Power module heat dissipation structure

Abstract

The invention discloses a power module heat dissipation structure, and relates to the technical field of power module heat dissipation. Heat dissipation of an existing power module cannot meet the heat dissipation requirement of millisecond-level thermal shock. The invention provides a power module heat dissipation structure which comprises a power module, the power module comprises a chip and a substrate below the chip, and the power module further comprises an upper heat dissipation part located above a source electrode area of the chip and a lower heat dissipation part located above a source electrode area of the chip; a phase-change material is arranged in the closed inner cavity of the upper heat dissipation part, the upper heat dissipation part is provided with a heat pipe framework, and the heat pipe framework is used for dissipating heat of the power module and transferring heat to the phase-change material. According to the invention, the heat pipe skeleton with the built-in phase-change material is used for replacing a common heat dissipation rack with a metal frame, so that the heat during overcurrent and overload can be conducted to the phase-change material in time, and the instant heat dissipation requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of power module heat dissipation, and in particular to a power module heat dissipation structure with integrated heat pipes. Background Art

[0002] Silicon carbide power modules are widely used to control and convert power signals because of their high temperature resistance and stability in high temperature environments. As the power consumption of silicon carbide power modules increases, the heat generated also increases, and heat dissipation becomes an important factor affecting the long-term stable operation of silicon carbide power modules. In addition, during the operation of the power grid, silicon carbide power modules also have surge problems, that is, the instantaneous current of the power module will increase by 2 to 3 times in a short period of time, and the large amount of heat generated instantly puts higher requirements on heat dissipation.

[0003] At present, liquid cooling is usually used for high-voltage and high-current high-voltage silicon carbide power modules of the above-mentioned power grid system. However, the current liquid cooling method is mostly to weld or bond a water-cooling plate (interface material) under the copper-clad ceramic substrate of the power module to cool the chip on one side. The heat dissipation effect is not good enough, and because the increase in instantaneous current is often within the millisecond range, such liquid cooling cannot achieve instantaneous heat dissipation. In addition, the existing technology also uses a heat pipe metal frame sintered above the chip, and the phase change material in the metal frame is used to enhance the heat dissipation capacity, but the thermal conductivity of the metal is still not enough to quickly dissipate the millisecond-level thermal shock generated instantly by the power module. Summary of the invention

[0004] The object of the present invention is to provide a power module heat dissipation structure, which replaces the heat dissipation metal frame with a heat pipe skeleton and combines phase change materials to improve the heat dissipation efficiency.

[0005] The present invention is implemented by the following technical scheme: a power module heat dissipation structure, comprising: a power module, the power module comprising a chip and a substrate below the chip, the power module further comprising: an upper heat dissipation portion located above the source region of the chip; a phase change material is arranged in the closed inner cavity of the upper heat dissipation portion, a heat pipe skeleton is arranged on the upper heat dissipation portion, the heat pipe skeleton is used for heat dissipation of the power module and for transferring heat to the phase change material The upper heat dissipation part is adapted to the size of the chip source; the inner cavity of the heat pipe skeleton is provided with a cooling medium, the bottom surface and the surrounding wall of the upper heat dissipation part are the heat pipe skeleton, and the bottom surface of the upper heat dissipation part is connected to the chip source. The bottom surface and the surrounding wall of the upper heat dissipation part are composed of the heat pipe skeleton, which has a good heat dissipation effect. The heat pipe skeleton is directly connected to the chip and has fast heat transfer; the heat pipe skeleton on the surrounding wall of the upper heat dissipation part is in direct contact with the outside, which is easier to dissipate heat.

[0006] In order to further improve the heat dissipation efficiency, a heat pipe skeleton is arranged in the inner cavity of the upper heat dissipation part, and the heat pipe skeletons in the inner cavity are arranged crosswise.

[0007] The bottom surface of the upper heat dissipation part is connected to the chip source, and the top surface is provided with a liquid cooling plate, which can realize the "evaporation-condensation" cycle of the heat pipe, and has a faster response speed and better heat dissipation effect during heat dissipation.

[0008] In order to ensure the safe connection of the liquid cooling plate and ensure the heat transfer, an insulating layer is arranged on the top surface of the upper heat dissipation part, a metal layer is covered on the insulating layer, and the liquid cooling plate is installed on the metal layer.

[0009] Furthermore, the bottom surface of the liquid cooling plate is connected to the top surface of the upper heat dissipation portion, and two opposite side walls of the liquid cooling plate are provided with a plurality of through holes for the inflow and outflow of the refrigerant.

[0010] The substrate is a copper-clad ceramic plate, which includes a copper layer and a ceramic layer. The copper layer disposed on the top surface of the ceramic layer is used to connect with the chip. The bottom surface of the substrate is provided with a plurality of grooves to form microchannels for the circulation of the refrigerant, so that the substrate becomes a lower heat dissipation part. The lower heat dissipation part provided with microchannels can further enhance the heat dissipation effect of the power module, and no additional water cooling plate needs to be welded.

[0011] Furthermore, a manifold plate matching the shape of the substrate is further provided on the bottom surface of the substrate away from the chip, a plurality of manifolds are provided on the bottom wall inside the manifold plate, a channel for the flow of refrigerant is formed between the manifold and the inner wall of the manifold plate, after the manifold plate is connected to the substrate, the manifold and the microchannel form a manifold-type microchannel, and a plurality of through holes for the flow of refrigerant into and out of the manifold are provided on the opposite side walls of the manifold plate. The manifold-type microchannel can further increase the heat dissipation capacity of the lower heat dissipation part.

[0012] The heat pipe skeleton is electrically connected to the chip source electrode, the substrate is a copper-clad ceramic board, and the copper layer of the substrate is electrically connected to each electrode of the chip and the heat pipe skeleton. The connection between the heat pipe skeleton and the copper layer can play a role in heat dissipation.

[0013] In order to prevent the influence of extrusion, vibration and the like, a packaging shell is fixedly connected to the substrate to seal the power module, and the outer wall of the packaging shell is bonded to the connection terminal.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention improves the heat dissipation effect of the power module by combining the heat pipe and the phase change material. The heat dissipation structure of the present invention utilizes the high thermal conductivity of the heat pipe to timely conduct the heat during overcurrent and overload to the phase change material. At the same time, the phase change material absorbs the conducted heat and utilizes the phase change latent heat to absorb the instantaneous heat of overcurrent and overload, thereby maintaining the temperature of the chip within a normal range. Furthermore, the present invention adds embedded cooling of microchannels to the chip, eliminating the thermal interface layer, effectively reducing the heat transfer group, improving the heat transfer efficiency, and ensuring that the high-power chip can operate normally for a long time; Furthermore, the present invention also adds a liquid cooling plate on the heat pipe skeleton to ensure the efficient and long-term operation of the phase change material and the heat pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of a power module with an upper heat dissipation portion according to Embodiment 1; Figure 2 is a schematic diagram of the upper heat dissipation portion of the first embodiment; Figure 3 is a cross-sectional view of the upper heat dissipation portion of the first embodiment; Figure 4 This is a schematic diagram of a liquid cooling plate according to Embodiment 2; Figure 5 is a schematic diagram of a substrate of Embodiment 3; Figure 6 is a schematic diagram of the bottom surface of the substrate of Example 3; Figure 7 This is a schematic diagram of a diverter plate in Embodiment 3; Figure 8 It is a schematic diagram of the chip and the lower heat dissipation part after being connected in the third embodiment; Fig. 9 This is a schematic diagram of the power module packaging structure of the fourth embodiment; Fig.10 This is a schematic diagram of the fourth embodiment after the connecting pipe is installed.

[0016] In the figure: 1. power module; 11. chip; 2. substrate; 21. copper layer; 22. ceramic layer; 23. microchannel; 3. upper heat dissipation part; 31. heat pipe skeleton; 32. insulation layer; 33. metal layer; 4. liquid cooling plate; 5. manifold; 51. manifold; 52. inlet; 53. outlet; 6. packaging shell; 61. terminal; 7. connecting pipe. DETAILED DESCRIPTION The present invention will be described in more detail below in conjunction with the accompanying drawings. It should be noted that the description of the present invention with reference to the accompanying drawings is only illustrative and not restrictive. The various embodiments can be combined with each other to form other embodiments not shown in the following description.

[0017] Embodiment 1 This embodiment provides a power module heat dissipation structure, which sinters a heat pipe metal frame above the chip, improves heat transfer efficiency through the heat pipe, and absorbs the impact of overcurrent and overload through the phase change material in the heat pipe frame.

[0018] In response to the instantaneous overcurrent and overload problem of power modules, there are existing solutions that use a skeleton with metal phase change material to sinter under the chip to absorb the heat of the chip, and then the metal is connected to the copper-clad ceramic. The latent heat of the phase change material is used to absorb the heat generated when the chip is overcurrent and overloaded. However, this method has the following problems: the heat dissipation performance of the phase change material is limited. For high-power modules, the latent heat of the phase change is completely dissipated only during normal operation. When an overcurrent overload occurs, the phase change material cannot play a role in thermal buffering. In addition, the thermal conductivity of the metal skeleton is limited. When the instantaneous heat flow is large, the heat conduction of the metal skeleton alone cannot transfer the heat to the cooling section for dissipation in time, thereby failing to weaken the instantaneous surge in heat flow. Thirdly, for multiple chips, it is generally necessary to sinter a large area of ​​metal skeleton below, and then sinter it with the copper-clad ceramic, which causes the copper-clad ceramic board to be difficult or difficult to be applied in practice.

[0019] Therefore, this embodiment has been improved on the basis of the above-mentioned existing technology. A heat pipe metal frame is sintered above the chip, and heat pipes are used to replace the traditional metal skeleton, thereby greatly enhancing the conduction efficiency of the skeleton and further enhancing the thermal load capacity during overcurrent overload. When overcurrent overload occurs, the phase change material above the chip is used to absorb the impact of the overcurrent overload.

[0020] Please refer to Figure 1 The schematic diagram of the power module 1 and the schematic diagram of the upper heat dissipation part 3 shown in the figure are a power module heat dissipation structure, including: a power module 1, the power module 1 includes a chip 11 and a substrate 2 under the chip, please refer to Figure 2 The schematic diagram of the upper heat sink 3 shown in the figure, the power module 1 also includes: an upper heat sink 3 located above the source region of the chip 11; a phase change material is arranged in the closed inner cavity of the upper heat sink 3, and a heat pipe skeleton 31 is arranged on the upper heat sink 3, and the heat pipe skeleton 31 is used for heat dissipation of the power module 1 and for transferring heat to the phase change material. Since the gate level of the chip 11 only provides a driving circuit, and the heat generation of the chip 11 is concentrated in the source region, this embodiment only constructs an upper heat sink 3 composed of a heat pipe skeleton 31 corresponding to the source size of the chip 11 of the power module 1. The upper heat sink 3 can be sintered to the source region on the front of the chip 11 by interface interconnection methods such as brazing, soldering, silver sintering, copper sintering, etc.

[0021] In this embodiment, the frame of the entire upper heat dissipation part 3 is a heat pipe skeleton 31. Specifically, the upper heat dissipation part 3 is adapted to the source size of the chip 11. The inner cavity of the heat pipe skeleton 31 is provided with a cooling medium. The bottom surface and the surrounding wall of the upper heat dissipation part 3 are the heat pipe skeleton 31. The bottom surface of the upper heat dissipation part 3 is connected to the source of the chip 11. Please refer to Figure 3The cross-sectional view of the upper heat dissipation part 3 shown. In the inner cavity of the upper heat dissipation part 3, a heat pipe framework 31 is arranged. The heat pipe frameworks 31 in the inner cavity are arranged in a cross pattern. The cross arrangement can expand the contact area and enhance the heat dissipation and heat transfer effects. The interiors of the heat pipe frameworks 31 are interconnected. The specific cross arrangement method can be the "abundant" character structure shown in the figure, or can be correspondingly set according to the size of the actual power module 1, the size and quantity of the chips 11, etc.

[0022] The top of the upper heat dissipation part 3 is used for heat evaporation. The specific structure of this embodiment is not limited thereto. It can be set as a metal top surface to facilitate heat dissipation and the connection of other components, or can be set as an insulating top surface to facilitate insulation.

[0023] It should be noted that the phase change material is arranged in the cavity between the inner walls of the heat pipe frameworks 31 that form the bottom wall and the peripheral wall of the upper heat dissipation part 3 and the outer walls of the heat pipe frameworks 31 in the inner cavity of the upper heat dissipation part 3.

[0024] In summary, the framework of the upper heat dissipation part 3 in this embodiment is the heat pipe framework 31, which has good heat transfer effect. It can make full use of the good heat transfer property of the heat pipe framework 31 to realize the transfer of the heat of the chip 11 to the phase change material, and improve the heat dissipation efficiency on the basis of the metal framework.

[0025] Embodiment 2 Embodiment 2 is an improvement based on Embodiment 1. By adding a liquid cooling plate, the heat dissipation efficiency of the upper heat dissipation part is further improved.

[0026] Please refer to Figure 2 The top view of the upper heat dissipation part 3 shown and Figure 4 The schematic diagram of the liquid cooling plate 4 shown. The bottom surface of the upper heat dissipation part 3 is connected to the source electrode of the chip 11, and the liquid cooling plate 4 is arranged on the top surface. The added liquid cooling plate 4 in this embodiment is used for the heat pipe evaporation-condensation cycle. The evaporation end of the heat pipe framework 31 is connected and encapsulated with the liquid cooling plate 4, so that the heat dissipation response speed is faster and it can better meet the millisecond-level thermal shock.

[0027] To facilitate the installation of the liquid cooling plate 4, an insulating layer 32 is arranged on the top surface of the upper heat dissipation part 3, and a metal layer 33 is covered above the insulating layer 32. The liquid cooling plate 4 is installed on the metal layer 33. The installation methods include welding such as brazing, soldering, silver sintering, copper sintering, or bonding with glue, silicone grease, gel, etc., as long as the connection is firm. Specifically, 300 nm to 500 nm of silicon oxide is deposited above the heat pipe framework 31 as the insulating layer 32, and at the same time, a layer of metal, such as gold, silver, copper, is sputtered on the surface of the insulating layer 32 to form the metal layer 33 for subsequent interface interconnection. The bottom surface of the liquid cooling plate 4 is connected to the top surface of the upper heat dissipation part 3, and several through holes for the refrigerant to flow in and out are arranged on two opposite side walls of the liquid cooling plate 4.

[0028] In summary, the liquid cooling plate 4 added in this embodiment has a fast response speed, and after being connected to the upper heat dissipation part 3, a coupled heat dissipation mode of liquid cooling and phase change material is formed, so that the overall structure of the power module 1 is compact, no additional connectors are required, the heat transfer effect is better, and it can meet the millisecond level thermal shock. When running at high power, the heat generated by the chip 11 can be absorbed by liquid cooling to reduce the latent heat consumption of the phase change material; when an overcurrent overload occurs, the phase change material above the chip 11 absorbs the impact of the overcurrent overload. This embodiment combines the good heat dissipation effect of liquid cooling and the characteristics of the phase change material that can absorb the impact of overcurrent overload.

[0029] Embodiment 3 Embodiment 3 is a further improvement based on Embodiment 1 or Embodiment 2.

[0030] Traditional heat dissipation methods usually use single-sided cold plates, which have two disadvantages: The heat transfer resistance is large. After the power chip generates heat, it can only dissipate through the interface material-cold plate-fluid path. The corresponding thermal resistance of the interface material, the thermal conductivity resistance of the water-cooled plate shell, and the thermal resistance of the fluid and the cold plate heat exchange gradually accumulate, affecting the heat dissipation efficiency.

[0031] The chip does not dissipate heat on one side, and there is temperature non-uniformity inside the chip. The surface temperature of the chip where it is attached to the cold plate is the lowest, and the temperature of the chip far from the cold plate is higher. The temperature difference between the upper and lower surfaces leads to an internal temperature gradient, which affects the service life of the chip. And as the power increases, in order to ensure the normal operation of the power chip, the fluid flow rate is usually increased, but this method will increase the temperature difference inside the chip and reduce the reliability of the chip.

[0032] Based on the above technical issues, please refer to Figure 5 and Figure 6The schematic diagram of the substrate 2 shown in the figure shows that the substrate 2 is a copper-clad ceramic plate, which includes a copper layer 21 and a ceramic layer 22. The copper layer 21 arranged on the top surface of the ceramic layer 22 is used to connect with the chip 11. The bottom surface of the substrate 2 is provided with a number of grooves to form a microchannel 23 for the circulation of the refrigerant, so that the substrate 2 becomes the lower heat dissipation part. The microchannel 23 can be constructed under the copper-clad ceramic plate by machining, laser etching, wet etching, etc. In this embodiment, the width of the microchannel 23 is between 0.08 mm and 1 mm, and the ratio of width to depth is between 1 and 10. The specific size can be set according to the actual heat dissipation requirements and packaging requirements. By directly embedding the microchannel 23 under the substrate 2, compared with the common bonding cold plate that needs to be installed additionally, the embedded heat transfer path is short and the thermal resistance is smaller. The principle of heat dissipation through the microchannel 23 is to increase the heat dissipation area through the microchannel to improve the heat dissipation efficiency, and optimize the channel structure by using the principle of fluid dynamics, reduce the flow resistance, and enhance the heat exchange effect. A refrigerant, such as a cooling liquid, flows at high speed in the plurality of microchannels 23 to absorb the heat generated by the chip 11.

[0033] Please refer to Figure 7 As shown, the bottom surface of the substrate 2 facing away from the chip 11 is also provided with a manifold 5 that matches the shape of the substrate 2. The bottom wall of the manifold 5 is provided with a plurality of manifolds 51. A channel for the flow of the refrigerant is formed between the manifold 51 and the inner wall of the manifold 5. After the manifold 5 is connected to the substrate 2, the manifold 51 and the microchannel 23 form a manifold-type microchannel. The opposite side walls of the manifold 5 are provided with a plurality of through holes for the flow of the refrigerant to flow in and out. The refrigerant flows in from the through holes. Figure 7 As shown, the refrigerant flows in from the inlet 52 , enters the microchannel 23 , and then flows out through the outlet 53 .

[0034] The manifold 5 can be connected to the copper-clad ceramic plate of the substrate 2 with the microchannel 23 engraved thereon by brazing, soldering, silver sintering, copper sintering, etc. It should be noted that since the substrate 2 needs to be connected to the manifold 5, the bottom of the substrate 2 is also a copper layer 21, that is, the bottom of the ceramic layer 22 / the top surface of the microchannel 23 is a copper layer 21.

[0035] Please refer to Figure 8 As shown, the chip 11 is connected to the copper-clad ceramic plate on which the sintered diverter plate 5 is connected by interface interconnection methods such as brazing, soldering, silver sintering, copper sintering, etc.

[0036] Compared with the common microchannel heat dissipation, the manifold microchannel has better pressure drop and heat exchange performance, and because the cooling and heat exchange area of ​​the microchannel 23 is large and the heat exchange efficiency is high, the heat generated by the chip 11 can be effectively taken away, so that the chip 11 can be cooled quickly, ensuring that the high-power chip can operate normally for a long time.

[0037] It should be noted that due to the presence of thermal resistance such as the ceramic layer 22 on the substrate 2, transient overcurrent overload (millisecond level shock) cannot be promptly taken away by the lower heat dissipation portion in this embodiment. Therefore, an upper heat dissipation portion 3 needs to be added above the chip 11 to transfer heat to the PCM phase change material by relying on the high thermal conductivity of the heat pipe, and utilize the latent heat of phase change to absorb transient overcurrent thermal shock.

[0038] Embodiment 4 The fourth embodiment mainly describes the packaging structure and electrical connection method of the power module.

[0039] Please refer to Figure 1 and Figure 4 As shown, the heat pipe skeleton 31 is electrically connected to the source electrode of the chip 11 , the substrate 2 is a copper-clad ceramic board, and the copper layer 21 of the substrate 2 is electrically connected to each electrode of the chip 11 and the heat pipe skeleton 31 .

[0040] Since the chip is directly connected to the copper layer 21 and the aluminum wire, it can only provide electrical connection and cannot play a role in heat dissipation. The connection between the heat pipe skeleton 31 and the copper layer 21 can play the role of electrical connection and heat dissipation at the same time. Specifically, the copper-clad ceramic plate (substrate 2) and the electrodes of the chip 11 are connected by wires. Since the heat pipe skeleton 31 is conductive, the heat pipe skeleton 31 and the chip source are at the same potential. The heat pipe skeleton 31 is connected to the copper layer 21 to replace the connection method of the source and the copper layer 21 in the prior art. The electrical connection can be achieved by connecting wires and other connection methods. The implementation method of the electrical connection belongs to conventional technical means, so this embodiment will not be described in detail.

[0041] The module usually needs to be sealed in practical applications, and glue needs to be poured over the chip 11 to prevent squeezing, vibration, etc. In addition, the power module 1 is easily corroded by the outside world or contaminated by particles. Therefore, this embodiment also adds a packaging shell 6 to the power module 1. Please refer to Fig. 9 As shown, a packaging shell 6 is fixedly connected to the substrate 2 to seal the power module 1 , and the outer wall of the packaging shell 6 is bonded with a connection terminal 61 .

[0042] In addition, please refer to Fig.10 As shown, a connecting pipe 7 can be installed at the through hole for the refrigerant to flow in and out. The connection method can be based on the specific material of the connecting pipe. For example, when the connecting pipe 7 is a metal pipe, it can be welded or bonded. If it is a non-metallic material, bonding, raw tape filling, etc. can be considered to finally complete the packaging.

[0043] Embodiment 5 The fifth embodiment mainly provides a schematic illustration of the specific processing flow of the power module.

[0044] The specific processing flow includes: The microchannel 23 is constructed on the back side of the copper-clad ceramic plate of the substrate 2 by machining, laser etching, wet etching, etc.

[0045] The ceramic layer 22 of the copper-clad ceramic plate with the channel engraved is sintered and connected to the shunt plate 5 by brazing, soldering, silver sintering, copper sintering, etc. Then, the chip 11 in the power module 1 is connected to the copper-clad ceramic plate with the sintered shunt plate 5 by brazing, soldering, silver sintering, copper sintering, etc.

[0046] An upper heat dissipation part 3 (heat pipe skeleton 31) corresponding to the source size of the chip 11 is constructed. Since the heat pipe skeleton 31 needs to be connected to the liquid cooling plate 4, 300nm~500nm of silicon oxide is deposited on the skeleton as an insulating layer 32, and a layer of metal (gold, silver, copper) is sputtered on the surface of the insulating layer 32 for subsequent interface interconnection.

[0047] The constructed upper heat dissipation part 3 is sintered to the source area on the front side of the chip 11 by means of interface interconnection methods such as brazing, soldering, silver sintering, copper sintering, etc., and the copper-clad ceramic plate and each electrode of the chip 11 are connected by wires, and the heat pipe skeleton 31 is connected to the copper layer 21 of the substrate 2.

[0048] The liquid cooling plate 4 is connected to the upper part of the upper heat dissipation part 3. The specific connection method includes welding using brazing, soldering, silver sintering, copper sintering, etc., or bonding methods such as glue, silicone grease, gel, etc. to maintain a firm connection.

[0049] The package shell 6 is bonded to the surface of the substrate 2 (copper-clad ceramic board), and the external terminal is bonded at the same time. The terminal 61 needs to correspond to the potential of the internal copper-clad ceramic board. Finally, the connecting tube 7 is installed to complete the packaging of the power module 1.

[0050] Embodiment 6 Embodiment 6 is a practical simulation description of the heat dissipation structure of the power module of the present invention.

[0051] The simulation of this embodiment is performed when the base heating value of the chip 11 is 150 W. Please refer to Table 1, which shows the comparison of the average chip temperature of each solution.

[0052] Table 1

[0053] It can be seen that the cooling effect of the heat dissipation structure of the present invention is significantly better than the other heat dissipation solutions mentioned above, and can effectively and quickly reduce the temperature of the chip 11.

[0054] Please refer to Table 2. This embodiment also simulates when the chip suddenly has a double overcurrent, that is, when the heat generation is close to four times the basic heat generation. Table 2 shows the average temperature comparison of the chip after heating for 5 seconds.

[0055] Table 2

[0056] It can be seen from Table 2 that even if the instantaneous heat generation is huge, the heat dissipation structure of the present invention can still effectively dissipate heat, so that the temperature of the chip 11 can be maintained within a healthy / normal temperature range, avoiding damage due to excessive temperature or a reduction in the life of the chip 11.

[0057] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A power module heat dissipation structure, comprising: A power module, the power module includes a chip and a substrate below the chip, characterized in that the power module also includes: an upper heat dissipation portion located above the source region of the chip; a phase change material is arranged in the closed inner cavity of the upper heat dissipation portion, and a heat pipe skeleton is arranged on the upper heat dissipation portion, and the heat pipe skeleton is used for heat dissipation of the power module and for transferring heat to the phase change material.

2. A power module heat dissipation structure according to claim 1, characterized in that: The upper heat dissipation part is adapted to the size of the chip source; a cooling medium is arranged in the inner cavity of the heat pipe skeleton, the bottom surface and the surrounding wall of the upper heat dissipation part are the heat pipe skeleton, and the bottom surface of the upper heat dissipation part is connected to the chip source.

3. A power module heat dissipation structure according to claim 1 or 2, characterized in that: A heat pipe skeleton is arranged in the inner cavity of the upper heat dissipation part, and the heat pipe skeletons in the inner cavity are arranged crosswise.

4. A power module heat dissipation structure according to claim 1 or 2, characterized in that: The bottom surface of the upper heat dissipation part is connected to the chip source, and a liquid cooling plate is arranged on the top surface.

5. A power module heat dissipation structure according to claim 4, characterized in that: An insulating layer is arranged on the top surface of the upper heat dissipation part, a metal layer is covered on the insulating layer, and the liquid cooling plate is installed on the metal layer.

6. The power module heat dissipation structure according to claim 4, characterized in that: The bottom surface of the liquid cooling plate is connected to the top surface of the upper heat dissipation portion, and two opposite side walls of the liquid cooling plate are provided with a plurality of through holes for the inflow and outflow of refrigerant.

7. The power module heat dissipation structure according to claim 1, characterized in that: The substrate is a copper-clad ceramic board, which includes a copper layer and a ceramic layer. The copper layer arranged on the top surface of the ceramic layer is used to connect with the chip. A plurality of grooves are provided on the bottom surface of the substrate to form microchannels for the circulation of refrigerant, so that the substrate becomes a lower heat dissipation part.

8. A power module heat dissipation structure according to claim 7, characterized in that: A diverter plate adapted to the shape of the substrate is also provided on the bottom surface of the substrate facing away from the chip, and a plurality of manifolds are provided on the bottom wall inside the diverter plate, and a channel for the flow of refrigerant is formed between the manifold and the inner wall of the diverter plate. After the diverter plate is connected to the substrate, the manifold and the microchannel form a manifold-type microchannel, and a plurality of through holes for the flow of refrigerant into and out of the diverter plate are provided on the opposite side walls.

9. The power module heat dissipation structure according to claim 1, characterized in that: The heat pipe skeleton is electrically connected to the chip source electrode, the substrate is a copper-clad ceramic plate, and the copper layer of the substrate is electrically connected to each electrode of the chip and the heat pipe skeleton.

10. The power module heat dissipation structure according to claim 1, characterized in that: A packaging shell is fixedly connected to the substrate to seal the power module, and the outer wall of the packaging shell is bonded with the connection terminal.

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