Composite structure coated with dissimilar metals or alloys on opposite surfaces of ceramics

Abstract

The present invention provides a composite structure coated with dissimilar metals or alloys on opposite surfaces of a ceramic, comprising: a ceramic substrate; a first metal layer bonded to a first surface of the ceramic substrate; and a second metal layer bonded to a second surface of the ceramic substrate, wherein the first surface and the second surface are located on opposite sides of the ceramic substrate, and the first metal layer and the second metal layer are dissimilar metals or alloys. The composite structure in the present invention can avoid the problem of delamination of the metallized ceramic substrate due to thermal expansion and contraction; in addition, in the composite structure of the present invention, both surfaces of the ceramic substrate can be coated with dissimilar metals, thus achieving both excellent electrical conductivity and heat dissipation performance.

Description

Composite structure with dissimilar metals or alloys coated on opposite surfaces of ceramics Technical Field

[0001] The present invention relates to a composite structure in which opposite surfaces of ceramics are coated with dissimilar metals or alloys, and in particular to a composite structure in which ceramics and dissimilar metals or alloys are joined by a special joining method. Background Art

[0002] In the fields of electronics, aerospace, automobiles, and the chemical industry, surface metallized ceramic materials have a variety of uses and applications. For example, they can be used as electronic components or other composite materials, thereby enabling the components or materials to obtain the excellent properties of metals while retaining the excellent properties of ceramics, such as electrical conductivity, thermal conductivity, heat dissipation, corrosion resistance, and wear resistance.

[0003] A common method for metallizing ceramic substrates is to bond a circuit layer formed of any one of pure aluminum plates, aluminum alloy plates, pure copper plates, and copper alloy plates to one side of the ceramic substrate having an insulating layer, and to bond a metal layer formed of a pure aluminum or aluminum alloy metal plate to the other side of the insulating layer.

[0004] In the above structure, due to the different thermal expansion coefficients of ceramics and various metals (especially aluminum and copper), the different rates and degrees of thermal expansion and contraction of each material can lead to cracking of the ceramic substrate or delamination of the layers. Therefore, to address these issues, conventional techniques typically coat both sides of the ceramic substrate with copper or aluminum.

[0005] However, for high-power components, this structure has the following disadvantages: if aluminum is coated on both sides, the ceramic substrate has poor conductivity. Although it can withstand high voltage, it cannot withstand high current, which can cause the ceramic substrate to crack or delaminate. On the other hand, if copper is coated on both sides, the cost is higher and the weight is heavier.

[0006] Additionally, existing technologies for bonding a metal layer to a ceramic material include a solid phase diffusion method, a high temperature and high pressure furnace process, and an induction heating method.

[0007] The solid-phase diffusion (also known as diffusion bonding) method mainly uses high temperature and high pressure in a vacuum environment to cause plastic deformation of the contact surface of the two metal materials and to make the distance between them reach the atomic spacing, so that the atoms can embed and diffuse with each other, thereby bonding the metal and ceramic materials together.

[0008] The currently known solid phase diffusion method is used for metallization of ceramic substrates because it must be in a vacuum environment (vacuum degree of 10 -7 to 10 -5bar) to pressurize the metal material (the mechanical pressure is 10 2 to 10 3 kg / cm 2 ), requiring extremely high mechanical pressure and expensive equipment, resulting in high costs. Furthermore, during the diffusion bonding process, the metal softens slowly, requiring a long time to form a uniform metallization layer. This results in poor efficiency and makes it unsuitable for mass production. High-temperature, high-pressure (HP) furnace processes require heating the entire furnace cavity, resulting in poor heating efficiency, slow metal softening, and high energy consumption. Furthermore, the design, designed to withstand the extremely high mechanical pressure, limits the space within the furnace, making it difficult to manufacture in large quantities.

[0009] Induction heating, which uses electromagnetic induction to directly heat the solder (metal) or brazing (e.g., brazing copper clad) for bonding, can cause dramatic thermal expansion and contraction, potentially cracking the ceramic substrate. Furthermore, induction heating is only suitable for metals with good electrical conductivity and cannot achieve the desired bonding effect with materials with poor or inferior electrical conductivity.

[0010] In summary, an improved method for metallizing the surface of a ceramic substrate is needed, wherein a composite structure using a special bonding method can solve the problem of cracking of the ceramic substrate during metallization or the problem of delamination and peeling of the composite structure due to thermal expansion and contraction when used as an electronic component.

[0011] Summary of the Invention

[0012] In view of the problems encountered in the prior art, the present invention aims to provide a composite structure in which dissimilar metals or alloys are coated on opposite surfaces of ceramics, wherein the ceramics and the dissimilar metals or alloys are bonded by a special bonding method.

[0013] According to the present invention, a composite structure is provided in which dissimilar metals or alloys are coated on opposite surfaces of a ceramic, comprising: a ceramic substrate; a first metal layer bonded to the first surface of the ceramic substrate; and a second metal layer bonded to the second surface of the ceramic substrate, wherein the first surface and the second surface are located on opposite sides of the ceramic substrate, and the first metal layer and the second metal layer are different types of metals or alloys.

[0014] In one embodiment of the present invention, the material of the ceramic substrate includes one or more of aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxynitride, silicon dioxide, boron nitride, beryllium oxide, and zirconium oxide toughened alumina (ZTA).

[0015] In one embodiment of the present invention, the first metal layer is used for conducting electricity, and the second metal layer is used for heat dissipation.

[0016] In one embodiment of the present invention, the softening temperatures of the first metal layer and the second metal layer are both lower than 2000°C.

[0017] In one embodiment of the present invention, the materials of the first metal layer and the second metal layer independently include one or more of silver, copper, titanium, nickel, aluminum, tin, zinc, tungsten, niobium and vanadium.

[0018] In one embodiment of the present invention, the melting point difference between the first metal layer and the second metal layer exceeds 300°C.

[0019] In one embodiment of the present invention, the thermal expansion coefficients of the first metal layer and the second metal layer are respectively more than twice that of the ceramic substrate.

[0020] In one embodiment of the present invention, the first metal layer and the second metal layer are each bonded to the ceramic substrate using pressure and optionally heating.

[0021] In one embodiment of the present invention, the heating method includes electric heating, infrared quartz tube heating, high frequency induction heating, infrared vacuum heating, arc heating, and magnetron electron beam heating.

[0022] In one embodiment of the present invention, the method of bonding the first metal layer and the second metal layer to the ceramic substrate further includes AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding.

[0023] In summary, the metallization method of the present invention can avoid cracking during ceramic processing, facilitating mass production. It can also prevent delamination of the metallized ceramic substrate due to thermal expansion and contraction when used as an electronic component. Furthermore, the composite structure produced by the metallization method of the present invention, with dissimilar metals coated on both sides of the ceramic substrate, exhibits both excellent electrical conductivity and heat dissipation properties.

[0024] The effects of the present invention are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other effects not mentioned from the description of the scope of claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a perspective view showing a composite structure according to a first embodiment of the present invention;

[0026] FIG2 is a perspective view showing a composite structure according to a second embodiment of the present invention;

[0027] FIG3 is a perspective view showing a composite structure according to a third embodiment of the present invention;

[0028] 4 is a cross-sectional schematic diagram showing a fourth embodiment of the present invention, wherein a ceramic substrate covered with a metallized layer is pressurized;

[0029] 5 is a cross-sectional schematic diagram showing a fifth embodiment of the present invention, wherein a ceramic substrate covered with a metallized layer is pressurized;

[0030] 6 is a cross-sectional schematic diagram showing a sixth embodiment of the present invention, wherein a ceramic substrate covered with a metallization layer is pressurized;

[0031] 7 is a cross-sectional schematic diagram showing a seventh embodiment of the present invention, wherein a ceramic substrate covered with a metallized layer is pressurized;

[0032] FIG8 is a flow chart showing a method for metallizing a surface of a ceramic substrate according to fourth and fifth embodiments of the present invention; and

[0033] FIG. 9 is a flow chart illustrating a method for metallizing a surface of a ceramic substrate according to sixth and seventh embodiments of the present invention.

[0034] [Description of symbols] 10, 10', 10": Ceramic substrate 20, 20', 20": First metal layer 21, 21', 21": Second metal layer 30: First tool 31: Second tool 32: Intermediate tool a, b, c, d, e, f, g, h: Steps a1, b1, b2, c1, c2, c3, d1, f1: Steps Z, Z': Direction DETAILED DESCRIPTION

[0035] Advantages and features of the present invention and methods for implementing the same will be more clearly understood from the embodiments described below with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, but can be implemented in various forms.

[0036] In the absence of any contradiction, the technical features in any embodiment of the present invention may be combined with other embodiments of the present invention.

[0037] 1 , according to a first embodiment of the present invention, a composite structure is provided in which dissimilar metals or alloys are coated on opposing surfaces of a ceramic. The composite structure includes: a ceramic substrate 10 in the form of a flat plate, with its two opposing surfaces having the largest areas defined as an upper surface and a lower surface; a first metal layer 20 bonded to the lower surface of the ceramic substrate 10; and a second metal layer 21 bonded to the upper surface of the ceramic substrate 10.

[0038] The material of the ceramic substrate 10 may include, for example, one or more of aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxynitride, silicon dioxide, boron nitride, beryllium oxide, and zirconium oxide toughened alumina (ZTA).

[0039] The materials of the first metal layer 20 and the second metal layer 21 can each independently include one or more of silver, copper, titanium, nickel, aluminum, tin, zinc, tungsten, niobium, and vanadium. In addition, the materials of the first metal layer 20 and the second metal layer 21 can be different types of metals or alloys.

[0040] In one embodiment of the present invention, the first metal layer 20 may be, for example, copper, for conducting electricity; and the second metal layer 21 may be, for example, aluminum, for dissipating heat.

[0041] The advantages of coating both sides of the ceramic substrate 10 with dissimilar metals are as follows: the copper-coated side can provide excellent current conduction performance for connecting electronic components or wires, while the aluminum-coated side can provide effective heat conduction, conducting and dissipating heat, and improving heat dissipation efficiency.

[0042] The melting points of the first metal layer 20 and the second metal layer 21 differ by more than 300°C.

[0043] Large differences in the melting points of the metal layers can better provide both thermal and electrical conductivity. For example, in components requiring high heat dissipation, metal materials with lower melting points can be selected as heat dissipation layers. Generally speaking, metals with lower melting points have the advantage of higher thermal conductivity. Therefore, the present invention provides a composite structure in which dissimilar metals or alloys are bonded to opposing surfaces of a ceramic substrate 10. This composite structure not only exhibits excellent thermal conductivity but also excellent electrical conductivity.

[0044] The thickness of the ceramic substrate 10 is greater than that of the first metal layer 20 and the second metal layer 21 .

[0045] The softening temperatures of the first metal layer 20 and the second metal layer 21 are both lower than 2000° C., and the thermal expansion coefficients of both are more than twice that of the ceramic substrate 10 .

[0046] In one embodiment of the present invention, the first metal layer 20 and the second metal layer 21 may be bonded to the ceramic substrate 10 using heating and optionally pressurization.

[0047] The heating method may include electric heating, infrared quartz tube heating, high frequency induction heating, infrared vacuum heating, arc heating, and magnetron electron beam heating. An example of a method for heating the laminate will be described below.

[0048] Electric heating

[0049] A method of converting electrical energy into thermal energy for heating. When current passes through a metal conductor, energy is generated due to the collision of electrons in the conductor, which ultimately causes heat generation.

[0050] Infrared quartz tube heating

[0051] The electromagnetic radiation heat is combined with a transparent quartz tube heater. Its working principle is to heat the quartz tube by turning on the power, and transmit the infrared radiation energy to the heated object in the form of thermal radiation.

[0052] High frequency induction heating

[0053] High frequency, also known as high-frequency wave, refers to electromagnetic wave with a frequency greater than 100 kHz. Its working principle is to generate induced current inside the heated object under the action of high-frequency electric field, thereby generating resistive heat.

[0054] Infrared vacuum heating

[0055] Its working principle is to use an infrared radiation heater in a vacuum environment, and the infrared radiation energy generated by the radiation heater directly acts on the heated object.

[0056] Arc heating

[0057] Heat is generated by arc discharge. Arc is achieved by applying voltage between two electrodes to form a current path for gas discharge, producing a strong arc discharge phenomenon, thereby generating high temperature and heat energy.

[0058] Magnetron electron beam heating

[0059] By controlling the high-speed electron beam to collide with the object to be heated, the kinetic energy of the electron beam is converted into thermal energy.

[0060] The pressurizing method is described in detail below with respect to the fourth to seventh embodiments of the present invention.

[0061] Alternatively, the method of bonding the first metal layer 20 and the second metal layer 21 to the ceramic substrate 10 may further include AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding. Examples of methods for bonding the ceramic substrate 10 to the first metal layer 20 or the second metal layer 21 are described below.

[0062] Active Metal Brazing (AMB)

[0063] By adding active metals such as titanium to the solder, the interface between the ceramic and metal can be wetted and reacted, improving the wettability of the ceramic and thus allowing the ceramic substrate to be bonded to the metal.

[0064] Direct Bonded Copper (DBC)

[0065] During the sintering process, oxygen is introduced between copper and ceramic to form a copper-oxygen eutectic liquid, which reacts with the ceramic substrate to generate composite oxides such as CuAlO2 or CuAl2O4 as solder, which wets the interface between the copper foil and the ceramic, thereby bonding the ceramic substrate to the copper.

[0066] Direct Plated Copper (DPC)

[0067] Copper is sputtered onto a ceramic substrate using semiconductor process technology, thereby bonding the ceramic substrate and the copper.

[0068] Direct Bonded Aluminum (DBA)

[0069] The surface of the ceramic substrate is brought into contact with liquid aluminum. At this time, aluminum can quickly wet the ceramic surface, that is, aluminum and ceramic have good wettability, thereby bonding the ceramic substrate and aluminum.

[0070] Friction Welding

[0071] Mechanical friction motion is used to generate heat on the friction surface, and the materials are plastically deformed under the action of frictional heat and pressure to join together.

[0072] Laser Cladding

[0073] A high-power laser is used to heat the substrate, and metal powder is fed into the molten pool formed by the laser beam heating. After the molten metal powder cools down, a layer of other metal material is melted onto the surface of the original substrate.

[0074] Ultrasonic Welding

[0075] Ultrasonic waves refer to sound waves with a frequency exceeding 20 kHz. They are converted into high-frequency signals. Under high-frequency vibration, friction between molecules at the bonding interface generates frictional heat, causing the materials to undergo plastic deformation and bond together.

[0076] 2 , according to a second embodiment of the present invention, a composite structure is provided in which dissimilar metals or alloys are coated on opposing surfaces of a ceramic. The structure includes: a ceramic substrate 10 ′ having a flat plate shape and two opposing surfaces of relatively small areas defined as an upper surface and a lower surface; a first metal layer 20 ′ bonded to the lower surface of the ceramic substrate 10 ′; and a second metal layer 21 ′ bonded to the upper surface of the ceramic substrate 10 ′.

[0077] 3 , according to a third embodiment of the present invention, a composite structure is provided in which dissimilar metals or alloys are coated on opposing surfaces of a ceramic, including: a ceramic substrate 10″ in the shape of a rectangular strip, with two opposing surfaces of relatively larger areas defined as an upper surface and a lower surface, respectively; a first metal layer 20″ bonded to the lower surface of the ceramic substrate 10″; and a second metal layer 21″ bonded to the upper surface of the ceramic substrate 10″.

[0078] Except for the shape of the ceramic substrate and the positions of the bonding surfaces between the first metal layer and the second metal layer and the ceramic substrate, the technical features of the ceramic substrate, the first metal layer, and the second metal layer of the second and third embodiments are respectively the same as the technical features of the ceramic substrate, the first metal layer, and the second metal layer of the first embodiment, and therefore are not repeated here.

[0079] 4 , 5 and 8 , the method for metallizing the surface of a ceramic substrate according to the fourth and fifth embodiments of the present invention will be described in detail. The method can be used to prepare the composite structure according to the first to third embodiments of the present invention.

[0080] The method according to the fourth embodiment of the present invention comprises the following steps:

[0081] a) placing a first metal layer 20 on the lower surface of the ceramic substrate 10;

[0082] b) contacting the other surface of the first metal layer 20 that is not in contact with the ceramic substrate 10 with the first tool 30;

[0083] c) optionally pressing the first metal layer 20 toward the ceramic substrate 10 along the Z direction using the first tool 30; and

[0084] d) Heating the first mold 30 to conduct heat to the first metal layer 20 to metallize the lower surface of the ceramic substrate 10 .

[0085] Step c) is optional, and the pressurizing pressure may be adjusted according to the different materials, or even no pressurization may be performed.

[0086] In step d), the heating method may be the heating method for bonding the metal layer to the ceramic substrate according to the first to third embodiments of the present invention.

[0087] The first tool 30 may be, for example, a laminate and made of a high-resistance conductor, such as one or more of molybdenum, molybdenum alloy, tungsten, tungsten alloy, tantalum, tantalum alloy, graphite, silicon, and silicon carbide.

[0088] In addition, the melting point of the first tool 30 is greater than 2000°C, and no solid solution, diffusion, or eutectic reaction occurs with the first metal layer 20 during the processing. Moreover, the melting point of the first metal layer 20 is lower than 80% of the melting point temperature of the first tool 30. Therefore, the tool can be separated and recycled after the metallization process is completed so as to be reused in the next process, which not only reduces costs but also facilitates mass production.

[0089] As shown in FIG4 , in a fourth embodiment of the present invention, a first metal layer 20 (e.g., aluminum) is covered on the lower surface of a ceramic substrate 10, and a first tool 30 (e.g., a laminate) is fixed under the first metal layer 20. Subsequently, pressure is applied toward the ceramic substrate 10 along the Z direction, and the first tool 30 is heated by electric heating. The heated first tool 30 conducts heat to the first metal layer 20, softening or melting it, and then tightly bonds with or diffuses toward the ceramic substrate 10, thereby achieving metallization of the ceramic substrate 10.

[0090] To prevent adhesion between the tool and the metal layer, the tool can be treated with nickel plating or a release agent. Alternatively, adhesion between the metal layer and the tool or other metal layers can be avoided without heating the metal layer above its melting point.

[0091] In addition, the ceramic substrate 10 is made of a material with high thermal conductivity and high bending strength, so the pressing force required by the present invention is intended to fix the material without destroying the overall structure.

[0092] The fourth embodiment of the present invention described above is an implementation of a composite structure with metal or alloy coated on one side. In the fifth embodiment of the present invention, the opposite surfaces of the ceramic substrate 10 may also be metallized simultaneously or sequentially.

[0093] Therefore, compared to the fourth embodiment, the method according to the fifth embodiment of the present invention may further include the following steps:

[0094] e) placing a second metal layer 21 on the upper surface of the ceramic substrate 10;

[0095] f) contacting the other surface of the second metal layer 21 that is not in contact with the ceramic substrate 10 with the second tool 31;

[0096] g) optionally pressing the second metal layer 21 toward the ceramic substrate 10 along the Z′ direction using a second tool 31 ; and

[0097] h) heating the second mold 31 to conduct heat to the second metal layer 21 , thereby metallizing the upper surface of the ceramic substrate 10 .

[0098] As shown in FIG5 , compared to the fourth embodiment, in the fifth embodiment of the present invention, a second metal layer 21 (e.g., copper) is further coated on the upper surface of the ceramic substrate 10, and a second tool 30 (e.g., another plate) is fixed on top of the second metal layer 21. Then, pressure is applied toward the ceramic substrate 10 along the Z' direction, and the second tool 30 is heated by electric heating. The heated second tool 30 conducts heat to the second metal layer 21, softening or melting it, and then tightly bonds with the ceramic substrate 10 or diffuses toward the ceramic substrate 10, thereby realizing metallization of the ceramic substrate 10.

[0099] Except that both sides of the ceramic substrate 10 are covered with metal or alloy and the joint surface positions of the metal layer and the ceramic substrate are different, the technical features and processing methods of the ceramic substrate, second metal layer, second tool and other components of the fifth embodiment are the same as the technical features and processing methods of the ceramic substrate, first metal layer, first tool and other components of the fourth embodiment, and therefore are not repeated here.

[0100] The fifth embodiment of the present invention described above is an implementation method in which only one composite structure is formed during one metallization process. In the sixth and seventh embodiments of the present invention, multiple composite structures can also be formed during one metallization process to better achieve mass production of composite structures.

[0101] 6, 7 and 9, the following describes in detail the method for metallizing the surface of a ceramic substrate according to the sixth and seventh embodiments of the present invention, which can be used to prepare multiple composite structures according to the first to third embodiments of the present invention at one time.

[0102] The method according to the sixth embodiment of the present invention comprises the following steps:

[0103] a1) arranging a plurality of ceramic substrates 10 in a manner spaced apart from each other in parallel;

[0104] b1) providing a first metal layer 20 on the lower surface of each ceramic substrate 10;

[0105] b2) providing a second metal layer 21 on the upper surface of each ceramic substrate 10;

[0106] c1) making the other surface of the bottom first metal layer 20 that is not in contact with the corresponding ceramic substrate 10 contact the first mold 30;

[0107] c2) contacting the other surface of the uppermost second metal layer 21 that is not in contact with the corresponding ceramic substrate 10 with the second tool 31;

[0108] c3) arranging a plurality of intermediate molds 32 correspondingly between the first metal layer 20 and the second metal layer 21 facing each other between adjacent ceramic substrates 10;

[0109] d1) optionally pressing the ceramic substrates 10 , the first metal layers 20 , and the second metal layers 21 toward the center along the Z direction and the Z′ direction respectively using a first tool 30 and a second tool 31 ; and

[0110] f1) heating the first mold 30 and the second mold 31 to conduct heat to the first metal layers 20 and the second metal layers 21 , thereby metallizing the upper and lower surfaces of each ceramic substrate 10 .

[0111] Generally speaking, step b1) and step b2) can be performed simultaneously or sequentially. Step c1), step c2) and step c3) can be performed simultaneously or sequentially; alternatively, step c3) can be performed between step b2) and step c1), between step c1) and step c2), or between step c2) and step d1).

[0112] The intermediate tool 32 may be the same tool as the first tool 30 and the second tool 31 .

[0113] As shown in FIG6 , in a sixth embodiment of the present invention, a first metal layer 20 and a second metal layer 21 are respectively covered on the lower and upper surfaces of each ceramic substrate 10, and a first tool 30, a second tool 30, and a plurality of intermediate tools 32 are respectively arranged below the lowest first metal layer 20, above the highest second metal layer 21, and between other adjacent first metal layers 20 and second metal layers 21. Then, pressure is applied toward the center along the Z direction and the Z' direction, and the lowest and highest first tools 30 and second tools 30 are heated by electric heating at the same time. The heated first tools 30 and second tools 30 conduct heat to each first metal layer 20 and each second metal layer 21 through the intermediate tools 32 and the ceramic substrate 10 in the middle, thereby softening or melting them, and tightly bonding with the ceramic substrate 10 or diffusing them to the ceramic substrate 10, so as to realize the metallization of multiple ceramic substrates 10 at one time.

[0114] The sixth embodiment of the present invention described above is an implementation method of using an intermediate tool between multiple composite structures. In the seventh embodiment of the present invention, it is also possible not to use an intermediate tool between multiple composite structures to save tooling costs.

[0115] As shown in FIG7 , in the seventh embodiment of the present invention, a metallization method similar to that of FIG6 is used, except that no intermediate tool is required between adjacent metal layers. After heating the bottom and top first tools 30 and second tools 31, heat can be conducted to each metal layer through the ceramic substrate 10 itself, causing the metal layers to melt or melt, and to be tightly bonded to or diffused toward the ceramic substrate 10, thereby achieving metallization of multiple ceramic substrates 10 at one time without setting an intermediate tool.

[0116] In summary, the metallization method of the present invention can avoid cracking during ceramic processing, facilitating mass production. It can also prevent delamination of the metallized ceramic substrate due to thermal expansion and contraction when used as an electronic component. Furthermore, the composite structure produced by the metallization method of the present invention, with dissimilar metals coated on both sides of the ceramic substrate, exhibits both excellent electrical conductivity and heat dissipation properties.

[0117] Those skilled in the art to which the present invention relates will understand that various modifications and changes may be made to the above embodiments without departing from the basic characteristics of the present invention, such as combination, separation, replacement, and configuration change.

[0118] Therefore, the embodiments of the present invention are intended to illustrate the scope of the technical concept of the present invention, and the scope of the present invention is not limited by the above embodiments. Therefore, any modifications or changes made to the present invention under the same inventive spirit should still be included in the scope of protection intended by the present invention.

Claims

1. A composite structure in which the opposite surfaces of a ceramic are coated with dissimilar metals or alloys, comprising: Ceramic substrate; a first metal layer bonded to the first surface of the ceramic substrate; as well as a second metal layer bonded to the second surface of the ceramic substrate, The first surface and the second surface are located at opposite sides of the ceramic substrate, and the first metal layer and the second metal layer are different types of metals or alloys.

2. The composite structure according to claim 1, wherein: The material of the ceramic substrate includes one or more of aluminum oxide, aluminum nitride, silicon carbide, silicon nitride, silicon oxynitride, silicon dioxide, boron nitride, beryllium oxide, and zirconium oxide toughened aluminum oxide.

3. The composite structure according to claim 1, wherein: The first metal layer is used for conducting electricity, and the second metal layer is used for dissipating heat.

4. The composite structure according to claim 1, wherein: The softening temperatures of the first metal layer and the second metal layer are both lower than 2000°C.

5. The composite structure according to claim 1, wherein: The materials of the first metal layer and the second metal layer each independently include one or more of silver, copper, titanium, nickel, aluminum, tin, zinc, tungsten, niobium and vanadium.

6. The composite structure of claim 1, wherein: The melting points of the first metal layer and the second metal layer differ by more than 300°C.

7. The composite structure of claim 1, wherein: The first metal layer and the second metal layer are each bonded to the ceramic substrate using heat and optionally pressure.

8. The composite structure according to claim 7, wherein: The heating methods include electric heating, infrared quartz tube heating, high frequency induction heating, infrared vacuum heating, arc heating, and magnetron electron beam heating.

9. The composite structure according to claim 7, wherein: The method of bonding the first metal layer and the second metal layer to the ceramic substrate further includes AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding.

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