CN101804526A - A welding material containing diamond particles and its preparation method - Google Patents

Abstract

The invention discloses a welding material containing diamond particles and a preparation method thereof, comprising a soldering tin material and a plurality of film-coated diamond particles mixed with the soldering tin material; the coated diamond particles comprise a metal carbide coating formed on the surface of the diamond particles and at least one metal coating combined on the surface of the metal carbide coating; the metal carbide coating on the surface of the diamond particles helps the diamond particles and the metal coating to be stably combined, so that the diamond particles can not be separated and lose the combining effect due to repeated cyclic heating and cooling, and the coated diamond particles can be uniformly mixed in the soldering tin material; by adjusting the size and the occupied ratio of the coated diamond particles, welding materials with different properties are manufactured, so that the welding material containing the diamond particles can be suitable for different purposes.

Description

A welding material containing diamond particles and its preparation method

technical field

The invention relates to a welding material containing diamond particles and a preparation method, in particular to a welding material containing diamond particles used in microelectronic packaging and heat dissipation structures.

Background technique

The packaging of general electronic components or the combination of electronic components such as (LED, CPU, GPU, etc.) to dissipate heat. The soldering material contains tin, and the thermal conductivity of tin is 66.6W/(m·K), which is much lower than 401W/(m·K) of copper. Therefore, in the process of heat transfer, the solder layer with low thermal conductivity will cause Large thermal resistance reduces heat transfer efficiency.

U.S. Patent No. 6,365,973 discloses a solder filling material, which includes a plurality of coating filling particles in the solder material, wherein the coating filling particles change the coefficient of thermal expansion of the filling solder material. The coating filling particles are made of a material with a low thermal expansion coefficient coated with a coating layer that can produce a wetting effect with the solder material; materials such as graphite (graphite), carbon fiber (carbon fiber), diamond (diamond) ), boron nitride, aluminum nitride, silicon carbide, silicon nitride, zinc oxide, aluminum, titanium diboride ( Titanium diboride) and silicon oxide (silica), etc.; coating materials such as cobalt, copper, copper oxide, nickel, iron, tin, tin dioxide, zinc and their alloys.

Although the solder filling material disclosed in the above-mentioned US patent contains diamond particles, which can increase its thermal conductivity, if the diamond particles are directly coated with a layer of metal material that can wet the solder material, the diamond cannot chemically bond with the metal. It is difficult for the material to be firmly attached to the surface of the diamond particles. After several cycles of heating and cooling, because the difference in thermal expansion coefficient between the two is too large, it is easy to cause the metal material to separate from the diamond particles, reducing the welding strength and increasing the thermal resistance. Filled solder material loses the function of soldering.

Contents of the invention

In order to improve the known solder materials containing diamond particles, make the combination of diamond particles and solder materials more stable, and make solder materials suitable for various purposes by selecting the size and occupancy ratio of diamond particles, and propose the present invention.

A welding material containing diamond particles, comprising: a solder material; a plurality of coated diamond particles mixed with the solder material; wherein the plurality of coated diamond particles respectively include:

A diamond particle having a metal carbide coating on its surface;

at least one metal coating bonded to the metal carbide coating surface;

Wherein the metal carbide coating is used to help the diamond grains to combine stably with the metal coating.

A preparation method of a welding material containing diamond particles, comprising the steps of:

Step 1: The diamond particles are coated with a layer of metal materials that form carbides with the diamond particles by micro-evaporation or vacuum evaporation or sputtering deposition procedures, including chromium, molybdenum, tungsten, titanium, vanadium, tantalum, zirconium or silicon Material, and then after the high-temperature program reaction, the above-mentioned coated metal material reacts with the carbon of the diamond particles to form a metal carbide coating, including CrC, MoC, WC, TiC, VC, TaC, ZrC, SiC.

Step 2: The above-mentioned diamond particles with a metal carbide coating are plated with a metal coating to form a coated diamond particle by electroless plating or electroplating; the metal of the metal coating layer includes but is not limited to the following materials: gold, silver, copper , iron, aluminum, nickel, cobalt, titanium, tungsten, chromium, tin, zinc or their alloy materials.

Step 3: uniformly mix the coated diamond particles and the solder material to form a diamond particle welding material; wherein the metal coating of the coated diamond particles can produce a wetting effect with the solder material to facilitate uniform mixing; the materials of the solder material include but are not limited to the following materials: Tin, silver, copper, bismuth or lead.

The application of a welding material containing diamond particles, the welding material containing coated diamond particles is used to weld LED, CPU or GPU electronic components to metal radiators.

The main purpose of the present invention is to provide a welding material containing diamond particles, wherein there is a metal carbide coating between the diamond particles and the metal coating of the wetting effect, so that the metal coating can be firmly combined with the diamond particles and the metal solder , so that the coated diamond particles can be evenly mixed in the solder material.

Another object of the present invention is to provide a welding material containing diamond particles. By adjusting the size and volume ratio of coated diamond particles, welding materials with different properties can be made, so that the welding materials containing diamond particles can be suitable for different applications. use.

The advantages of the present invention are: since the metal carbide coating on the surface of the diamond particle helps the diamond particle to be stably combined with the metal coating, it is less likely to lose its bonding effect due to repeated heating and cooling cycles, so that the coated diamond particle can be uniform mixed in the solder material; and by adjusting the size and occupation ratio of the coated diamond particles, solder materials with different properties are produced, so that the solder materials containing diamond particles can be used for different purposes.

For other purposes and functions of the present invention, please refer to the drawings and embodiments, and the details are as follows.

Description of drawings

A more complete and better understanding of the invention, and many of its attendant advantages, will readily be learned by reference to the following detailed description when considered in conjunction with the accompanying drawings, but the accompanying drawings illustrated herein are intended to provide a further understanding of the invention and constitute A part of the present invention, the exemplary embodiment of the present invention and its description are used to explain the present invention, and do not constitute an improper limitation of the present invention, wherein:

Fig. 1 is a schematic diagram of the welding material containing diamond particles of the present invention.

Fig. 2 is a schematic diagram of coated diamond particles of the present invention.

Fig. 3 is a schematic diagram of an application example of a welding material containing diamond particles according to the present invention.

Description of main component symbols:

Solder material 1 containing diamond particles; solder material 11; coated diamond particles 12; diamond particles 121; metal carbide coating 122; metal plating 123; electronic components 2; metal radiator 3.

Detailed ways

Embodiments of the present invention will be described with reference to FIGS. 1 to 3 .

As shown in Figures 1, 2, and 3, the present invention adds a certain volume ratio and a certain size of coated diamond particles 12 in the solder material 11. Since the thermal conductivity of the diamond particles 121 is 1200-2000W/(m K), The thermal conductivity is 66.6 W/(m·K), which is much higher than that of tin, so the thermal conductivity of the solder material 1 can be greatly increased. But because there is no wetting effect between the diamond particles 121 and the solder material 11, so when the solder material 11 is heated and melted, the lighter diamond particles 121 will be taken away by the flux in the solder material 11, floating on the surface of the solder material 11. Therefore, it is necessary to coat the surface of the diamond particles 121 with a metal coating 123 that can produce a wetting effect with the solder material 11 . However, the surface of the diamond particle 121 cannot be directly electroplated with the metal coating 123, so it is necessary to utilize micro-evaporation or vacuum evaporation or sputtering deposition, and then generate a layer of metal carbide coating on the surface of the diamond particle 121 through methods such as high-temperature programmed reaction. layer 122 , and then plate the required metal coating 123 on the surface of the carbide coating 122 to produce a wetting effect with the solder material 11 .

As shown in Figures 1, 2, and 3, the present invention contains a solder material 1 of diamond particles, comprising a solder material 11 (solder material) and a plurality of coated diamond particles 12 mixed with it; the coated diamond particles 12 are included in the diamond particles The metal carbide coating 122 on the surface of the diamond 121 is combined with at least one metal coating 123 ; the metal carbide coating 122 on the surface of the diamond particles 121 helps the diamond particles 121 to be stably combined with the metal coating 122 . The thermal expansion coefficient of the metal carbide coating 122 is between that of the diamond particles 121 and that of the metal coating 123 .

There is a buffered metal carbide coating 122 between the diamond particles 121 and the metal coating 123 of the coated diamond particles 12 of the present invention. Although the temperature is raised and lowered through multiple cycles, it is less likely to be caused by the friction between the diamond particles 121 and the metal coating 123. The difference in coefficient of thermal expansion is too large, which causes the metal coating 123 to separate from the diamond particles 121 and lose their bonding effect, so that the welding material 1 containing diamond particles has a relatively stable welding function.

The volume of the coated diamond particles 121 of the present invention is 5% to 30% of the volume of the solder material 11, wherein 10% to 20% is optimal, and when it exceeds 30%, the welding strength will be reduced. The size of the diamond particles 121 is from 0.001 mm to 0.2 mm, with 0.005 to 0.02 mm being the best. The type of diamond particles 121 may be high temperature high pressure (HTHP) synthetic diamond.

As shown in Fig. 1,2,3, the preparation method of the welding material 1 that the present invention contains diamond particle comprises the steps:

1. The diamond particles 121 are coated with a metal material that can form carbides with the diamond particles 121 by micro-evaporation or vacuum evaporation or sputtering deposition procedures, such as containing chromium, molybdenum, tungsten, titanium, vanadium, tantalum, zirconium , silicon (Cr, Mo, W, Ti, V, Ta, Zr, Si) and other materials, and then after the high-temperature program reaction, the above-mentioned coated metal material will react with the carbon of the diamond particles 121 to form a metal carbide coating 122 , such as CrC, MoC, WC, TiC, VC, TaC, ZrC, SiC, etc.

2. The above-mentioned diamond particles 121 with the metal carbide coating 122 are plated with a metal coating 123 to form a coated diamond particle 12 by chemical plating or electroplating; the metal of the metal coating layer 123 includes but is not limited to the following materials: gold , silver, copper, iron, aluminum, nickel, cobalt, titanium, tungsten, chromium, tin, zinc or their alloys and other materials.

3. The coated diamond particle 12 is uniformly mixed with the solder material 11 to form the solder material 1 of the diamond particle; wherein the metal coating 123 of the coated diamond particle 12 can produce a wetting effect with the solder material 11 to facilitate uniform mixing; the material of the solder material 11 includes But not limited to the following materials: tin, silver, copper, bismuth or lead, etc.

As shown in Figure 3, a use of a welding material containing diamond particles, the welding material containing coated diamond particles is used to weld LED, CPU or GPU electronic components to a metal heat sink.

The welding material 1 containing coated diamond particles of the present invention is used to weld electronic components 2 such as LEDs, CPUs, GPUs, etc. on metal radiators 3; The heat generated by the component 2 is quickly transferred to the metal radiator 3 for heat dissipation; and the welding material 1 containing diamond particles can be firmly combined with the electronic component 2 and welded to the metal radiator 3 .

The welding material containing diamond particles of the present invention has a metal carbide coating between the diamond particles of the coated diamond particles and the metal coating layer of the wetting effect, so that the metal coating layer can be firmly combined with the diamond particles, and it is less likely to be damaged due to multiple passes. The cycle of heating and cooling will break away from the loss of bonding, and make the coated diamond particles evenly mixed in the solder material; and by adjusting the size and volume ratio of the coated diamond particles, solder materials with different properties can be produced. Granular welding materials are available for different purposes.

As mentioned above, although the Example of this invention was demonstrated in detail, it is obvious to those skilled in the art that many modifications can be made as long as the inventive point and effect of this invention are not substantially deviated. Therefore, all such modified examples are also included in the protection scope of the present invention.

Claims (10)

1. A welding material containing diamond particles is characterized in that it comprises: a solder material; a plurality of coating diamond particles are mixed with the solder material; wherein the plurality of coating diamond particles comprise respectively: A diamond particle having a metal carbide coating on its surface; at least one metal coating bonded to the metal carbide coating surface; Wherein the metal carbide coating is used to help the diamond grains to combine stably with the metal coating. 2. The solder material containing diamond particles according to claim 1, wherein the size of the diamond particles is 0.001 mm to 0.2 mm; or the volume of the plurality of coated diamond particles is 5% of the volume of the solder material % to 30%. 3. The solder material containing diamond particles according to claim 1, wherein the size of the diamond particles is 0.005 mm to 0.02 mm; the volume of the plurality of coated diamond particles is 10% to 10% of the volume of the solder material. 20%; or wherein the diamond grains are HPHT man-made diamonds. 4. The welding material containing diamond particles according to any one of claims 2 to 3, wherein the diamond particles are deposited by one of micro-evaporation or vacuum evaporation or sputtering deposition procedures Coating a layer of metal material that can form carbides with the diamond particles, and then reacting with the diamond particles to form the metal carbide coating after a high-temperature program reaction. 5. The welding material containing diamond particles according to claim 4, wherein the metal carbide coating surface is combined with the at least one metal coating by one of the procedures of electroless plating or electroplating; The thermal expansion coefficient of the metal carbide coating is between that of the diamond particles and that of the metal coating. 6. The welding material containing diamond particles according to claim 5, wherein the metal carbide coating is a compound of chromium, tungsten, titanium, vanadium, molybdenum, tantalum, zirconium or silicon and carbon respectively one. 7. The welding material containing diamond particles according to claim 6, wherein the material of the at least one metal coating is gold, silver, copper, iron, aluminum, nickel, cobalt, titanium, tungsten, chromium, One of tin, zinc or their alloys. 8. The solder material with diamond particles according to claim 7, wherein the solder material contains one of tin, silver, copper, bismuth or lead. 9. A preparation method for a welding material containing diamond particles, characterized in that it may further comprise the steps: Step 1: The diamond particles are coated with a layer of metal materials that form carbides with the diamond particles by micro-evaporation or vacuum evaporation or sputtering deposition procedures, including chromium, molybdenum, tungsten, titanium, vanadium, tantalum, zirconium or silicon Material, and then after the high-temperature program reaction, the above-mentioned coated metal material reacts with the carbon of the diamond particles to form a metal carbide coating, including CrC, MoC, WC, TiC, VC, TaC, ZrC, SiC. Step 2: The above-mentioned diamond particles with a metal carbide coating are plated with a metal coating to form a coated diamond particle by electroless plating or electroplating; the metal of the metal coating layer includes but is not limited to the following materials: gold, silver, copper , iron, aluminum, nickel, cobalt, titanium, tungsten, chromium, tin, zinc or their alloy materials. Step 3: uniformly mix the coated diamond particles and the solder material to form a diamond particle welding material; wherein the metal coating of the coated diamond particles can produce a wetting effect with the solder material to facilitate uniform mixing; the materials of the solder material include but are not limited to the following materials: Tin, silver, copper, bismuth or lead. 10. A use of a welding material containing diamond particles, characterized in that the welding material containing coated diamond particles is used to weld LED, CPU or GPU electronic components on a metal heat sink.

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