Composite structure with heat dissipation material coated on single surface of ceramic substrate

Abstract

The invention provides a composite structure with a heat dissipation material coated on a single surface of a ceramic substrate. The composite structure comprises the ceramic substrate; a first heat dissipation layer bonded to one surface of the ceramic substrate; and a second heat dissipation layer bonded to the other surface of the first heat dissipation layer that is not in contact with the ceramic substrate. According to the present invention, by using aluminum as the metal of the intermediate layer, it is possible to achieve easy process bonding, and to release waste heat generated in high-power use, thereby achieving the effect of protecting the element. The composite structure of the present invention can achieve excellent heat dissipation characteristics even in harsh environments such as high operating voltage, current, high power, and the like, and facilitates weight reduction and cost reduction.

Description

Technical Field

[0001] The present invention relates to a composite structure with a heat dissipation material coated on one side of a ceramic substrate, and in particular to a composite structure which utilizes a thick aluminum layer as an intermediate layer to effectively connect various layers of an electronic component while maintaining heat dissipation performance. Background Art

[0002] In the fields of electronics, aerospace, automobile, chemical industry, etc., ceramic materials coated with metals, alloys or other materials (such as high thermal conductivity ceramics) have various uses and applications. For example, they can be used as electronic components or other composite materials, so that while retaining the excellent properties of ceramics, the components or materials can additionally obtain the excellent properties of metals, alloys or other materials, such as electrical conductivity, thermal conductivity, heat dissipation, corrosion resistance and wear resistance.

[0003] Especially in the field of electric vehicles, since the electronic components in the electric vehicle system will generate a lot of heat under high voltage, high current and high power use, good heat dissipation performance can effectively increase the service life of the electronic components.

[0004] In the prior art, in order to avoid the problem of substrate cracking or delamination caused by the different thermal expansion coefficients of different metals, alloys or other materials, the two sides of the ceramic substrate are usually covered with the same metal, alloy or other material, such as copper or aluminum, because copper and aluminum have good electrical and thermal conductivity. Among them, copper has better electrical and thermal conductivity than aluminum, so it is theoretically a more ideal metal layer material.

[0005] However, copper metal has disadvantages such as high hardness, difficulty in processing and bonding, heavy weight, easy to peel off, and high cost.

[0006] In comparison, aluminum metal has the advantages of strong activity, easy diffusion bonding, good plasticity, low melting point, soft and easy processing, and light weight, and the cost of aluminum metal is also low. In addition, aluminum metal is also easier to bond with other materials or components, such as copper, aluminum or silicon carbide, or the heat sinks they manufacture, including fins, vapor chambers, and heat sinks.

[0007] Therefore, in view of the above technical bottlenecks, the inventors have developed an improved composite structure of electronic components of electric vehicles using the above material properties. Using aluminum metal as a bonding layer can solve the problem of copper metal being difficult to process and bond and easy to peel off in the prior art, and can also significantly reduce the cost and weight of copper metal. Moreover, although the thermal conductivity of aluminum metal is slightly lower than that of copper, it is still better than other metals, so it is a very ideal alternative material that can effectively dissipate the large amount of heat generated by electronic components of electric vehicles under high voltage, high current and high power use.

[0008] In summary, there is a need for a composite structure with excellent heat dissipation performance to ensure the safety, efficiency and reliability of electronic components during high power operation. Summary of the invention

[0009] In view of the problems encountered in the prior art, the present invention provides an improved composite structure, in which at least two layers of metal, alloy or high thermal conductivity material with excellent heat dissipation are bonded to one side of a ceramic substrate, wherein by using aluminum as the metal of the intermediate layer, the purposes of easy processing and bonding, weight reduction, and cost reduction can be achieved.

[0010] According to the present invention, a composite structure with heat dissipation material coated on one side of a ceramic substrate includes: a ceramic substrate; a first heat dissipation layer bonded to one surface of the ceramic substrate; and a second heat dissipation layer bonded to another surface of the first heat dissipation layer that is not in contact with the ceramic substrate.

[0011] In one embodiment of the present invention, the second heat dissipation layer may be in the form of a plate-shaped, column-shaped or needle-shaped heat-dissipating device.

[0012] In one embodiment of the present invention, the ceramic substrate is first bonded to the first heat dissipation layer, and then the first heat dissipation layer is bonded to the second heat dissipation layer; or, the ceramic substrate, the first heat dissipation layer and the second heat dissipation layer are bonded simultaneously.

[0013] In one embodiment of the present invention, the ceramic substrate is an insulating heat dissipation ceramic substrate.

[0014] In one embodiment of the present invention, the thickness of the first heat dissipation layer is in millimeter order.

[0015] 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).

[0016] In one embodiment of the present invention, a main material of the first heat dissipation layer is aluminum.

[0017] In one embodiment of the present invention, the second heat dissipation layer is composed of a material with a thermal conductivity of 150 W / mk or more, such as aluminum alloy, copper alloy, or high thermal conductivity ceramic (such as silicon carbide). Preferably, the density of the material is less than 4 g / cm3.

[0018] In one embodiment of the present invention, the ceramic substrate and the first heat dissipation layer, and the first heat dissipation layer and the second heat dissipation layer are respectively bonded to each other by heating and optionally pressurizing.

[0019] 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.

[0020] In one embodiment of the present invention, the bonding method further includes AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding.

[0021] In summary, the composite structure of the present invention is a composite structure in which thick aluminum having excellent processing and bonding properties and excellent heat dissipation properties is bonded to a ceramic substrate, and another metal, alloy or high thermal conductivity material having excellent heat dissipation properties is bonded to the thick aluminum layer. This enables the composite structure of the present invention to achieve excellent heat dissipation characteristics even in harsh environments such as high operating voltage, current and high power, and is conducive to lightweighting and cost reduction.

[0022] 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 claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A three-dimensional diagram showing a composite structure in which a double layer of heat dissipation material is coated on one side of a ceramic substrate according to a first embodiment of the present invention;

[0024] Figure 2 It is a three-dimensional diagram showing a composite structure in which a double layer of heat dissipation material is coated on one side of a ceramic substrate and the second heat dissipation layer is a heat spreader according to a second embodiment of the present invention.

[0025] Description of Reference Numerals

[0026] 1: Ceramic substrate

[0027] 10: First heat dissipation layer

[0028] 11,11': Second heat dissipation layer DETAILED DESCRIPTION

[0029] Advantages and features of the present invention and methods of 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.

[0030] 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.

[0031] Reference Figure 1According to a first embodiment of the present invention, a composite structure is provided in which a heat dissipation material is coated on one side of a ceramic substrate, including: a ceramic substrate 1 in a flat plate shape; a first heat dissipation layer 10 bonded to one surface of the ceramic substrate 1; and a second heat dissipation layer 11 bonded to the other surface of the first heat dissipation layer 10 that is not in contact with the ceramic substrate 1.

[0032] The material of the ceramic substrate 1 may be an insulating heat dissipation ceramic substrate, for example, including 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).

[0033] In one embodiment of the present invention, the first heat dissipation layer 10 may be, for example, aluminum, preferably millimeter-level thick aluminum.

[0034] In electronic components for high current use, in addition to the excellent processing and bonding uses as an intermediate layer between the ceramic substrate 1 and the second heat dissipation layer 11 as described above, in order to suppress heat generation when power is supplied, the first heat dissipation layer 10 is preferably made of aluminum metal, which has particularly excellent heat dissipation properties. Therefore, the ceramic substrate 1 bonded with thick aluminum as the first heat dissipation layer 10 can have excellent heat dissipation performance, protect the component from overheating damage, and enhance the reliability and life of the component.

[0035] In one embodiment of the present invention, the second heat dissipation layer 11 may be made of a material with a thermal conductivity of 150 W / mk or more, including but not limited to aluminum alloy, copper alloy, and high thermal conductivity ceramics (such as silicon carbide). More preferably, the thermal conductivity of the material is 150 W / mk or more and the density is less than 4 g / cm 3 , because materials with low density are relatively light, which helps meet the demand for lightweighting.

[0036] In one embodiment of the present invention, the ceramic substrate 1 is first bonded to the first heat dissipation layer 10, and then the first heat dissipation layer 10 is bonded to the second heat dissipation layer 11; or, the ceramic substrate 1, the first heat dissipation layer 10 and the second heat dissipation layer 11 can be bonded simultaneously.

[0037] The bonding method using the first heat dissipation layer 10 whose main material is aluminum as the intermediate layer has the following advantages: first, aluminum is highly active and easily diffusible to the ceramic substrate, and can be evenly attached to the ceramic substrate, which helps to improve the bonding strength; second, aluminum has good plasticity and a low melting point, which helps the processing process; third, aluminum is light in weight, which can reduce the weight of the entire electronic component, especially in weight-sensitive applications such as portable electronic devices and automobiles; fourth, aluminum has a lower cost.

[0038] The ceramic substrate 1 and the first heat dissipation layer 10 , and the first heat dissipation layer 10 and the second heat dissipation layer 11 are each bonded to each other using heating and optionally pressure.

[0039] In an embodiment where the ceramic substrate 1 is first bonded to the first heat dissipation layer 10 and then the first heat dissipation layer 10 is bonded to the second heat dissipation layer 11, the bonding method may include the following steps:

[0040] a) placing a first heat dissipation layer 10 on the lower surface of the ceramic substrate 1;

[0041] b) contacting the other surface of the first heat dissipation layer 10 that is not in contact with the ceramic substrate 1 with the mold;

[0042] c) optionally pressurizing the first heat dissipation layer 10 toward the ceramic substrate 1 through a tool;

[0043] d) heating the mold to conduct heat to the first heat dissipation layer 10 so that the lower surface of the ceramic substrate 1 is bonded to the first heat dissipation layer 10;

[0044] e) placing the second heat dissipation layer 11 on the lower surface of the first heat dissipation layer 10 which is not in contact with the ceramic substrate 1;

[0045] f) contacting the other surface of the second heat dissipation layer 11 that is not in contact with the first heat dissipation layer 10 with the mold;

[0046] g) optionally pressurizing the second heat dissipation layer 11 toward the first heat dissipation layer 10 on the ceramic substrate 1 through a tool;

[0047] h) heating the mold to transfer the heat to the second heat dissipation layer 11 , so that the first heat dissipation layer 10 and the second heat dissipation layer 11 are bonded together.

[0048] In addition, in the embodiment where the ceramic substrate 1, the first heat dissipation layer 10 and the second heat dissipation layer 11 are bonded simultaneously, the bonding method may include the following steps:

[0049] a') placing a first heat dissipation layer 10 on the lower surface of the ceramic substrate 1;

[0050] b′) placing the second heat dissipation layer 11 on the lower surface of the first heat dissipation layer 10 that is not in contact with the ceramic substrate 1;

[0051] c') contacting the other surface of the second heat dissipation layer 11 that is not in contact with the first heat dissipation layer 10 with the mold;

[0052] d′) optionally pressurizing the second heat dissipation layer 11 and the first heat dissipation layer 10 toward the ceramic substrate 1 through a tool;

[0053] e′) heating the mold to transfer heat to the second heat dissipation layer 11 and the first heat dissipation layer 10 , so that the ceramic substrate 1 , the first heat dissipation layer 10 and the second heat dissipation layer 11 are bonded simultaneously.

[0054] In one embodiment of the present invention, the tool can be, for example, a laminate, which is made of a conductor and does not produce solid solution, diffusion, and eutectic reaction with the first heat dissipation layer 10 and the second heat dissipation layer 11 during the processing, and the melting point of the first heat dissipation layer 10 and the second heat dissipation layer 11 is lower than 80% of the melting point temperature of the tool.

[0055] In addition, in order to prevent adhesion between the tool and the metal layer, the tool can be first subjected to surface treatment such as nickel plating or coating with a release agent. Alternatively, adhesion between the metal layer and the tool can be avoided without heating the metal layer above its melting point.

[0056] In one embodiment of the present invention, the conductor includes one or more of molybdenum, molybdenum alloy, tungsten, tungsten alloy, tungsten, tantalum, tantalum alloy, graphite, silicon, and silicon carbide.

[0057] The above-mentioned method of heating the mold may include electric heating, infrared quartz tube heating, high frequency induction heating, infrared vacuum heating, arc heating, and magnetron electron beam heating. Examples of the heating method will be described below.

[0058] Electric heating

[0059] 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.

[0060] Infrared quartz tube heating

[0061] The electromagnetic radiation heat is combined with a transparent quartz tube heater. Its working principle is to heat up the quartz tube by turning on the power, and transmit the infrared radiation energy to the heated object in the form of thermal radiation.

[0062] High frequency induction heating

[0063] 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.

[0064] Infrared vacuum heating

[0065] 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.

[0066] Arc Heating

[0067] 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.

[0068] Magnetron Electron Beam Heating

[0069] 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.

[0070] Alternatively, the method of bonding the ceramic substrate 1 and the first heat dissipation layer 10, and the first heat dissipation layer 10 and the second heat dissipation layer 11 may further include AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding. Examples of bonding methods will be described below.

[0071] Active Metal Brazing (AMB)

[0072] By adding active metals such as titanium to the solder, the interface between the ceramic and the metal can be wetted and reacted, improving the wettability of the ceramic, thereby bonding the ceramic substrate to the metal.

[0073] Direct Bonded Copper (DBC)

[0074] 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, thereby wetting the interface between the copper foil and the ceramic, thereby bonding the ceramic substrate to the copper.

[0075] Direct Plated Copper (DPC)

[0076] The copper is sputtered onto the ceramic substrate using semiconductor process technology, thereby bonding the ceramic substrate and the copper.

[0077] Direct Bonded Aluminum (DBA)

[0078] 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, so that the ceramic substrate and aluminum are bonded.

[0079] Friction Welding

[0080] The mechanical friction motion is used to generate heat on the friction surface, and the materials are plastically deformed under the action of friction heat and pressure to join together.

[0081] Laser Cladding

[0082] 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.

[0083] Ultrasonic Welding

[0084] Ultrasonic waves refer to sound waves with a frequency exceeding 20 kHz. They are converted into high-frequency signals. Under high-frequency vibration, friction heat is generated through the friction between molecules at the bonding interface, causing the materials to undergo plastic deformation and bond with each other.

[0085] Or, refer to Figure 2 In the second embodiment of the present invention, in order to increase the heat dissipation effect, the second heat dissipation layer 11 of the first embodiment can be replaced by a second heat dissipation layer 11'. The second heat dissipation layer 11' can include a plate-shaped, columnar or needle-shaped heat dissipation device. The heat dissipation device can be, for example, a fin, a vapor chamber, or a heat sink.

[0086] The composite structure of the present invention is characterized in that: by using the above-mentioned heating method in combination with the tool, the first heat dissipation layer 10 (such as aluminum) can be completely or partially melted under the condition of rapid temperature increase, and then a thick aluminum (first heat dissipation layer 10) is coated on one side of the ceramic substrate 1 without sputtering or noble metal soldering. Similarly, the first heat dissipation layer 10 can also be bonded to the second heat dissipation layer 11 or the second heat dissipation layer 11' as a heat spreader, such as a heat sink.

[0087] Therefore, compared with the metallization means of the prior art (such as AMB, DBC, DPC, etc.), the composite structure of the present invention has the following advantages: first, it is fast to prepare and can improve production efficiency; second, since the metal or alloy (such as aluminum, copper alloy and aluminum alloy) softens or melts during the bonding process, the problem of stress cracking of the ceramic substrate during the bonding process is reduced; third, the grain growth of the metal or alloy during the bonding process can be limited by rapid temperature control, thereby completely maintaining the electrical conductivity, thermal conductivity and ductility of the metal or alloy.

[0088] In summary, the composite structure of the present invention has thick aluminum with excellent processing and bonding performance and excellent heat dissipation performance bonded to one side of the ceramic substrate, and another metal, alloy or high thermal conductivity material with excellent heat dissipation performance bonded to the other side of the thick aluminum layer, so that the composite structure of the present invention can achieve excellent heat dissipation characteristics even in harsh environments such as high operating voltage, current and high power, and is conducive to lightweighting and cost reduction.

[0089] Based on the above detailed description of the present invention, other modifications and variations are obvious to those skilled in the art. However, it is obvious that such other modifications and variations can be made without departing from the spirit and scope of the present invention.

Claims

1. A composite structure in which a heat dissipation material is coated on one side of a ceramic substrate, comprising: Ceramic substrate; a first heat dissipation layer bonded to the surface of the ceramic substrate; as well as The second heat dissipation layer is bonded to the other surface of the first heat dissipation layer that is not in contact with the ceramic substrate.

2. The composite structure according to claim 1, wherein: The second heat dissipation layer is in the form of a plate-shaped, column-shaped or needle-shaped heat-dissipating device.

3. The composite structure according to claim 1 or 2, wherein: The ceramic substrate is first bonded to the first heat dissipation layer, and then the first heat dissipation layer is bonded to the second heat dissipation layer; or the ceramic substrate, the first heat dissipation layer and the second heat dissipation layer are bonded simultaneously.

4. The composite structure according to claim 1 or 2, 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.

5. The composite structure according to claim 1 or 2, wherein: The main material of the first heat dissipation layer is aluminum.

6. The composite structure according to claim 1 or 2, wherein: The second heat dissipation layer is composed of a material with a thermal conductivity of 150 W / mk or more, and the material includes aluminum alloy, copper alloy, or high thermal conductivity ceramics.

7. The composite structure according to claim 6, wherein: The high thermal conductivity ceramic includes silicon carbide.

8. The composite structure of claim 6, wherein: The second heat dissipation layer has a thermal conductivity of more than 150 W / mk and a density of less than 4 g / cm 3 material composition.

9. The composite structure according to claim 1 or 2, wherein: The ceramic substrate and the first heat dissipation layer, and the first heat dissipation layer and the second heat dissipation layer are each bonded to each other using a heating and optional pressure method, and 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.

10. The composite structure of claim 9, wherein: The bonding method further includes AMB, DBC, DPC, DBA, diffusion bonding, friction welding, laser cladding, or ultrasonic welding.

Images