Heat dissipation substrate for power module

Abstract

The utility model relates to the technical field of heat dissipation devices, in particular to a heat dissipation substrate for a power module, which comprises a substrate, a plurality of radiating fins and a plurality of radiating fins. The welding surface is fixedly connected with the surface of the power module to be cooled; the substrate has a preset curve in the direction towards the welding surface; the preset curve is opposite to the deformation of the substrate at the working temperature of the power module. In order to solve the problem that in the prior art, a heat dissipation assembly is prone to poor contact due to thermal deformation when a power module emits heat, and the heat dissipation effect is affected, in the embodiment, a preset curve with the middle protruding and the edge sinking is designed on one side of the welding face of a substrate in advance, and then the substrate is welded to the power module. When the power module works and emits heat, the substrate is heated to deform, and the deformation amount is compensated through the preset curve, so that the substrate can be accurately attached to the welding surface of the power module in the heated state, and the heat conduction efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation device technology, and specifically to a heat dissipation substrate for power modules. Background Technology

[0002] Power modules, also known as power semiconductor components, encompass two main categories: power devices and power ICs. Power ICs are relatively low-power, low-voltage integrated chips. They have a high degree of integration, meaning they integrate high-voltage power devices with their control circuits, peripheral interface circuits, and protection circuits onto a single chip. They are primarily used in low-voltage products such as mobile phones. Power devices include diodes, transistors, and thyristors, with transistors having the largest market share. Transistors are further subdivided into IGBTs, MOSFETs, bipolar transistors, etc. Power devices are larger products used to handle higher power and voltage, such as automotive IGBTs. Because power semiconductors frequently switch between different states during operation, they generate significant heat, thus requiring additional heat dissipation components for cooling.

[0003] For example, Chinese patent CN201810278947.7 discloses a heat dissipation structure for a power device, including a circuit board. The circuit board is provided with a heat sink and several power devices. The heat sink is made of metal material and has at least two fixing parts and at least two heat dissipation parts. The surface of the circuit board is provided with copper foil. The fixing parts of the heat sink and the pads of the power devices are welded and fixed to the circuit board, with the copper foil located between the fixing parts and the circuit board, and between the pads and the circuit board. The fixing parts of the heat sink are arranged parallel to the circuit board, and the heat dissipation parts of the heat sink are arranged perpendicular to the circuit board. Every two heat dissipation parts are located between two fixing parts. The lower end of the heat dissipation part is connected to the edge of the fixing part, and a connecting part is provided between the heat dissipation part and the fixing part.

[0004] For example, Chinese patent CN202311787712.8 provides a heat dissipation device for power devices, comprising: a substrate having a first accommodating space communicating with the outside; a first heat sink located within the first accommodating space and exposed on a first surface of the substrate; a second heat sink disposed on the first surface of the substrate, and a second accommodating space for accommodating the power device being formed between the second heat sink and the first heat sink; and a third heat sink disposed on the side of the second heat sink away from the first heat sink, wherein the thermal conductivity of the third heat sink is less than that of the second heat sink; the projected area of ​​the third heat sink on the projection surface is greater than that of the second heat sink on the projection surface, and the ratio of the projected area of ​​the third heat sink to that of the second heat sink is between 1.44 and 9. This achieves double-sided heat dissipation, which can promptly dissipate the heat generated by the power device and diffuse the heat in a timely manner, preventing heat accumulation on the outer periphery of the power device and improving the heat dissipation performance of the heat dissipation device.

[0005] However, in actual implementation, the inventors found that during the implementation of this type of technical solution, the power devices generate a lot of heat when they are working. Since the power devices, circuit boards, and heat dissipation components are made of different materials, their thermal expansion rates are different. As a result, gaps exist between the power devices, circuit boards, and heat dissipation components due to thermal expansion. This leads to a decrease in the contact effect between the power devices and the heat dissipation components, affecting the heat dissipation effect. Utility Model Content

[0006] In view of the above-mentioned problems in the prior art, a heat dissipation substrate for power modules is provided.

[0007] The specific technical solution is as follows:

[0008] A heat dissipation substrate for a power module includes a substrate, the substrate including a soldering surface and a heat dissipation surface;

[0009] The welding surface is connected and fixed to the surface of the power module to be cooled;

[0010] The substrate has a preset curve in the direction toward the welding surface;

[0011] The preset curve is opposite to the deformation of the substrate at the operating temperature of the power module.

[0012] On the other hand, welding bosses are provided on the welding surface.

[0013] On the other hand, the welding boss is rectangular, circular, or trapezoidal.

[0014] On the other hand, the height of the welding boss is between 0 and 0.2 mm.

[0015] On the other hand, multiple heat dissipation columns are distributed in a dot matrix on the heat dissipation surface, and the heat dissipation columns are arranged perpendicular to the heat dissipation surface.

[0016] On the other hand, the heat dissipation column can be a regular square prism, a straight square prism, a cylinder, or a fin.

[0017] On the other hand, the surfaces of the heat dissipation surface and the heat dissipation column are coated.

[0018] On the other hand, the height difference of the preset curve is between 0.1 and 1 mm.

[0019] On the other hand, the edges of the heat dissipation column are chamfered.

[0020] On the other hand, the height of the heat dissipation column is between 0 and 10 millimeters.

[0021] The above technical solution has the following advantages or beneficial effects:

[0022] To address the issue in existing heat dissipation components that suffer from poor contact and reduced heat dissipation due to thermal deformation when the power module heats up, this embodiment employs a pre-designed curve with a raised center and recessed edges on one side of the substrate's welding surface before welding it to the power module. When the power module operates and generates heat, the substrate deforms due to heat, and the pre-designed curve compensates for the amount of deformation. This ensures that the substrate accurately conforms to the welding surface of the power module under heat, improving heat conduction efficiency. Attached Figure Description

[0023] Embodiments of the present invention will be described more fully with reference to the accompanying drawings. However, the accompanying drawings are for illustration and explanation only and do not constitute a limitation on the scope of the present invention.

[0024] Figure 1 This is a partial cross-sectional schematic diagram of an embodiment of the present utility model;

[0025] Figure 2 This is a schematic diagram of the heat dissipation surface in an embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments of the present invention can be combined with each other.

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0029] This utility model includes:

[0030] A heat dissipation substrate for power modules, such as Figure 1 As shown, it includes a substrate 1, which includes a welding surface 2 and a heat dissipation surface 3;

[0031] Welding surface 2 is fixedly connected to the surface of the power module to be cooled;

[0032] The substrate 1 has a preset curve in the direction facing the welding surface 2;

[0033] The preset curve is opposite to the deformation of substrate 1 at the operating temperature of the power module.

[0034] Specifically, addressing the issue in existing technologies where heat dissipation components are prone to poor contact and reduced heat dissipation due to thermal deformation when the power module heats up, this embodiment pre-designs a curve with a raised center and recessed edges on one side of the welding surface 2 of the substrate 1 before welding it to the power module. When the power module operates and generates heat, the substrate deforms due to heat, and the pre-designed curve compensates for the amount of deformation, ensuring that the substrate accurately fits the welding surface of the power module under heat, thus improving heat conduction efficiency.

[0035] In one embodiment, the height difference of the preset curves is between 0.1 and 1 millimeter.

[0036] Specifically, after testing common substrates under the heating conditions of several typical power semiconductor devices, the inventors found that by determining the height difference between the top and edge of the preset curve to be between 0.1 and 1 mm, and then designing the preset curve, a better thermal deformation compensation effect can be achieved, thereby improving the fit between the power module and the substrate 1 under the operating conditions.

[0037] In one embodiment, a welding boss 21 is provided on the welding surface 2.

[0038] Specifically, in order to achieve a better bonding and fixing effect, in this embodiment, a welding boss 21 is also processed above the welding surface 2. The welding boss 21 is a boss processed on the substrate 1 facing the welding surface 2, which is formed by cutting or welding the substrate 1 with the same or different alloys.

[0039] In some embodiments, it can be a transition alloy with a coefficient of thermal expansion between that of the substrate 1 and the power module. By providing the welding boss 21, a better bonding effect can be achieved, making the two weld firmly and reducing thermal deformation.

[0040] After setting the welding boss 21, the preset curve is set above the welding boss 21.

[0041] In one embodiment, the welding boss 21 is rectangular, circular, or trapezoidal.

[0042] Specifically, in order to achieve a better welding effect, in this embodiment, the welding boss 21 is set to a rectangular, circular or trapezoidal shape to achieve a better fit with the power module.

[0043] In one embodiment, the height of the welding boss 21 is between 0 and 0.2 mm.

[0044] Specifically, in order to achieve better thermal conductivity and better matching effect with the thermal deformation of the substrate 1 and the power module, in this embodiment, the inventors conducted experiments on substrates 1 and power modules of different materials and collected thermal deformation data. They found that setting the height of the welding boss 21 between 0-0.2 mm can achieve a better matching effect.

[0045] In one embodiment, such as Figure 2 As shown, multiple heat dissipation columns 31 are distributed in a dot matrix pattern on the heat dissipation surface 3, and the heat dissipation columns are set perpendicular to the heat dissipation surface 31.

[0046] Specifically, in order to achieve better heat dissipation, in this embodiment, multiple heat dissipation columns 31 are distributed in a dot matrix on the heat dissipation surface 3. The heat dissipation columns are set perpendicular to the heat dissipation surface 31, and there is a certain gap between the heat dissipation columns 31 to allow the cooling medium, usually coolant or air, to pass through and carry away the heat.

[0047] In one embodiment, the heat dissipation column 31 is a regular square prism, a straight square prism, a cylinder, or a fin.

[0048] Specifically, in order to achieve better heat dissipation, in this embodiment, the heat dissipation column 31 is selected as one of a regular square prism, a straight square prism, a cylinder, or a fin, so that the cooling medium can effectively pass through the gap between the heat dissipation columns 31, thereby achieving better heat dissipation efficiency.

[0049] In one embodiment, the surfaces of the heat dissipation surface 3 and the heat dissipation column 31 are coated.

[0050] Specifically, in order to achieve better thermal conductivity, in this embodiment, a coating is also provided on the surface of the heat dissipation surface 3 and the heat dissipation column 31. The coating is preferably a copper alloy coating to achieve better thermal conductivity.

[0051] In one embodiment, the edges of the heat dissipation column 31 are chamfered.

[0052] Specifically, in order to avoid the problem of debris appearing in the water channel due to edge wear of the heat dissipation column 31 when the cooling medium passes through, in this embodiment, the edges of the heat dissipation column 31 are chamfered so that the cooling medium can pass through smoothly, avoiding the problem of debris caused by local low flow rate and edge erosion.

[0053] In one embodiment, the height of the heat dissipation column 31 is between 0 and 10 millimeters.

[0054] Specifically, in order to achieve better thermal conductivity, in this embodiment, the inventors conducted experiments on substrates 1 and power modules of different materials and collected thermal deformation data. They found that setting the height of the heat dissipation column 31 between 0 and 10 millimeters could achieve better heat dissipation.

[0055] The above are merely preferred embodiments of the present utility model and are not intended to limit the implementation methods and protection scope of the present utility model. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat dissipation substrate for a power module, characterized in that, Includes a substrate, the substrate including a welding surface and a heat dissipation surface; The welding surface is connected and fixed to the surface of the power module to be cooled; The substrate has a preset curve in the direction toward the welding surface; The preset curve is opposite to the amount of deformation of the substrate at the operating temperature of the power module; A welding boss is provided on the welding surface; The welding boss is formed on the substrate using a transition alloy. The thermal conductivity of the transition alloy is between that of the substrate and the power module; The preset curve is formed above the welding boss.

2. The heat dissipation substrate according to claim 1, characterized in that, The welding boss is rectangular, circular, or trapezoidal.

3. The heat dissipation substrate according to claim 1, characterized in that, The height of the welding boss is between 0 and 0.2 mm.

4. The heat dissipation substrate according to claim 1, characterized in that, The heat dissipation surface has multiple heat dissipation columns distributed in a dot matrix pattern, and the heat dissipation columns are arranged perpendicular to the heat dissipation surface.

5. The heat dissipation substrate according to claim 4, characterized in that, The heat dissipation column can be a regular square prism, a straight square prism, a cylinder, or a fin.

6. The heat dissipation substrate according to claim 4, characterized in that, The surfaces of the heat dissipation surface and the heat dissipation column are coated.

7. The heat dissipation substrate according to claim 1, characterized in that, The height difference of the preset curve is between 0.1 and 1 mm.

8. The heat dissipation substrate according to claim 4, characterized in that, The edges of the heat dissipation column are chamfered.

9. The heat dissipation substrate according to claim 4, characterized in that, The height of the heat dissipation column is between 0 and 10 millimeters.

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