Liquid cooling radiator applied to power module and motor controller

Abstract

The invention discloses a liquid cooling radiator applied to a power module and a motor controller, and relates to the technical field of new energy automobile power electronic equipment heat dissipation. The liquid cooling radiator applied to the power module is composed of a pin fin structure, a radiator substrate, an NTC sampling encapsulation groove and a power semiconductor device mounting surface. The motor controller comprises a cooling liquid water channel, a three-phase output, a power module, a high-voltage direct-current interface and a high-voltage thin-film capacitor, wherein the power module comprises a power semiconductor device and a liquid cooling radiator applied to the power module. According to the design, the heat conduction path is optimized, the heat dissipation area is increased, and the contact thermal resistance is reduced. Compared with the prior art, the heat dissipation efficiency is improved by more than 40%, the temperature uniformity is improved by 60%, the power density is improved by about 25%, part of insulating part materials are omitted, and the material and process cost is reduced by about 10% while the design of the power inversion module is more compact.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of power electronic equipment for new energy vehicles, and in particular to a liquid-cooled radiator applied to a power module and a motor controller. Background Art

[0002] In new energy vehicle powertrains, liquid cooling technology has become a core thermal management solution for automotive inverters, particularly in the high-power-density, automotive-grade IGBT / SiC power modules. This technology can be categorized into two types: indirect and direct liquid cooling, depending on the contact method between the cooling medium and the power unit. The key difference between the two lies in the contact method between the power unit and the coolant.

[0003] Indirect liquid cooling systems primarily utilize a combination of a water-cooled plate and a flat heat sink. This system achieves close contact with the cooling plate by coating the bottom surface of the substrate with thermally conductive silicone grease. The heat conduction path exhibits a multi-layered structure: Chip heat is transferred sequentially through the DBC substrate, the flat heat sink, and the thermally conductive medium layer to the liquid cooling plate, where it is ultimately exchanged by the circulating coolant. Due to the presence of multiple thermal resistance interfaces between the power module and the cooling medium, this indirect contact approach restricts overall heat dissipation efficiency, creating a bottleneck in increasing power density.

[0004] In contrast, direct liquid cooling technology optimizes the heat transfer path through innovative structural design. This solution utilizes a heat dissipation substrate with an integrated pin-fin structure, embedding precisely designed fins directly into the coolant circulation channels. This streamlines the heat transfer process: chip → DBC substrate → pin-fin substrate → coolant. This design eliminates the thermal resistance of thermal grease and exponentially increases the heat dissipation contact area through the fin structure.

[0005] It's important to emphasize that both liquid cooling solutions rely on high-performance heat sinks as a key support. These substrates require multi-dimensional engineering properties: high thermal conductivity materials to ensure rapid heat transfer; thermal expansion coefficients that match those of components like the ceramic substrate to prevent thermal stress damage; and specialized structural designs that meet mechanical strength and service life requirements. As one of the most valuable components in a power module, the heat sink's material and specialized structural design directly impact the reliability and power output of the entire system.

[0006] However, the currently commonly used heat dissipation substrates have high contact thermal resistance and limited heat dissipation performance, and in actual production, the product material cost and process cost need to be further reduced. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a liquid-cooled radiator and a motor controller for power modules, which can effectively improve the heat dissipation performance and temperature uniformity, reduce the contact thermal resistance and increase the power density through direct heat dissipation, make the power inverter module more compact in design and development, and make the material variety and production cost more competitive.

[0008] A liquid cooling radiator for power modules, comprising a pin-fin structure, a radiator substrate, an NTC sampling potting tank, and a power semiconductor device mounting surface;

[0009] The pin-fin structure is connected to the heat sink substrate in a three-dimensional integrated manner using a gradient density distribution method. The pin-fin distribution density in the area corresponding to the back of the power semiconductor device mounting surface is increased by 40%-60% compared to the peripheral area, forming a non-uniform enhanced heat exchange structure.

[0010] The heat sink substrate forms an embedded three-dimensional cooling network with the power semiconductor device mounting surface through internal serpentine microchannels. The channels are manufactured using selective laser melting technology, with a wall thickness controlled within the range of 0.5-1.2mm. The channel cross-section presents a teardrop-shaped special-shaped structural design.

[0011] The NTC sampling potting tank adopts an embedded cavity structure and is directly welded to the heat flow core area of the radiator substrate. A 0.1mm thick thermal insulation layer is set at the bottom to achieve physical isolation from the cooling medium.

[0012] The surface of the power semiconductor device mounting surface is formed with a 20-50 μm thick Al2O3 ceramic layer through a micro-arc oxidation process, and is connected to the radiator substrate using a vacuum diffusion welding process, with an interface thermal resistance of less than 0.05K·cm 2 / W;

[0013] The pin-fin structure and the radiator base plate are integrally formed using extrusion molding technology, and staggered cooling channels are formed inside the radiator base plate at an angle of 55 degrees to the axial direction of the pin-fins;

[0014] The radiator substrate is a convex structure, and there is a height difference of 4-6mm between the convex bottom and the substrate mounting surface;

[0015] The NTC potting tank adopts a pre-embedded secondary packaging process, and realizes airtight interface connection through laser remelting after the radiator substrate is formed.

[0016] Furthermore, the pin-fin structure is a combination of one or more shapes including elliptical, circular, and diamond.

[0017] Furthermore, the surface of the heat sink substrate has one or more protrusions, and the protrusions are connected to the power semiconductor device by welding.

[0018] Furthermore, the NTC sampling potting tank is a groove, and the temperature sampling device is buried in the groove.

[0019] In addition, an embodiment of the present invention further provides a motor controller, which includes a coolant channel, a three-phase output, a power module, a high-voltage DC interface, and a high-voltage film capacitor;

[0020] When the motor controller is connected to an external power battery, the high-voltage DC power of the power battery is transmitted to the high-voltage film capacitor through a filter. The high-voltage film capacitor converts the DC power into the AC power required by the motor through a power module.

[0021] Furthermore, the power module includes a power semiconductor device and a liquid cooling radiator applied to the power module;

[0022] The power semiconductor device includes an IGBT or SiC chip and a DBC substrate; the DBC substrate is connected to a liquid-cooled radiator used in the power module through welding or sintering process, and direct heat dissipation is performed between the liquid-cooled radiator used in the power module and the power semiconductor device.

[0023] Furthermore, in the power module, the number of power semiconductor devices is determined according to actual output current capability.

[0024] Furthermore, in the power module, the power semiconductor devices are connected in series or in parallel, or in a combination of these.

[0025] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0026] (1) The present invention proposes a liquid-cooled heat sink for power modules that is extruded from a pin-fin structure. The pin-fin structure is a combination of one or more elliptical, circular, and diamond shapes, and the heat sink base is a convex structure. This increases the heat dissipation contact area and optimizes the heat conduction path, resulting in a more than 40% increase in heat dissipation efficiency and a 60% improvement in temperature uniformity. Furthermore, it can better meet the requirements of mechanical strength and service life.

[0027] (2) In a motor controller proposed by the present invention, the DBC substrate of the power semiconductor device in the power module is connected to the liquid cooling radiator through welding or sintering process to achieve direct heat dissipation, reduce the intermediate layers in the heat conduction process, eliminate the thermal resistance effect caused by thermal grease, etc., simplify the heat dissipation structure, and improve the heat dissipation performance.

[0028] (3) The present invention proposes a liquid-cooled heat sink and motor controller for a power module, which improves heat dissipation efficiency and reduces contact thermal resistance, thereby increasing power density by approximately 25%. The optimized heat dissipation structure enables a more compact design and development of the power inverter module, accommodating more power semiconductor devices within the same volume, thereby improving power output capability and, in turn, power density.

[0029] (4) The liquid-cooled radiator proposed in the present invention solves the problem of electrical clearance between the bolts and the power semiconductor device by optimizing the structure. The height difference of 4-6 mm between the convex bottom of the radiator substrate and the mounting surface of the substrate is used, thereby eliminating the conventional necessary insulating materials and reducing the product material cost and process cost in the overall design by about 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a bottom view of a liquid-cooled radiator applied to a power module proposed by the present invention.

[0031] Figure 2 This is an axial side view of a liquid cooling radiator applied to a power module proposed by the present invention.

[0032] Figure 3 This is a cross-sectional view of a liquid-cooled radiator applied to a power module proposed by the present invention.

[0033] Figure 4 Schematic diagram of the power module proposed in the present invention.

[0034] Figure 5 This is a schematic diagram of a vehicle motor controller proposed by the present invention.

[0035] Among them: 100, liquid-cooled radiator; 110, pin-fin structure; 120, radiator substrate; 130, NTC sampling potting tank; 140, power semiconductor device mounting surface; 150, power device welding surface; 160, substrate mounting surface; 210, power semiconductor device; 310, controller water channel; 320, three-phase output; 330, power module; 340, high-voltage DC interface; 350, high-voltage film capacitor. DETAILED DESCRIPTION

[0036] The following further describes the specific embodiments of the present invention in conjunction with the accompanying drawings, clearly and completely describing the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Combine Figures 1 to 3, a liquid cooling radiator applied to a power module, comprising a pin-fin structure (110), a radiator substrate (120), an NTC sampling potting groove (130) and a power semiconductor device mounting surface (140);

[0038] The pin-fin structure (110) is connected to the heat sink substrate (120) in a three-dimensional integral molding manner by adopting a gradient density distribution method. The pin-fin distribution density in the area corresponding to the back side of the power semiconductor device mounting surface (140) is increased by 40% to 60% compared with the peripheral area, forming a non-uniform enhanced heat exchange structure.

[0039] The heat sink substrate (120) forms an embedded three-dimensional cooling network with the power semiconductor device mounting surface (140) through an internal serpentine microchannel, the channel is manufactured using selective laser melting technology, the wall thickness is controlled within the range of 0.5-1.2 mm, and the channel cross section presents a water drop-shaped special-shaped structural design;

[0040] The NTC sampling potting tank (130) adopts an embedded cavity structure and is directly welded to the heat flow core area of the radiator substrate (120), and a 0.1 mm thick heat conductive insulation layer is provided at the bottom thereof to achieve physical isolation from the cooling medium;

[0041] The surface of the power semiconductor device mounting surface (140) is formed with an Al2O3 ceramic layer having a thickness of 20-50 μm by a micro-arc oxidation process, and is connected to the radiator substrate (120) by a vacuum diffusion welding process, with an interface thermal resistance of less than 0.05 K·cm 2 / W;

[0042] The pin-fin structure (110) and the radiator base plate (120) are integrally formed using extrusion molding technology, so that the liquid-cooled radiator has good consistency, and a staggered cooling channel is formed inside the radiator base plate (120) at an angle of 55 degrees to the axial direction of the pin-fin.

[0043] The heat sink substrate (120) is a convex structure, and there is a height difference of 4-6 mm between the convex bottom and the substrate mounting surface (160), so as to solve the problem of electrical clearance between the input or output copper busbar of the power semiconductor device and the heat sink substrate (120), eliminating the need for conventional necessary insulating materials;

[0044] The NTC potting groove (130) adopts a pre-embedded secondary packaging process, and after the radiator substrate (120) is formed, airtight interface connection is achieved through laser remelting.

[0045] Furthermore, the pin-fin structure (110) is a combination of one or more of an elliptical shape, a circular shape, and a diamond shape.

[0046] Furthermore, the surface of the heat sink substrate (120) has one or more protrusions, and the protrusions are connected to the power semiconductor device (210) by welding.

[0047] Furthermore, the NTC sampling potting groove (130) is a groove in which a temperature sampling device is buried. The number of the NTC sampling potting grooves (130) is not limited to two on the left and right sides in the specific embodiment proposed in the present invention, and the shape and number can be designed in a targeted manner according to needs.

[0048] In addition, an embodiment of the present invention further provides a motor controller, which includes a coolant channel (310), a three-phase output (320), a power module (330), a high-voltage DC interface (340), and a high-voltage film capacitor (350). Figure 5 As shown;

[0049] When the motor controller is connected to an external power battery, the high-voltage direct current of the power battery is transmitted to the high-voltage film capacitor (350) through a filter, and the high-voltage film capacitor (350) converts the direct current into the alternating current required by the motor through the power module (330).

[0050] Combine Figure 4 , further, the power module (330) includes a power semiconductor device (210) and a liquid cooling radiator (100) applied to the power module;

[0051] The power semiconductor device (210) comprises an IGBT or SiC chip and a DBC substrate; the DBC substrate is connected to a liquid cooling radiator (100) applied to a power module through a welding or sintering process, and direct heat dissipation is performed between the liquid cooling radiator (100) applied to the power module and the power semiconductor device (210).

[0052] Furthermore, in the power module (330), the number of power semiconductor devices (210) is determined according to actual output current capability.

[0053] Furthermore, in the power module (330), the power semiconductor devices (210) are connected in a manner of either series connection or parallel connection, or in combination of the two.

[0054] Furthermore, the motor controller (300) can be used in a variety of hybrid, range-extended, and pure electric platforms by increasing the number of power modules (330) during actual use.

[0055] The above implementation scheme is only the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical scheme in accordance with the technical idea proposed by the present invention fall within the protection scope of the present invention.

Claims

1. A liquid cooling radiator for a power module, characterized in that: It consists of a pin-fin structure (110), a heat sink base plate (120), an NTC sampling potting groove (130) and a power semiconductor device mounting surface (140); The pin-fin structure (110) is connected to the heat sink substrate (120) in a three-dimensional integrated manner by adopting a gradient density distribution method. The pin-fin distribution density in the area corresponding to the back side of the power semiconductor device mounting surface (140) is increased by 40% to 60% compared with other areas, forming a non-uniform enhanced heat exchange structure. The heat sink substrate (120) forms an embedded three-dimensional cooling network with the power semiconductor device mounting surface (140) through an internal serpentine microchannel, the channel is manufactured using selective laser melting technology, the wall thickness is controlled within the range of 0.5-1.2 mm, and the channel cross section presents a water drop-shaped special-shaped structural design; The NTC sampling potting tank (130) adopts an embedded cavity structure and is directly welded to the heat flow core area of the radiator substrate (120), and a 0.1 mm thick heat conductive insulation layer is provided at the bottom thereof to achieve physical isolation from the cooling medium; The surface of the power semiconductor device mounting surface (140) is formed with an Al2O3 ceramic layer having a thickness of 20-50 μm by a micro-arc oxidation process, and is connected to the radiator substrate (120) by a vacuum diffusion welding process, with an interface thermal resistance of less than 0.05 K·cm 2 / W; The pin-fin structure (110) and the radiator base plate (120) are integrally formed using an extrusion molding technology, and a staggered cooling flow channel is formed inside the radiator base plate (120) at an angle of 55° to the axial direction of the pin-fins; The radiator substrate (120) is a convex structure, and there is a height difference of 4-6 mm between the convex bottom and the substrate mounting surface (160); The NTC potting groove (130) adopts a pre-embedded secondary packaging process, and after the radiator substrate (120) is formed, airtight interface connection is achieved through laser remelting.

2. The liquid cooling radiator for a power module according to claim 1, characterized in that: The pin-fin structure (110) is in the shape of an ellipse, a circle, a diamond, or a combination of one or more shapes.

3. The liquid cooling radiator for a power module according to claim 1, characterized in that: The surface of the heat sink substrate (120) has one or more protrusions, and the protrusions are connected to the power semiconductor device (210) by welding.

4. The liquid cooling radiator for a power module according to claim 1, characterized in that: The NTC sampling potting groove (130) is a groove, in which a temperature sampling device is buried.

5. A motor controller, characterized in that: The power module of the motor controller is provided with a liquid cooling radiator applied to the power module according to any one of claims 1 to 4, and the motor controller comprises a cooling liquid channel (310), a three-phase output (320), a power module (330), a high-voltage DC interface (340), and a high-voltage film capacitor (350); When the motor controller (300) is connected to an external power battery, the high-voltage direct current of the power battery is transmitted to the high-voltage film capacitor (350) through a filter, and the high-voltage film capacitor (350) converts the direct current into the alternating current required by the motor through the power module (330).

6. A motor controller according to claim 5, characterized in that: The power module (330) comprises a power semiconductor device (210) and a liquid cooling radiator (100) applied to the power module; The power semiconductor device (210) comprises an IGBT or SiC chip and a DBC substrate; the DBC substrate is connected to a liquid cooling radiator (100) applied to a power module through a welding or sintering process, and direct heat dissipation is performed between the liquid cooling radiator (100) applied to the power module and the power semiconductor device (210).

7. The motor controller according to claim 5, characterized in that: In the power module (330), the number of power semiconductor devices (210) is determined according to actual output current capability.

8. The motor controller according to claim 5, characterized in that: In the power module (330), the power semiconductor devices (210) are connected in a series or parallel manner, or in a combination of the two or more.

Images