A power module with high efficiency heat dissipation and low inductance

Abstract

The present invention relates to the technical field of power modules, and in particular to a power module with efficient heat dissipation and low inductance. The power module with efficient heat dissipation and low inductance includes a heat dissipation component, DBC. The heat dissipation component includes a base, a groove, an inlet, an outlet, a heat dissipation substrate, and a spoiler strip. The spoiler unit includes a first spoiler and a second spoiler. Both ends of the first spoiler are connected to the heat dissipation substrate and are close to the adjacent first spoiler. The arrangement direction of the plurality of first spoilers is perpendicular to the arrangement direction of the inlet and the outlet, and the second spoiler is located between two adjacent first spoilers. The coolant will be divided into two layers when passing through the spoiler strip, and a part of the coolant enters the first spoiler and is compressed to increase the flow speed. The other part enters the second spoiler, which increases the heat exchange area between the coolant and the spoiler strip and improves the heat dissipation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and in particular to a power module with high efficiency in heat dissipation and low inductance. Background Art

[0002] The power module is a key component that integrates power electronics technology. It is mainly composed of control circuits and power drive circuits and is commonly used in motor control, lighting control, battery management systems, etc. Today, the new energy vehicle industry is developing rapidly, and the requirements for automotive power semiconductor devices are becoming more and more stringent, making automotive power semiconductor devices develop rapidly in the direction of high power and density. Among them, silicon carbide modules stand out with their own advantages such as high density, high power, and low loss.

[0003] The current automotive silicon carbide power modules are commonly used in 800V and 1200V platforms. Under this voltage platform, the existing silicon carbide modules in the market generally adopt a connection scheme of 8 chips in parallel. However, with the increase in the number of silicon carbide chips in the module, the requirements for the module's heat dissipation capacity and its own inductance performance are also getting higher and higher. The heat dissipation of power modules in the prior art is to pass the coolant through the columnar heat sink needles at the bottom of the power module for heat exchange, such as the power module heat dissipation structure, heat dissipation substrate and power module disclosed in application number CN202311803122.X. However, the heat dissipation effect of the columnar heat sink needle is not good, and the performance of the silicon carbide chip cannot be fully utilized. Summary of the invention

[0004] In view of this, the present invention provides a power module with high heat dissipation efficiency and low inductance to solve the above technical problems.

[0005] A power module with high efficiency heat dissipation and low inductance, the power module with high efficiency heat dissipation and low inductance comprises a heat dissipation component, a plurality of DBCs arranged on the heat dissipation component, and a shell arranged on the DBC. The heat dissipation component comprises a base, a groove arranged on the base, an inlet arranged at one end of the base, an outlet arranged at the other end of the base, a heat dissipation substrate arranged on the base, and a spoiler strip arranged on the heat dissipation substrate. The spoiler strip comprises a plurality of spoiler units arranged in a row, and each spoiler unit has the same structure. The arrangement direction of the plurality of spoiler units is parallel to the arrangement direction of the inlet and the outlet, and each row of the spoiler units comprises a plurality of first spoilers arranged on the heat dissipation substrate, and a plurality of second spoilers arranged on the first spoiler. The first spoiler is a hollow truncated cone structure, the two ends of the first spoiler are connected to the heat dissipation substrate and are close to the adjacent first spoilers, the arrangement direction of the plurality of first spoilers is perpendicular to the arrangement direction of the inlet and the outlet, and the central axis of the first spoiler is parallel to the arrangement direction of the inlet and the outlet. The diameter of the first spoiler gradually decreases from one end close to the inlet to one end close to the outlet, and the second spoiler is located between two adjacent first spoilers. The second spoiler has an arc-shaped structure and its two ends are respectively connected to the outer side walls of the two adjacent first spoilers, and the diameter of the second spoiler gradually decreases from one end close to the inlet to one end close to the outlet.

[0006] Furthermore, the groove is opened on the end surface of the base facing the heat dissipation substrate, and a spoiler boss is arranged at the bottom of the groove, one end of the spoiler boss is spaced apart from the inlet, and the other end of the spoiler boss is spaced apart from the outlet, and both sides of the spoiler boss are connected to the side walls of the groove.

[0007] Furthermore, one end of the inlet passes through the side wall of the base and the other end is connected to the groove, one end of the outlet passes through the side wall of the base and the other end is connected to the groove, and the inlet and outlet serve as the inlet and outlet of the coolant respectively.

[0008] Furthermore, the DBC includes a ceramic insulating layer, a lower copper layer arranged under the ceramic insulating layer, an upper copper layer arranged on the ceramic insulating layer, a plurality of silver paste layers arranged on the upper copper layer, a plurality of chips arranged on the ceramic insulating layer, a positive power terminal arranged on the ceramic insulating layer, a negative power terminal arranged on the ceramic insulating layer, a three-phase terminal arranged on the ceramic insulating layer, and a plurality of copper clips connecting the chips.

[0009] Furthermore, the ceramic insulating layer is located between the upper copper layer and the lower copper layer, and the thickness of the lower copper layer is greater than the thickness of the upper copper layer.

[0010] Furthermore, the chips are symmetrically distributed on the upper copper layer of the ceramic insulating layer.

[0011] Furthermore, the positive power terminal and the negative power terminal are located at the same end of the ceramic insulating layer, the three-phase terminal is located at the other end of the ceramic insulating layer, one end of the positive power terminal is connected to the upper copper layer, and the other end is inserted in the outer shell, and one end of the negative power terminal is connected to the upper copper layer and is U-shaped, and the other end is inserted in the outer shell.

[0012] Furthermore, the planes where the positive power terminal and the negative power terminal are located are parallel and spaced apart.

[0013] Furthermore, one copper clip connects the chips on the same side, and the copper clips are symmetrically distributed.

[0014] Furthermore, the housing is provided with a plurality of through holes, each of which is used to accommodate the DBC.

[0015] Compared with the prior art, the spoiler strip of the power module with high efficiency heat dissipation and low inductance provided by the present invention includes a first spoiler and a second spoiler. The first spoiler is in an arc-shaped structure and is connected to the heat dissipation substrate at both ends. The central axis of the first spoiler is parallel to the arrangement direction of the inlet and the outlet, and the arrangement direction of the first spoiler is perpendicular to the arrangement direction of the inlet and the outlet. The diameter of the first spoiler gradually decreases from the end close to the inlet to the end close to the outlet. The second spoiler is located between two adjacent first spoilers, and the second spoiler is in an arc-shaped structure and is connected to the outer side walls of the two adjacent first spoilers at both ends. When the coolant passes through the spoiler strip, it will be divided into two layers, and a part of the coolant enters the first spoiler and is compressed to increase the flow rate. The other part of the coolant enters the second spoiler, which increases the heat exchange area between the coolant and the spoiler strip, and also increases the flow rate of the coolant, thereby improving the heat dissipation efficiency. In addition, the positive power terminal and the negative power terminal adopt a stacked design, so that the magnetic flux generated by the upper and lower opposite currents will be offset, so that the loop inductance is reduced, thus greatly reducing the loop inductance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a power module with high heat dissipation efficiency and low inductance provided by the present invention.

[0017] Figure 2 for Figure 1 Schematic diagram of the decomposed structure of a power module with efficient heat dissipation and low inductance.

[0018] Figure 3 for Figure 1 A schematic diagram of the structure of a heat dissipation substrate of a power module with efficient heat dissipation and low inductance.

[0019] Figure 4 for Figure 3 An enlarged schematic diagram of the power module A with efficient heat dissipation and low inductance.

[0020] Figure 5 for Figure 1 Schematic diagram of the structure of the DBC of a power module with efficient heat dissipation and low inductance.

[0021] Figure 6 for Figure 1 Cross-sectional view of a power module with efficient heat dissipation and low inductance.

[0022] Explanation of the accompanying drawings: heat dissipation assembly 10, DBC20, housing 30, base 11, groove 12, inlet 13, outlet 14, heat dissipation substrate 15, spoiler strip 16, spoiler boss 17, spoiler unit 161, first spoiler plate 162, second spoiler plate 163, ceramic insulating layer 21, lower copper layer 22, upper copper layer 23, silver paste layer 24, chip 25, positive power terminal 26, negative power terminal 27, three-phase terminal 28, copper clip 29, through hole 31, reinforcing rib 32. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are further described in detail below. It should be understood that the description of the embodiments of the present invention herein is not intended to limit the protection scope of the present invention.

[0024] like Figures 1 to 6 As shown, it is a schematic diagram of the structure of the power module with high efficiency heat dissipation and low inductance provided by the present invention. The power module with high efficiency heat dissipation and low inductance includes a heat dissipation component 10, a plurality of DBCs 20 arranged on the heat dissipation component 10, and a housing 30 arranged on the DBC 20. It can be imagined that the power module with high efficiency heat dissipation and low inductance also includes some other functional modules, such as connection components, installation components, etc., which are well known to those skilled in the art and will not be repeated here.

[0025] The heat dissipation assembly 10 includes a base 11, a groove 12 arranged on the base 11, an inlet 13 arranged at one end of the base 11, an outlet 14 arranged at the other end of the base 11, a heat dissipation substrate 15 arranged on the base 11, and a spoiler strip 16 arranged on the heat dissipation substrate 15.

[0026] The base 11 and the heat dissipation substrate 15 are used to carry the above-mentioned functional modules. The groove 12 is provided on the end surface of the base 11 facing the heat dissipation substrate 15. The groove 12 is used to accommodate the spoiler strip 16 and the coolant. A spoiler boss 17 is provided at the bottom of the groove 12. One end of the spoiler boss 17 is spaced apart from the inlet 13, and the other end of the spoiler boss 17 is spaced apart from the outlet 14. Both sides of the spoiler boss 17 are connected to the side walls of the groove 12, so that the spoiler boss 17 is located between the inlet 13 and the outlet 14, so that when the coolant enters, it will hit the side wall of the spoiler boss 17 and then gradually surge onto the surface of the spoiler boss 17, so as to increase the turbulent disturbance of the coolant after it flows in from the inlet, thereby improving the heat exchange capacity of the coolant.

[0027] One end of the inlet 13 passes through the side wall of the base 11, and the other end is connected to the groove 12. One end of the outlet 14 passes through the side wall of the base 11, and the other end is connected to the groove 12. The inlet 13 and the outlet 14 serve as the inlet and outlet of the coolant, respectively.

[0028] The heat dissipation substrate 15 is fixed to the base 11 by screws and covers the groove 12 , thereby covering the groove 12 to form a channel for the circulation of the coolant. The spoiler strip 16 is arranged on the end surface of the heat dissipation substrate 12 facing the base 11 .

[0029] The spoiler strip 16 is disposed on the end surface of the heat dissipation substrate 15 facing the groove 12 . The spoiler strip 16 is located in the groove 12 and immersed in the coolant, so as to exchange heat with the flowing coolant to take away the heat of the chip.

[0030] The spoiler strip 16 includes a plurality of spoiler units 161 arranged in rows, each spoiler unit 161 has the same structure, and the arrangement direction of the plurality of spoiler units 161 is parallel to the arrangement direction of the inlet 13 and the outlet 14, so that the flowing coolant will flow through the spoiler units 161 arranged in multiple rows in sequence.

[0031] Each row of the spoiler units 161 includes a plurality of first spoiler plates 162 disposed on the heat dissipation substrate 15 , and a plurality of second spoiler plates 163 disposed on the first spoiler plates 162 .

[0032] The first spoiler 162 is a hollow truncated cone structure, and both ends of the first spoiler 162 are connected to the heat dissipation substrate 15 and are close to the adjacent first spoiler 162. The arrangement direction of the plurality of first spoilers 162 is perpendicular to the arrangement direction of the inlet 13 and the outlet 14. The central axis of the first spoiler 162 is parallel to the arrangement direction of the inlet 13 and the outlet 14, so that the coolant can pass through the center of the first spoiler 162 for heat exchange.

[0033] The diameter of the first spoiler 162 gradually decreases from the end close to the inlet 13 to the end close to the outlet 14, so that the coolant flows into the large diameter inlet of the first spoiler 162 and flows out from the small diameter outlet. According to the principle of liquid flow, the flow speed of the coolant is increased after being compressed by the first spoiler 162, thereby improving the heat exchange capacity of the coolant. At the same time, the speed of the liquid will undergo a cycle of contraction and expansion under the action of the first spoiler 162, further increasing its spoiler effect.

[0034] The second spoiler 163 is located between two adjacent first spoilers 162. The second spoiler 163 is an arc-shaped structure and its two ends are respectively connected to the outer side walls of the two adjacent first spoilers 162, that is, the second spoiler 163 is mounted on the outer side walls of the two adjacent first spoilers 162. The diameter of the second spoiler 163 gradually decreases from the end close to the inlet 13 to the end close to the outlet 14, so that the coolant is divided into two layers when passing through the spoiler unit 161. A part of the coolant enters the first spoiler 162 and is compressed to increase the flow speed. The other part of the coolant enters the second spoiler 163, which increases the heat exchange area between the coolant and the spoiler strip 16, and also improves the spoiler effect of the coolant and the heat dissipation efficiency.

[0035] ‌‌The DBC20 is a direct copper-bonded ceramic substrate (DBC). The direct copper-bonded ceramic substrate (DBC) is formed by eutectic sintering of a ceramic substrate and a copper foil at a high temperature. It is mainly used in power electronic modules and has excellent thermal conductivity and insulation properties. The DBC20 should be a prior art and will not be described in detail here. The number of the DBC20 is set according to actual needs. In this embodiment, there are three DBC20. The three DBC20 have the same structure, and each of the DBC20 includes a ceramic insulating layer 21, a lower copper layer 22 arranged under the ceramic insulating layer 21, an upper copper layer 23 arranged on the ceramic insulating layer 21, a plurality of silver paste layers 24 arranged on the upper copper layer 23, a plurality of chips 25 arranged on the ceramic insulating layer 21, a positive power terminal 26 arranged on the ceramic insulating layer 21, a negative power terminal 27 arranged on the ceramic insulating layer 21, a three-phase terminal 28 arranged on the ceramic insulating layer 21, and a plurality of copper clips 29 connecting the chips 25.

[0036] The ceramic insulating layer 21 is located between the upper copper layer 23 and the lower copper layer 22. The lower copper layer 22 is located on the end surface of the ceramic insulating layer 21 facing the heat dissipation substrate 15 and is used to be soldered with the heat dissipation substrate 15 through tin sheets or solder paste, while the upper copper layer 23 located away from the heat dissipation substrate 15 is used to set various electronic components such as chips 25, three-phase terminals 28, etc. The thickness of the lower copper layer 22 is greater than the thickness of the upper copper layer 23. Copper has a strong heat dissipation capacity, and the heat flow is transferred downward from the chip 25. After the copper layer is thickened to a certain extent, the thermal resistance of the copper layer of the module can be effectively reduced, so that the heat flow exchange of the module from the chip to the bottom is faster and more effective, thereby effectively reducing the junction temperature of the silicon carbide module. And after the lower copper layer 22 is thickened, the number of conductor loops corresponding to the lower side of the silicon carbide module increases when the silicon carbide module works at high frequency, and the increase in the number of conductor loops can effectively reduce the stray inductance of the overall module loop, thereby improving the performance of the silicon carbide module.

[0037] The chip 25 is symmetrically distributed on the upper copper layer 23 of the ceramic insulating layer 21 using a silver paste sintering process. The symmetrical distribution adopted makes the loop length of each chip 25 consistent, effectively reduces the difference in stray inductance of the loops of each chip 25, and ensures the consistency of the switch of each chip 25. The chip 25 itself should be prior art, and its structure and working principle are not repeated here. The silver paste layer 24 is formed after the silver paste sintering process, and is used to carry the chip 25.

[0038] The positive power terminal 26 and the negative power terminal 27 are located at the same end of the ceramic insulating layer 21, and the three-phase terminal 28 is located at the other end of the ceramic insulating layer 21. One end of the positive power terminal 26 is connected to the upper copper layer 23, and the other end is inserted into the shell 30. One end of the negative power terminal 27 is connected to the upper copper layer 23 and is U-shaped, and the other end is inserted into the shell 30. The planes where the positive power terminal 26 and the negative power terminal 27 are located are parallel and spaced apart. The negative power terminal 27 and the positive power terminal 26 are used for the outflow and inflow of current respectively. At the same time, since the positive power terminal 26 and the negative power terminal 27 are spaced apart and a stacking design is adopted, the magnetic flux generated by the upper and lower opposite currents will be offset, so that the circuit inductance is reduced, which greatly reduces the circuit inductance. One end of the negative power terminal 27 is a U-shaped inward folding structure, which can increase the effective area of ​​the stacking, further reduce the stray inductance of the overall module circuit, and improve the performance of the silicon carbide power module.

[0039] The copper clip 29 is used to connect the chip 25 and the upper copper layer of the ceramic insulating layer 21 to achieve connectivity of the circuit inside the DBC 20. The connectivity and circulation of the DBC 20 circuit should be prior art and will not be described here. One copper clip 29 connects the chip 25 on the same side. Since the copper clip 29 is symmetrically distributed on the basis of the symmetrical distribution of the chip 25, it can effectively reduce the stray inductance of the connecting part of each chip, effectively increase the heat exchange between each chip, improve the temperature uniformity of the chip heat dissipation, and achieve the temperature uniformity effect of the module.

[0040] The housing 30 is provided with a through hole 31 and a plurality of reinforcing ribs 32 separating the through holes 31. The reinforcing ribs 32 are used to improve the strength of the housing 30 and separate the plurality of DBCs 20 to avoid mutual interference. The housing 30 is used to carry the above-mentioned functional modules, so the housing 30 is provided with a variety of functional structures, such as screws, bolts, through holes, etc., to complete the installation and assembly of the above-mentioned functional modules, which can be arranged according to actual needs and will not be described in detail one by one here.

[0041] Compared with the prior art, the spoiler strip 16 of the power module with high efficiency heat dissipation and low inductance provided by the present invention includes a first spoiler 162 and a second spoiler 163. The first spoiler 162 is in an arc-shaped structure and is connected to the heat dissipation substrate 15 at both ends. The central axis of the first spoiler 162 is parallel to the arrangement direction of the inlet 13 and the outlet 14, and the arrangement direction of the first spoiler 162 is perpendicular to the arrangement direction of the inlet 13 and the outlet 14. The diameter of the first spoiler 162 gradually decreases from the end close to the inlet 13 to the end close to the outlet 14. The second spoiler 163 is located between two adjacent first spoilers 162. The second spoiler 163 is in an arc-shaped structure and is connected to the outer side walls of the two adjacent first spoilers 162 at both ends. When the coolant passes through the spoiler strip 16, it will be divided into two layers, and a part of the coolant enters the first spoiler 162 and is compressed to increase the flow speed. Another part of the coolant enters the second spoiler 163, increasing the heat exchange area between the coolant and the spoiler strip 16, and also increasing the flow speed of the coolant, thereby improving the heat dissipation efficiency. In addition, the positive power terminal 26 and the negative power terminal 27 are designed in a laminated manner, so that the magnetic flux generated by the opposite currents above and below will be offset, reducing the circuit inductance, thereby greatly reducing the circuit inductance.

[0042] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modification, equivalent substitution or improvement within the spirit of the present invention is included in the scope of the claims of the present invention.

Claims

1. A power module with high efficiency heat dissipation and low inductance, characterized in that: The power module with high efficiency in heat dissipation and low inductance comprises a heat dissipation component, a plurality of DBCs arranged on the heat dissipation component, and a shell arranged on the DBC, the heat dissipation component comprises a base, a groove arranged on the base, an inlet arranged at one end of the base, an outlet arranged at the other end of the base, a heat dissipation substrate arranged on the base, and a spoiler belt arranged on the heat dissipation substrate, the inlet and the outlet are respectively located on opposite sides of the base, the spoiler belt comprises a plurality of spoiler units arranged in rows, each spoiler unit has the same structure, the arrangement direction of the plurality of spoiler units is parallel to the arrangement direction of the inlet and the outlet, and each row of the spoiler units comprises a plurality of first spoilers arranged on the heat dissipation substrate A plate, and multiple second spoilers arranged on the first spoiler, the first spoiler is a hollow frustum-shaped structure, both ends of the first spoiler are connected to the heat dissipation substrate and are close to the adjacent first spoiler, the arrangement direction of the multiple first spoilers is perpendicular to the arrangement direction of the inlet and the outlet, the central axis of the first spoiler is parallel to the arrangement direction of the inlet and the outlet, the diameter of the first spoiler gradually decreases from an end close to the inlet toward an end close to the outlet, the second spoiler is located between two adjacent first spoilers, the second spoiler is an arc-shaped structure and its two ends are respectively connected to the outer side walls of the two adjacent first spoilers, and the diameter of the second spoiler gradually decreases from an end close to the inlet toward an end close to the outlet.

2. The power module with high efficiency heat dissipation and low inductance as claimed in claim 1, characterized in that: The groove is opened on the end surface of the base facing the heat dissipation substrate, and a spoiler boss is arranged at the bottom of the groove. One end of the spoiler boss is spaced apart from the inlet, and the other end of the spoiler boss is spaced apart from the outlet. Both sides of the spoiler boss are connected to the side walls of the groove.

3. The power module with high efficiency heat dissipation and low inductance as claimed in claim 1, characterized in that: One end of the inlet passes through the side wall of the base, and the other end is connected to the groove. One end of the outlet passes through the side wall of the base, and the other end is connected to the groove. The inlet and the outlet serve as the inlet and outlet of the coolant respectively.

4. The power module with high efficiency heat dissipation and low inductance as claimed in claim 1, characterized in that: The DBC includes a ceramic insulating layer, a lower copper layer arranged under the ceramic insulating layer, an upper copper layer arranged on the ceramic insulating layer, multiple silver paste layers arranged on the upper copper layer, multiple chips arranged on the ceramic insulating layer, a positive power terminal arranged on the ceramic insulating layer, a negative power terminal arranged on the ceramic insulating layer, a three-phase terminal arranged on the ceramic insulating layer, and multiple copper clips connecting the chips.

5. The power module with high efficiency heat dissipation and low inductance as claimed in claim 4, characterized in that: The ceramic insulating layer is located between the upper copper layer and the lower copper layer, and the thickness of the lower copper layer is greater than the thickness of the upper copper layer.

6. The power module with high efficiency heat dissipation and low inductance as claimed in claim 4, characterized in that: The chips are symmetrically distributed on the upper copper layer of the ceramic insulating layer.

7. The power module with high efficiency heat dissipation and low inductance as claimed in claim 4, characterized in that: The positive power terminal and the negative power terminal are located at the same end of the ceramic insulating layer, and the three-phase terminal is located at the other end of the ceramic insulating layer. One end of the positive power terminal is connected to the upper copper layer, and the other end is inserted in the outer shell. One end of the negative power terminal is connected to the upper copper layer and is U-shaped, and the other end is inserted in the outer shell.

8. The power module with high efficiency heat dissipation and low inductance as claimed in claim 4, characterized in that: The planes where the positive power terminal and the negative power terminal are located are parallel and spaced apart.

9. The power module with high heat dissipation efficiency and low inductance as claimed in claim 4, characterized in that: One copper clip connects the chips on the same side, and the copper clips are symmetrically distributed.

10. The power module with high heat dissipation efficiency and low inductance as claimed in claim 1, characterized in that: The housing is provided with a plurality of through holes, each of which is used to accommodate the DBC.

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