a second circuit board 6, wherein the second circuit board 6 is arranged to intersect with the two first circuit boards 2, and the second power device 32 is arranged on the second circuit board 6. The first power component 10c1 and the second power component 10c2 further form a group of components with the cooling device 1c, and then are assembled with the second circuit board 6; specifically, the two first circuit boards 2 are inserted and fixed on the second circuit board 6, and the electrical connection between the two is, for example but not limited to, through-flow connection using solder fingers, so as to reliably realize the through-flow connection between the first power device 31 of the first power component 10c1 and the second power component 10c2 and the second power device 32 on the second circuit board 6.

[0087] Optionally, in a specific implementation, the first power component 10c1, the second power component 10c2, the second circuit board 6 and the cooling device 1c can be integrally formed into a package body 9 by a glue-filling process to improve thermal conductivity. In other possible implementations, other materials with a higher thermal conductivity than air can be used for packaging, which is not limited in the present embodiment.

[0088] In order to further improve the heat dissipation performance of the heat dissipation structure, optionally, an auxiliary cooling device 7 may also be included. Fig. 9 As shown, the auxiliary cooling device 7 is in contact with the cooling device 1c to transfer heat from the cooling device 1c side to the auxiliary cooling device 7, thereby improving the overall heat dissipation capacity.

[0089] The auxiliary cooling device 7 is adapted to the surface of the second section 1c2 of the cooling device 1c away from the first section 1c1, and an auxiliary heat-conducting layer 8 is provided between the two. In a specific implementation, the auxiliary heat-conducting layer 8 can be formed of a semi-solid heat-conducting material, such as but not limited to heat-conducting silicone grease, heat-conducting silica gel or heat-conducting gel; in other specific implementations, the auxiliary heat-conducting layer 8 can also be a heat-conducting pad or a ceramic sheet.

[0090] Optionally, a liquid cooling channel 71 may be provided in the auxiliary cooling device 7, and the liquid cooling channel 71 may be connected to the circuit of the liquid cooling system to quickly remove the heat generated by the power device. It is understandable that in addition to being applied to liquid cooling scenarios, the heat dissipation structure provided by the present application is also applicable to natural cooling and air cooling scenarios.

[0091] This embodiment can achieve low thermal resistance and high thermal conductivity heat dissipation between the power component and the cooling device, and at the same time can reasonably control the space occupied by the heat dissipation structure.

[0092] by Figure 1 The heat dissipation structure 100′ shown in FIG. 1 is a comparative example 1, and is different from the present embodiment. Fig. 9 The heat dissipation structure 100c shown in the figure is subjected to simulation test, and the measured data is compared with Fig.10 The thermal simulation cloud diagram shown in Figure 1 is shown in Figure 2. Fig.10 Figure (a) shows the Figure 1 The thermal simulation cloud diagram of the comparative example shown, its simulation test temperature is 103.4℃; Fig.10 Figure (b) shows the Fig. 9 The thermal simulation cloud diagram of the heat dissipation structure shown in the figure shows that the simulation test temperature is approximately 90.83°C.

[0093] from Fig.10 It can be seen from the test simulation results in that the heat dissipation structure 100c adopted in this embodiment shows a better heat dissipation effect in the test simulation. Compared with the heat dissipation structure scheme of comparative example 1, the temperature of the power device is reduced by about 12.57°C.

[0094] by Figure 2 The heat dissipation structure 100" described in the second embodiment is a comparative example. Fig. 9 The heat dissipation structure 100c shown was subjected to simulation test, and the comparison of the measured data is shown in the following table.

[0095] Table 1

[0096]

[0097] It can be seen from the test simulation results in Table 1 that the present embodiment uses thermally conductive gel to form a thermally conductive layer, and realizes electrical insulation between the first circuit board and the cooling device through a semi-cured sheet layer. Compared with the solution of comparative example 2 using a thermally conductive insulating film for electrical insulation, the absolute thermal resistance of the present embodiment is reduced by 20%.

[0098] by Fig.11 The heat dissipation structure shown is a comparative example 3, which is different from the present embodiment. Fig. 9 The heat dissipation structure 100c shown in FIG. 1 is compared with the heat dissipation structure 100c shown in FIG. 1 , and both of them respectively perform heat dissipation processing on four power devices. Fig.11 The heat dissipation structure of the comparative example 3 shown in the figure consists of two Figure 2 The heat dissipation structure 100" shown in the figure is combined, and the module is (number * length * height * thickness) 2*32mm*80mm*9mm=46080mm 3 The volume of this embodiment is (length * height * thickness) 32mm * 80mm * 13mm = 33280mm 3 The overall module volume is reduced by about 27.78%, with better integration. The saved space can be used to layout more devices and achieve higher power density.

[0099] In addition, the surface-mounted nut protrudes from the first board surface of the first circuit board (not shown in the figure) as a comparative example 4, which is different from the embodiment of the present invention. Fig. 9 For comparison, the heat dissipation structure 100c shown in FIG. 1 is used as an example. Taking three threaded fasteners with M3 threads as an example, the total area of ​​the first circuit board is 27 mm*80 mm=2160 mm. 2 , three nuts occupy a plate area of ​​3*π*(5mm 2 )=78.5mm 2 , which can reduce the local board area occupied by threaded fasteners by about 36.3%, shorten the screw length from M3*12 to M3*10, and reduce the module volume by about 5%.

[0100] The foregoing Figure 7 and Fig. 9 In the described embodiment, the connection surface of the cooling device and the abutting power component are both arranged vertically, or in other words, arranged perpendicularly relative to the second circuit board. In other specific implementations, the connection surface of the cooling device and the abutting power component can also be arranged to intersect with the second circuit board at other angles.

[0101] See also Fig.12 , which is a schematic diagram of another heat dissipation structure provided in an embodiment of the present application.

[0102] As shown in the figure, the cooling device 1d of the heat dissipation structure 100d is tilted relative to the second circuit board 6d, and accordingly, the first heat dissipation surface 11d and the second heat dissipation surface 14d of the cooling device 1d are tilted, the first power component 10d1 is abutted against the first heat dissipation surface 11d through its first circuit board 2, and the second power component 10d2 is abutted against the second heat dissipation surface 14d through its first circuit board 2, and the two first circuit boards 2 are respectively fixed to the second circuit board 6 and electrically connected.

[0103] Other configurations and implementations of the heat dissipation structure 100d described in this embodiment are similar to Fig. 9 The described implementation scheme is consistent, so it will not be described in detail.

[0104] In the above embodiments, one or two power components are respectively provided for the cooling device. In other possible implementations, a plurality of other power components may also be provided for the cooling device.

[0105] In one implementation, multiple power components can be arranged on one connection surface of the cooling device. Fig.13 , which is a schematic diagram of another heat dissipation structure provided in an embodiment of the present application.

[0106] The heat dissipation structure 100e includes a cooling device 1e and a plurality of power components 10e, which are respectively arranged on the cooling device 1e. Fig.12 As shown in , three power components 10e are arranged at intervals on a connection surface of the cooling device 1e, and the first circuit board 2 of one power component 10e is fixed and electrically connected to the second circuit board 6e. In a specific implementation, according to the functional requirements of the actual application scenario, the first circuit board 2 of each power component 10e can be fixedly electrically connected to the second circuit board 6e to achieve the corresponding flow connection function.

[0107] Optionally, multiple power components may also be arranged on the other side connection surface of the cooling device 1e to improve the overall integration of the heat dissipation structure and meet the requirements of high-density layout in different application scenarios. The other structures and implementation methods of the heat dissipation structure 100e described in this embodiment are consistent with those in the above embodiment. Therefore, they will not be described in detail.

[0108] In another implementation, the cooling device may include three or more connection surfaces to correspond to the plurality of power components. Fig.14 , which is a schematic diagram of another heat dissipation structure provided in an embodiment of the present application.

[0109] The heat dissipation structure 100f includes a cooling device 1f and a plurality of power components 10f, which are respectively arranged on the cooling device 1f. Fig.14As shown in FIG. 1 , the cooling device 1 f includes four connection surfaces, and a power component 10 f is arranged on each connection surface.

[0110] It should be understood that Fig.14 In the example, one power component 10f is arranged on each connection surface, and the actual number of arrangements can be determined according to needs, and the number of power components 10f arranged on each connection surface can be the same or different. The other structures and implementation methods of the heat dissipation structure 100e described in this embodiment are consistent with the above-mentioned embodiments. Therefore, they will not be described in detail.

[0111] The implementation schemes of the heat dissipation structures described in the above embodiments can be widely applied to various electronic devices or power components to be cooled. Fig.15 , which is a schematic diagram of an electronic device provided in an embodiment of the present application.

[0112] The electronic device 1000 includes a body 200 and a heat dissipation structure 100 . The heat dissipation structure may be the heat dissipation structure described in the above embodiments and is specifically arranged on the body 200 .

[0113] In a specific implementation, the electronic device 100 can be a power supply, a mobile phone, an antenna, a battery, an in-vehicle electronic product, a server, etc. Based on the heat dissipation structure provided in each embodiment of the present application, the heat generated by the power device on the electronic device can be quickly dissipated to provide a good ambient temperature and ensure the stable and reliable operation of the electronic device.

[0114] For example, taking the electronic device as a switching power supply, the heat dissipation structure provided by the embodiment of the present application can solve the electrical insulation problem between the secondary circuit and the housing in a high-density layout, and the basic insulation electrical gap can be 1mm. In other high-density application scenarios, the technical advantages are also significant.

[0115] It should be noted that the ordinal numbers "first" and "second" used in this article are only used to describe the same functional composition or structure in the technical solution. It is understandable that the use of the above ordinal numbers does not constitute an understanding of the technical solution for protection of this application.

[0116] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat dissipation structure, characterized in that: It includes a cooling device, a heat-conducting layer, a first circuit board and a first power device; The first power device is fixedly arranged on the first board surface of the first circuit board to form a power component; The first circuit board is fixedly connected to the cooling device, and the second board surface of the first circuit board abuts against the connection surface of the cooling device; The connection surface of the cooling device is provided with an inner recess, the outer contour of the inner recess is located in the area where the first circuit board and the cooling device abut, and a semi-solid heat-conducting material is placed in the inner recess to form the heat-conducting layer.

2. The heat dissipation structure according to claim 1, characterized in that: The solder resist layer on one side of the second board surface of the first circuit board includes a solder resist window, at least part of the solder resist window overlaps with the inner recess, and the semi-solid thermal conductive material is placed in the inner recess and the solder resist window to form the thermal conductive layer.

3. The heat dissipation structure according to claim 2, characterized in that: The solder resist opening is consistent with the outer contour of the inner recess.

4. The heat dissipation structure according to any one of claims 1 to 3, characterized in that: The copper foil layer on the side of the first circuit board close to the cooling device is a copper foil layer without electrical connection.

5. The heat dissipation structure according to any one of claims 1 to 4, characterized in that: The conductor layer of the first circuit board is located between the copper foil layer without electrical connection and the first board surface. The first circuit board is provided with holes connecting the conductor layers and penetrating to the first board surface. The holes include blind holes, buried holes or stacked holes.

6. The heat dissipation structure according to any one of claims 1 to 5, characterized in that: The semi-solid heat-conducting material is heat-conducting silicone grease, heat-conducting silica gel or heat-conducting gel.

7. The heat dissipation structure according to any one of claims 1 to 6, characterized in that: The first circuit board is a high density interconnect printed circuit board.

8. The heat dissipation structure according to any one of claims 1 to 7, characterized in that: A plurality of first power devices are disposed on the first board surface of the first circuit board. The plurality of first power devices are the same first power devices or different first power devices.

9. The heat dissipation structure according to any one of claims 1 to 8, characterized in that: A surface nut is provided on the first circuit board, and a through hole is correspondingly opened on the cooling device; one end of the surface nut protrudes from the second board surface of the first circuit board and extends into the through hole of the cooling device, and the other end of the surface nut does not exceed the first board surface of the first circuit board; a screw adapted to the surface nut is inserted into the through hole from the cooling device side.

10. The heat dissipation structure according to any one of claims 1 to 8, characterized in that: The cooling device comprises two connection surfaces, which are a first connection surface and a second connection surface arranged opposite to each other, and at least one power component is fixedly arranged on the first connection surface and the second connection surface respectively.

11. The heat dissipation structure according to claim 10, characterized in that: The power component arranged on the first connecting surface is a first power component, and the power component arranged on the second connecting surface is a second power component; a surface nut is arranged on the first circuit board of the first power component, and through holes are respectively opened on the first circuit board of the cooling device and the second power component; one end of the surface nut extends out of the second board surface of the first circuit board of the first power component and extends into the through hole of the cooling device, and the other end of the surface nut does not exceed the first board surface of the first circuit board of the first power component; a screw adapted to the surface nut is inserted into the through hole from the side of the second power component.

12. The heat dissipation structure according to any one of claims 1 to 11, characterized in that: It also includes a second circuit board and a second power device arranged on the second circuit board. The second circuit board is arranged to intersect with the first circuit board. The first circuit board is inserted and fixed on the second circuit board and the two are electrically connected.

13. The heat dissipation structure according to any one of claims 1 to 9, characterized in that: The cooling device comprises a plurality of connection surfaces, and at least one power component is fixedly arranged on each of the connection surfaces.

14. The heat dissipation structure according to any one of claims 1 to 11, characterized in that: It also includes an auxiliary cooling device, which abuts against the cooling device.

15. The heat dissipation structure according to claim 14, characterized in that: The cooling device is "T"-shaped, including a first section and a second section arranged to intersect each other; the connecting surface is located on the first section extending vertically, the auxiliary cooling device is adapted to the surface of the second section facing away from the first section, and both are provided with an auxiliary heat-conducting layer.

16. The heat dissipation structure according to claim 15, characterized in that: A liquid cooling channel is arranged in the auxiliary cooling device.

17. An electronic device, characterized in that: The electronic device comprises the heat dissipation structure according to any one of claims 1 to 16.

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