CN119997471B

CN119997471B - High-power-density hybrid potting SIC module

Info

Publication number: CN119997471B
Application number: CN202510467437.4A
Authority: CN
Inventors: 唐卓凡; 欧东赢; 吴瑞; 彭昊
Original assignee: Zhejiang Cuizhan Microelectronics Co ltd
Current assignee: Zhejiang Cuizhan Microelectronics Co ltd
Priority date: 2025-04-15
Filing date: 2025-04-15
Publication date: 2025-06-13
Anticipated expiration: 2045-04-15
Also published as: CN119997471A

Abstract

The invention relates to the technical field of power modules, in particular to a high-power-density hybrid potting SIC module. The high-power density hybrid potting SIC module comprises a heat dissipation substrate, a chip assembly and a shell assembly. The heat dissipation post assembly comprises a first heat dissipation post, a second heat dissipation post and a third heat dissipation post. The cooling liquid is forcedly guided to the lower part of the chip through the second heat dissipation columns positioned on the central line and the second heat dissipation columns positioned on the two sides, so that the cooling liquid is ensured to fully cover the high heating area, the invalid circulation of the cooling liquid in the edge area is avoided, and the efficient utilization of cooling resources is ensured. The housing assembly includes a housing, a liquid epoxy, and a silicone gel. A circle of buffer area is arranged on the inner side wall of the shell, and the liquid epoxy flows into the buffer area. The buffer area delays the path of moisture permeation along the interface, the stress in a single direction is decomposed into tiny deformations in multiple directions, and the problem that the power module is easy to delaminate and has poor reliability in a high-temperature and high-humidity environment is solved.

Description

High-power-density hybrid potting SIC module

Technical Field

The invention relates to the technical field of power modules, in particular to a high-power-density hybrid potting SIC module.

Background

With the rapid development of power electronics technology, silicon carbide (SiC) power modules are widely used in the fields of new energy, electric vehicles, industrial frequency conversion and the like due to the characteristics of high frequency, high temperature, high efficiency and the like. However, the existing SiC power modules still have a plurality of technical bottlenecks in terms of packaging technology, reliability, cost, power density and the like, which restrict the large-scale application thereof.

In terms of packaging technology, the traditional power module is sealed by adopting a single encapsulating material (such as liquid epoxy resin or silicone gel), and although the requirements of basic insulation and protection can be met, the cost and the reliability are difficult to be simultaneously achieved. For example, liquid epoxy encapsulation is several times more costly than silicone gel, and has a large Young's modulus, which can generate more stress on SIC chips when used in a large area, and silicone gel alone has a weak vibration resistance and poor mechanical strength. In terms of packaging structure, the existing module is easy to generate layering problem of encapsulating materials and shells under high-temperature and high-humidity environment, and long-term reliability is seriously affected. Considering the power density and stray inductance problems, how to play the advantages of high-frequency switching and low loss of the SIC wafer through layout optimization and large-area laminated busbar design. In the aspect of heat dissipation, because the chip in the power module generates heat when the work is far more than other electronic components such as signal pin for the different regional heating of power module is different, and the radiating fin in prior art is mostly evenly set up, leads to the radiating effect in the high region that generates heat poor, and the radiating effect in the low region that generates heat is excessive.

Disclosure of Invention

In view of the above, the present invention provides a high power density hybrid potting SIC module to solve the above technical problems.

The high-power density hybrid potting SIC module comprises a heat dissipation substrate, a chip component arranged on the heat dissipation substrate and a shell component arranged on the heat dissipation substrate. The heat dissipation substrate is provided with a heat dissipation column assembly at one side facing away from the chip assembly. The heat dissipation column assembly comprises at least two first heat dissipation columns arranged on the heat dissipation substrate, a plurality of second heat dissipation columns arranged on the heat dissipation substrate and a plurality of third heat dissipation columns arranged on the heat dissipation substrate in an array mode. The first heat dissipation columns are in strip shapes, the extending direction of the first heat dissipation columns is parallel to the flowing direction of the cooling liquid, the two first heat dissipation columns are located on two sides of the heat dissipation substrate, and the arrangement direction of the two first heat dissipation columns is perpendicular to the flowing direction of the cooling liquid. The opposite ends of the two first heat dissipation columns are in a zigzag shape, and the second heat dissipation columns are arranged on the central line of the heat dissipation substrate and on two sides of the heat dissipation substrate. The housing assembly includes a housing disposed on the heat dissipating substrate, a liquid epoxy disposed within the housing, and a silicone gel disposed within the housing. A circle of buffer area is arranged on the inner side wall of the shell. The buffer zone comprises a first buffer groove arranged on the inner side wall of the shell and a second buffer groove connected with the first buffer groove. One end of the first buffer groove is communicated with the inner side wall of the shell, the other end of the first buffer groove is connected with the second buffer groove, one end of the second buffer groove is communicated with the bottom of the shell, liquid epoxy flows into the buffer area during filling and sealing, the chip component is filled with the liquid epoxy through filling and sealing, and the silicone gel is covered and sealed.

Further, the chip assembly includes an AMB substrate, a plurality of chips disposed on the AMB substrate, a plurality of CLIP copper sheets connecting the AMB substrate and the chips, an Ac terminal disposed on the AMB substrate, a DC negative terminal disposed on the AMB substrate, a DC positive terminal disposed on the AMB substrate, and a plurality of signal pins disposed on the AMB substrate.

Further, the chips are arranged at two sides of the AMB substrate in a plurality of rows, and the chips are connected with the AMB substrate by adopting a copper sintering technology.

Further, one end of the Ac terminal is connected with the AMB substrate, the other end of the Ac terminal penetrates through the housing assembly, one end of the DC negative electrode terminal and one end of the DC positive electrode terminal are connected with the AMB substrate, the other end of the DC negative electrode terminal penetrates through the housing assembly, planes of the DC negative electrode terminal and the DC positive electrode terminal are parallel and are arranged at intervals, and the DC negative electrode terminal and the DC positive electrode terminal form a laminated busbar structure.

Further, the centers of the DC negative terminal and the DC positive terminal are provided with an opening for penetrating the signal pin.

Further, the shell is of a rectangular frame structure, and the center of the shell is hollow.

Further, the first buffer groove and the second buffer groove are mutually and vertically connected, and the section of the buffer area is of an L-shaped structure.

Further, the height of the liquid epoxy is greater than the height of the CLIP copper sheet.

Compared with the prior art, the cooling column assembly of the high-power-density hybrid potting SIC module provided by the invention forcedly guides the cooling liquid to the lower part of the chip through the second cooling columns positioned on the central line and the second cooling columns positioned on the two sides, so that the cooling liquid is ensured to fully cover a high heating area, the invalid circulation of the cooling liquid in an edge area is avoided, and the high-efficiency utilization of cooling resources is ensured. The liquid epoxy and the silica gel are encapsulated in two layers, the liquid epoxy filling main body structure is encapsulated first, then the silica gel is covered as an outer layer, and the advantages of rigidity, excellent insulativity and low modulus, low cost and damp and heat resistance of the epoxy are combined, so that the internal devices are protected, and the performance short plate of a single material is avoided. In addition, in order to prevent delamination during use. A circle of buffer area is arranged on the inner side wall of the shell. One end of the first buffer groove is communicated with the inner side wall of the shell, the other end of the first buffer groove is connected with the second buffer groove, and one end of the second buffer groove is communicated with the bottom of the shell, so that liquid epoxy can flow into the buffer area during filling and sealing. The cross section of the buffer zone is of an L-shaped structure, the liquid epoxy is filled to form a flexible transition layer during filling and sealing, and for moisture permeation, the path of moisture along the interface permeation is delayed, so that the moisture needs to bypass the tortuous path of the L-shaped groove, and the direct erosion of the moisture to the bonding layer is reduced. For stress accumulation, the L-shaped structure of the buffer zone decomposes the stress in a single direction into tiny deformation in multiple directions, so that stress concentration is avoided, and the problem that the power module is easy to delaminate and has poor reliability in a high-temperature and high-humidity environment is solved.

Drawings

Fig. 1 is a schematic structural diagram of a high-power-density hybrid potting SIC module provided by the present invention.

Fig. 2 is an exploded schematic view of the high power density hybrid potting SIC module of fig. 1.

Fig. 3 is a top view of the high power density hybrid potting SIC module of fig. 1.

Fig. 4 is a cross-sectional view of the high power density hybrid potting SIC module of fig. 1.

Fig. 5 is a schematic structural diagram of a chip assembly of the high power density hybrid potting SIC module of fig. 1.

Detailed Description

Specific embodiments of the present invention are described in further detail below. It should be understood that the description herein of the embodiments of the invention is not intended to limit the scope of the invention.

Fig. 1 to 5 are schematic structural diagrams of a high-power-density hybrid potting SIC module according to the present invention. The high power density hybrid potting SIC module includes a heat sink substrate 10, a chip assembly 20 disposed on the heat sink substrate 10, and a housing assembly 30 disposed on the heat sink substrate 10. It is conceivable that the high power density hybrid potting SIC module also includes other functional modules, such as connection components, mounting components, etc., which are well known to those skilled in the art and will not be described in detail herein.

The heat dissipation substrate 10 is provided with a heat dissipation post assembly 11 on a side facing away from the chip assembly 20, the heat dissipation post assembly 11 is disposed corresponding to components in the chip assembly 20, heat generated during operation of the chip assembly 20 is conducted to the heat dissipation post assembly 11, and specific descriptions of the heat dissipation post assembly 11 will be described below in conjunction with the chip assembly 20. The heat dissipation post assembly 11 is matched with a heat dissipation base (not shown) provided with a water channel, and the heat dissipation post assembly 11 is immersed in the cooling liquid in the water channel, so that heat exchange is performed with the flowing cooling liquid to take away heat of the chip, which is not described in detail herein.

The chip assembly 20 includes an AMB substrate 21, a plurality of chips 22 disposed on the AMB substrate 21, a plurality of CLIP copper sheets 23 connecting the AMB substrate 21 and the chips 22, an Ac terminal 24 disposed on the AMB substrate 21, a DC negative terminal 25 disposed on the AMB substrate 21, a DC positive terminal 26 disposed on the AMB substrate 21, and a plurality of signal pins 27 disposed on the AMB substrate 21.

‌ The AMB substrate 21 is a ceramic substrate realized by an active metal brazing technique, and the AMB substrate 21 is formed by combining ceramic and copper layers by an active metal brazing technique. The middle of the AMB substrate 21 provides excellent insulation and thermal conductivity for the ceramic layer, and the upper and lower layers are copper layers for realizing circuit connection and heat dissipation.

The chips 22 are arranged in a plurality of rows on both sides of the AMB substrate 21. The chip 22 and the AMB substrate 21 are connected by copper sintering technology, and compared with silver sintering, copper sintering has lower cost and can realize metal interconnection with larger area. The chip 22 itself should be of a prior art, and the structure and operation thereof will not be described in detail herein.

The area of the heat dissipation post assembly 11 is larger than that of the AMB substrate 21, and components with low heat productivity, such as the signal pins 27, etc., and the chips 22 with high heat productivity are disposed in the chip assembly 20, so that the cooling liquid can flow through the heat dissipation posts at the bottom of the chips 22 in a concentrated manner. The heat dissipation post assembly 11 includes at least two first heat dissipation posts 111 disposed on the heat dissipation substrate 10, a plurality of second heat dissipation posts 112 disposed on the heat dissipation substrate 10, and a plurality of third heat dissipation posts 113 disposed in an array on the heat dissipation substrate 10.

The first heat dissipation columns 111 are in a strip shape, the extending directions of the first heat dissipation columns 111 are parallel to the flowing direction of the cooling liquid, the two first heat dissipation columns 111 are located on two sides of the heat dissipation substrate 10, the arrangement directions of the two first heat dissipation columns 111 are perpendicular to the flowing direction of the cooling liquid, one ends of the two first heat dissipation columns 111, which are opposite, are in a zigzag shape, the first heat dissipation columns 111 are used for guiding water flow to the center of a module forcibly and pass through the lower portion of the chip 22, invalid circulation of the cooling liquid in an edge area is avoided, efficient utilization of cooling resources is guaranteed, meanwhile, laminar flow states of the water flow are damaged by the heat dissipation columns in a strip-shaped zigzag structure, and turbulent flow is formed in the cooling liquid guided to the lower portion of the chip 22 in an induced mode. The turbulence can significantly enhance the heat exchange efficiency between the fluid and the heat-dissipating studs, thereby accelerating the transfer of heat from the heat-dissipating studs to the cooling water. The second heat-dissipating studs 112 are disposed on the central line of the heat-dissipating substrate 10 and on both sides of the heat-dissipating substrate 10, and in this embodiment, since the chips 22 are disposed in a plurality of rows on both sides of the AMB substrate 21 such that the chips 22 are located between the first heat-dissipating studs 111 and the second heat-dissipating studs 112, the cooling liquid is forced to be guided to the lower side of the chips 22 by the second heat-dissipating studs 112 located on the central line and the second heat-dissipating studs 112 located on both sides, thereby ensuring that the cooling liquid sufficiently covers the highly heat-generating region. The third heat dissipation columns 113 are uniformly arranged on the side of the heat dissipation substrate 10 facing away from the chip assembly 20, and the plurality of third heat dissipation columns 113 are used for ensuring large-area contact with the cooling liquid, ensuring heat exchange effect, and meanwhile, the regular arrangement can form uniform runner gaps, and the third heat dissipation columns 113 cooperate with the diversion effect of the first heat dissipation columns 111 and the second heat dissipation columns 112 to force cooling water to flow through a critical area below the chip 22 in a concentrated manner, so that the heat dissipation capacity of the cooling liquid is utilized to the maximum through the third heat dissipation columns 113.

The CLIP copper sheet 23 connects the chip 22 and the AMB substrate 21, and the chip and terminal connection is achieved by soldering a copper strip or copper sheet to the upper copper layer of the AMB substrate 21.

The Ac terminals 24 are used for outputting Ac power after module conversion. The Ac terminal 24 has one end connected to the AMB substrate 21 and the other end penetrating through the housing assembly 30.

The DC negative terminal 25 and the DC positive terminal 26 are respectively used for connecting an external DC power supply negative electrode and an external DC power supply positive electrode to form a DC loop together to supply power to the module. The DC negative terminal 25 and the DC positive terminal 26 are connected to the AMB substrate 21 at one end and pass through the case assembly 30 at the other end. The planes of the DC negative electrode terminal 25 and the DC positive electrode terminal 26 are parallel and are arranged at intervals, the negative electrode power terminal 27 and the positive electrode power terminal 26 are overlapped in a large area mode, and therefore magnetic fluxes generated by currents which are opposite up and down are counteracted, loop noise is reduced, loop noise is greatly reduced, and the requirements of the SIC module high-frequency switch are met. The center of the DC negative terminal 25 and the DC positive terminal 26 is provided with an opening 28 for penetrating the signal pin 27, thereby allowing the signal pin 27 to directly penetrate the terminal without occupying additional module space, thereby optimizing layout and improving the overall size of the module to be significantly reduced. And simultaneously, holes are formed in the areas with lower current density, such as the geometric center of the terminal, so that the current bearing capacity of the terminal is ensured not to be influenced.

The signal pins 27 are vertically disposed on the AMB substrate 21 and function ‌ to transmit signals and control commands, and are responsible for transmitting control signals from the control system to the modules, thereby controlling the operation states and output power of the modules. The signal pin 27 should be of the prior art and will not be described in detail herein.

The housing assembly 30 includes a housing 31 disposed on the heat dissipating substrate 10, a liquid epoxy 32 disposed within the housing 31, and a silicone gel 33 disposed within the housing 31.

The shell 31 is in a rectangular frame structure, and the center of the shell is hollow. The housing 31 is used for accommodating the chip assembly 20 and for potting the liquid epoxy 32 and the silicone gel 33.

The housing 31 is made of PPS material. A ring of buffer 34 is provided on the inner side wall of the housing 31. The buffer 34 includes a first buffer tank 341 provided on an inner sidewall of the housing 31, and a second buffer tank 342 connected to the first buffer tank 341.

One end of the first buffer groove 341 is communicated with the inner side wall of the shell 31, the other end of the first buffer groove 342 is connected with the second buffer groove 342, and one end of the second buffer groove 342 is communicated with the bottom of the shell 31, so that the liquid epoxy 32 can flow into the buffer area 34 during filling and sealing. The first buffer tank 341 and the second buffer tank 342 are vertically connected to each other, so that the section of the buffer area 34 is in an L-shaped structure. Since the potting material and the material of the housing 31 have different expansion coefficients in a high-temperature and high-humidity environment when in actual use, the difference in expansion coefficient is likely to cause interfacial stress accumulation when the temperature is changed. And moisture is permeated into the bonding connection part along the interface between the encapsulating material and the shell 31, so that delamination is finally caused at the connection part between the encapsulating material and the shell, and the tightness and reliability of the module are reduced. Therefore, a buffer area 34 is formed on the inner wall of the shell 31, and the liquid epoxy 32 is filled to form a flexible transition layer during encapsulation, so that the path of moisture permeation along an interface is delayed for moisture permeation, and the moisture needs to bypass the tortuous path of the L-shaped groove, thereby reducing direct erosion of the bonding layer by the moisture. For stress accumulation, the buffer area 34 increases the contact area between the potting material and the housing 31, so as to disperse stress, and the L-shaped structure of the buffer area 34 breaks down the stress in a single direction into micro deformations in multiple directions, so that stress concentration is avoided. Meanwhile, the corners of the L-shaped grooves allow the liquid epoxy 32 to be slightly elastically deformed when expanding with heat and contracting with cold, so that the peeling of the connecting parts caused by stress concentration is avoided.

The height of the liquid epoxy 32 is greater than the height of the CLIP copper sheet 23, thereby completely sealing the CLIP copper sheet 23 and the chip 22. The liquid epoxy 32 is filled in the chip assembly 20, and the silicone gel 33 is covered and encapsulated as an outer layer, so that the silicone gel 33 is encapsulated on the liquid epoxy 32 by adopting double-layer encapsulation. The liquid epoxy 32 has the characteristics of high mechanical strength, excellent insulativity and chemical corrosion resistance, but has higher cost, and when the consumption is large, larger stress is easily applied to the chip in the curing stage, so that the liquid epoxy 32 is used for sealing the inside of the chip assembly 20 on the premise of ensuring the coverage of the bonding wires, and the insulation and vibration resistance of the chip assembly 20 are ensured. The silicone gel 33 has low modulus, low cost, and moisture and heat resistance, so the silicone gel 33 is used as an external seal, and the impact of thermal expansion and contraction stress and vibration absorption is buffered by the silicone gel 33, so that the liquid epoxy 32 and the chip assembly 20 of the next layer are prevented from being affected. In addition, the amount of the silica gel 33 is reduced, and the silica gel is only used as an outer layer, so that the module cost is reduced on the premise of ensuring the reliability of the module.

Compared with the prior art, the heat dissipation column assembly 11 of the high-power-density hybrid potting SIC module provided by the invention forcedly guides the cooling liquid to the lower part of the chip 22 through the second heat dissipation columns 112 positioned on the central line and the second heat dissipation columns 112 positioned on the two sides, so that the cooling liquid is ensured to fully cover a high heating area, the invalid circulation of the cooling liquid in the edge area is avoided, and the high-efficiency utilization of cooling resources is ensured. The liquid epoxy 32 and the silica gel 33 are encapsulated in two layers, the liquid epoxy 32 is encapsulated to fill the main structure, and then the silica gel 33 is covered as an outer layer, so that the advantages of rigidity, excellent insulativity and low modulus of the silica gel, low cost and wet heat resistance of the epoxy are combined, the internal devices are protected, and the performance short plate of a single material is avoided. In addition, in order to prevent delamination during use. A ring of buffer 34 is provided on the inner side wall of the housing 31. One end of the first buffer groove 341 is communicated with the inner side wall of the shell 31, the other end of the first buffer groove 342 is connected with the second buffer groove 342, and one end of the second buffer groove 342 is communicated with the bottom of the shell 31, so that the liquid epoxy 32 can flow into the buffer area 34 during filling and sealing. The cross section of the buffer area 34 is in an L-shaped structure, the liquid epoxy 32 is filled to form a flexible transition layer during encapsulation, and for moisture permeation, the path of moisture permeation along an interface is delayed, so that the moisture needs to bypass the tortuous path of the L-shaped groove, and the direct erosion of the moisture to the adhesive layer is reduced. For stress accumulation, the L-shaped structure of the buffer area 34 decomposes the stress in a single direction into tiny deformations in multiple directions, so that stress concentration is avoided, and the problem that the power module is easy to delaminate and has poor reliability in a high-temperature and high-humidity environment is solved.

The above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalent substitutions or improvements within the spirit of the present invention are intended to be covered by the claims of the present invention.

Claims

1. The utility model provides a high power density mixes embedment SIC module, high power density mixes embedment SIC module cooperatees with a heat dissipation base of seting up the water course, carries out heat transfer through flowing coolant liquid and takes away chip heat, its characterized in that: the high-power density hybrid encapsulation SIC module comprises a heat dissipation substrate, a chip assembly arranged on the heat dissipation substrate, and a shell assembly arranged on the heat dissipation substrate, wherein one side of the heat dissipation substrate, which is opposite to the chip assembly, is provided with a heat dissipation column assembly, the heat dissipation column assembly comprises at least two first heat dissipation columns arranged on the heat dissipation substrate, a plurality of second heat dissipation columns arranged on the heat dissipation substrate, and a plurality of third heat dissipation columns arranged on the heat dissipation substrate in an array manner, the first heat dissipation columns are in a strip shape and are parallel to the flowing direction of cooling liquid, the two first heat dissipation columns are positioned on two sides of the heat dissipation substrate, the arrangement direction of the two first heat dissipation columns is perpendicular to the flowing direction of the cooling liquid, one ends of the two first heat dissipation columns are in a zigzag shape, the second heat dissipation columns are arranged on the central line of the heat dissipation substrate and on two sides of the substrate, the shell assembly comprises a shell arranged on the heat dissipation substrate, a plurality of second heat dissipation columns are arranged on the heat dissipation substrate, and a third heat dissipation column arranged on the heat dissipation substrate, the first heat dissipation column is arranged in an array manner, the first heat dissipation column is arranged on the heat dissipation substrate is parallel to the first heat dissipation column, the first heat dissipation column is connected with a first inner side wall, a buffer zone is arranged on the first buffer zone, the inner side wall is connected with the first buffer zone is arranged on the first buffer zone, and the second buffer zone is connected with the second buffer zone is arranged on the inner side buffer zone, and has the inner buffer tank, and the first buffer zone is connected with the first buffer zone, one end of the second buffer groove is communicated with the bottom of the shell, liquid epoxy flows into the buffer area during filling and sealing, the chip component is filled with the liquid epoxy in a filling and sealing mode, and then the silicone gel is covered and sealed.

2. The high power density hybrid potting SIC module of claim 1 wherein the chip assembly comprises an AMB substrate, a plurality of chips disposed on the AMB substrate, a plurality of CLIP copper sheets connecting the AMB substrate and the chips, an Ac terminal disposed on the AMB substrate, a DC negative terminal disposed on the AMB substrate, a DC positive terminal disposed on the AMB substrate, and a plurality of signal pins disposed on the AMB substrate.

3. The high power density hybrid potting SIC module of claim 2, wherein the chips are disposed in multiple rows on either side of the AMB substrate, and the chips are connected to the AMB substrate by copper sintering.

4. The high power density hybrid potting SIC module of claim 2, wherein one end of the Ac terminal is connected with the AMB substrate, the other end of the Ac terminal penetrates through the housing assembly, one end of the DC negative terminal and one end of the DC positive terminal are connected with the AMB substrate, the other end of the DC negative terminal and one end of the DC positive terminal penetrate through the housing assembly, the planes of the DC negative terminal and the DC positive terminal are parallel and are arranged at intervals, and the DC negative terminal and the DC positive terminal form a laminated busbar structure.

5. The high power density hybrid potting SIC module of claim 2 wherein the center of the DC negative terminal and the DC positive terminal is provided with an aperture for threading the signal pin.

6. The high power density hybrid potting SIC module of claim 1, wherein the housing is a rectangular frame structure with a hollow center.

7. The high-power-density hybrid potting SIC module of claim 1, wherein the first buffer tank and the second buffer tank are connected vertically, and the section of the buffer zone is L-shaped.

8. The high power density hybrid potting SIC module of claim 2 wherein the height of the liquid epoxy is greater than the height of the CLIP copper sheet.