CN116682796A - Silicon carbide substrate, manufacturing method thereof and power module - Google Patents

Silicon carbide substrate, manufacturing method thereof and power module Download PDF

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Publication number
CN116682796A
CN116682796A CN202210163509.2A CN202210163509A CN116682796A CN 116682796 A CN116682796 A CN 116682796A CN 202210163509 A CN202210163509 A CN 202210163509A CN 116682796 A CN116682796 A CN 116682796A
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China
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silicon carbide
carbide substrate
micro
groove
channel
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张小宾
廖安谋
王云
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Institute of Microelectronics of CAS
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Institute of Microelectronics of CAS
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Priority to CN202210163509.2A priority Critical patent/CN116682796A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/46—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids
    • H01L23/473—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids by flowing liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H01L21/76895—Local interconnects; Local pads, as exemplified by patent document EP0896365
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3738—Semiconductor materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/52—Arrangements for conducting electric current within the device in operation from one component to another, i.e. interconnections, e.g. wires, lead frames

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

Abstract

Compared with the prior art that a copper-clad ceramic substrate with lower heat conductivity is adopted to bond a copper radiating substrate embedded with a micro-channel in the power module package, the application ensures that the heat of a power device can reach the copper radiating substrate embedded with the micro-channel for circulating cooling liquid after passing through two copper metal layers, a ceramic substrate and heat conducting glue.

Description

Silicon carbide substrate, manufacturing method thereof and power module
Technical Field
The application relates to the technical field of power module packaging, in particular to an embedded micro-channel silicon carbide substrate for power module packaging, a manufacturing method thereof and a power module.
Background
In power electronics applications, to increase the current carrying capacity of a power module, it is common to configure the power module as a multi-chip package using multiple chips. As a multi-chip package power module, not only excellent electrothermal performance but also good thermo-mechanical reliability is required, which determines the service life of the power module.
With the continuous downsizing of silicon carbide power devices and the increasing of power density, the packaging of power modules is more miniaturized and lighter, and compared with silicon-based power modules, the junction temperature of the power devices in the silicon carbide power modules is much higher, and high temperature becomes a necessary condition for the operation of the power modules. However, high temperature is again a major factor affecting the thermo-mechanical reliability of the power module. Therefore, for wide bandgap silicon carbide power devices, the high voltage, high temperature and high frequency operating characteristics of the devices provide new challenges for packaging and heat dissipation of the power modules.
Disclosure of Invention
In order to solve the technical problems, the embodiment of the application provides an embedded micro-channel silicon carbide substrate, a manufacturing method thereof and a power module, so as to shorten the heat transfer path from a power device to a cooling medium flowing in a micro-channel of a packaging substrate, reduce thermal resistance, improve the heat dissipation efficiency of the packaging substrate and achieve the purpose of quickly reducing the junction temperature of the power device.
In order to achieve the above purpose, the embodiment of the present application provides the following technical solutions:
a silicon carbide substrate, comprising:
the silicon carbide substrate is internally provided with a micro-channel, the input end of the micro-channel is communicated with the liquid inlet, and the output end of the micro-channel is communicated with the liquid outlet, so that a cooling medium enters the micro-channel from the liquid inlet, flows in the micro-channel and is discharged from the liquid outlet to carry heat out;
and the first metal layer is positioned on the first surface of the silicon carbide substrate, and is used for welding the silicon carbide substrate and the power devices and interconnecting the power devices.
Optionally, the silicon carbide substrate includes: a first silicon carbide substrate and a second silicon carbide substrate disposed opposite in a first direction, the first direction being perpendicular to a first surface of the silicon carbide substrate;
the first surface of the first silicon carbide substrate is provided with a first groove, the first surface of the second silicon carbide substrate is provided with a second groove, the opening of the first groove on the first surface of the first silicon carbide substrate and the opening of the second groove on the first surface of the second silicon carbide substrate are the same in size and are symmetrically arranged along the first direction;
A first bonding layer is arranged on the first surface of the first silicon carbide substrate in other areas except the first groove, a second bonding layer is arranged on the first surface of the second silicon carbide substrate in other areas except the second groove, and the first silicon carbide substrate and the second silicon carbide substrate are connected in a bonding mode through the first bonding layer and the second bonding layer, so that the first groove and the second groove are connected along the first direction to form the micro channel;
the second surface of the first silicon carbide substrate is a first surface of the silicon carbide substrate, and the second surface of the first silicon carbide substrate and the first surface of the first silicon carbide substrate are arranged opposite to each other along the first direction.
Optionally, the silicon carbide substrate further includes:
the second metal layer is positioned on the second surface of the silicon carbide substrate, and is used for welding the silicon carbide substrate and other heat dissipation devices, and the second surface of the silicon carbide substrate is opposite to the first surface of the silicon carbide substrate.
Optionally, the silicon carbide substrate further includes:
a nano silver sintered layer positioned on the surface of the first metal layer facing away from the silicon carbide substrate;
And the copper gasket layer is positioned on the surface of the nano silver sintering layer, which is away from the first metal layer.
Optionally, the power device comprises a silicon carbide power device.
A method of fabricating a silicon carbide substrate, comprising:
providing a silicon carbide substrate;
forming a micro-channel in the silicon carbide substrate, wherein the input end of the micro-channel is communicated with a liquid inlet, and the output end of the micro-channel is communicated with a liquid outlet, so that a cooling medium enters the micro-channel from the liquid inlet, flows in the micro-channel and is discharged from the liquid outlet to carry out heat;
and forming a first metal layer on the first surface of the silicon carbide substrate, wherein the first metal layer is used for welding the silicon carbide substrate and the power devices and interconnecting the power devices.
Optionally, the silicon carbide substrate includes: a first silicon carbide substrate and a second silicon carbide substrate disposed opposite in a first direction, the first direction being perpendicular to a first surface of the silicon carbide substrate;
the process of forming a microchannel within the silicon carbide substrate comprises:
cleaning the first silicon carbide substrate and the second silicon carbide substrate, and plating seed layers on the first surface of the first silicon carbide substrate and the first surface of the second silicon carbide substrate;
Etching a first surface of the first silicon carbide substrate to form a first groove, and etching a first surface of the second silicon carbide substrate to form a second groove, wherein the opening of the first groove on the first surface of the first silicon carbide substrate and the opening of the second groove on the first surface of the second silicon carbide substrate are the same in size and are symmetrically arranged along the first direction;
forming a first bonding layer on the first surface of the first silicon carbide substrate in other areas except the first groove, and forming a second bonding layer on the first surface of the second silicon carbide substrate in other areas except the second groove;
bonding and connecting the first silicon carbide substrate and the second silicon carbide substrate through the first bonding layer and the second bonding layer, so that the first groove and the second groove are connected along the first direction to form the micro-channel;
the second surface of the first silicon carbide substrate is a first surface of the silicon carbide substrate, and the second surface of the first silicon carbide substrate and the first surface of the first silicon carbide substrate are arranged opposite to each other along the first direction.
Optionally, the method further comprises:
And forming a second metal layer on the second surface of the silicon carbide substrate, wherein the second metal layer is used for welding the silicon carbide substrate and other heat dissipation devices, and the second surface of the silicon carbide substrate is opposite to the first surface of the silicon carbide substrate.
Optionally, the method further comprises:
cutting the formed silicon carbide substrate to obtain a silicon carbide substrate with a preset area;
printing nano silver solder paste on the surface of the first metal layer, which is away from the silicon carbide substrate, in the silicon carbide substrate with the preset area;
placing a copper gasket layer on the surface of the nano silver soldering paste, which faces away from the first metal layer, and extruding the copper gasket layer to bond the nano silver soldering paste and the copper gasket layer;
and placing the silicon carbide substrate with the preset area in a silver sintering furnace, so that the nano silver soldering paste is sintered into a nano silver sintering layer, and the copper gasket layer and the first metal layer are interconnected.
A power module comprising a plurality of power devices and a silicon carbide substrate according to any of the preceding claims, wherein the plurality of power devices are interconnected by the first metal layer and soldered to the silicon carbide substrate by the first metal layer.
Compared with the prior art, the technical scheme has the following advantages:
the silicon carbide substrate provided by the embodiment of the application comprises the following components: the silicon carbide substrate is internally provided with a micro-channel, the input end of the micro-channel is communicated with the liquid inlet, and the output end of the micro-channel is communicated with the liquid outlet, so that a cooling medium enters the micro-channel from the liquid inlet and is discharged from the liquid outlet after flowing in the micro-channel to carry heat out; the first metal layer is located on the first surface of the silicon carbide substrate, and is used for welding the silicon carbide substrate and the power devices and interconnecting the power devices. Therefore, compared with the copper radiating substrate with the micro-channels embedded therein, which is bonded by the copper-clad ceramic substrate with lower heat conductivity in the traditional power module package, the silicon carbide substrate provided by the embodiment of the application has the advantages that the ceramic substrate with lower heat conductivity is abandoned, the silicon carbide substrate with higher heat conductivity and the same insulation is adopted, and the micro-channels are directly arranged in the silicon carbide substrate, so that the heat generated by the power device can reach the silicon carbide substrate with the micro-channels embedded therein with the circulating cooling medium only through one metal layer, thereby greatly shortening the heat transfer path of the power device reaching the cooling medium circulating in the micro-channels embedded in the silicon carbide substrate, reducing the thermal resistance, improving the radiating efficiency of the power module package substrate, and realizing the purpose of quickly reducing the junction temperature of the power device.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a package substrate of a conventional power module;
FIG. 2 is a schematic view of a silicon carbide substrate according to an embodiment of the present application;
FIG. 3 is a schematic top view of one connection of multiple segments of microchannels in a silicon carbide substrate according to an embodiment of the present application;
FIG. 4 is a schematic top view of another connection method of multiple segments of micro-channels in a silicon carbide substrate according to an embodiment of the present application;
FIG. 5 is a schematic diagram of another connection method of multiple segments of micro-channels in a SiC substrate according to an embodiment of the present application;
FIG. 6 is a schematic view of a silicon carbide substrate according to another embodiment of the present application;
FIGS. 7 (a) -7 (g) are schematic structural diagrams corresponding to the process steps in preparing the silicon carbide substrate of the silicon carbide substrate shown in FIG. 6;
FIG. 8 is a schematic view of a silicon carbide substrate according to another embodiment of the present application;
FIG. 9 is a schematic view of a silicon carbide substrate according to yet another embodiment of the present application;
FIG. 10 is a flow chart of a method for fabricating a silicon carbide substrate according to an embodiment of the present application;
FIG. 11 is a flow chart of a method for fabricating a silicon carbide substrate according to another embodiment of the present application;
FIG. 12 is a flow chart of a method for fabricating a silicon carbide substrate according to another embodiment of the present application;
fig. 13 is a flow chart illustrating a method for fabricating a silicon carbide substrate according to still another embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present application is not limited to the specific embodiments disclosed below.
In the following detailed description of the embodiments of the present application, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration only, and in which is shown by way of illustration only, and in which the scope of the application is not limited for ease of illustration. In addition, the three-dimensional dimensions of length, width and depth should be included in actual fabrication.
As described in the background section, for wide bandgap silicon carbide power devices, the high voltage, high temperature and high frequency operating characteristics of the devices present new challenges for packaging and dissipating heat from the power module.
Fig. 1 is a schematic view of a package substrate of a conventional power module, and as shown in fig. 1, in a conventional power module package, a copper-clad ceramic substrate, which is formed by directly bonding copper metal layers 02 on upper and lower surfaces of a ceramic substrate 01, is mainly referred to as a DBC (Direct Bonding Copper, DBC) substrate. In specific operation, a power device is attached to a copper metal layer 02 bonded to the upper surface of a ceramic substrate 01, in order to improve the heat dissipation efficiency of a copper-clad ceramic substrate, the copper metal layer 02 bonded to the lower surface of the copper-clad ceramic substrate and a heat conducting adhesive 03 (also called solder) are generally bonded to a copper heat dissipation substrate 04, a micro-channel 05 is embedded in the copper heat dissipation substrate 04, the micro-channel 05 is respectively communicated with a liquid inlet 06 and a liquid outlet 07, a cooling liquid is input into the micro-channel 05 through the liquid inlet 06, and the cooling liquid and carried heat in the micro-channel 05 are output outwards through the liquid outlet.
The inventor researches and discovers that for the existing copper-clad ceramic substrate, heat of the power device can reach the copper heat-dissipating substrate 04 after passing through the copper metal layer 02 positioned on the upper surface of the ceramic substrate 01, the copper metal layer 02 positioned on the lower surface of the ceramic substrate 01 and the heat conducting glue 03, and then reaches cooling liquid flowing in the micro-channel 05 embedded in the copper heat-dissipating substrate 04, namely, the heat transfer path of the power device reaching the copper heat-dissipating substrate embedded with the micro-channel is longer, and the heat conductivity of the ceramic substrate and the heat conducting glue is lower, so that the heat dissipation efficiency of the whole package substrate is lower.
In view of this, an embodiment of the present application provides a silicon carbide substrate, as shown in fig. 2, including:
a silicon carbide substrate 10, wherein a micro-channel 11 is arranged in the silicon carbide substrate 10, the input end of the micro-channel 11 is communicated with a liquid inlet 20, the output end of the micro-channel 11 is communicated with a liquid outlet 30, so that a cooling medium enters the micro-channel 11 through the liquid inlet 20, flows in the micro-channel 11 and is discharged through the liquid outlet 30 to carry out heat;
a first metal layer 40, the first metal layer 40 being located on a first surface of the silicon carbide substrate 10 (e.g., an upper surface of the silicon carbide substrate 10 as shown in fig. 2), the first metal layer 40 being used to bond the silicon carbide substrate 10 to and interconnect a plurality of power devices.
During specific operation, heat generated by the power devices passes through the first metal layer 40 to reach the silicon carbide substrate 10, and then reaches a cooling medium flowing in a micro-channel 11 arranged in the silicon carbide substrate 10, and enters the micro-channel 11 through the liquid inlet 20 along with the cooling medium, and is discharged through the liquid outlet 30 after flowing in the micro-channel 11, so that heat generated by the power devices is discharged. Wherein the plurality of power devices are located on a side of the first metal layer 40 facing away from the silicon carbide substrate 10, not shown in fig. 2.
The number of the micro-channels 11 provided in the silicon carbide substrate 10 is not limited in the present application. Alternatively, in one embodiment of the present application, the microchannel 11 is only a section of the microchannel, the input end of the section of the microchannel is in communication with the liquid inlet 20, and the output end of the section of the microchannel is in communication with the liquid outlet 30. Considering that the larger the number of the micro-channels, the larger the heat dissipation area of the cooling medium flowing in the micro-channels can be, so as to further improve the heat dissipation efficiency of the silicon carbide substrate, therefore, in another embodiment of the present application, the micro-channels 11 may optionally include multiple sections of micro-channels, and the cooling medium enters the micro-channels 11 from the liquid inlet 20, passes through the multiple sections of micro-channels 11, and is discharged from the liquid outlet 30.
In addition, when the micro-channel 11 includes multiple sections of micro-channels, the connection manner of the multiple sections of micro-channels is not limited in the present application, for example, fig. 3-5 enumerate three connection manners, where fig. 3 shows a schematic top view of one connection manner of multiple sections of micro-channels in the silicon carbide substrate, and it can be seen from fig. 3 that after the cooling medium enters the micro-channel 11 through the liquid inlet 20, the cooling medium is collected through multiple sections of parallel micro-channels and then discharged through the liquid outlet 30; fig. 4 is a schematic top view of another connection manner of multiple segments of micro-channels in a silicon carbide substrate, and as can be seen from fig. 4, after the cooling medium enters the micro-channels 11 from the liquid inlet 20, the cooling medium passes through multiple segments of micro-channels connected end to end in turn and is discharged from the liquid outlet 30; fig. 5 shows a schematic diagram of another connection manner of multiple micro-channels in a silicon carbide substrate, and as can be seen from fig. 5, after the cooling medium enters the micro-channels 11 from the liquid inlet 20, in the process of circulating in the main micro-channels, the cooling medium passes through one or multiple branch micro-channels close to the first surface of the silicon carbide substrate 10, and finally merges in the main micro-channels, and is discharged through the liquid outlet 30, and as the branch micro-channels close to the first surface of the silicon carbide substrate 10 are closer to the multiple power devices, the heat transfer paths of the multiple power devices reach the branch micro-channels more closely, so that the design of the micro-channels is beneficial to further improving the heat dissipation efficiency of the silicon carbide substrate.
The shape of the micro-channel 11 disposed in the silicon carbide substrate 10 is not limited in the present application, and the micro-channel 11 may be various shapes such as triangle, square, hexagon, etc., as the case may be.
The location of the micro-channel 11 disposed in the silicon carbide substrate 10 is not limited in the present application, and may be specifically determined according to the heat generated by the plurality of power devices. Alternatively, in one embodiment of the present application, referring to fig. 5, the micro-channels 11 may be near the first surface of the silicon carbide substrate, so as to further shorten the heat transfer path of the plurality of power devices to the cooling medium flowing in the micro-channels disposed in the silicon carbide substrate.
The application is not limited to the degree of density of the micro-channels 11 disposed in the silicon carbide substrate 10, and can be specifically determined according to the heat generated by the power devices. For example, when the heat generated by the power devices is larger, a plurality of sections of micro-channels which are closely arranged can be arranged in the silicon carbide substrate, so that the heat dissipation efficiency of the silicon carbide substrate is improved; when the heat generated by the power devices is smaller, fewer sections of micro-channels which are arranged in a sparse mode can be arranged in the silicon carbide substrate, and only the heat generated by the power devices can be timely discharged.
Therefore, compared with the copper radiating substrate with the micro-channels embedded therein, which is bonded by the copper-clad ceramic substrate with lower heat conductivity in the traditional power module package, the silicon carbide substrate provided by the embodiment of the application has the advantages that the ceramic substrate with lower heat conductivity is abandoned, the silicon carbide substrate with higher heat conductivity and the same insulation is adopted, and the micro-channels are directly arranged in the silicon carbide substrate, so that the heat generated by the power device can reach the silicon carbide substrate with the micro-channels embedded therein with the circulating cooling medium only through one metal layer, thereby greatly shortening the heat transfer path of the power device reaching the cooling medium circulating in the micro-channels embedded in the silicon carbide substrate, reducing the thermal resistance, improving the radiating efficiency of the power module package substrate, and realizing the purpose of quickly reducing the junction temperature of the power device.
Optionally, the first metal layer is a copper metal layer, but the application is not limited thereto, and the first metal layer may be other metal layers.
Optionally, the power device may be a silicon carbide power device, at this time, the silicon carbide substrate and the silicon carbide power device are made of the same material, and have the same material characteristics such as thermal expansion coefficients, and the compatibility of the silicon carbide substrate and the silicon carbide power device is better.
Considering that the depth of the micro-channel 11 is limited when the micro-channel 11 is directly etched in the silicon carbide substrate 10, in an embodiment of the present application, as shown in fig. 6, the silicon carbide substrate 10 includes: a first silicon carbide substrate 12 and a second silicon carbide substrate 13 disposed opposite to each other in a first direction perpendicular to a first surface of the silicon carbide substrate 10;
a first groove 121 is formed in the first surface of the first silicon carbide substrate 12, a second groove 131 is formed in the first surface of the second silicon carbide substrate 13, and openings of the first groove 121 on the first surface of the first silicon carbide substrate 12 and openings of the second groove 131 on the first surface of the second silicon carbide substrate 13 are the same in size and are symmetrically arranged along the first direction;
a first bonding layer 122 is disposed on the first surface of the first silicon carbide substrate 12 in the other area except the first groove 121, a second bonding layer 132 is disposed on the first surface of the second silicon carbide substrate 13 in the other area except the second groove 131, and the first silicon carbide substrate 12 and the second silicon carbide substrate 13 are bonded and connected through the first bonding layer 122 and the second bonding layer 132, so that the first groove 121 and the second groove 131 are connected along the first direction to form the micro channel 11;
The second surface of the first silicon carbide substrate 12 is a first surface of the silicon carbide substrate 10, and the second surface of the first silicon carbide substrate 12 is opposite to the first surface of the first silicon carbide substrate 12 along the first direction.
It should be noted that, if the micro-channel 11 is directly etched in the silicon carbide substrate 10, the depth of the micro-channel 11 may be limited, so in this embodiment, the first groove 121 is etched on the first surface of the first silicon carbide substrate 12, and the second groove 131 is etched on the first surface of the second silicon carbide substrate 13, and the first groove 121 and the second groove 131 are bonded and connected by the first bonding layer 122 and the second bonding layer 132, so that the micro-channel 11 is formed by connecting the first groove 122 and the second groove 131 along the first direction, thereby improving the depth of the micro-channel 11 to further meet the heat dissipation requirement of the silicon carbide substrate.
In this embodiment, since the micro-channel 11 is connected from the liquid inlet 20 to the liquid outlet 30, and the micro-channel 11 is formed by connecting the first groove 121 and the second groove 131 along the first direction, it is necessary to ensure that the opening of the first groove 121 on the first surface of the first silicon carbide substrate 12 and the opening of the second groove 131 on the first surface of the second silicon carbide substrate 13 are the same in size and are symmetrically located along the first direction, and at this time, since the first bonding layer 122 is located in the other area of the first surface of the first silicon carbide substrate 12 than the first groove 121, and the second bonding layer 132 is located in the other area of the first surface of the second silicon carbide substrate 13 than the second groove 131, the first bonding layer 122 and the second bonding layer 132 are the same in area and are located along the first direction, and are symmetrically located along the first direction, so that when the first bonding layer 122 and the second bonding layer 122 are located along the first direction, the first bonding layer 122 and the second bonding layer 131 are formed, and the first bonding layer 132 are connected to each other, and the first bonding layer 122 and the first bonding layer 13 are connected along the first direction, and the micro-channel 13 is formed.
Specifically, as shown in fig. 6, the bonding surface AA ' of the first surface of the first silicon carbide substrate 12 and the bonding surface AA ' of the first surface of the second silicon carbide substrate 13 are symmetrical planes, and the AA ' planes are parallel to the first surface of the silicon carbide substrate 10 and perpendicular to the first direction, as can be seen in fig. 6, the openings of the first groove 121 and the openings of the second groove 131 are equal in size and are symmetrically arranged along the AA ' planes (i.e., symmetrically arranged along the first direction), and the first bonding layer 122 and the second bonding layer 132 are equal in area and are symmetrically arranged along the AA ' planes (i.e., symmetrically arranged along the first direction), so that when the first bonding layer 122 and the second bonding layer 132 are bonded together, the first groove 121 and the second groove 131 are bonded together along the first direction to form the closed microchannel 11.
It should be noted that, the shape of the first groove 121 provided on the first surface of the first silicon carbide substrate 12 and the shape of the second groove 131 provided on the first surface of the second silicon carbide substrate 13 may be the same, for example, as shown in fig. 6, the first groove 121 and the second groove 131 may be both trapezoidal, or may be different, for example, the first groove 121 may be rectangular, and the second groove 131 may be trapezoidal.
Since the openings of the first grooves 121 on the first surface of the first silicon carbide substrate 12 and the openings of the second grooves 131 on the first surface of the second silicon carbide substrate 13 are identical in size and are symmetrically arranged along the first direction, in an alternative embodiment of the present application, the first silicon carbide substrate 12 and the second silicon carbide substrate 13 may be identical substrates, and the first grooves 121 and the second grooves 131 (including the positions and the shapes of the first grooves 121 and the second grooves 131, etc.) are completely symmetrically arranged along the first direction, as shown in fig. 6, and at this time, the process for preparing the first silicon carbide substrate and the second silicon carbide substrate is completely identical, thereby simplifying the process steps for preparing the silicon carbide substrate.
Specifically, in the actual process, first, as shown in fig. 7 (a), the first silicon carbide substrate 12 and the second silicon carbide substrate 13 are cleaned, and a seed layer coating (not shown in fig. 7 (a)) is performed on the first surface of the first silicon carbide substrate 12 and the first surface of the second silicon carbide substrate 13, where the seed layer may be a nickel metal layer or the like, so as to facilitate the subsequent formation of a first bonding layer on the first surface of the first silicon carbide substrate 12 and the formation of a second bonding layer on the first surface of the second silicon carbide substrate 13;
Next, as shown in fig. 7 (b), a glue 120 is applied to the first surface of the first silicon carbide substrate 12, and an etching position exposing the first groove is developed, and in the same way, a glue 130 is applied to the surface of the second silicon carbide substrate 13, and an etching position exposing the second groove is developed;
then, as shown in fig. 7 (c), etching is performed on the first surface of the first silicon carbide substrate 12 to form the first recess 121 and remove the glue coating 120, and similarly, as shown in fig. 7 (d), etching is performed on the first surface of the second silicon carbide substrate 13 to form the second recess 13 and remove the glue coating 130;
thereafter, as shown in fig. 7 (e), a first bonding layer 122 is formed on the first surface of the first silicon carbide substrate 12 in the other region than the first recess 121, and similarly, as shown in fig. 7 (f), a second bonding layer 132 is formed on the first surface of the second silicon carbide substrate 13 in the other region than the second recess 131;
finally, as shown in fig. 7 (g), the first silicon carbide substrate 12 and the second silicon carbide substrate 13 are bonded through the first bonding layer 122 and the second bonding layer 132, so that the first groove 121 and the second groove 131 are connected along the first direction to constitute the micro channel 11.
Optionally, the first bonding layer 121 and the second bonding layer 131 are gold bonding layers, that is, the first bonding layer 121 and the second bonding layer 131 are bonded to form a gold-gold bonding layer.
In order to further improve the heat dissipation effect of the silicon carbide substrate on the plurality of power devices based on any of the above embodiments, the silicon carbide substrate may be soldered to other heat dissipation devices, similar to the conventional copper-clad ceramic substrate being bonded to a copper heat dissipation substrate, so that, optionally, in one embodiment of the present application, as shown in fig. 8, the silicon carbide substrate further includes: and the second metal layer 50 is positioned on the second surface of the silicon carbide substrate, the second metal layer 50 is used for welding the silicon carbide substrate and other heat dissipation devices, and the second surface of the silicon carbide substrate is opposite to the first surface of the silicon carbide substrate.
Optionally, the second metal layer 50 is a copper metal layer, but the present application is not limited thereto, and the second metal layer may be another metal layer.
It should be noted that, in the above embodiments, the first metal layer is used not only to bond the silicon carbide substrate and the plurality of power devices, but also to interconnect the plurality of power devices, when the operating current of the plurality of power devices is large, the thickness of the first metal layer needs to be increased correspondingly to improve the current carrying capability of the silicon carbide substrate, but the thickness of the metal layer formed by electroplating on the surface of the silicon carbide substrate is generally thinner, that is, the thickness of the first metal layer is thinner, so, alternatively, in one embodiment of the present application, as shown in fig. 9, the silicon carbide substrate further includes:
A nano-silver sintered layer 60, the nano-silver sintered layer 60 being located on a surface of the first metal layer 40 facing away from the silicon carbide substrate 10;
a copper shim layer 70, the copper shim layer 70 being located on a surface of the nano-silver sintered layer 60 facing away from the first metal layer 10.
In this embodiment, the plurality of power devices are located on a side of the copper gasket layer 70 facing away from the nano silver sintering layer 60, and are welded together by the copper gasket layer 70, the nano silver sintering layer 60, the first metal layer 40 and the silicon carbide substrate 10, at this time, the copper gasket layer 70 is welded on a surface of the first metal layer 40 facing away from the silicon carbide substrate 10 by the nano silver sintering layer 60, so that a stack assembly formed by the first metal layer 40, the nano silver sintering layer 60 and the copper gasket layer 70 is used as a metal layer for welding together the silicon carbide substrate 10 and the plurality of power devices, and is further used for interconnecting the plurality of power devices, and compared with the first metal layer, the thickness of the metal layer is increased, thereby improving the current carrying capacity of the silicon carbide substrate.
The nano silver sintered layer 60 is made of a material having a high thermal conductivity, and has a higher thermal conductivity than the thermal conductive paste, so that the heat dissipation efficiency of the silicon carbide substrate can be further improved.
Specifically, in the actual process, after the silicon carbide substrate 10 with the micro-channels embedded therein, the first metal layer 40 located on the first surface of the silicon carbide substrate, and the second metal layer 50 located on the second surface of the silicon carbide substrate are prepared, a screen printing process may be used to print the nano silver solder paste on the first metal layer 40 on the first surface of the silicon carbide substrate 10; then, the copper gasket layer 70 is placed on the nano silver soldering paste and lightly pressed, so that the copper gasket layer and the nano silver soldering paste are fully adhered; and then, placing the silicon carbide substrate into a silver sintering furnace, and sintering the printed nano silver soldering paste into a nano silver sintering layer 60, so as to complete silver sintering interconnection of the copper gasket layer 70 and the first metal layer 40.
The embodiment of the application also provides a manufacturing method of the silicon carbide substrate, as shown in fig. 10, the method comprises the following steps:
s100: as shown in fig. 2, a silicon carbide substrate 10 is provided;
s200: continuing to show in fig. 2, a micro-channel 11 is formed in the silicon carbide substrate 10, an input end of the micro-channel 11 is communicated with a liquid inlet 20, an output end of the micro-channel 11 is communicated with a liquid outlet 30, so that a cooling medium enters the micro-channel 11 through the liquid inlet 20, flows in the micro-channel 11 and is discharged through the liquid outlet 30 to carry out heat;
S300: continuing with fig. 2, a first metal layer 40 is formed on the first surface of the silicon carbide substrate 10, the first metal layer 40 being used to bond the silicon carbide substrate to and interconnect the plurality of power devices.
Alternatively, the first metal layer is a copper metal layer, and the first metal layer 40 is formed on the first surface of the silicon carbide substrate 10 by using an electroplating technology, but the present application is not limited thereto, and the first metal layer may be other metal layers.
Optionally, the power device may be a silicon carbide power device, at this time, the silicon carbide substrate and the silicon carbide power device are made of the same material, and have the same material characteristics such as thermal expansion coefficients, and the compatibility of the silicon carbide substrate and the silicon carbide power device is better.
The number of the micro-channels 11 provided in the silicon carbide substrate 10 is not limited in the present application. Alternatively, in one embodiment of the present application, the microchannel 11 is only a section of the microchannel, the input end of the section of the microchannel is in communication with the liquid inlet 20, and the output end of the section of the microchannel is in communication with the liquid outlet 30. Considering that the larger the number of the micro-channels, the larger the heat dissipation area of the cooling medium flowing in the micro-channels can be, so as to further improve the heat dissipation efficiency of the silicon carbide substrate, therefore, in another embodiment of the present application, the micro-channels 11 may optionally include multiple sections of micro-channels, and the cooling medium enters the micro-channels 11 from the liquid inlet 20, passes through the multiple sections of micro-channels 11, and is discharged from the liquid outlet 30.
In addition, when the micro-channel 11 includes multiple sections of micro-channels, the connection manner of the multiple sections of micro-channels is not limited in the present application, for example, fig. 3-5 enumerate three connection manners, where fig. 3 shows a schematic top view of one connection manner of multiple sections of micro-channels in the silicon carbide substrate, and it can be seen from fig. 3 that after the cooling medium enters the micro-channel 11 through the liquid inlet 20, the cooling medium is collected through multiple sections of parallel micro-channels and then discharged through the liquid outlet 30; fig. 4 is a schematic top view of another connection manner of multiple segments of micro-channels in a silicon carbide substrate, and as can be seen from fig. 4, after the cooling medium enters the micro-channels 11 from the liquid inlet 20, the cooling medium passes through multiple segments of micro-channels connected end to end in turn and is discharged from the liquid outlet 30; fig. 5 shows a schematic diagram of another connection manner of multiple micro-channels in a silicon carbide substrate, and as can be seen from fig. 5, after the cooling medium enters the micro-channels 11 from the liquid inlet 20, in the process of circulating in the main micro-channels, the cooling medium passes through one or multiple branch micro-channels close to the first surface of the silicon carbide substrate 10, and finally merges in the main micro-channels, and is discharged through the liquid outlet 30, and as the branch micro-channels close to the first surface of the silicon carbide substrate 10 are closer to the multiple power devices, the heat transfer paths of the multiple power devices reach the branch micro-channels more closely, so that the design of the micro-channels is beneficial to further improving the heat dissipation efficiency of the silicon carbide substrate.
The shape of the micro-channel 11 disposed in the silicon carbide substrate 10 is not limited in the present application, and the micro-channel 11 may be various shapes such as triangle, square, hexagon, etc., as the case may be.
The location of the micro-channel 11 disposed in the silicon carbide substrate 10 is not limited in the present application, and may be specifically determined according to the heat generated by the plurality of power devices. Alternatively, in one embodiment of the present application, referring to fig. 5, the micro-channels 11 may be near the first surface of the silicon carbide substrate, so as to further shorten the heat transfer path of the plurality of power devices to the cooling medium flowing in the micro-channels disposed in the silicon carbide substrate.
The application is not limited to the degree of density of the micro-channels 11 disposed in the silicon carbide substrate 10, and can be specifically determined according to the heat generated by the power devices. For example, when the heat generated by the power devices is larger, a plurality of sections of micro-channels which are closely arranged can be arranged in the silicon carbide substrate, so that the heat dissipation efficiency of the silicon carbide substrate is improved; when the heat generated by the power devices is smaller, fewer sections of micro-channels which are arranged in a sparse mode can be arranged in the silicon carbide substrate, and only the heat generated by the power devices can be timely discharged.
Therefore, compared with the copper radiating substrate with the micro-channels embedded therein, which is bonded by the copper-clad ceramic substrate with lower heat conductivity in the traditional power module package, the heat of the power device can reach the copper radiating substrate with the micro-channels embedded therein with circulating cooling liquid after passing through the two copper metal layers, the ceramic substrate and the heat conducting glue, the silicon carbide substrate formed by the manufacturing method provided by the embodiment of the application has the advantages that the ceramic substrate with lower heat conductivity is abandoned, the silicon carbide substrate with higher heat conductivity and the same insulation is adopted, and the micro-channels are directly arranged in the silicon carbide substrate, so that the heat generated by the power device can reach the silicon carbide substrate with the micro-channels embedded therein with circulating cooling medium only through one metal layer, thereby greatly shortening the heat transfer path of the power device to the cooling medium circulating in the micro-channels embedded in the silicon carbide substrate, reducing the heat resistance, improving the heat radiating efficiency of the power module package substrate, and realizing the purpose of quickly reducing the junction temperature of the power device.
Considering that the depth of the micro-channel 11 is limited when the micro-channel 11 is directly etched in the silicon carbide substrate 10, in an embodiment of the present application, as shown in fig. 6, the silicon carbide substrate 10 includes: a first silicon carbide substrate 12 and a second silicon carbide substrate 13 disposed opposite in a first direction, the first direction being perpendicular to a first surface of the silicon carbide substrate;
As shown in fig. 11, the process of forming the micro-channel 11 in the silicon carbide substrate 10 includes:
s210: as shown in fig. 7 (a), the first silicon carbide substrate 12 and the second silicon carbide substrate 13 are cleaned, and seed layer plating is performed on the first surface of the first silicon carbide substrate 12 and the first surface of the second silicon carbide substrate 13.
It should be noted that, since the first bonding layer is required to be formed on the first surface of the first silicon carbide substrate 12 and the second bonding layer is required to be formed on the first surface of the second silicon carbide substrate 13, both the first bonding layer and the second bonding layer may be gold bonding layers, and in actual process, the plating of the gold bonding layer directly on the surface of the silicon carbide material is not easy, and therefore, in step S210, after the cleaning of the first silicon carbide substrate 12 and the second silicon carbide substrate 13, the seed layer plating (seed layer is not shown in fig. 7 (a)) is performed on the first surface of the first silicon carbide substrate 12 and the first surface of the second silicon carbide substrate 13, the seed layer may be a nickel metal layer or the like, so that the first bonding layer is formed on the first surface of the first silicon carbide substrate 12 and the second bonding layer is formed on the first surface of the second silicon carbide substrate 13 conveniently.
S220: a first groove 121 is etched on the first surface of the first silicon carbide substrate 12, and a second groove 131 is etched on the first surface of the second silicon carbide substrate 13, wherein the openings of the first groove 121 on the first surface of the first silicon carbide substrate 12 and the openings of the second groove 131 on the first surface of the second silicon carbide substrate 13 are the same in size and are symmetrically arranged along the first direction.
Specifically, in the actual process, as shown in fig. 7 (b), a glue 120 is applied to the first surface of the first silicon carbide substrate 12, and an etching position exposing the first groove is developed, and similarly, a glue 130 is applied to the surface of the second silicon carbide substrate 13, and an etching position exposing the second groove is developed;
then, as shown in fig. 7 (c), a deep reactive ion etching process is performed on the first surface of the first silicon carbide substrate 12 to form the first recess 121 and remove the glue coating 120, and similarly, as shown in fig. 7 (d), a deep reactive ion etching process is performed on the first surface of the second silicon carbide substrate 13 to form the second recess 13 and remove the glue coating 130.
S230: as shown in fig. 7 (e) and 7 (f), a first bonding layer 122 is formed on the first surface of the first silicon carbide substrate 12 in the other region than the first groove 121, and a second bonding layer 132 is formed on the first surface of the second silicon carbide substrate 13 in the other region than the second groove 131.
Specifically, in the actual process, taking the example of forming the first bonding layer 122 on the first surface of the first silicon carbide substrate 12 in the other area except the first groove 121 as an example, first, the first bonding layer 122 is formed by sputtering on the first surface of the first silicon carbide substrate 12; then, removing the first bonding layer 122 of the first surface of the first silicon carbide substrate 12 corresponding to the region of the first groove 121, and reserving the first bonding layer 122 of the first surface of the first silicon carbide substrate 12 in other regions except the first groove 121; similarly, a second bonding layer 132 is obtained in the region of the first surface of the second silicon carbide substrate 13 other than the second recess 131.
Optionally, the first bonding layer and the second bonding layer are both gold bonding layers, i.e. the first bonding layer and the second bonding layer may be bonded to form a gold-gold bonding layer.
S240: as shown in fig. 7 (g), the first silicon carbide substrate 12 and the second silicon carbide substrate 13 are bonded and connected by the first bonding layer 121 and the second bonding layer 131, so that the first groove 121 and the second groove 131 are connected along the first direction to constitute the micro channel 11;
The second surface of the first silicon carbide substrate 12 is a first surface of the silicon carbide substrate, and the second surface of the first silicon carbide substrate 12 and the first surface of the first silicon carbide substrate 12 are disposed opposite to each other along the first direction.
It should be noted that, if the micro-channel 11 is directly etched in the silicon carbide substrate 10, the depth of the micro-channel 11 may be limited, so in this embodiment, the first groove 121 is etched on the first surface of the first silicon carbide substrate 12, and the second groove 131 is etched on the first surface of the second silicon carbide substrate 13, and the first groove 121 and the second groove 131 are bonded and connected by the first bonding layer 122 and the second bonding layer 132, so that the micro-channel 11 is formed by connecting the first groove 122 and the second groove 131 along the first direction, thereby improving the depth of the micro-channel 11 to further meet the heat dissipation requirement of the silicon carbide substrate.
In this embodiment, since the micro-channel 11 is connected from the liquid inlet 20 to the liquid outlet 30, and the micro-channel 11 is formed by connecting the first groove 121 and the second groove 131 along the first direction, it is necessary to ensure that the opening of the first groove 121 on the first surface of the first silicon carbide substrate 12 and the opening of the second groove 131 on the first surface of the second silicon carbide substrate 13 are the same in size and are symmetrically located along the first direction, and at this time, since the first bonding layer 122 is located in the other area of the first surface of the first silicon carbide substrate 12 than the first groove 121, and the second bonding layer 132 is located in the other area of the first surface of the second silicon carbide substrate 13 than the second groove 131, the first bonding layer 122 and the second bonding layer 132 are the same in area and are located along the first direction, and are symmetrically located along the first direction, so that when the first bonding layer 122 and the second bonding layer 122 are located along the first direction, the first bonding layer 122 and the second bonding layer 131 are formed, and the first bonding layer 132 are connected to each other, and the first bonding layer 122 and the first bonding layer 13 are connected along the first direction, and the micro-channel 13 is formed.
Specifically, as shown in fig. 6, the bonding surface AA ' of the first surface of the first silicon carbide substrate 12 and the bonding surface AA ' of the first surface of the second silicon carbide substrate 13 are symmetrical planes, and the AA ' planes are parallel to the first surface of the silicon carbide substrate 10 and perpendicular to the first direction, as can be seen in fig. 6, the openings of the first groove 121 and the openings of the second groove 131 are equal in size and are symmetrically arranged along the AA ' planes (i.e., symmetrically arranged along the first direction), and the first bonding layer 122 and the second bonding layer 132 are equal in area and are symmetrically arranged along the AA ' planes (i.e., symmetrically arranged along the first direction), so that when the first bonding layer 122 and the second bonding layer 132 are bonded together, the first groove 121 and the second groove 131 are bonded together along the first direction to form the closed microchannel 11.
It should be noted that, the shape of the first groove 121 provided on the first surface of the first silicon carbide substrate 12 and the shape of the second groove 131 provided on the first surface of the second silicon carbide substrate 13 may be the same, for example, as shown in fig. 6, the first groove 121 and the second groove 131 may be both trapezoidal, or may be different, for example, the first groove 121 may be rectangular, and the second groove 131 may be trapezoidal.
Since the openings of the first grooves 121 on the first surface of the first silicon carbide substrate 12 and the openings of the second grooves 131 on the first surface of the second silicon carbide substrate 13 are identical in size and are symmetrically arranged along the first direction, in an alternative embodiment of the present application, the first silicon carbide substrate 12 and the second silicon carbide substrate 13 may be identical substrates, and the first grooves 121 and the second grooves 131 (including the positions and the shapes of the first grooves 121 and the second grooves 131, etc.) are completely symmetrically arranged along the first direction, as shown in fig. 6, and at this time, the process for preparing the first silicon carbide substrate and the second silicon carbide substrate is completely identical, thereby simplifying the process steps for preparing the silicon carbide substrate.
In order to further improve the heat dissipation effect of the silicon carbide substrate on the plurality of power devices based on any of the above embodiments, the silicon carbide substrate may be soldered to other heat dissipation devices, similar to the conventional copper-clad ceramic substrate being bonded to a copper heat dissipation substrate, so optionally, in one embodiment of the present application, as shown in fig. 12, the method further includes:
S400: as shown in fig. 8, a second metal layer 50 is formed on a second surface of the silicon carbide substrate 10, and the second metal layer 50 is used for soldering the silicon carbide substrate 10 and other heat dissipation devices, where the second surface of the silicon carbide substrate 10 is disposed opposite to the first surface of the silicon carbide substrate 10.
Optionally, the second metal layer 50 is a copper metal layer, and the second metal layer 50 is formed on the second surface of the silicon carbide substrate 10 by using an electroplating technology, but the present application is not limited thereto, and the second metal layer may be other metal layers.
Step 300 is to form the first metal layer 40 on the first surface of the silicon carbide substrate 10, and step 400 is to form the second metal layer 50 on the second surface of the silicon carbide substrate 10, where steps 300 and 400 may be performed simultaneously or separately, as the case may be.
It should be noted that, in the above embodiments, the first metal layer is used not only to bond the silicon carbide substrate and the plurality of power devices, but also to interconnect the plurality of power devices, when the operating current of the plurality of power devices is large, the thickness of the first metal layer needs to be increased correspondingly to improve the current carrying capability of the silicon carbide substrate, but the thickness of the metal layer formed by electroplating on the surface of the silicon carbide substrate is generally thinner, that is, the thickness of the first metal layer is thinner, so, optionally, in one embodiment of the present application, as shown in fig. 13, the method further includes:
S500: and cutting the formed silicon carbide substrate to obtain the silicon carbide substrate with the preset area.
In practical application, the silicon carbide substrate usually corresponds to a wafer with a larger size, so the silicon carbide substrate formed in step S500 is cut, firstly, the silicon carbide substrate with a required area can be obtained, and secondly, silver sintering is conveniently performed after the nano silver soldering paste and the copper gasket layer are formed on the first metal layer.
S600: as shown in fig. 9, a nano-silver solder paste 60 is printed on the surface of the first metal layer 40 facing away from the silicon carbide substrate 10 in the silicon carbide substrate of the preset area;
s700: as shown in fig. 9, a copper gasket layer 70 is placed on the surface of the nano-silver paste 60 facing away from the first metal layer 10, and is pressed so that the nano-silver paste 60 and the copper gasket layer 70 are bonded;
s800: the silicon carbide substrate of the predetermined area is placed in a silver sintering furnace such that the nano-silver paste 60 is sintered into a nano-silver sintered layer 60, thereby interconnecting the copper pad layer 70 and the first metal layer 40.
In this embodiment, the plurality of power devices are located on a side of the copper pad layer 70 facing away from the nano silver sintered layer 60, and are welded together by the copper pad layer 70, the nano silver sintered layer 60, the first metal layer 40 and the silicon carbide substrate 10, and at this time, a stack formed by the first metal layer 40, the nano silver sintered layer 60 and the copper pad layer 70 is integrally used as a metal layer for welding together the silicon carbide substrate 10 and the plurality of power devices, and is further used for interconnecting the plurality of power devices, and the metal layer is increased in thickness compared with the first metal layer, so that the current carrying capacity of the silicon carbide substrate can be improved.
The nano silver sintered layer 60 is made of a material having a high thermal conductivity, and has a higher thermal conductivity than the thermal conductive paste, so that the heat dissipation efficiency of the silicon carbide substrate can be further improved.
In addition, the embodiment of the application also provides a power module, which comprises a plurality of power devices and the silicon carbide substrate provided by any embodiment, wherein the power devices are interconnected through the first metal layer and welded with the silicon carbide substrate through the first metal layer.
In summary, compared with the copper radiating substrate with the micro-channels embedded therein, which is bonded by the copper-clad ceramic substrate with lower heat conductivity in the existing power module package, the silicon carbide substrate provided by the embodiment of the application has the advantages that the ceramic substrate with lower heat conductivity is abandoned, the silicon carbide substrate with higher heat conductivity is adopted, and the micro-channels are directly arranged in the silicon carbide substrate, so that the heat generated by the power device can reach the silicon carbide substrate with the micro-channels embedded therein by only one metal layer, thereby greatly shortening the heat transfer path of the power device reaching the cooling medium circulating in the micro-channels embedded in the silicon carbide substrate, reducing the thermal resistance, improving the radiating efficiency of the power module package substrate, and realizing the purpose of quickly reducing the junction temperature of the power device.
Further, the interconnection of the copper gasket and the metal layer on the surface of the silicon carbide substrate is realized through the nano silver sintered layer with high heat conductivity, so that the thickness of the metal layer for interconnecting the silicon carbide substrate and the power device is increased, the current carrying capacity of the silicon carbide substrate is improved, and meanwhile, the heat dissipation efficiency of the silicon carbide substrate is also improved.
In the description, each part is described in a parallel and progressive mode, and each part is mainly described as a difference with other parts, and all parts are identical and similar to each other.
The features described in the various embodiments of the present disclosure may be interchanged or combined with one another in the description to enable those skilled in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. A silicon carbide substrate, comprising:
the silicon carbide substrate is internally provided with a micro-channel, the input end of the micro-channel is communicated with the liquid inlet, and the output end of the micro-channel is communicated with the liquid outlet, so that a cooling medium enters the micro-channel from the liquid inlet, flows in the micro-channel and is discharged from the liquid outlet to carry heat out;
and the first metal layer is positioned on the first surface of the silicon carbide substrate, and is used for welding the silicon carbide substrate and the power devices and interconnecting the power devices.
2. The silicon carbide substrate of claim 1, wherein the silicon carbide substrate comprises: a first silicon carbide substrate and a second silicon carbide substrate disposed opposite in a first direction, the first direction being perpendicular to a first surface of the silicon carbide substrate;
the first surface of the first silicon carbide substrate is provided with a first groove, the first surface of the second silicon carbide substrate is provided with a second groove, the opening of the first groove on the first surface of the first silicon carbide substrate and the opening of the second groove on the first surface of the second silicon carbide substrate are the same in size and are symmetrically arranged along the first direction;
A first bonding layer is arranged on the first surface of the first silicon carbide substrate in other areas except the first groove, a second bonding layer is arranged on the first surface of the second silicon carbide substrate in other areas except the second groove, and the first silicon carbide substrate and the second silicon carbide substrate are connected in a bonding mode through the first bonding layer and the second bonding layer, so that the first groove and the second groove are connected along the first direction to form the micro channel;
the second surface of the first silicon carbide substrate is a first surface of the silicon carbide substrate, and the second surface of the first silicon carbide substrate and the first surface of the first silicon carbide substrate are arranged opposite to each other along the first direction.
3. The silicon carbide substrate as claimed in claim 1 or 2, further comprising:
the second metal layer is positioned on the second surface of the silicon carbide substrate, and is used for welding the silicon carbide substrate and other heat dissipation devices, and the second surface of the silicon carbide substrate is opposite to the first surface of the silicon carbide substrate.
4. The silicon carbide substrate as claimed in claim 1 or 2, further comprising:
A nano silver sintered layer positioned on the surface of the first metal layer facing away from the silicon carbide substrate;
and the copper gasket layer is positioned on the surface of the nano silver sintering layer, which is away from the first metal layer.
5. The silicon carbide substrate of claim 1 or 2, wherein the power device comprises a silicon carbide power device.
6. A method of manufacturing a silicon carbide substrate, comprising:
providing a silicon carbide substrate;
forming a micro-channel in the silicon carbide substrate, wherein the input end of the micro-channel is communicated with a liquid inlet, and the output end of the micro-channel is communicated with a liquid outlet, so that a cooling medium enters the micro-channel from the liquid inlet, flows in the micro-channel and is discharged from the liquid outlet to carry out heat;
and forming a first metal layer on the first surface of the silicon carbide substrate, wherein the first metal layer is used for welding the silicon carbide substrate and the power devices and interconnecting the power devices.
7. The method of claim 6, wherein the silicon carbide substrate comprises: a first silicon carbide substrate and a second silicon carbide substrate disposed opposite in a first direction, the first direction being perpendicular to a first surface of the silicon carbide substrate;
The process of forming a microchannel within the silicon carbide substrate comprises:
cleaning the first silicon carbide substrate and the second silicon carbide substrate, and plating seed layers on the first surface of the first silicon carbide substrate and the first surface of the second silicon carbide substrate;
etching a first surface of the first silicon carbide substrate to form a first groove, and etching a first surface of the second silicon carbide substrate to form a second groove, wherein the opening of the first groove on the first surface of the first silicon carbide substrate and the opening of the second groove on the first surface of the second silicon carbide substrate are the same in size and are symmetrically arranged along the first direction;
forming a first bonding layer on the first surface of the first silicon carbide substrate in other areas except the first groove, and forming a second bonding layer on the first surface of the second silicon carbide substrate in other areas except the second groove;
bonding and connecting the first silicon carbide substrate and the second silicon carbide substrate through the first bonding layer and the second bonding layer, so that the first groove and the second groove are connected along the first direction to form the micro-channel;
The second surface of the first silicon carbide substrate is a first surface of the silicon carbide substrate, and the second surface of the first silicon carbide substrate and the first surface of the first silicon carbide substrate are arranged opposite to each other along the first direction.
8. The method according to claim 6 or 7, further comprising:
and forming a second metal layer on the second surface of the silicon carbide substrate, wherein the second metal layer is used for welding the silicon carbide substrate and other heat dissipation devices, and the second surface of the silicon carbide substrate is opposite to the first surface of the silicon carbide substrate.
9. The method according to claim 6 or 7, further comprising:
cutting the formed silicon carbide substrate to obtain a silicon carbide substrate with a preset area;
printing nano silver solder paste on the surface of the first metal layer, which is away from the silicon carbide substrate, in the silicon carbide substrate with the preset area;
placing a copper gasket layer on the surface of the nano silver soldering paste, which faces away from the first metal layer, and extruding the copper gasket layer to bond the nano silver soldering paste and the copper gasket layer;
and placing the silicon carbide substrate with the preset area in a silver sintering furnace, so that the nano silver soldering paste is sintered into a nano silver sintering layer, and the copper gasket layer and the first metal layer are interconnected.
10. A power module comprising a plurality of power devices and the silicon carbide substrate of any of claims 1-5, wherein the plurality of power devices are interconnected by the first metal layer and bonded to the silicon carbide substrate by the first metal layer.
CN202210163509.2A 2022-02-22 2022-02-22 Silicon carbide substrate, manufacturing method thereof and power module Pending CN116682796A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117238949A (en) * 2023-11-13 2023-12-15 苏州中瑞宏芯半导体有限公司 Copper bridge welded silicon carbide power module

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117238949A (en) * 2023-11-13 2023-12-15 苏州中瑞宏芯半导体有限公司 Copper bridge welded silicon carbide power module
CN117238949B (en) * 2023-11-13 2024-02-06 苏州中瑞宏芯半导体有限公司 Copper bridge welded silicon carbide power module

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