A power module based on silicon carbide devices

Abstract

The utility model discloses a kind of power module based on silicon carbide device, including main power plate, silicon carbide chip and radiator, radiator is annular, and the outer edge surface of radiator is polygonal, the outer edge surface of each radiator is attached with silicon carbide chip, the inner edge surface of radiator is provided with the fin of fish fin shape, radiator is attached on main power plate.The utility model discloses a kind of power module based on silicon carbide device, using main power plate and coaxial circle design of drive board, radiator is attached on main power plate, and silicon carbide chip is attached on the outer edge surface of radiator, to shorten current path, reduce parasitic inductance, reduce thermal coupling by symmetrical layout, the central airflow channel (diameter 40mm) formed by combining fin center Forced convection, temperature difference can be reduced to <5 ℃, in combination with the fan of radiator top, low thermal resistance, high power density and electromagnetic compatibility optimization can be realized.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and more specifically, to a power module based on silicon carbide devices. Background Technology

[0002] Silicon carbide (SiC) power modules, as a typical representative of third-generation semiconductor technology, have gradually entered the commercial application stage since 2010. Early products (such as early modules from Cree / Wolfspeed) mainly used the packaging architecture of silicon-based IGBTs (such as 62mm packages or EconoDUAL packages). However, due to the high-frequency and high-temperature characteristics of SiC devices, traditional packaging architectures have gradually revealed significant defects in thermal management, parasitic parameter control, and reliability.

[0003] With the rapid development of new energy vehicles, renewable energy, and other fields, the market demand for high power density and high temperature stability continues to rise, which has strongly promoted the technological iteration of SiC modules. However, existing technologies still face several core challenges:

[0004] In terms of structural design, current mainstream SiC modules (such as Infineon CoolSiC™ HybridPACK Drive series) generally adopt a rectangular layout with power devices arranged in a straight line, which causes a series of problems: First, the current path is asymmetrical, with the difference in current path length between edge devices and center devices reaching more than 20%, resulting in uneven current distribution in parallel (current imbalance exceeding 15%), significantly reducing the overall current carrying capacity of the module; Second, the parasitic inductance is too high, and the long bus design (typical value exceeding 10nH) will generate significant voltage overshoot (ΔV>100V) during high-frequency switching (>50kHz), requiring additional absorption circuits and increasing system complexity; Third, the space utilization is low, and the stacked design of the drive board and power board results in a total thickness of ≥30mm, which is difficult to meet the installation requirements of compact devices such as on-board chargers.

[0005] To address the limitations of rectangular layouts, some patents have attempted to adopt circular designs (such as CN111063679A "Layout Circuit Board for a Multi-Device Parallel Power Module"), but significant shortcomings remain: Firstly, the heat sink has poor adaptability; when a circular power board is paired with traditional radial heat sink fins, the heat dissipation efficiency in the central area is low, with a temperature difference between the center and the edge ≥25℃. Secondly, driver integration is lacking; the driver circuit and power board cannot be integrated on the same plane, still requiring external connection cables, which not only increases parasitic capacitance but also limits the module's high-frequency performance.

[0006] In terms of heat dissipation, existing technologies face significant bottlenecks. Uneven heat flow distribution is a prominent issue. For example, heat sinks for rectangular modules typically employ a straight or U-shaped fin layout (such as the Fuji Electric 6th generation SiC module), causing components near the heat sink edge to experience airflow obstruction (flow rate reduction of 40%–60%), resulting in junction temperatures 20–30°C higher than those at the center (measured data). Simultaneously, thermally conductive interface materials (TIMs) are prone to aging under high-temperature environments, leading to a 5%–8% annual increase in thermal resistance and a more than 30% decrease in heat dissipation capacity over the module's lifespan. Furthermore, existing solutions (such as the Mitsubishi Electric J1 series) largely rely on high-power fans (>10W) or liquid cooling systems (flow rate ≥2L / min) for heat dissipation, directly causing a decrease in system energy efficiency (typically 3%–5%).

[0007] In terms of system integration, existing technologies face challenges related to deteriorating electromagnetic compatibility (EMI) and insufficient drive protection. Regarding EMI, the long lead layout of traditional modules (e.g., bond wire length ≥ 15mm) leads to increased high-frequency loop inductance, easily causing strong electromagnetic radiation (EMI exceeding the standard by more than 20dB) during switching transients. Regarding drive protection, existing drive circuits (such as the TI UCC5350 series) are not optimized for the high-temperature characteristics of SiC. When the junction temperature > 175℃, gate voltage fluctuations (drift ±1V) may occur, potentially causing false turn-off. Simultaneously, the desaturation protection delay increases by 30%–50% at high temperatures, significantly increasing the risk of short-circuit failure.

[0008] Therefore, it is necessary to propose a power module based on silicon carbide devices. Utility Model Content

[0009] This invention provides a power module based on silicon carbide devices. By optimizing its structure, it becomes more compact, has lower thermal resistance, and higher power density, thereby solving the problems of conflicting heat dissipation performance and high-frequency switching, as well as poor electromagnetic compatibility in existing power modules.

[0010] According to one aspect of the present invention, a power module based on silicon carbide devices is provided, including a main power board, a silicon carbide chip, and a heat sink. The heat sink is ring-shaped, and the outer edge of the heat sink is polygonal. The silicon carbide chip is attached to the outer edge of each heat sink, and fin-shaped heat sink fins are provided on the inner edge of the heat sink. The heat sink is attached to the main power board.

[0011] Based on the above scheme, the outer edge of the heat sink has a regular dodecagonal structure, and there are twelve silicon carbide chips, with each silicon carbide chip being attached to the outer edge of each heat sink.

[0012] Based on the above scheme, a preferred embodiment is that every two silicon carbide chips are connected in parallel.

[0013] Based on the above scheme, a preferred embodiment is that the free end of the heat sink forms a central airflow channel.

[0014] Preferably, based on the above scheme, the thickness of the heat sink is 2mm, and the distance between the roots of adjacent heat sinks is 5mm.

[0015] Based on the above scheme, the main power board is preferably ring-shaped, and the central aperture of the main power board is 40mm.

[0016] Preferably, based on the above-mentioned solution, the top of the heat sink is integrated with a fan.

[0017] This utility model discloses a power module based on silicon carbide devices. It adopts a coaxial circular design of main power board and driver board, with heat sink attached to the main power board and silicon carbide chip attached to the outer edge of the heat sink to shorten the current path and reduce parasitic inductance. The symmetrical layout reduces thermal coupling, and the forced convection formed by the central airflow channel (40mm in diameter) in the center of the heat sink can reduce the temperature difference to <5℃. Combined with the fan on the top of the heat sink, it can achieve low thermal resistance, high power density and optimized electromagnetic compatibility. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of a power module based on silicon carbide devices according to the present invention;

[0020] Figure 2 For the present utility model Figure 1 Top view;

[0021] Explanation of icon numbers:

[0022] 1. Main power board; 2. Silicon carbide chip; 3. Heat sink; 31. Heat sink plate. Detailed Implementation

[0023] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0024] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of a descriptive feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or sets.

[0025] To keep the drawings concise, only the parts relevant to this invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0026] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various components of this invention are relative rather than absolute. These descriptions are appropriate when these components are in the positions shown in the drawings. If the descriptions of the positions of these components change, these directional indications also change accordingly.

[0028] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0030] Please see Figure 1 and combined Figure 2 As shown, a power module based on silicon carbide devices according to this utility model includes a main power board 1, a silicon carbide chip 2, and a heat sink 3. The heat sink 3 is installed on one side of the main power board 1, and a drive board is installed on the other side of the main power board 1. The heat sink 3 is ring-shaped, and the outer edge of the heat sink 3 is polygonal. A silicon carbide chip 2 is attached to the outer edge of each heat sink 3, and a fin-shaped heat sink 31 is provided on the inner edge of the heat sink 3.

[0031] By attaching the heat sink 3 to the main power board 1 and evenly distributing the silicon carbide chips 2 along the circumference of the heat sink 3, the current path is shortened and parasitic inductance is reduced. The silicon carbide chip 2 has a single-channel rated current of 240A and a peak current of 600A.

[0032] The outer edge of the heat sink 3 of this utility model has a regular dodecagonal structure. There are twelve silicon carbide chips 2, which are model CSC16N120. The silicon carbide chips 2 are respectively attached to the outer edge of each heat sink 3, and every two silicon carbide chips 2 are connected in parallel.

[0033] Specifically, the heat sink 3 of this invention adopts a regular dodecagonal prism shape, with the heat dissipation surface directly attached to the silicon carbide chip 2. The symmetrical layout reduces thermal coupling. Furthermore, the free end of the heat sink 31 forms a central airflow channel, which, combined with forced convection (40mm in diameter), reduces the temperature difference to <5℃. Preferably, the silicon carbide chip 2 is a TO-247-4L packaged device.

[0034] This utility model adopts a ring topology reconstruction: through the geometric matching of the main power board 1's ring layout (120mm diameter / 40mm center hole) and the dodecagonal heat sink 3, the symmetry of the current path is optimized (path length difference <5%; parasitic inductance reduced to <10nH (traditional solution >30nH); thermal-electric synergistic design: the thickness of the heat sink 3 fins is 2mm, the spacing between the roots of adjacent heat sinks 3 is 5mm, the coupling of heat sink 3 and airflow channel (center hole diameter is 40mm) results in a temperature difference of <5℃ and a 40% reduction in fan power consumption; integrated drive and power: the drive board is directly connected to the main power board 1 via pins, eliminating cable parasitic parameters and supporting MHz-level switching frequencies.

[0035] To further confirm the technical effect of this utility model, the temperature will be simulated and measured in a specific embodiment. Specifically, the boundary conditions are: ambient temperature 20℃, total thermal power consumption of SiC MOSFET 240W, and cooling fan airflow 70CFM.

[0036] Among them, radiator 3 adopts a regular dodecagonal prism structure, with each face serving as a test surface. The specific measurement results are as follows:

[0037] Surface measurement Minimum temperature (°C) Maximum temperature (°C) Average temperature (°C) Stdev Area / volume heatsink 92.887 97.834 94.947 1.12294 0.04343 m2 source1 95.789 97.461 96.895 0.39671 0.00038 m2 source2 96.362 97.439 97.047 0.339197 0.00038 m2 source3 95.611 97.268 96.662 0.392014 0.00038 m2 source4 96.365 97.587 97.163 0.377882 0.00038 m2 source5 95.594 97.064 96.577 0.380206 0.00038 m2 source6 95.636 97.096 96.583 0.376616 0.00038 m2 source7 95.999 97.155 96.731 0.328301 0.00038 m2 source8 95.736 97.188 96.7 0.379516 0.00038 m2 source9 95.507 97.126 96.515 0.390614 0.00038 m2 source10 95.494 97.038 96.522 0.384776 0.00038 m2 source11 96.486 97.834 97.319 0.380131 0.00038 m2 source12 95.581 97.276 96.652 0.401281 0.00038 m2

[0038] In summary, the performance comparison of this utility model with the prior art is as follows:

[0039] Comparison Dimensions Traditional rectangular module Existing circular patent (CN111063679A) The solution of this utility model Heat dissipation uniformity Temperature difference ≥ 15℃ (edge ​​hotspot) Temperature difference ≥10℃ (low efficiency at the center) Temperature difference < 5℃ (dodecagonal symmetrical heat dissipation) Power density ≤3kW / L 3.5kW / L ≥5kW / L (compressive circular layout) Parasitic inductance >20nH 15nH <10nH (Pin direct connection to driver board) High temperature adaptability Maximum junction temperature 175℃ (requires liquid cooling) Maximum junction temperature 160℃ (natural cooling) Maximum junction temperature 200℃ (forced air cooling) Cost coefficient 1.0 (Baseline) 1.2 1.1 (Optimize packaging process)

[0040] The heat sink 31 of this invention has a thickness of 2mm, and the spacing between adjacent heat sinks 31 is 5mm. The main power board 1 is ring-shaped, and the central aperture of the main power board 1 is 40mm. A fan is integrated on the top of the heat sink 3. The fan integrated on the top of the heat sink 3 forms an airflow channel with the central airflow channel. The fins are 2mm thick and spaced 5mm apart. Combined with the pin connection on the back of the drive board, it achieves low thermal resistance, high power density, and optimized electromagnetic compatibility.

[0041] This utility model discloses a power module based on silicon carbide devices. It adopts a coaxial circular design of main power board 1 and driver board, with heat sink 3 attached to main power board 1 and silicon carbide chip 2 attached to the outer edge of heat sink 3 to shorten the current path and reduce parasitic inductance. The symmetrical layout reduces thermal coupling. Combined with the central airflow channel (40mm in diameter) formed by the center of heat sink 31 for forced convection, the temperature difference can be reduced to <5℃. Combined with the fan on the top of heat sink 3, low thermal resistance, high power density and electromagnetic compatibility optimization can be achieved.

[0042] Finally, the method described in this application is merely a preferred embodiment and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A power module based on silicon carbide devices, characterized in that, The device includes a main power board, a silicon carbide chip, and a heat sink. The heat sink is ring-shaped, and its outer edge is polygonal. The silicon carbide chip is attached to the outer edge of each heat sink, and fin-shaped heat sink fins are provided on the inner edge of the heat sink. The heat sink is attached to the main power board.

2. A power module based on silicon carbide devices as described in claim 1, characterized in that, The outer edge of the heat sink has a regular dodecagonal structure, and there are twelve silicon carbide chips, which are respectively attached to the outer edge of each heat sink.

3. A power module based on silicon carbide devices as described in claim 1, characterized in that, Each pair of silicon carbide chips is connected in parallel.

4. A power module based on silicon carbide devices as described in claim 1, characterized in that, The free end of the heat sink forms a central airflow channel.

5. A power module based on silicon carbide devices as described in claim 1, characterized in that, The thickness of the heat sink is 2mm, and the distance between the roots of adjacent heat sinks is 5mm.

6. A power module based on silicon carbide devices as described in claim 1, characterized in that, The main power board is ring-shaped, and the central aperture of the main power board is 40mm.

7. A power module based on silicon carbide devices as described in claim 1, characterized in that, The top of the radiator is integrated with a fan.

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