A silicon carbide diamond composite liner plate and a preparation method thereof

Abstract

The application discloses a silicon carbide diamond composite lining plate and a preparation method thereof, and relates to the technical field of semiconductors. The silicon carbide diamond composite lining plate comprises a silicon carbide base, a diamond layer, a metallurgical bonding metal layer, an insulating ceramic layer and a copper layer. The preparation method comprises the following steps: step one, surface treatment is performed on the silicon carbide base to form a plurality of pits; step two, the diamond layer is formed by depositing the diamond on one side of the silicon carbide base provided with the pits; step three, the metallurgical bonding metal layer is formed on the diamond layer, and the contact position of the diamond layer and the metallurgical bonding metal layer forms a carbide layer; step four, the insulating ceramic layer is formed on the metallurgical bonding metal layer, and the ceramic particles of the insulating ceramic layer can enter the metallurgical bonding metal layer; and step five, the copper layer is arranged on the insulating ceramic layer, and the copper layer is etched to obtain the silicon carbide diamond composite lining plate. The application solves the problems of poor insulation, poor bending resistance and poor thermal shock resistance of the silicon carbide lining plate.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a silicon carbide diamond composite substrate and its preparation method. Background Technology

[0002] In chip packaging, especially in the design and manufacturing process of power semiconductor chips, ceramic substrates are often the primary factor limiting the high-power operation of chips or modules. Currently, common ceramic substrates, such as alumina and silicon nitride, have low thermal conductivity, making it difficult to meet the ever-increasing heat dissipation requirements of chips.

[0003] Silicon carbide wafers or silicon carbide composite ceramic materials possess high thermal conductivity. However, silicon carbide materials have poor insulation properties, making it difficult to meet the high insulation requirements of ceramic substrates. Under high voltage fluctuations, the substrate is prone to breakdown, leading to the failure of the entire module. Therefore, silicon carbide substrates have the problem of insufficient insulation to meet usage requirements. In addition, silicon carbide substrates have poor bending resistance and poor thermal shock resistance, which can easily lead to cracks or breakage in the substrate during subsequent packaging stages or actual environmental testing. Summary of the Invention

[0004] The purpose of this invention is to provide a silicon carbide diamond composite liner and its preparation method, which solves the problems of poor insulation, poor bending resistance, and poor thermal shock resistance of silicon carbide liners.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] The present invention provides a silicon carbide diamond composite liner, comprising: a silicon carbide substrate, and at least on one side of the silicon carbide substrate, a diamond layer, a metallurgical bonding metal layer, an insulating ceramic layer and a copper layer are sequentially disposed from the side closer to the silicon carbide substrate to the side farther away from the silicon carbide substrate.

[0007] The present invention also provides a method for preparing the silicon carbide diamond composite liner, comprising the following steps:

[0008] Step 1: Perform surface treatment on the silicon carbide substrate to form several pits on the surface of the silicon carbide substrate;

[0009] Step 2: Deposit diamond on the side of the silicon carbide substrate with the pits to form a diamond layer;

[0010] Step 3: A metallurgical bonding metal layer is formed on the diamond layer, and a carbide layer is formed at the contact point between the diamond layer and the metallurgical bonding metal layer.

[0011] Step 4: An insulating ceramic layer is formed on the metallurgical bonding metal layer, and the ceramic particles of the insulating ceramic layer can enter the metallurgical bonding metal layer.

[0012] Step 5: A copper layer is deposited on the insulating ceramic layer, and the copper layer is etched to obtain a silicon carbide diamond composite backing plate.

[0013] In some specific solutions, step one involves texturing the surface of the silicon carbide substrate. The texturing process includes:

[0014] A1, surface cleaning of the silicon carbide substrate;

[0015] A2, using screen printing technology to print adhesive onto the surface of a silicon carbide substrate;

[0016] A3, fixing the optical particles onto the glue;

[0017] A4, using laser etching, etches the areas on the silicon carbide substrate where no adhesive is applied, forming several pits;

[0018] A5, remove glue and optical particles, and perform surface cleaning on the silicon carbide substrate.

[0019] In some specific embodiments, the optical particles in A3 are alumina, zirconium oxide, or silicon dioxide.

[0020] In some specific embodiments, in A3, after the coupling agent is mixed into the optical particles, the optical particles are fixed onto the adhesive.

[0021] In some specific implementations, step three involves bombarding the diamond layer with molten metal.

[0022] In some specific implementations, in step three, the metal of the metallurgical bonding metal layer is titanium, molybdenum, tungsten, chromium, or tantalum.

[0023] In some specific implementations, in step four, oxygen is introduced to oxidize the metal in the metallurgical bonding layer.

[0024] In some specific implementations, step four involves bombarding the metallurgically bonded metal layer with molten ceramic particles.

[0025] In some specific embodiments, in step four, the ceramic particles are yttrium oxide, aluminum oxide, titanium dioxide, molybdenum dioxide, tungsten oxide, chromium trioxide, or tantalum pentoxide.

[0026] The present invention achieves the following technical effects compared to the prior art:

[0027] The silicon carbide-diamond composite liner of this invention uses silicon carbide as the matrix, which is inexpensive and has thermal conductivity suitable for most materials. Diamond and silicon carbide have similar coefficients of thermal expansion; therefore, using a diamond layer as a transition layer can further reduce interfacial thermal stress. By incorporating a diamond layer and an insulating ceramic layer, this invention achieves high thermal conductivity and high insulation in the overall structure. Furthermore, the diamond layer provides the overall structure with high flexural strength and high elastic modulus, significantly improving the overall mechanical properties as a coating. This invention achieves a comprehensive improvement in mechanical, thermal conductivity, insulation, and bonding strength through a diamond layer, a metallurgically bonded metal layer, and an insulating ceramic layer. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a silicon carbide diamond composite liner in some embodiments of the present invention. Figure 1 ;

[0030] Figure 2 for Figure 1 A magnified view of part A;

[0031] Figure 3 This is a schematic diagram of a silicon carbide diamond composite liner in some embodiments of the present invention. Figure 2 ;

[0032] Figure 4 for Figure 3 A magnified view of section B;

[0033] Figure 5 This is a schematic diagram illustrating the preparation method of silicon carbide diamond composite liner in some embodiments of the present invention.

[0034] Figure 6 This is a schematic diagram of a silicon carbide substrate in some embodiments of the present invention;

[0035] Figure 7 This is a schematic diagram of step one of the preparation methods of silicon carbide diamond composite liner in some embodiments of the present invention.

[0036] Figure 8 This is a schematic diagram of step two in the preparation method of silicon carbide diamond composite liner in some embodiments of the present invention.

[0037] Figure 9This is a schematic diagram of step three in the preparation method of silicon carbide diamond composite liner in some embodiments of the present invention.

[0038] Figure 10 This is a schematic diagram of step four in the preparation method of silicon carbide diamond composite liner in some embodiments of the present invention.

[0039] In the diagram: 1-Silicon carbide substrate, 2-Diamond layer, 3-Metallurgical bonding metal layer, 4-Insulating ceramic layer, 5-Copper layer, 6-Pit. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The purpose of this invention is to provide a silicon carbide diamond composite liner and its preparation method, which solves the problems of poor insulation, poor bending resistance, and poor thermal shock resistance of silicon carbide liners.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Example 1

[0044] like Figures 1 to 4As shown, this embodiment provides a silicon carbide diamond composite liner, comprising: a silicon carbide substrate 1, and at least on one side of the silicon carbide substrate 1, a diamond layer 2, a metallurgical bonding metal layer 3, an insulating ceramic layer 4, and a copper layer 5 sequentially disposed from the side closest to the silicon carbide substrate 1 to the side furthest from the silicon carbide substrate 1. The silicon carbide diamond composite liner of this embodiment can, as needed, have the diamond layer 2, metallurgical bonding metal layer 3, insulating ceramic layer 4, and copper layer 5 sequentially disposed on one side of the silicon carbide substrate 1, or it can have the diamond layer 2, metallurgical bonding metal layer 3, insulating ceramic layer 4, and copper layer 5 disposed on both sides of the silicon carbide substrate 1. The silicon carbide diamond composite liner of this embodiment uses silicon carbide as the substrate, which is inexpensive, and its thermal conductivity meets the requirements of most materials. Since diamond and silicon carbide have similar coefficients of thermal expansion, using the diamond layer 2 as a transition layer can further reduce interfacial thermal stress. This embodiment, by incorporating a diamond layer 2 and an insulating ceramic layer 4, enables the overall structure to possess high thermal conductivity and high insulation. Furthermore, the diamond layer 2 provides the overall structure with high flexural strength and high elastic modulus, significantly enhancing the overall mechanical properties as a coating. This embodiment achieves a comprehensive improvement in mechanical, thermal conductivity, insulation, and bonding strength through the diamond layer 2, the metallurgically bonded metal layer 3, and the insulating ceramic layer 4.

[0045] In practical applications, the thermal conductivity and insulation properties of the silicon carbide diamond composite liner in this embodiment can be adjusted by adjusting the thickness of the diamond layer 2 and the insulating ceramic layer 4.

[0046] Example 2

[0047] like Figures 1 to 10 The present embodiment provides a method for preparing a silicon carbide diamond composite liner according to Embodiment 1, including the following steps:

[0048] Step 1: Surface treatment is performed on the silicon carbide substrate 1 to form several pits 6 on the surface of the silicon carbide substrate 1. The pits 6 increase the contact area between the silicon carbide substrate 1 and the diamond, thereby increasing the mechanical interlocking force between the diamond layer 2 and the silicon carbide substrate 1. Furthermore, based on the chemical bond between the diamond and silicon carbide, the bonding force between the diamond layer 2 and the silicon carbide substrate 1 is further increased.

[0049] Step 2: Deposit diamond on the side of silicon carbide substrate 1 where the pit 6 is provided to form diamond layer 2. Diamond layer 2 serves as a transition insulating layer, which can further reduce interfacial thermal stress.

[0050] Step 3: A metallurgical bonding metal layer 3 is formed on the diamond layer 2. A carbide layer is formed at the contact position between the diamond layer 2 and the metallurgical bonding metal layer 3, and a metallurgical bond is formed between the diamond layer 2 and the metallurgical bonding metal layer 3.

[0051] Step four: An insulating ceramic layer 4 is formed on the metallurgical bonding metal layer 3. The ceramic particles of the insulating ceramic layer 4 can enter the metallurgical bonding metal layer 3. In this embodiment, a metallurgical bonding metal layer 3 is set between the diamond layer 2 and the insulating ceramic layer 4, so that the metallurgical bonding metal layer 3 is bonded to the diamond layer 2 and the insulating ceramic layer 4 respectively, thereby improving the bonding force between the insulating ceramic layer 4 and the diamond layer 2.

[0052] Step 5: A copper layer 5 is deposited on the insulating ceramic layer 4, and the copper layer 5 is etched to obtain a silicon carbide diamond composite substrate.

[0053] In some specific embodiments, the silicon carbide substrate 1 is conductive silicon carbide, semi-insulating silicon carbide, silicon carbide composite material, or silicon carbide wafer. On the surface of the silicon carbide substrate 1, pits 6 can be prepared by means of reactive etching, laser patterning etching, etc., and the bonding force between the silicon carbide substrate 1 and the diamond layer 2 is enhanced based on this structure.

[0054] In some specific embodiments, in step one, the silicon carbide substrate 1 undergoes surface texturing treatment. The texturing treatment process includes:

[0055] A1. Surface cleaning of silicon carbide substrate 1 is performed; specifically, ultrasonic cleaning is performed sequentially using acetone (5 min), anhydrous ethanol (5 min), and deionized water, followed by drying with nitrogen gas.

[0056] A2. The adhesive is printed onto the surface of the silicon carbide substrate 1 using screen printing technology. Specifically, a ceramic high-temperature adhesive is selected, which is resistant to high temperatures of 200℃-500℃ and has a viscosity of 500mPa·s-2000mPa·s. The adhesive is printed onto the surface of the silicon carbide substrate 1 using a precision screen printing machine. The amount of adhesive applied is about 0.8mL-2mL on a 100×100mm silicon carbide substrate 1. The printing speed is 60mm / s-100mm / s. After printing, the substrate is left to stand for 5 minutes to allow the adhesive to flow and level naturally, reducing burrs on the edges of the adhesive.

[0057] A3. Fixing optical particles onto the adhesive; specifically, ceramic particles with a particle size of 1μm-10μm, such as alumina (Al2O3), zirconium oxide (ZrO2), silicon dioxide (SiO2), etc., with an optical transmittance of 40%-70%, are used. After vacuum drying, 1%-5% of silane coupling agent is mixed into the optical particles to improve compatibility with the adhesive. The optical particles are evenly coated onto the adhesive using methods such as sprinkling, scraping, suspension spraying, and compaction, and excess optical particles are blown away. A segmented heating and heat preservation method is used to avoid excessively rapid heating that could cause bubbles or interface cracking, so that the adhesive is cured at high temperature, fixing the optical particles onto the surface of the silicon carbide substrate 1.

[0058] A4. Using laser etching, the areas on the silicon carbide substrate 1 where no adhesive is applied are etched to form several pits 6. The density of the pits 6 is 10. 3 pcs / mm 2 -10 4 pcs / mm 2 Specifically, an ultraviolet, infrared, or fiber laser etching machine is used, with a spot size of 5μm-10μm, a power of 5W-30W, and a scanning speed of 500m / s-1500m / s. The silicon carbide substrate 1 with optical particles is placed under the laser galvanometer, and relevant laser parameters are set for ultrafast laser etching. Due to the presence of transparent optical particles in some areas, the laser is further refracted on the surface of the optical particles, resulting in a reduction in the laser focal length. This significantly reduces the etching effect in areas where optical particles form a grating, thereby achieving the formation of a high-density array of micro-pits 6 in areas where no optical particles are present. The density of the pits 6 can be adjusted according to the particle size of the selected optical particles, achieving a grating-like effect, with an etching depth of 1μm-20μm.

[0059] A5, remove the adhesive and optical particles, and clean the surface of the silicon carbide substrate 1; specifically, place the etched silicon carbide substrate 1 in a descaling agent for adhesive removal, and after completely removing the printed adhesive and optical particles, place it in acetone and ethanol for ultrasonic cleaning.

[0060] In some specific embodiments, in step two, a layer of diamond is deposited on the side of the silicon carbide substrate 1 where the pit 6 is provided, based on diamond growth methods such as direct current jet chemical vapor deposition, hot filament chemical vapor deposition, microwave plasma chemical vapor deposition, etc., and the thickness of the diamond layer 2 is 1μm-300μm.

[0061] In some specific embodiments, in step three, the metallurgical bonding metal layer 3 includes, but is not limited to, metals capable of forming strong carbides, such as titanium, molybdenum, tungsten, chromium, or tantalum. Based on physical vapor deposition, plasma spraying equipment, evaporation equipment, etc., the metallurgical bonding metal layer 3 is prepared on the diamond layer 2. The molten metal, which is molten at high temperature and moves at high speed, bombards the diamond layer 2. After the reaction, a gradually transitioning carbide layer is formed, forming a good metallurgical bond and improving the interfacial bonding force between the diamond layer 2 and the metallurgical bonding metal layer 3.

[0062] In some specific embodiments, in step four, oxygen is introduced to oxidize the metal in the metallurgical bonded metal layer 3. This oxidation, combined with the diamond layer 2 and the insulating ceramic layer 4, improves the overall insulation. Molten ceramic particles are used to bombard the metallurgical bonded metal layer 3. The ceramic particles are yttrium oxide, aluminum oxide, or metal oxides that can form a stable transition carbide layer, such as titanium dioxide, molybdenum dioxide, tungsten oxide, chromium trioxide, or tantalum pentoxide. Specifically, insulating oxides are prepared on the metallurgical bonded metal layer 3 using physical vapor deposition, plasma spraying equipment, or vapor deposition equipment to construct the insulating ceramic layer 4. This method offers fast preparation speed and low cost. In this embodiment, by adjusting the oxygen composition, the transition from a composite metal to a metal oxide in the metallurgical bonded metal layer 3 can be achieved.

[0063] In some specific embodiments, when the ceramic particles are alumina, in step five, based on the DBC (Direct Bonded Copper) process, thermal oxidation is performed on the lower surface of the copper layer 5, and it is attached to the insulating ceramic layer 4 under a certain pressure to form a silicon carbide-based insulating ceramic copper-clad board. The patterned silicon carbide diamond composite backing board is obtained through an etching process.

[0064] In some specific embodiments, the ceramic particles of the insulating ceramic layer 4 can not only serve as an insulating layer, but also, in conjunction with the existing copper thermal oxidation process, form eutectic bonds with copper to directly prepare a silicon carbide-based ceramic copper-clad laminate with good adhesion.

[0065] In the description of this invention, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0066] In the description of this invention, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0067] If this invention discloses or relates to components or structural parts that are fixedly connected to each other, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws) or a non-detachable fixed connection (e.g., riveting, welding). Of course, a fixed connection can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0068] In addition, unless otherwise stated, the terms used in any of the technical solutions disclosed in this invention to indicate positional relationships or shapes include states or shapes that are similar to, close to, or approximate with those states or shapes.

[0069] Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured by a one-piece molding process.

[0070] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only used to complement the content disclosed in the specification, so as to enable those skilled in the art to understand and read them, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0071] It should also be noted that in the embodiments of this application, the same reference numerals are used to denote the same component or the same part.

[0072] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0073] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for preparing a silicon carbide diamond composite liner, characterized in that: Includes the following steps: Step 1: Perform surface treatment on the silicon carbide substrate to form several pits on the surface of the silicon carbide substrate. Step 2: Deposit diamond on the side of the silicon carbide substrate with the pits to form a diamond layer; Step 3: A metallurgical bonding metal layer is formed on the diamond layer, and a carbide layer is formed at the contact point between the diamond layer and the metallurgical bonding metal layer. Step 4: An insulating ceramic layer is formed on the metallurgical bonding metal layer, and the ceramic particles of the insulating ceramic layer can enter the metallurgical bonding metal layer. Step 5: A copper layer is deposited on the insulating ceramic layer, and the copper layer is etched to obtain a silicon carbide diamond composite backing plate.

2. The preparation method according to claim 1, characterized in that: In step one, the silicon carbide substrate undergoes surface texturing treatment. The texturing process includes: A1, surface cleaning of the silicon carbide substrate; A2, using screen printing technology to print adhesive onto the surface of a silicon carbide substrate; A3, fixing the optical particles onto the glue; A4, using laser etching, etches the areas on the silicon carbide substrate where no adhesive is applied, forming several pits; A5, remove glue and optical particles, and perform surface cleaning on the silicon carbide substrate.

3. The preparation method according to claim 2, characterized in that: In A3, the optical particles are aluminum oxide, zirconium oxide, or silicon dioxide.

4. The preparation method according to claim 2, characterized in that: In A3, after the coupling agent is mixed into the optical particles, the optical particles are fixed on the adhesive.

5. The preparation method according to claim 1, characterized in that: In step three, molten metal is used to bombard the diamond layer.

6. The preparation method according to claim 1, characterized in that: In step three, the metal of the metallurgical bonding metal layer is titanium, molybdenum, tungsten, chromium, or tantalum.

7. The preparation method according to claim 1, characterized in that: In step four, oxygen is introduced to oxidize the metal in the metallurgical bonding layer.

8. The preparation method according to claim 1, characterized in that: In step four, molten ceramic particles are used to bombard the metallurgically bonded metal layer.

9. The preparation method according to claim 1, characterized in that: In step four, the ceramic particles are yttrium oxide, aluminum oxide, titanium dioxide, molybdenum dioxide, tungsten oxide, chromium trioxide, or tantalum pentoxide.

10. A silicon carbide diamond composite liner prepared by any one of claims 1-9, characterized in that: include: A silicon carbide substrate, and at least on one side of the silicon carbide substrate, a diamond layer, a metallurgical bonding metal layer, an insulating ceramic layer, and a copper layer are sequentially disposed from the side closest to the silicon carbide substrate to the side furthest from the silicon carbide substrate.

Images