A double-sided cooling type power semiconductor package structure

Abstract

The application discloses a double-sided cooling type power semiconductor packaging structure and belongs to the technical field of power semiconductor device packaging. The packaging structure comprises three layers of water cooling parts which are sequentially stacked, detachable positioning material layers are connected between two adjacent layers of the water cooling parts, each layer of the water cooling parts is provided with an inlet, an outlet and a cooling medium flow channel, the cooling medium flow channel is in communication with the inlet and the outlet, a die assembly is fixedly arranged between two adjacent layers of the water cooling parts by the positioning material layers, and the die assembly forms surface contact with the two adjacent layers of the water cooling parts. The double-sided contact cooling form enlarges the heat dissipation area, the heat conduction performance is improved by means of a heat-conducting insulating coating, and the packaging structure is detachable, so that the power module packaging structure has the advantages of high-efficiency heat dissipation, reliable insulation and high recyclability. The packaging structure helps to promote the development of power electronic devices in the direction of high power density, long service life and sustainability.

Description

Technical Field

[0001] This invention belongs to the field of power semiconductor device packaging technology, and in particular to a double-sided cooling power semiconductor packaging structure. Background Technology

[0002] Traditional power semiconductor packaging technologies often employ direct copper-clad (DBC) ceramic packaging structures, which achieve insulation through the ceramic layer. However, the low thermal conductivity of ceramic materials severely limits heat dissipation efficiency, especially in wide-bandgap semiconductor (such as silicon carbide SiC and gallium nitride GaN) devices, where high heat flux density leads to chip overheating. Furthermore, the rigid connections of multiple heterogeneous materials (ceramic, copper, solder, etc.) in the DBC structure are prone to interfacial stress due to mismatched coefficients of thermal expansion, potentially leading to delamination and cracking after long-term operation, significantly reducing device reliability.

[0003] Furthermore, power semiconductor packaging designs commonly feature an integrated structure, where chips, heat sinks, and insulating materials are tightly bonded together using soldering or bonding, making them difficult to disassemble. When devices reach the end of their lifespan or when some components fail due to aging, the entire package structure is often discarded, resulting not only in the waste of high-value core components but also increased recycling costs due to the difficulty in separating dissimilar materials.

[0004] Therefore, the packaging technology of power semiconductor devices urgently needs improvement, and there is a pressing need to address issues related to heat dissipation, insulation reliability, and recyclability. Summary of the Invention

[0005] The purpose of this invention is to provide a double-sided cooled power semiconductor packaging structure to address at least one of the shortcomings of the aforementioned background technology. The double-sided cooled power semiconductor packaging structure provided in this application expands the heat dissipation area through double-sided contact cooling, enhances thermal conductivity through a thermally conductive insulating coating, and features a removable packaging structure. Therefore, it combines efficient heat dissipation, reliable insulation, and high recyclability in a power module packaging structure. This packaging structure helps promote the development of power electronic devices towards higher power density, longer lifespan, and sustainability.

[0006] To solve the above problems, the technical solution adopted in this application is as follows.

[0007] This application provides an example of a double-sided cooled power semiconductor package structure, including: The three layers of water-cooled components are stacked sequentially, with a detachable positioning material layer connecting each adjacent layer of the water-cooled components. Each layer of the water-cooled components is provided with an inlet, an outlet, and a cooling medium flow channel, and the cooling medium flow channel is connected to the inlet and the outlet. The core assembly is fixedly disposed between two adjacent water-cooling components by the positioning material layer, and the core assembly and the two adjacent water-cooling components are in surface contact.

[0008] The three layers of water-cooled components are connected by a positioning material layer to form a stacked structure. The core assembly is fixed by the positioning material layer and forms surface contact with the two adjacent water-cooled components. The core assembly efficiently conducts its heat to the two adjacent water-cooled components through surface contact. By connecting the inlet and outlet of the water-cooled components to an external cooling device, the cooling medium channels can be filled with coolant, thus achieving heat dissipation and dissipating the heat conducted from the core assembly to the water-cooled components. The removable positioning material layer facilitates the disassembly and assembly of the overall encapsulation structure, making component replacement convenient.

[0009] Based on the examples above, the cooling medium channels are arranged in a bidirectional convection manner.

[0010] Based on the examples above, a thermally conductive and insulating coating is formed on the inner surface of the cooling medium flow channel.

[0011] Based on some of the examples above, the thermally conductive insulating coating is graphene or ceramic.

[0012] Based on the examples above, the surface of the water-cooled component that contacts the core assembly is provided with a heat transfer interface layer.

[0013] Based on the examples above, the material of the heat transfer interface layer is molybdenum.

[0014] Based on the examples above, the die assembly includes: Semiconductor chips, encapsulated in a plastic casing; Both the source power terminal and the drain terminal are soldered to the semiconductor chip, with the source power terminal located on the upper surface of the semiconductor chip and the drain terminal located on the lower surface of the semiconductor chip. Both the source power terminal and the drain terminal form surface contact with the water-cooling component; and... Both the gate control terminal and the source control terminal are bonded to the semiconductor chip.

[0015] Based on the examples above, the source power terminal includes a copper plate and a copper pillar, one end of which is integrally formed with the copper plate, and the other end is soldered to the upper surface of the semiconductor chip.

[0016] Based on the examples above, each layer of the water-cooled component has a connection terminal formed thereon, and the connection terminals on adjacent layers of the water-cooled component are staggered.

[0017] According to some of the examples above, a pressure application device is also included, which is used to apply a compressive force in opposite directions to the two outermost layers of the water-cooled components. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a double-sided cooled power semiconductor packaging structure provided in an embodiment of this application; Figure 2 A schematic diagram of a die assembly provided in an embodiment of this application from a first-view perspective; Figure 3 This is an exploded view of a die assembly provided in an embodiment of this application from a second perspective; Figure 4 This is a schematic diagram of the arrangement of cooling medium flow channels on a water-cooled component, provided for an embodiment of this application.

[0019] In the picture: 1. Water-cooled component; 2. Positioning material layer; 3. Cooling medium flow channel; 31. First cooling medium flow channel; 32. Second cooling medium flow channel; 4. Die assembly; 41. Semiconductor chip; 42. Plastic casing; 43. Copper plate; 44. Drain terminal; 45. Gate control terminal; 46. Source control terminal; 47. Bonding wire; 48. Copper pillar; 5. Connecting terminals. Detailed Implementation

[0020] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0021] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a double-sided cooled power semiconductor package structure includes: three layers of water-cooled components 1 stacked sequentially. Each water-cooled component 1 can be a flat plate with a certain thickness. A reconfigurable positioning material layer 2 connects adjacent water-cooled component 1 layers. Each water-cooled component 1 layer has an inlet, an outlet, and a cooling medium channel 3. The cooling medium channel 3 is positioned at the midpoint of the thickness of the water-cooled component and extends from the inlet at one end to the outlet at the other end, i.e., the cooling medium channel 3 communicates with both the inlet and the outlet. The cooling medium channel 3 can be formed by etching the water-cooled component 1. A die assembly 4 is fixed between adjacent water-cooled component 1 layers by the positioning material layer 2, and the die assembly 4 forms surface contact with both adjacent water-cooled component 1 layers to facilitate heat conduction. The positioning material layer 2 is made of polyethylene etherimide (PEI). The polyethylene etherimide (PEI) filled between the two water-cooling components 1 can fix the core assembly 4. Polyethylene etherimide (PEI) is decomposable and remodelable, so it can be recycled and reused after the encapsulation structure is disassembled.

[0022] The three-layer water-cooled component 1 is connected by a positioning material layer 2 to form a stacked structure. The core assembly 4 is fixed by the positioning material layer 2 and forms surface contact with the two adjacent water-cooled components 1. The core assembly 4 efficiently conducts its heat to the two adjacent water-cooled components 1 through surface contact. By connecting the inlet and outlet of the water-cooled component 1 to an external cooling device, the cooling medium flow channel 3 can be filled with coolant, thus achieving heat dissipation and dissipating the heat conducted from the core assembly 4 to the water-cooled component 1. The reconfigurable positioning material layer 2 facilitates the separation and disassembly of the overall encapsulation structure, making component replacement convenient. For example, a single core assembly 4 or water-cooled component 1 can be replaced relatively easily.

[0023] In some embodiments, the cooling medium channels 3 are arranged in a bidirectional convection manner. For example, the water-cooled component 1 is provided with a plurality of parallel cooling medium channels 3. Two adjacent cooling medium channels 3 are, as shown in the figure, the first cooling medium channel 31 and the second cooling medium channel 32. The coolant flows in opposite directions in the adjacent first cooling medium channel 31 and second cooling medium channel 32. This bidirectional convection arrangement facilitates the efficient dissipation of heat from the core assembly 4.

[0024] In some embodiments, a thermally conductive and insulating coating is formed on the inner surface of the cooling medium channel 3. The insulating properties of the thermally conductive and insulating coating improve the reliability of the encapsulation structure, while also facilitating the rapid removal of heat by the coolant. For example, the thermally conductive and insulating coating is graphene or ceramic, which has insulating properties and good heat transfer efficiency.

[0025] In some embodiments, a heat transfer interface layer is provided on the surface of the water-cooled component 1 that contacts the die assembly 4 to reduce interface stress. This helps prevent delamination and cracking of the packaged structure during long-term operation. The heat transfer interface layer is made of a thermal stress buffer material with a low coefficient of thermal expansion. For example, the material of the heat transfer interface layer is molybdenum or a molybdenum-silver composite material, thereby reducing the thermal stress generated at the two surfaces of the die assembly 4 and the water-cooled component 1 that contact each other. The high electrical and thermal conductivity and high mechanical strength of molybdenum help improve the electrical reliability of the packaged structure.

[0026] The following describes the die assembly 4 in further detail. The die assembly 4 includes: a semiconductor chip 41, encapsulated within a plastic housing 42; a source power terminal and a drain terminal 44, both soldered to the semiconductor chip 41, with the source power terminal located on the upper surface of the semiconductor chip 41 and the drain terminal 44 located on the lower surface of the semiconductor chip 41. Both the source power terminal and the drain terminal 44 form surface contact with the water-cooling component 1; and a gate control terminal 45 and a source control terminal 46, both connected to the semiconductor chip 41 via bonding wires 47. In a specific implementation, the lengths of the gate control terminal 45 and the source control terminal 46 are both longer than the source power terminal, so that the drive circuit containing the gate control terminal 45 and the source control terminal 46 is separated from the power circuit containing the source power terminal.

[0027] To further improve the heat dissipation efficiency of the semiconductor chip 41, the source power terminal includes a copper plate 43 and a copper pillar 48. One end of the copper pillar 48 is integrally formed with the copper plate 43, and the other end is welded to the upper surface of the semiconductor chip 41. The copper plate 43 forms surface contact with the surface of the water-cooling component 1, and the copper pillar 48 rapidly dissipates the heat generated by the semiconductor chip 41. Furthermore, the copper plate 43 and copper pillar 48 structure replaces the traditional aluminum wire bonding connection, thus reducing parasitic parameters. The drain terminal 44 can also adopt a copper plate structure to conduct heat.

[0028] To facilitate the connection between the encapsulation structure and the external busbar, a connection terminal 5 is formed on each layer of the water-cooling component 1, and the connection terminals 5 on adjacent layers of the water-cooling component 1 are staggered so that the connection terminals 5 are staggered by a certain space to facilitate the connection operation.

[0029] In some embodiments, the double-sided cooled power semiconductor package structure further includes a pressure application device (not shown) for applying a pressure force in opposite directions to the two outermost water-cooled components 1 (e.g., from...). Figure 1A downward pressure is applied to the upper surface of the topmost water-cooled component 1, or an upward pressure is applied to the lower surface of the bottommost water-cooled component 1, thereby ensuring good surface contact between the core assembly 4 and the water-cooled component 1.

[0030] In the foregoing description of this application, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this application, those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Based on the above description of this application, those skilled in the art will also understand that the terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are based on the orientation or positional relationship shown in the accompanying drawings of this application. They are only for the purpose of facilitating the explanation of the solution of this application and simplifying the description, and do not explicitly or implicitly suggest that the device or element involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as a limitation on the solution of this application.

[0032] Furthermore, the terms "first" or "second," etc., used in this application to refer to numbers or ordinal numbers are for descriptive purposes only and should not be construed as explicitly or implicitly indicating relative importance or specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, or more, unless otherwise explicitly specified.

[0033] While numerous embodiments of this application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will arise for those skilled in the art without departing from the spirit and intent of this application. It should be understood that various alternatives to the embodiments of this application described herein may be employed in the practice of this application. The appended claims are intended to define the scope of protection of this application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A double-sided cooling power semiconductor package structure, characterized by, include: The three layers of water-cooled components are stacked sequentially, with a detachable positioning material layer connecting each adjacent layer of the water-cooled components. Each layer of the water-cooled components is provided with an inlet, an outlet, and a cooling medium flow channel, and the cooling medium flow channel is connected to the inlet and the outlet. The core assembly is fixedly disposed between two adjacent water-cooling components by the positioning material layer, and the core assembly and the two adjacent water-cooling components are in surface contact.

2. The double-sided cooled power semiconductor package structure according to claim 1, characterized in that The cooling medium channels are arranged in a bidirectional convection manner.

3. In the double-sided cooling power semiconductor packaging structure according to claim 1 or 2, a thermally conductive and insulating coating is formed on the inner surface of the cooling medium channel.

4. The double-sided cooled power semiconductor package structure according to claim 3, characterized in that The thermally conductive and insulating coating is graphene or ceramic.

5. The double-sided cooled power semiconductor package structure according to claim 1, characterized in that, The surface of the water-cooled component that contacts the core assembly is provided with a heat transfer interface layer.

6. The double-sided cooled power semiconductor package structure according to claim 5, characterized in that The heat transfer interface layer is made of molybdenum.

7. The double-sided cooled power semiconductor package structure according to claim 1, characterized in that, The die assembly includes: Semiconductor chips, encapsulated in a plastic casing; Both the source power terminal and the drain terminal are soldered to the semiconductor chip, with the source power terminal located on the upper surface of the semiconductor chip and the drain terminal located on the lower surface of the semiconductor chip. Both the source power terminal and the drain terminal form surface contact with the water-cooling component; and... Both the gate control terminal and the source control terminal are bonded to the semiconductor chip.

8. The double-sided cooled power semiconductor package structure according to claim 7, characterized in that The source power terminal includes a copper plate and a copper pillar. One end of the copper pillar is integrally formed with the copper plate, and the other end is welded to the upper surface of the semiconductor chip.

9. The double-sided cooled power semiconductor package structure of claim 1, wherein, Each layer of the water-cooled component has a connection terminal formed thereon, and the connection terminals on adjacent layers of the water-cooled component are staggered.

10. The double-sided cooled power semiconductor package structure of claim 1, wherein, It also includes a pressure application device for applying a compressive force in opposite directions to the two outermost layers of the water-cooled components.

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