Power supply module

Abstract

The utility model discloses a power supply module, comprising a printed circuit board having a first surface and a second surface opposite to each other; the radiating fin is arranged above the first surface or below the second surface of the printed circuit board; the heat-conducting medium is arranged between the printed circuit board and the radiating fin; and a plurality of main power devices, when the cooling fin is arranged above the first surface of the printed circuit board, all the main power devices are arranged above the first surface of the printed circuit board, and when the cooling fin is arranged below the second surface of the printed circuit board, all the main power devices are arranged above the second surface of the printed circuit board; wherein heat generated by the main power device is conducted to the radiating fins through the heat-conducting medium. According to the utility model, all the main power devices are arranged on the surface of the printed circuit board, which is close to the radiating fins, so that the total heat resistance of heat conduction of the main power devices can be reduced, and the heat generated by the main power devices can be effectively dissipated.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, in particular to a power supply module with a high power density greater than 1kW / inch3. Background Art

[0002] Power semiconductor devices (Power Electronic Device), also known as power electronic devices or power electronic devices, refer to electronic devices that can be directly used in the main circuit to process electric energy and realize the conversion or control of electric energy. Their functions are mainly divided into power conversion, power amplification, power switching, line protection and rectification. They are indispensable electronic components in power control circuits and power switching circuits. They are intermediate products between the electronic equipment industry and the raw material industry. They are one of the basic and core devices of the electronic information industry.

[0003] Power semiconductor devices can be roughly divided into two categories: power discrete devices (including power modules) and power integrated circuits (Power ICs). Among them, power discrete devices refer to semiconductor devices that are specified to perform certain basic functions and cannot be further subdivided in terms of function. They may include, for example, diodes, switching tubes and magnetic components. Among them, switching tubes include thyristors, triodes, field effect transistors or insulated gate bipolar transistors (IGBTs), etc., magnetic components include transformer cores or inductor cores, and power integrated circuits may include, for example, AC / DC, DC / DC, power management ICs, driver ICs, etc.

[0004] In intelligent power module products, in pursuit of higher power density, there are strict restrictions on the size of the module. In order to be able to layout in a limited space, there are many restrictions on the placement of components, so that some main power components are placed on both surfaces of the PCB board. Under this layout, when the module works under full load conditions for a long time, it is easy to trigger high temperature protection. Figure 1A and Figure 1B As shown in the common topology diagram, the switch tube Q1, the switch tube Q2, the switch tube Q3, the switch tube Q4, the inductor L1, the inductor L2, the transformer T1, the diode D1, the diode D2, etc. are all main power devices.

[0005] In particular, in some cases where working conditions are more stringent, frequent and prolonged high temperatures will affect the service life and reliability of the power module. For example, when the power module is running under full load conditions, the temperature protection will be triggered, thereby affecting the operation of the system board, thereby affecting the reliability of the power module and increasing the use and maintenance costs of the system.

[0006] Figure 2A It is a schematic diagram of the structure of a power module with main power devices on both sides of the PCB. Figure 2A As shown, the power module 10 may include a PCB 11, a heat sink 12 and a thermal pad 13, wherein the PCB 11 has main power devices 14 on the front and back sides, and the thermal pad 13 is arranged between the front side of the PCB 11 and the heat sink 12. The heat of the PCB 11 and the main power devices 14 thereon can be transferred to the heat sink 12 along a heat conduction direction H through the thermal pad 13 and dissipated through the heat sink 12.

[0007] exist Figure 2A The total thermal resistance of the components on the front side of PCB 11 is θ 正面 =θ 正面器件 +θ 导热垫片 +θ 散热片 , and the total thermal resistance of the components on the back side of PCB 11 is θ 背面 =θ 背面器件 +θ PCB +θ 正面器件 +θ 导热垫片 +θ 散热片 The total thermal resistance of the back side device is θ 背面 The total thermal resistance of the device on the front side is θ 正面 Increase the thermal resistance between the PCB and the backside device itself (i.e., θ PCB and θ 背面器件 ), and generally the thermal resistance of the heat sink 12 and the thermal pad 13 is not large, mainly because the thermal resistance of the front device, the back device and the PCB 11 itself has a great influence on the heat dissipation, so the total thermal resistance θback of the back device may be twice or even higher than the total thermal resistance θfront of the front device.

[0008] Figure 2B yes Figure 2A The thermal simulation diagram of the power module is shown in Figure 1. Figure 2B It can be seen that the temperature of the main power device on the back of the PCB (such as the temperature of the dark red high temperature area HA) is very high, significantly higher than the temperature of the devices in other locations. When the module is running at full power, the high temperature protection will be easily triggered, causing the module to be unable to maintain full load operation for a long time. Utility Model Content

[0009] The purpose of the present invention is to provide a power module which can effectively solve at least one defect of the prior art.

[0010] In order to achieve the above-mentioned purpose, the utility model provides a power module, which includes: a printed circuit board, having a first surface and a second surface opposite to each other; a heat sink, arranged above the first surface or below the second surface of the printed circuit board; a heat conducting medium, arranged between the printed circuit board and the heat sink; and a plurality of main power devices, when the heat sink is arranged above the first surface of the printed circuit board, all the main power devices are arranged above the first surface of the printed circuit board, and when the heat sink is arranged below the second surface of the printed circuit board, all the main power devices are arranged above the second surface of the printed circuit board; wherein the heat generated by the main power devices is conducted to the heat sink through the heat conducting medium.

[0011] In one or more embodiments of the present invention, the main power device is a power device with a self-loss power greater than 0.5W.

[0012] In one or more embodiments of the present invention, the main power device includes a diode, a switch tube or a magnetic component.

[0013] In one or more embodiments of the present invention, the switch tube includes a thyristor, a triode, a field effect transistor or an insulated gate bipolar transistor, and the magnetic component includes a transformer core or an inductor core.

[0014] In one or more embodiments of the present invention, the main power device includes a plurality of primary-side switch tubes, a plurality of secondary-side switch tubes and at least one magnetic component.

[0015] In one or more embodiments of the present invention, a plurality of primary switch tubes are arranged close to a first side edge of a printed circuit board, at least one magnetic component is arranged close to a second side edge of the printed circuit board, and the first side edge is opposite to the second side edge, and a plurality of secondary switch tubes are arranged between the plurality of primary switch tubes and the at least one magnetic component.

[0016] In one or more embodiments of the present invention, multiple primary switch tubes are arranged in multiple columns along a first direction of the printed circuit board, and / or multiple primary switch tubes are arranged in multiple rows along a second direction of the printed circuit board, and the first direction is perpendicular to the second direction.

[0017] In one or more embodiments of the present invention, multiple secondary side switch tubes are arranged in multiple columns along a first direction of the printed circuit board, and / or multiple secondary side switch tubes are arranged in multiple rows along a second direction of the printed circuit board, and the first direction is perpendicular to the second direction.

[0018] In one or more embodiments of the present invention, the heat-conducting medium includes a heat-conducting paste or a heat-conducting pad.

[0019] In one or more embodiments of the present invention, the heat dissipation surface area of ​​the heat sink is larger than the area of ​​the printed circuit board.

[0020] In one or more embodiments of the present invention, the power module further includes: another circuit board, which is respectively arranged on the upper and lower sides of the printed circuit board with the heat sink; a heat conduction unit, which thermally connects at least one of the multiple main power devices and the other circuit board; wherein the heat generated by the at least one of the multiple main power devices is also conducted to the other circuit board through the heat conduction unit.

[0021] In one or more embodiments of the present invention, at least one of the plurality of main power devices is a transformer core.

[0022] In one or more embodiments of the present invention, the transformer core includes a first magnetic core and a second magnetic core, wherein the second magnetic core is thermally connected to one of the heat conducting unit and the heat conducting medium, and the first magnetic core is thermally connected to the other of the heat conducting unit and the heat conducting medium.

[0023] In one or more embodiments of the present invention, the heat conduction unit is connected to the other circuit board by welding.

[0024] In one or more embodiments of the present invention, thermal conductive glue is filled between the heat conductive unit and the at least one of the plurality of main power devices.

[0025] In one or more embodiments of the present invention, the thermal conductive adhesive is also filled in a gap between the printed circuit board and the other circuit board.

[0026] In one or more embodiments of the present invention, the heat conducting unit is a copper block.

[0027] In one or more embodiments of the present invention, a first copper-clad area corresponding to the heat conduction unit is disposed on the other circuit board.

[0028] In one or more embodiments of the present invention, the area of ​​the first copper-clad region is greater than or equal to the projected area of ​​the heat-conducting unit on the other circuit board.

[0029] In one or more embodiments of the present invention, the printed circuit board is connected to the other circuit board via copper pillars and / or connectors.

[0030] In one or more embodiments of the present invention, the heat-conducting unit is a heat-conducting adhesive, and the heat-conducting adhesive is also filled in the gap between the printed circuit board and the other circuit board.

[0031] The utility model can effectively reduce the total thermal resistance of device heat conduction by arranging all main power devices on the side of the printed circuit board close to the heat sink. When the module is fully loaded, the heat energy of the device can be more smoothly conducted to the heat sink, and then transferred to the air through the heat sink, thereby reducing the maximum temperature of the device during operation, so as not to trigger the high temperature protection of the module, and making the module work longer under full load conditions.

[0032] The utility model can also connect at least one of the multiple main power devices (such as a magnetic component with a larger thermal bottleneck) to another circuit board (such as a control board) with heat sinks disposed on the upper and lower sides of the printed circuit board respectively through a heat conduction unit, so that two different heat flow paths can be constructed through the heat sink and the other circuit board to achieve heat dissipation. At the same time, by using another circuit board with better thermal conductivity, the heat of at least one of the multiple main power devices with poor heat dissipation can be evenly distributed to the other circuit board, so that the temperature of the component with a larger thermal bottleneck (such as the I-CORE of the transformer core) can be lower, and the temperature of the component with a smaller thermal bottleneck (such as the control board) can be higher (but still within the allowable temperature range), thereby achieving "redistribution" of temperature and achieving better heat dissipation effect.

[0033] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other features and advantages of the present invention will become more apparent by describing in detail example embodiments thereof with reference to the attached drawings.

[0035] Figure 1A and Figure 1B It is a common topological diagram in the prior art;

[0036] Figure 2A It is a schematic diagram of the structure of a power module with main power devices on both sides of the PCB;

[0037] Figure 2B yes Figure 2A The thermal simulation schematic diagram of the power module shown;

[0038] Figure 3A This is a schematic diagram of the structure of a preferred power module of the utility model;

[0039] Figure 3B It is a front structural schematic diagram of a power module of the first embodiment of the utility model;

[0040] Figure 3C It is a front structural schematic diagram of a power module of the second embodiment of the utility model;

[0041] Figure 3D It is a thermal simulation schematic diagram of the power module of the utility model;

[0042] Figure 4A This is a schematic diagram of the structure of another preferred power module of the utility model;

[0043] Figure 4B yes Figure 4A A schematic diagram of the structure of a magnetic component (such as a transformer core) as one of the main power devices;

[0044] Figure 4C yes Figure 4A A schematic diagram of the structure of a printed circuit board (e.g., a main board);

[0045] Figure 4D yes Figure 4A A schematic structural diagram of another circuit board (such as a control board) and a heat conduction unit mounted thereon;

[0046] Figure 4E Parts (a), (b), and (c) of Figure 4A The top structure, bottom structure and assembled three-dimensional structure of the power module;

[0047] Figure 4F yes Figure 4A FIG. 1 is a schematic diagram of simulation results of heat dissipation capacity of a power module when there is no heat-conducting unit (such as a copper block) to distribute heat to an I-shaped core (i.e., I-CORE) of a transformer core, wherein part (a) shows the simulation results of heat dissipation capacity when viewed from the top, and part (b) shows the simulation results of heat dissipation capacity when viewed from the side;

[0048] Figure 4G yes Figure 4A The diagram shown is a schematic diagram of the heat dissipation capacity simulation results of the power module when a heat-conducting unit (such as a copper block) is used to distribute heat to the I-shaped core (i.e., I-CORE) of the transformer core, wherein part (a) shows the heat dissipation capacity simulation results viewed from the top, and part (b) shows the heat dissipation capacity simulation results viewed from the side. DETAILED DESCRIPTION

[0049] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0050] When introducing the elements / components / etc. described and / or illustrated herein, the terms "a", "an", "the", "said", and "at least one" are used to indicate that there are one or more elements / components / etc. The terms "comprising", "including", and "having" are used to indicate an open-ended inclusive meaning and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. In addition, the terms "first", "second", etc. in the claims are used only as labels and are not numerical limitations of their objects.

[0051] It should be understood that the phraseology or terminology herein is for the purpose of description rather than limitation, so that those skilled in the relevant art can interpret the phraseology or terminology of the specification according to the teachings herein.

[0052] Different embodiments or examples are provided below for implementing different features of the subject matter provided by the present utility model. Of course, these are merely examples and are not intended to be limiting. For example, the following description of "a first feature is formed on or above a second feature" may include in an embodiment that the first feature is in direct contact with the second feature, and may also include forming an additional feature between the first feature and the second feature so that the first feature and the second feature are not in direct contact. In addition, the present utility model may reuse component symbols and / or letters in various embodiments or examples. This repetition is for the purpose of simplicity and clarity, and does not itself limit the relationship between the various embodiments and / or configurations discussed.

[0053] Additionally, spatially relative terms, such as "on," "over," "above," "upper," "under," "below," "below," "lower," and the like, are used herein to simplify the description to describe the relationship of one element or feature to another element or feature as illustrated in the accompanying drawings. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein interpreted accordingly.

[0054] like Figure 3AAs shown, the structure of a preferred power module 20 of the utility model is shown. In the utility model, the power module 20 mainly includes a printed circuit board (PCB) 21, a heat sink 22, a heat conducting medium 23 and a plurality of main power devices 24. The printed circuit board 21 has a first surface (e.g., the front surface in the figure) 211 and a second surface (e.g., the back surface in the figure) 212 relative to each other. The heat sink 22 is arranged above the first surface 211 of the printed circuit board 21, or the heat sink 22 is arranged below the second surface 212 of the printed circuit board 21. The heat conducting medium 23 is arranged between the printed circuit board 21 and the heat sink 22. When the heat sink 22 is disposed above the first surface 211 of the printed circuit board 21, all the main power devices 24 are disposed on the first surface 211 of the printed circuit board 21; when the heat sink 22 is disposed below the second surface 212 of the printed circuit board 21, all the main power devices 24 are disposed on the second surface 212 of the printed circuit board 21; wherein the heat generated by these main power devices 24 can be transferred to the heat sink 22 through the heat conducting medium 23. For example, in Figure 3A In the illustrated embodiment, the heat of the printed circuit board 21 and all main power devices 24 disposed on the first surface 211 thereof can be transferred to the heat sink 22 located above along the upward heat conduction direction H through the heat conductive medium 23 and dissipated through the heat sink 22 .

[0055] In the present invention, the so-called "main power device" refers to a power device whose own power loss is greater than 0.5W. For example, the main power device may include one or more of the following: a diode, a switch tube or a magnetic component, wherein the switch tube includes a thyristor, a triode, a field effect tube or an insulated gate bipolar transistor (IGBT), etc., and the magnetic component includes a transformer core or an inductor core, but the present invention is not limited thereto. In the present invention, the so-called description such as "A is arranged on B" is used to describe the positional relationship between A and B, which may include A being completely placed on B, or A being partially placed on B, and A and B may be in direct contact, or A and B may include other additional features instead of direct contact.

[0056] In some embodiments, the main power device includes, for example, a plurality of primary switch tubes, a plurality of secondary switch tubes, and at least one magnetic component. Preferably, the plurality of primary switch tubes may be arranged close to a first side edge of the printed circuit board, the at least one magnetic component may be arranged close to a second side edge of the printed circuit board, and the first side edge is opposite to the second side edge, and the plurality of secondary switch tubes may be arranged between the plurality of primary switch tubes and the at least one magnetic component.

[0057] More preferably, the plurality of primary switch tubes may be arranged in multiple columns along a first direction of the printed circuit board, and / or the plurality of primary switch tubes may be arranged in multiple rows along a second direction of the printed circuit board, wherein the first direction is perpendicular to the second direction.

[0058] More preferably, the plurality of secondary switch tubes may be arranged in multiple columns along a first direction of the printed circuit board, and / or the plurality of secondary switch tubes may be arranged in multiple rows along a second direction of the printed circuit board, wherein the first direction is perpendicular to the second direction.

[0059] In some embodiments, the heat-conducting medium 23 is, for example, a heat-conducting paste or a heat-conducting pad, or other heat-conducting materials, but the present invention is not limited thereto, and other media that can transfer heat should also be within the protection scope of the present invention.

[0060] In some embodiments, the heat sink 22 may be, for example, a heat sink fin. Preferably, the area of ​​the heat dissipation surface 221 of the heat sink 22 is larger than the area of ​​the printed circuit board 21, but the present invention is not limited thereto.

[0061] The utility model can effectively reduce the total thermal resistance of device heat conduction by arranging all main power devices on one side of the printed circuit board close to the heat sink (for example, the front side). When the module is fully loaded, the heat energy of the device can be more smoothly conducted to the heat sink, and then transferred to the air through the heat sink, thereby reducing the maximum temperature of the device during operation, so as not to trigger the high temperature protection of the module, and making the module work longer under full load conditions.

[0062] The following two embodiments improve the heat dissipation of the module by arranging all the main power devices on the front side (ie, the first side) of the printed circuit board.

[0063] Embodiment 1:

[0064] like Figure 3B As shown, the heat sink 22 is arranged above the first surface 211 of the printed circuit board 21. The main power devices of the power module include, for example, four primary switch tubes 241, four secondary switch tubes 242, and a magnetic component 243. These main power devices are arranged on the first surface 211 of the printed circuit board. By arranging all the main power devices (241, 242, 243) of the module on the first surface 211 of the printed circuit board, the heat of the devices can be dissipated more quickly through the heat sink 22 (such as Figure 3A The maximum operating temperature of the device can be reduced, allowing the module to operate at full load for a longer period of time.

[0065] In this embodiment, the four primary switch tubes 241 are arranged close to the first side edge 21a of the printed circuit board, and are preferably arranged in two columns along the first direction D1, and in two rows along the second direction D2. The magnetic component 243 is arranged close to the second side edge 21b of the printed circuit board, and the first side edge 21a and the second side edge 21b are opposite. The four secondary switch tubes 242 are arranged between the four primary switch tubes 241 and the magnetic component 243, and are arranged in a column along the first direction D1, and in four rows along the second direction D2. The arrangement shown in this embodiment can be more conducive to the circuit layout of the power module and the connection between the power devices. However, it can be understood that these arrangements are not intended to limit the present invention.

[0066] Embodiment 2:

[0067] like Figure 3C As shown in FIG. 1 , the main power devices of the power module include, for example, 8 primary switch tubes 241, 4 secondary switch tubes 242, and a magnetic core 243. These main power devices are all arranged on the first surface 211 of the printed circuit board. Similarly, by arranging all the main power devices of the module on the first surface 211 of the printed circuit board, the heat of the devices can be dissipated more quickly through the heat sink 22 (such as Figure 3A The maximum operating temperature of the device can be reduced, allowing the module to operate at full load for a longer period of time.

[0068] In this embodiment, the eight primary switch tubes 241 are arranged close to the first side edge 21a of the printed circuit board, and are preferably arranged in two columns along the first direction D1, and in four rows along the second direction D2. The magnetic component 243 is arranged close to the second side edge 21b of the printed circuit board, and the first side edge 21a and the second side edge 21b are opposite. The four secondary switch tubes 242 are arranged between the eight primary switch tubes 241 and the magnetic component 243, and are arranged in a column along the first direction D1, and in four rows along the second direction D2. The arrangement shown in this embodiment can be more conducive to the circuit layout of the power module and the connection between the power devices. However, it can be understood that these arrangements are not intended to limit the present invention.

[0069] The utility model arranges all the main power devices on one side of the printed circuit board close to the heat sink (for example, the front side), and performs thermal simulation under the same loss and external conditions to obtain the following: Figure 3D The results are shown. Figure 3D As can be seen in the figure, after all the main power devices are placed on the first side of the printed circuit board, the overall temperature of the module is Figure 2B There is a significant improvement. There is no longer a deep red high-temperature area. The heat energy on the device is transferred to the heat sink more quickly, allowing the device to run at full load.

[0070] Embodiment 3:

[0071] like Figure 4A As shown, the structure of another preferred power module 30 of the present invention is shown.

[0072] and Figure 3A The power module 20 in the illustrated embodiment is similar in that Figure 4A The power module 30 in the illustrated embodiment also includes a printed circuit board (PCB) 31, a heat sink 32, a thermal conductive medium 33, and a plurality of main power devices 34, wherein the heat sink 32 is disposed above a first surface 311 (e.g., the front surface) of the printed circuit board 31, the thermal conductive medium 33 is disposed between the printed circuit board 31 and the heat sink 32, and all the main power devices 34 are disposed above the first surface 311 (e.g., the front surface) of the printed circuit board 31, and the heat generated by these main power devices 34 can be conducted upward to the heat sink 32 along the first heat flow path P1 through the thermal conductive medium 33.

[0073] The main power devices 34 may include one or more of the following: a diode, a switch tube, or a magnetic component. The magnetic component may include a transformer core or an inductor core. Figure 4A The embodiment shown is special in that a part of the main power devices 341 (for example, diodes and / or switch tubes, but the present invention is not limited thereto) of the main power devices 34 can be completely mounted on the first surface 311 of the printed circuit board 31 by surface mounting technology; and another part of the main power devices (for example, transformer cores 343, but the present invention is not limited thereto) can be partially embedded and installed in the printed circuit board 31 by embedding technology according to their structure (for example, Figure 4A The transformer core 343 is embedded in the left side of the printed circuit board 31, so that the top of the transformer core 343 is located above the first surface 311 of the printed circuit board 31, and the bottom of the transformer core 343 is located below the second surface 312 of the printed circuit board 31. Figure 4A From the perspective of FIG. 1 , although the bottom of the transformer core 343 after installation is located below the second surface 312 of the printed circuit board 31, the entire transformer core 343 can actually still be considered to be disposed on the first surface 311 (e.g., the front surface) of the printed circuit board 31. Moreover, the heat generated by these main power devices 34 (including 341 and 343) can be conducted upward to the heat sink 32 along the first heat flow path P1 through the heat conducting medium 33.

[0074] and Figure 3A The power module 20 shown is different in that Figure 4AThe power module 30 in the illustrated embodiment further includes another circuit board 35 and a heat conduction unit 36. The other circuit board 35 and the heat sink 32 are respectively disposed on the upper and lower sides of the printed circuit board 31. In addition, the heat conduction unit 36 ​​is heat-conductively connected to at least one of the plurality of main power devices 34 (e.g., the transformer core 343) and the other circuit board 35. The heat generated by the at least one of the main power devices 34 (e.g., the transformer core 343) can also be conducted downward to the other circuit board 35 along the second heat flow path P2 through the heat conduction unit 36, and the heat conducted to the other circuit board 35 can be further dissipated by the other circuit board 35, so that the heat can be effectively evenly distributed.

[0075] Thus, the power module 30 in the embodiment shown in 4A can effectively reduce the total thermal resistance of device heat conduction by placing all main power devices 34 (including 341 and 343) on one side (such as the front side) of the printed circuit board 31 close to the heat sink 32. In addition, the heat generated by these main power devices 34 (including 341 and 343) can be conducted upward to the heat sink 32 along the first heat flow path P1 through the heat conducting medium 33 for heat dissipation. As for the transformer core 343 with poor heat dissipation, Figure 4A The power module 30 in the illustrated embodiment can also be thermally connected to another circuit board 35 via a heat conduction unit 36 ​​so as to utilize the other circuit board 35 for evenly dissipating heat (i.e., evenly distributing the heat of the transformer core 343 with poor heat dissipation to the other circuit board 35), thereby achieving temperature "redistribution" and achieving better heat dissipation effect.

[0076] Figure 4A The illustrated embodiment utilizes the heat sink 32 and another circuit board 35 to construct two different heat flow paths (including an upward first heat flow path P1 and a downward second heat flow path P2) for heat dissipation, which enables better heat dissipation effect of the entire power module 30.

[0077] It is understandable that, in other embodiments, all the main power devices 34 may also be arranged on the second side 312 (for example, the back side) of the printed circuit board 31, and the heat sink 32 may also be arranged below the second side 312 (for example, the back side) of the printed circuit board 31, and another circuit board 35 may also be arranged above the first side 311 (for example, the front side) of the printed circuit board relative to the heat sink 32. These are not intended to limit the present invention.

[0078] Preferably, in Figure 4AIn the illustrated embodiment, other devices 344 may be disposed on the second side 312 (e.g., the back side) of the printed circuit board 31. In some specific embodiments, these other devices 344 may all be low-power devices (i.e., the heat generation power is less than 0.5 W). In addition, the printed circuit board 31 and another circuit board 35 may also be connected via copper pillars 39 and / or connectors 38.

[0079] like Figure 4B As shown, Figure 4A The magnetic component as one of the main power devices in the power module 30 in the illustrated embodiment is, for example, a transformer core 343, which may include a first core 3431 and a second core 3432. The first core 3431 and the second core 3432 may be bonded by glue. The shapes of the first core 3431 and the second core 3432 are not limited. The following description is made by taking the first core 3431 as an E-shaped core and the second core 3432 as an I-shaped core as an example. The I-shaped core 3432 may be connected to one of the heat conducting unit 36 ​​and the heat conducting medium 33 (for example Figure 4A The E-shaped magnetic core 3431 is thermally connected to the heat conducting unit 36 ​​and the other of the heat conducting medium 33 (eg Figure 4A More specifically, the E-shaped magnetic core 3431 may be composed of two parallel side pillars 3431a, a middle pillar 3431c located between the two side pillars 3431a, and a bottom 3431b connecting the two side pillars 3431a and the middle pillar 3431c to form an E-shaped structure with an E-shaped cross section. During installation, the middle pillar 3431c may be embedded in the corresponding mounting hole 315 (such as Figure 4C The I-shaped magnetic core 3432 may be in the shape of a straight plate.

[0080] like Figure 4D As shown, it shows Figure 4A The structure of another circuit board and the heat conduction unit installed thereon. Preferably, the other circuit board 35 can be, for example, a control board. The heat conduction unit 36 ​​is installed on the upper surface of the control board (i.e., the other circuit board 35) and is located on the left side of the control board corresponding to the I-shaped magnetic core 3432 of the transformer magnetic core 343. Figure 4A shown.

[0081] Preferably, the heat conducting unit 36 ​​can be a copper block, and the heat conducting unit 36 ​​can be connected to another circuit board 35 by welding. However, it can be understood that the heat conducting unit 36 ​​can also be made of other heat conducting materials, and the connection between it and another circuit board 35 is not limited to welding, which is not a limitation of the present invention.

[0082] Preferably, a first copper-clad area (not shown) corresponding to the heat-conducting unit 35 may also be provided on the other circuit board 35. The area of ​​the first copper-clad area may be greater than or equal to the projected area of ​​the heat-conducting unit 35 on the other circuit board 35, which will be more conducive to the heat-conducting unit 35 transferring the heat on the magnetic core 3432 to the other circuit board 35.

[0083] More preferably, the other circuit board 35 can be, for example, a control board with a high copper content and vias. The control board with vias has a stronger thermal conductivity and can spread the heat more effectively. Taking a 4-layer control board as an example, it can include, from top to bottom, a top layer, a first middle layer, a second middle layer, and a bottom layer, and the thickness of the control board can be, for example, 1 mm, the copper thickness of each layer can be, for example, 2 oz, and the copper content of the top layer, the first middle layer, the second middle layer, and the bottom layer can be, for example, 73.2%, 67.7%, 75.2%, and 92.3%, respectively. However, it can be understood that the layer structure, copper content, etc. of the other circuit board 35 in the utility model are not limited to this.

[0084] Preferably, combined with reference Figure 4A , the space between the heat-conducting unit 36 ​​and the I-shaped core 3432 of the transformer core 343 may also be filled with a heat-conducting adhesive 37. More preferably, the gap between the printed circuit board 31 and the other circuit board 35 may also be filled with a heat-conducting adhesive 374. For example, by filling the heat-conducting adhesive 374 in the gap between other devices 344 (such as low-power devices) and another circuit board 35 (such as a control board), the heat dissipation capacity of other devices 344 can be further improved and the temperature between other devices 344 and another circuit board 35 can be achieved. As a special case, the heat-conducting unit 36 ​​may also be a heat-conducting adhesive, that is, the second heat flow path P2 may be directly constructed using the heat-conducting adhesive, and the heat generated by the transformer core 343 and other devices 344 may be conducted downward to the other circuit board 35 through the heat-conducting adhesive. This special case may be achieved directly through the process step of "filling the heat-conducting adhesive" during the manufacturing process, so that the entire manufacturing process is simplified.

[0085] like Figure 4E As shown, parts (a), (b), and (c) respectively show Figure 4A The top structure, bottom structure and assembled three-dimensional structure of the power module 30 in FIG. Figure 4E As shown in part (a) of FIG. 3 , the plurality of main power devices 341 disposed on the first surface 311 of the printed circuit board 31 may be arranged in an array in rows and columns, and the top of the E-shaped magnetic core 3431 of the assembled transformer magnetic core 343 is exposed on the first surface 311 of the printed circuit board 31. Figure 4EAs shown in part (b) of FIG. 3 , other devices 344 disposed on the second surface 312 of the printed circuit board 31 may also be arranged in an array in rows and columns, and the bottom of the I-shaped magnetic core 3432 of the assembled transformer magnetic core 343 is exposed on the second surface 312 of the printed circuit board 31. Figure 4E As shown in part (c) of FIG. 3 , the outer contours of the E-shaped magnetic core 3431 and the I-shaped magnetic core 3432 of the assembled transformer magnetic core 343 are roughly matched, that is, the projections of the outer contours of the two in the vertical direction overlap. In addition, the assembled transformer magnetic core 343 has a width direction (e.g. Figure 4C The outer end surface along the width direction W of the main board is substantially flush with the corresponding outer end surface of the printed circuit board 31.

[0086] Combine the following Figure 4F , Figure 4G Further illustrate the utility model embodiment 3 as Figure 4A The power module 30 shown is used in a heat dissipation scenario where the heat sink 32 is a cold plate structure and its heat dissipation capability.

[0087] Figure 4F yes Figure 4A The power module 30 shown is a schematic diagram of the heat dissipation capacity simulation results when there is no heat-conducting unit 36 ​​(such as a copper block) to distribute heat to the I-shaped core (i.e., I-CORE) 3432 of the transformer core 343, wherein part (a) shows the heat dissipation capacity simulation results viewed from the top, and part (b) shows the heat dissipation capacity simulation results viewed from the side. Figure 4G yes Figure 4A The power module 30 shown is a schematic diagram of the heat dissipation capacity simulation results when a heat conducting unit 36 ​​(such as a copper block) is used to distribute heat to the I-shaped core (i.e., I-CORE) 3432 of the transformer core 343, wherein part (a) shows the heat dissipation capacity simulation results viewed from the top, and part (b) shows the heat dissipation capacity simulation results viewed from the side.

[0088] In the following Table 1, the maximum temperatures and average temperatures obtained by simulation for structures such as "I-shaped magnetic core (i.e., I-CORE)", "control board (i.e., another circuit board)", and "I-shaped magnetic core + control board" in the case of "no copper block (i.e., heat conduction unit)" are listed; and the maximum temperatures and average temperatures obtained by simulation for structures such as "I-shaped magnetic core (i.e., I-CORE)", "control board (i.e., another circuit board)", and "I-shaped magnetic core + control board + copper block" are listed in the case of "without copper block (i.e., heat conduction unit)".

[0089] Table 1:

[0090]

[0091] Combination Figure 4Fand Figure 4G , by analyzing the above simulation results on heat dissipation capacity, we can see that:

[0092] (1) In the heat dissipation scenario of the cold plate structure, for the "I-core" structure that is not good at heat dissipation, the maximum temperature and average temperature of the "I-core" in the case of "with copper block" are both reduced by 28°C (or more) compared with the case of "without copper block".

[0093] (2) For the "I-shaped magnetic core (i.e., I-CORE) + control board" structure, the average temperature before and after is 102°C (i.e., both meet the relevant temperature requirements). However, for the case of "no copper block", the temperature of the "I-shaped magnetic core" is higher, with a maximum temperature of 155°C (average temperature of 142°C), but the temperature of the "control board" is lower, with a maximum temperature of 92.3°C (average temperature of 88.1°C); and for the case of "with copper block", the temperature of the "I-shaped magnetic core" is lower, with a maximum temperature of 118°C (average temperature of 114°C), while the temperature of the "control board" is higher, with a maximum temperature of 108°C (average temperature of 97.2°C), but the temperature of the "control board" is still within the allowable temperature range. Therefore, it can be considered that the temperature is "redistributed" by using the "control board" with better thermal conductivity.

[0094] As shown in Example 3, the power module 30 of the utility model can connect at least one of the multiple main power devices (such as the transformer core 343) to another circuit board 35 (such as the control board) which is respectively arranged on the upper and lower sides of the printed circuit board 31 with the heat sink 32 through the heat conduction unit 36, so that two different heat flow paths, such as upward and downward, can be constructed through the heat sink 32 and the other circuit board 35 to achieve heat dissipation. At the same time, by using the other circuit board 35 with better heat conduction, the heat of at least one of the multiple main power devices (such as the transformer core 343) with poor heat dissipation can be evenly distributed to the other circuit board 35, so that the temperature of the component with a large heat bottleneck (such as the I-shaped core 3432 of the transformer core 343) can be lower, and the temperature of the component with a smaller heat bottleneck (such as the control board) can be higher (but still within the allowable temperature range), thereby achieving "redistribution" of temperature and achieving better heat dissipation effect.

[0095] The exemplary embodiments of the present invention are specifically shown and described above. It should be understood that the present invention is not limited to the disclosed embodiments, but rather, the present invention is intended to cover various modifications and equivalent arrangements contained within the spirit and scope of the appended claims.

Claims

1. A power module, characterized in that: include: a printed circuit board having opposing first and second sides; a heat sink, disposed above the first surface or below the second surface of the printed circuit board; A heat-conducting medium is disposed between the printed circuit board and the heat sink; as well as a plurality of main power devices, when the heat sink is disposed above the first surface of the printed circuit board, all the main power devices are disposed on the first surface of the printed circuit board; when the heat sink is disposed below the second surface of the printed circuit board, all the main power devices are disposed on the second surface of the printed circuit board; Wherein, the heat generated by the main power device is conducted to the heat sink through the heat conducting medium.

2. The power module according to claim 1, characterized in that: The main power device is a power device whose own power loss is greater than 0.5W.

3. The power module according to claim 1, characterized in that: The main power device includes a diode, a switch tube or a magnetic component.

4. The power module according to claim 3, characterized in that: The switch tube includes a thyristor, a triode, a field effect tube or an insulated gate bipolar transistor, and the magnetic component includes a transformer core or an inductor core.

5. The power module according to claim 4, characterized in that: The main power device includes a plurality of primary-side switch tubes, a plurality of secondary-side switch tubes and at least one magnetic component.

6. The power module according to claim 5, characterized in that: The multiple primary switch tubes are arranged close to the first side edge of the printed circuit board, the at least one magnetic component is arranged close to the second side edge of the printed circuit board, and the first side edge is opposite to the second side edge, and the multiple secondary switch tubes are arranged between the multiple primary switch tubes and the at least one magnetic component.

7. The power module according to claim 6, characterized in that: The plurality of primary switch tubes are arranged in multiple columns along a first direction of the printed circuit board, and / or the plurality of primary switch tubes are arranged in multiple rows along a second direction of the printed circuit board, and the first direction is perpendicular to the second direction.

8. The power module according to claim 6, characterized in that: The plurality of secondary-side switch tubes are arranged in multiple columns along a first direction of the printed circuit board, and / or the plurality of secondary-side switch tubes are arranged in multiple rows along a second direction of the printed circuit board, and the first direction is perpendicular to the second direction.

9. The power module according to claim 1, characterized in that: The heat-conducting medium includes heat-conducting paste or heat-conducting pad.

10. The power module according to claim 1, characterized in that: The area of ​​the heat dissipation surface of the heat sink is larger than the area of ​​the printed circuit board.

11. The power module according to claim 1, characterized in that: Also includes: Another circuit board, and the heat sink are respectively arranged on the upper and lower sides of the printed circuit board; a heat conduction unit, thermally connecting at least one of the plurality of main power devices and the other circuit board; Wherein, the heat generated by the at least one of the plurality of main power devices is also conducted to the other circuit board through the heat conduction unit.

12. The power module according to claim 11, characterized in that: The at least one of the plurality of primary power devices is a transformer core.

13. The power module according to claim 12, characterized in that: The transformer magnetic core includes a first magnetic core and a second magnetic core, wherein the second magnetic core is thermally connected to one of the heat conduction unit and the heat conduction medium, and the first magnetic core is thermally connected to the other of the heat conduction unit and the heat conduction medium.

14. The power module according to claim 11, characterized in that: The heat conduction unit is connected to the other circuit board by welding.

15. The power module according to claim 14, characterized in that: A thermal conductive adhesive is filled between the thermal conductive unit and the at least one of the plurality of main power devices.

16. The power module according to claim 15, characterized in that: The thermal conductive adhesive is also filled in the gap between the printed circuit board and the other circuit board.

17. The power module according to any one of claims 11 to 14, characterized in that: The heat conducting unit is a copper block.

18. The power module according to claim 11, characterized in that: The other circuit board is provided with a first copper clad area corresponding to the heat conduction unit.

19. The power module according to claim 18, characterized in that: The area of ​​the first copper clad region is greater than or equal to the projected area of ​​the heat conduction unit on the other circuit board.

20. The power module according to claim 11, characterized in that: The printed circuit board is connected to the other circuit board via copper pillars and / or connectors.

21. The power module according to claim 11, characterized in that: The heat-conducting unit is a heat-conducting adhesive, and the heat-conducting adhesive is also filled in the gap between the printed circuit board and the other circuit board.

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