Metal ceramic substrate structure, manufacturing method and power semiconductor device

Abstract

The invention relates to the technical field of metal ceramic substrates, and provides a metal ceramic substrate structure, a manufacturing method and a power semiconductor device. The circuit layer is arranged on one side of the ceramic base material, and a first bonding layer is arranged between the ceramic base material and the circuit layer; the heat dissipation layer is arranged on the other side of the ceramic base material, and a second joint layer is arranged between the ceramic base material and the heat dissipation layer; and the graphene sheet ink layer is arranged on the heat dissipation layer. The circuit layer achieves the required circuit function, and heat generated when the circuit layer works is conducted to the heat dissipation layer through the ceramic base material to be dissipated. The first bonding layer enables the connection between the circuit layer and the ceramic substrate to be more stable and reliable, and the second bonding layer enables the connection between the ceramic substrate and the heat dissipation layer to be more stable and reliable. More importantly, the graphene sheet ink layer is arranged on the heat dissipation layer, and the excellent heat conductivity of graphene is utilized, so that the heat dissipation performance is further improved, and the heat dissipation requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of cermet substrates, and particularly to a cermet substrate structure, a manufacturing method, and a power semiconductor device. Background Art

[0002] During the operation of semiconductor devices, a large amount of heat is generated. If the heat cannot be dissipated in time, the device temperature will rise. High temperature will not only increase circuit losses but may also cause mechanical stress mismatch of materials in semiconductor devices, thereby shortening the service life and even leading to circuit function failure, and further affecting the performance and reliability of semiconductor devices. Therefore, the heat dissipation performance of semiconductor devices is directly related to the stability and reliability of semiconductor devices. With the development of power semiconductor technology, the performance of power semiconductors has been gradually improved and is widely used in different fields, such as electric vehicles, railways, etc. The improvement of power semiconductor performance leads to an increase in working voltage and power, posing higher requirements for heat dissipation.

[0003] A cermet substrate is a composite material. The cermet substrate is composed of a metal layer with high thermal conductivity and an insulating ceramic substrate. The high-thermal-conductivity ceramic substrate has efficient heat conduction and electrical insulation characteristics, has excellent heat dissipation performance, and has the potential to meet the heat dissipation requirements of devices such as power semiconductors.

[0004] However, with the trend of gradually improving semiconductor performance, the requirements for heat dissipation performance will also gradually increase. Therefore, how to improve the heat dissipation efficiency performance of cermet substrates is an urgent problem to be solved. Summary of the Invention

[0005] The present invention provides a cermet substrate structure, a manufacturing method, and a power semiconductor device to solve the problem of how to improve the heat dissipation efficiency performance of cermet substrates in the prior art.

[0006] The present invention provides a cermet substrate structure, including: A ceramic substrate; A circuit layer disposed on one side of the ceramic substrate, with a first bonding layer provided between the ceramic substrate and the circuit layer; A heat dissipation layer disposed on the other side of the ceramic substrate, with a second bonding layer provided between the ceramic substrate and the heat dissipation layer; A graphene flake ink layer disposed on the heat dissipation layer.

[0007] According to a cermet substrate structure provided by the present invention, the ceramic substrate is made of alumina, aluminum nitride, zirconia-reinforced alumina, or silicon nitride.

[0008] The present invention also provides a manufacturing method for a cermet substrate, which is applied to the above cermet substrate structure and includes: Connect a conductive layer to one side of the ceramic substrate and connect a heat dissipation layer to the other side of the ceramic substrate; Coat the graphene flake ink on the heat dissipation layer and then perform a drying process to make the graphene flake ink form a graphene flake ink layer; Perform a photomask process on the conductive layer to make a circuit pattern, and the conductive layer is converted into a circuit layer; Perform a cutting process according to the circuit layer to form the metal-ceramic substrate structure.

[0009] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. The graphene flake ink is obtained by the following method: Crush graphite to obtain powdered graphite; Irradiate the powdered graphite with high-energy electron beams to convert the powdered graphite into graphene flakes; Crush the graphene flakes to form graphene flake particles; Mix and stir a solvent, a binder, and graphene flake particles to form a first mixture; Add a resin and a dispersant to the first mixture to form a second mixture; Perform three-roll grinding, stirring, and nano-dispersion processes on the second mixture to obtain the graphene flake ink.

[0010] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. The solvent is ethylene glycol, the resin is polycaprolactone diol and polyester. The graphene flake ink includes 10 to 30 wt% of ethylene glycol, 2 to 10 wt% of polycaprolactone diol, 1 to 10 wt% of polyester, 2 to 10 wt% of graphene flakes, and distilled water. The viscosity of the graphene flake ink is in the range of 500 to 200 cp. The thickness of the graphene flakes in the graphene flake ink is 5 to 50 nm and the particle size is on average below 30 um.

[0011] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. After coating the graphene flake ink on the heat dissipation layer and performing a drying process, it further includes: Form a thermal interface material layer and heat dissipation pins on the heat dissipation layer.

[0012] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. Connecting a conductive layer to one side of the ceramic substrate and connecting a heat dissipation layer to the other side of the ceramic substrate includes: Form a first brazing filler layer on one side of the ceramic substrate and form a second brazing filler layer on the other side of the ceramic substrate; Attach the conductive substrate to one side of the ceramic substrate, and attach the heat dissipation substrate to the other side of the ceramic substrate; Based on the soldering process, heat is applied to convert the first solder filling layer into a first bonding layer and the second solder filling layer into a second bonding layer. The conductive substrate is connected to the ceramic substrate through the first bonding layer to form the conductive layer, and the heat dissipation substrate is connected to the ceramic substrate through the second bonding layer to form the heat dissipation layer.

[0013] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. Forming a first solder filling layer on one side of the ceramic substrate and a second solder filling layer on the other side of the ceramic substrate includes: Coat the two sides of the ceramic substrate with a metal mixed paste to form the first solder filling layer and the second solder filling layer; Wherein, the metal mixed paste is formed by mixing solder filling metal powder, solvent and binder.

[0014] According to the present invention, a method for manufacturing a metal-ceramic substrate is provided. Forming a first solder filling layer on one side of the ceramic substrate and a second solder filling layer on the other side of the ceramic substrate includes: Based on physical vapor deposition, deposit a metal thin film with a preset thickness on both sides of the ceramic substrate through plasma sputtering process to form the first solder filling layer and the second solder filling layer.

[0015] The present invention also provides a power semiconductor device, which includes the above-mentioned metal-ceramic substrate structure and further includes a packaging structure that packages the metal-ceramic substrate structure therein.

[0016] A metal-ceramic substrate structure, manufacturing method and power semiconductor device provided by the present invention at least have the beneficial effects: a circuit layer is provided on one side of the ceramic substrate to achieve the required circuit functions, and a heat dissipation layer is provided on the other side of the ceramic substrate. The heat generated during the operation of the circuit layer is conducted through the ceramic substrate to the heat dissipation layer and dissipated. The heat dissipation layer can improve the heat dissipation performance. The first bonding layer between the ceramic substrate and the circuit layer makes the connection between the circuit layer and the ceramic substrate more stable and reliable. Similarly, the second bonding layer between the ceramic substrate and the heat dissipation layer makes the connection between the ceramic substrate and the heat dissipation layer more stable and reliable. More importantly, by providing a graphene flake ink layer on the heat dissipation layer, the excellent thermal conductivity of graphene is utilized, which is beneficial to further improving the heat dissipation performance and meeting the heat dissipation requirements of semiconductor devices. Description of the Drawings

[0017] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of one of the embodiments of a cermet substrate structure provided by the present invention.

[0019] Figure 2 It is a schematic diagram of the heat dissipation curve of a cermet substrate structure provided by the present invention.

[0020] Figure 3 It is one of the scanning electron microscope diagrams of the graphene flake ink layer in a cermet substrate structure provided by the present invention.

[0021] Figure 4 It is the second scanning electron microscope diagram of the graphene flake ink layer in a cermet substrate structure provided by the present invention.

[0022] Reference numerals: 100: Ceramic substrate; 200: Circuit layer; 300: First bonding layer; 400: Heat dissipation layer; 500: Second bonding layer; 600: Graphene flake ink layer. Detailed embodiments

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0024] The following combines Figure 1 Describe a cermet substrate structure of the present invention, including: Ceramic substrate 100; Circuit layer 200, disposed on one side of the ceramic substrate 100, and a first bonding layer 300 is disposed between the ceramic substrate 100 and the circuit layer 200; Heat dissipation layer 400, disposed on the other side of the ceramic substrate 100, and a second bonding layer 500 is disposed between the ceramic substrate 100 and the heat dissipation layer 400; Graphene flake ink layer 600, disposed on the heat dissipation layer 400.

[0025] On one side of the ceramic substrate 100, a circuit layer 200 is provided to achieve the required circuit functions. On the other side of the ceramic substrate 100, a heat dissipation layer 400 is provided. The heat generated during the operation of the circuit layer 200 is conducted through the ceramic substrate 100 to the heat dissipation layer 400 for dissipation, and the heat dissipation layer 400 can improve the heat dissipation performance. The first bonding layer 300 between the ceramic substrate 100 and the circuit layer 200 makes the connection between the circuit layer 200 and the ceramic substrate 100 more stable and reliable. Similarly, the second bonding layer 500 between the ceramic substrate 100 and the heat dissipation layer 400 makes the connection between the ceramic substrate 100 and the heat dissipation layer 400 more stable and reliable. More importantly, by providing a graphene flake ink layer 600 on the heat dissipation layer 400, and utilizing the excellent thermal conductivity of graphene, it is beneficial to further improve the heat dissipation performance and meet the heat dissipation requirements of semiconductor devices.

[0026] In some embodiments of the present invention, the circuit layer 200 can be formed by processing conductive metals such as copper through a photomask process. The heat dissipation layer 400 can be formed of materials with good heat dissipation performance such as copper plates.

[0027] Reference Figure 2 , in the figure, there are the temperature drop curves of pure copper with a graphene flake ink layer 600 provided on the heat dissipation layer 400 and pure copper without a graphene flake ink layer 600 on the heat dissipation layer 400. In the initial slow cooling stage, the cooling rate of the former is 0.5 °C / s, and the cooling rate of the latter is 0.55 °C / s. In the subsequent rapid cooling stage, the cooling rate of the former is 2.96 °C / s, and the cooling rate of the latter is 1.65 °C / s. By comparison, it can be seen that with the graphene flake ink layer 600 provided, in terms of the cooling rate, the heat dissipation performance is improved by approximately 50%.

[0028] In some embodiments of the present invention, the first bonding layer 300 and the second bonding layer 500 can be formed by mixing active metals such as titanium, silver, and copper in a suitable proportion as a brazing filler metal and processed through an active metal brazing (AMB) process; in some embodiments of the present invention, the first bonding layer 300 and the second bonding layer 500 can also be formed by a direct bonded copper (DBC) process.

[0029] In some embodiments of a metal-ceramic substrate structure of the present invention, the ceramic substrate 100 is made of alumina, aluminum nitride, zirconia-reinforced alumina, or silicon nitride.

[0030] According to different application environments, the ceramic substrate 100 made of alumina, aluminum nitride, zirconia-reinforced alumina or silicon nitride can be selected according to requirements. The thermal conductivity and structural strength of different materials vary. Under the condition of meeting the strength requirements of the use environment, materials with high thermal conductivity should be selected as much as possible to optimize the comprehensive performance of the ceramic substrate 100.

[0031] The ceramic substrate 100 requires excellent thermal conductivity and high strength, but the thermal conductivity and strength have a negative correlation to a certain extent, that is, when one increases, the other will decrease. Among the ceramic materials suitable for heat dissipation, aluminum nitride has the best thermal conductivity of 170 W / mk, but the strength is relatively low, at 500 Mpa; the thermal conductivity of silicon nitride is 90 W / mk, but the strength is as high as 800 MPa. Therefore, the appropriate ceramic substrate 100 is selected based on application requirements to meet the needs of the power semiconductor working environment. If the power semiconductor is in an environment without voltage or vibration influence below 600V, aluminum nitride with strong thermal conductivity can be selected; while in an environment with large voltage or large current and significant vibration influence such as in automobiles and railways, silicon nitride can be selected. Although the thermal conductivity of silicon nitride is lower than that of aluminum nitride, its strength is excellent, which can ensure the stability of the power semiconductor in application scenarios such as electric vehicles, so that modules made of power semiconductors, such as power modules, have higher reliability.

[0032] The following describes a method for manufacturing a metal-ceramic substrate provided by the present invention. The method for manufacturing a metal-ceramic substrate described below can be mutually referred to with the structure of a metal-ceramic substrate described above.

[0033] Reference Figure 1 , the present invention also provides a method for manufacturing a metal-ceramic substrate, which is applied to the above-mentioned metal-ceramic substrate structure and includes: Connect a conductive layer on one side of the ceramic substrate 100, and connect a heat dissipation layer 400 on the other side of the ceramic substrate 100; Coat graphene flake ink on the heat dissipation layer 400, and then perform a drying process to make the graphene flake ink form a graphene flake ink layer 600; Perform a photomask process on the conductive layer to make a circuit pattern, and the conductive layer is converted into a circuit layer 200; Perform a cutting process according to the circuit layer 200 to form the metal-ceramic substrate structure.

[0034] On both sides of the ceramic substrate 100, a conductive layer and a heat dissipation layer 400 are respectively connected. The conductive layer provides a basis for the subsequent fabrication of the circuit layer 200. Through photomask processing, the conductive layer is subjected to processes such as circuit pattern lithography, development, etching, and stripping to convert the conductive layer into the circuit layer 200, realizing the required circuit functions. On the other side of the ceramic substrate 100, there is a heat dissipation layer 400. The heat generated during the operation of the circuit layer 200 is conducted through the ceramic substrate 100 to the heat dissipation layer 400 for dissipation, and the heat dissipation layer 400 can improve the heat dissipation performance. More critically, by coating graphene flake ink on the heat dissipation layer 400 and drying it to form a graphene flake ink layer 600 on the heat dissipation layer 400, the excellent thermal conductivity of graphene is utilized to further improve the heat dissipation performance and meet the heat dissipation requirements.

[0035] In some embodiments of the present invention, the drying treatment of the graphene flake ink can specifically be: drying for 10 to 60 minutes within the range of 200 to 300 degrees Celsius and then drying at room temperature for 1 to 3 hours. The scanning electron microscope photos of the graphene flakes after drying are as Figure 3 and Figure 4 shown.

[0036] It can be understood that during actual processing, on the initial complete cermet substrate, the circuit layer 200 includes multiple identical circuit modules. By performing cutting processing according to the circuit layer 200, it is divided into individual circuit modules, corresponding to form multiple cermet substrate structures. In some embodiments of the present invention, the cutting processing can be achieved by means such as laser cutting.

[0037] In some embodiments of a method for fabricating a cermet substrate of the present invention, the graphene flake ink is obtained by the following method: Crush graphite to obtain powdered graphite; Irradiate the powdered graphite with high-energy electron beams to convert the powdered graphite into graphene flakes; Crush the graphene flakes to form graphene flake particles; Mix and stir a solvent, a binder, and the graphene flake particles to form a first mixture; Add a resin and a dispersant to the first mixture to form a second mixture; Perform three-roll grinding treatment, stirring treatment, and nano-dispersion treatment on the second mixture to obtain the graphene flake ink.

[0038] The graphite is crushed into a powdery form to obtain powdered graphite. After being irradiated by high-energy electron beams, the powdered graphite is explosively exfoliated by electron radiation to form graphene flakes. After the graphene flakes are crushed into particles, they are first mixed and stirred with a solvent and a binder to form a first mixture, and then a resin and a dispersant are added to the first mixture to form a second mixture. The resin provides a carrier for forming the graphene flake ink layer 600, and the dispersant makes the graphene flake particles more uniform. Then, through three-roll milling, stirring, and nano-dispersion treatment, the materials are uniformly mixed and dispersed to form graphene flake ink.

[0039] In some embodiments of the present invention, the thickness of the graphene flakes formed by electron radiation is preferably in the range of 5 to 50 nm, and the particle size is preferably in the range of 100 to 200 μm. The graphene flakes can be crushed into graphene flake particles by airjet milling, and the particle size is below 30 μm. The nano-dispersion treatment can be achieved by processing with a nano-dispersion machine.

[0040] In some embodiments of a method for manufacturing a cermet substrate of the present invention, the solvent is ethylene glycol, the resin is polycaprolactone diol and polyester, the graphene flake ink includes 10 to 30 wt% of ethylene glycol, 2 to 10 wt% of polycaprolactone diol, 1 to 10 wt% of polyester, 2 to 10 wt% of graphene flakes, and distilled water. The viscosity of the graphene flake ink is in the range of 500 to 200 cp. The thickness of the graphene flakes in the graphene flake ink is 5 to 50 nm and the average particle size is below 30 μm.

[0041] It can be understood that in some embodiments of the present invention, the solvents and resins used in the graphene flake ink can be of other types, and the proportions can also be adjusted accordingly.

[0042] In some embodiments of a method for manufacturing a cermet substrate of the present invention, after the graphene flake ink is coated on the heat dissipation layer 400 and dried, it further includes: A thermal interface material layer and heat dissipation pins are formed on the heat dissipation layer 400.

[0043] After the graphene flake ink layer 600 is formed on the heat dissipation layer 400, further manufacturing a thermal interface material layer and heat dissipation pins on the heat dissipation layer 400 is beneficial to further improve the heat dissipation efficiency. The graphene flake ink layer 600 is located between the heat dissipation layer 400 and the thermal interface material layer.

[0044] In some embodiments of a method for manufacturing a cermet substrate according to the present invention, connecting a conductive layer to one side of the ceramic substrate 100 and connecting a heat dissipation layer 400 to the other side of the ceramic substrate 100 includes: Forming a first brazing filler layer on one side of the ceramic substrate 100 and forming a second brazing filler layer on the other side of the ceramic substrate 100; Bonding a conductive substrate to one side of the ceramic substrate 100 and bonding a heat dissipation substrate to the other side of the ceramic substrate 100; Based on a brazing process, heating is performed to convert the first brazing filler layer into a first bonding layer 300 and the second brazing filler layer into a second bonding layer 500. The conductive substrate is connected to the ceramic substrate 100 through the first bonding layer 300 to form the conductive layer, and the heat dissipation substrate is connected to the ceramic substrate 100 through the second bonding layer 500 to form the heat dissipation layer 400.

[0045] By providing the first brazing filler layer and the second brazing filler layer and heating based on the brazing process, the first brazing filler layer and the second brazing filler layer are melted and filled between the ceramic substrate 100 and the conductive substrate and between the ceramic substrate 100 and the heat dissipation substrate. After cooling, the first brazing filler layer forms the first bonding layer 300 to reliably connect the ceramic substrate 100 and the conductive substrate, and the conductive substrate serves as the conductive layer. The second brazing filler layer forms the second bonding layer 500 to reliably connect the ceramic substrate 100 and the heat dissipation substrate, and the heat dissipation substrate serves as the heat dissipation layer 400. In this way, by providing the first brazing filler layer and the second brazing filler layer and processing to form the first bonding layer 300 and the second bonding layer 500 based on the brazing process, the connection between the ceramic substrate 100 and the conductive layer and the heat dissipation layer 400 is made more stable and reliable, avoiding the situation of easy separation and peeling caused by the poor compatibility between the materials of the conductive layer, the heat dissipation layer 400 and the ceramic substrate 100, which is beneficial to improving the reliability of the overall structure.

[0046] In some embodiments of the present invention, the first brazing filler layer and the second brazing filler layer can be formed by metals with excellent thermal conductivity such as titanium, silver, copper, gold, and aluminum in a certain proportion. For example, about 70% silver, about 30% copper, and 1% to 2% titanium can be formed. The first bonding layer 300 and the second bonding layer 500 have excellent thermal conductivity to be able to quickly conduct heat.

[0047] In some embodiments of the present invention, the thickness of the first bonding layer 300 and the second bonding layer 500 can be 0.3 to 1 mm. In some embodiments of the present invention, the conductive substrate and the heat dissipation substrate can be implemented using materials such as copper.

[0048] In some embodiments of the present invention, in addition to brazing, the connection between the ceramic substrate 100 and the conductive substrate and the heat dissipation substrate can also be achieved through direct copper bonding, so as to form a conductive layer and a heat dissipation layer 400.

[0049] Due to the difference in the thermal expansion coefficients of the ceramic substrate 100, the conductive substrate, and the heat dissipation substrate, for example, the thermal expansion coefficient of copper is about 6 times that of ceramics, a large shear stress will be generated at high temperatures. Excessive temperature leads to excessive shear stress, which will cause problems such as cracks and damage to the ceramic substrate 100. Therefore, when heating based on the brazing process, the temperature needs to be controlled within a suitable range. In some embodiments of the present invention, the maximum temperature range is 850°C to 900°C.

[0050] As an implementation manner of forming the first brazing filler layer and the second brazing filler layer, in some embodiments of a method for manufacturing a metal-ceramic substrate of the present invention, forming the first brazing filler layer on one side of the ceramic substrate 100 and forming the second brazing filler layer on the other side of the ceramic substrate 100 includes: Coating the two sides of the ceramic substrate 100 with a metal mixed paste to form the first brazing filler layer and the second brazing filler layer; Wherein, the metal mixed paste is formed by mixing brazing filler metal powder, solvent, and binder.

[0051] Forming the first brazing filler layer and the second brazing filler layer by coating with a metal mixed paste is simple in processing and is beneficial to improving processing efficiency.

[0052] In some embodiments of the present invention, the powder of brazing filler metals such as titanium, silver, and copper can be configured in a certain proportion and mixed with a solvent and a binder to form a metal mixed paste.

[0053] As another implementation manner of forming the first brazing filler layer and the second brazing filler layer, in some embodiments of a method for manufacturing a metal-ceramic substrate of the present invention, forming the first brazing filler layer on one side of the ceramic substrate 100 and forming the second brazing filler layer on the other side of the ceramic substrate 100 includes: Based on physical vapor deposition, depositing a metal thin film with a preset thickness on both sides of the ceramic substrate 100 through a plasma sputtering process to form the first brazing filler layer and the second brazing filler layer.

[0054] Through the plasma sputtering process, the target metal can be evaporated and deposited on the ceramic substrate 100 to form a metal thin film, which serves as the first brazing filler layer and the second brazing filler layer. The first brazing filler layer and the second brazing filler layer formed by the plasma sputtering process are more tightly and reliably bonded to the ceramic substrate 100, which is beneficial to the subsequent formation of the first bonding layer 300 and the second bonding layer 500, and improves the connection stability and reliability between the ceramic substrate 100 and the conductive layer and the heat dissipation layer 400. Moreover, based on the plasma sputtering process, thinner first bonding layer 300 and second bonding layer 500 can be formed, which is beneficial to further improving the heat dissipation performance.

[0055] In some embodiments of the present invention, a single-layer titanium or a composition ratio of a two-component system of titanium-silver, or a composition ratio of a three-component system of titanium-silver-copper, etc. can be adopted to form the first brazing filler layer and the second brazing filler layer.

[0056] In the case where the first brazing filler layer and the second brazing filler layer are formed by a metal mixed paste, the thickness of the subsequently formed first bonding layer 300 and second bonding layer 500 is approximately 10 to 15 μm; in the case where the first brazing filler layer and the second brazing filler layer are formed by plasma sputtering, the thickness of the subsequently formed first bonding layer 300 and second bonding layer 500 is in the range of approximately 1 μm to 5 μm, and even below 1 μm.

[0057] A power semiconductor device provided by the present invention will be described below. A power semiconductor device described below can be mutually referred to in correspondence with a metal-ceramic substrate structure and a method for manufacturing a metal-ceramic substrate described above.

[0058] The present invention also provides a power semiconductor device, including the above-mentioned metal-ceramic substrate structure, and further including a packaging structure that encapsulates the metal-ceramic substrate structure therein.

[0059] The packaging structure encapsulates the above-mentioned metal-ceramic substrate structure. In the metal-ceramic substrate structure, a circuit layer 200 is provided on one side of the ceramic substrate 100 to achieve the required circuit functions, and a heat dissipation layer 400 is provided on the other side of the ceramic substrate 100. The heat generated during the operation of the circuit layer 200 is conducted through the ceramic substrate 100 to the heat dissipation layer 400 for dissipation, and the heat dissipation layer 400 can improve the heat dissipation performance. The first bonding layer 300 between the ceramic substrate 100 and the circuit layer 200 makes the connection between the circuit layer 200 and the ceramic substrate 100 more stable and reliable. Similarly, the second bonding layer 500 between the ceramic substrate 100 and the heat dissipation layer 400 makes the connection between the ceramic substrate 100 and the heat dissipation layer 400 more stable and reliable. More importantly, by providing a graphene thin film ink layer 600 on the heat dissipation layer 400, taking advantage of the excellent thermal conductivity of graphene, it is beneficial to further improve the heat dissipation performance and meet the heat dissipation requirements of the power semiconductor device.

[0060] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0061] In the description of this specification, the descriptions with reference to the terms "an embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0062] All actions of obtaining signals, information, or data in this application are carried out on the premise of complying with the corresponding data protection regulations and policies of the location and with the authorization given by the owner of the corresponding device.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cermet substrate structure, characterized in that, Comprising: A ceramic substrate (100); A circuit layer (200), disposed on one side of the ceramic substrate (100), and a first bonding layer (300) is provided between the ceramic substrate (100) and the circuit layer (200); A heat dissipation layer (400), disposed on the other side of the ceramic substrate (100), and a second bonding layer (500) is provided between the ceramic substrate (100) and the heat dissipation layer (400); A graphene flake ink layer (600), disposed on the heat dissipation layer (400).

2. The metal-ceramic substrate structure according to claim 1, characterized in that, The ceramic substrate (100) is made of alumina, aluminum nitride, zirconia-reinforced alumina or silicon nitride.

3. A method for manufacturing a cermet substrate, characterized in that, Applied to a cermet substrate structure as described in claim 1 or 2, comprising: Connecting a conductive layer to one side of the ceramic substrate (100), and connecting a heat dissipation layer (400) to the other side of the ceramic substrate (100); Coating the heat dissipation layer (400) with graphene flake ink, and then performing a drying process to form the graphene flake ink layer (600); Performing a photomask process on the conductive layer to fabricate a circuit pattern, and converting the conductive layer into a circuit layer (200); Performing a cutting process according to the circuit layer (200) to form the cermet substrate structure.

4. The manufacturing method of a cermet substrate according to claim 3, characterized in that The graphene flake ink is obtained by the following method: Crushing graphite to obtain powdered graphite; Irradiating the powdered graphite with high-energy electron beams to convert the powdered graphite into graphene flakes; Crushing the graphene flakes to form graphene flake particles; Mixing and stirring a solvent, a binder and the graphene flake particles to form a first mixture; Adding a resin and a dispersant to the first mixture to form a second mixture; Performing three-roll grinding, stirring and nano-dispersion processes on the second mixture to obtain the graphene flake ink.

5. The manufacturing method of a cermet substrate according to claim 4, characterized in that The solvent is ethylene glycol, the resin is polycaprolactone diol and polyester, the graphene flake ink comprises 10 to 30 wt% of ethylene glycol, 2 to 10 wt% of polycaprolactone diol, 1 to 10 wt% of polyester, 2 to 10 wt% of graphene flakes and distilled water, the viscosity of the graphene flake ink is in the range of 500 to 200 cp, and the thickness of the graphene flakes in the graphene flake ink is 5 to 50 nm and the particle size is on average below 30 uml.

6. The manufacturing method of a cermet substrate according to claim 3, characterized in that, After coating the graphene flake ink on the heat dissipation layer (400) and performing a drying process, it further comprises: Forming a thermal interface material layer and heat dissipation pins on the heat dissipation layer (400).

7. A method for manufacturing a cermet substrate according to claim 3, characterized in that, The connecting a conductive layer to one side of the ceramic substrate (100) and connecting a heat dissipation layer (400) to the other side of the ceramic substrate (100) comprises: Forming a first brazing filler layer on one side of the ceramic substrate (100), and forming a second brazing filler layer on the other side of the ceramic substrate (100); Bonding a conductive substrate to one side of the ceramic substrate (100), and bonding a heat dissipation substrate to the other side of the ceramic substrate (100); Heat is applied based on the brazing process to convert the first brazing filler layer into the first bonding layer (300) and the second brazing filler layer into the second bonding layer (500). The conductive substrate is connected to the ceramic substrate (100) through the first bonding layer (300) to form the conductive layer, and the heat dissipation substrate is connected to the ceramic substrate (100) through the second bonding layer (500) to form the heat dissipation layer (400).

8. A method for fabricating a cermet substrate according to claim 7, wherein Forming a first brazing filler layer on one side of the ceramic substrate (100) and a second brazing filler layer on the other side of the ceramic substrate (100) includes: Coating metal mixed paste on both sides of the ceramic substrate (100) to form the first brazing filler layer and the second brazing filler layer; Among them, the metal mixed paste is formed by mixing brazing filler metal powder, solvent, and binder.

9. The manufacturing method of a cermet substrate according to claim 7, characterized in that Forming a first brazing filler layer on one side of the ceramic substrate (100) and a second brazing filler layer on the other side of the ceramic substrate (100) includes: Based on physical vapor deposition, depositing a metal thin film with a preset thickness on both sides of the ceramic substrate (100) through a plasma sputtering process to form the first brazing filler layer and the second brazing filler layer.

10. A power semiconductor device, characterized in that, A metal-ceramic substrate structure according to claim 1 or 2, further comprising a packaging structure that packages the metal-ceramic substrate structure therein.

Images