TW201502458A - Heat dissipating plate and method for fabricating the same - Google Patents

Abstract

A heat dissipating plate comprises a first metal layer, a diamond layer and a second metal layer. The diamond layer is located evenly on the first metal layer. The second metal layer is located on the first metal layer in such a manner that the diamond layer is sandwiched there-between. The characteristic is that, by using a pressing device to press the second and first metal layers in a predetermined high-pressure and high-temperature for a predetermined time period in order to proceed the heat-fusing process, the heat dissipating plate will become an integral structure. The first metal layer is thinner than the second metal layer. The overall thickness of the heat dissipating plate is between 0.1mm~1mm.

Description

Heat sink and its preparation method

The present invention relates to a heat sink and a method of making, in particular, a diamond particle interlayer in the heat sink.

With the rapid development of high technology, the volume of electronic components has become smaller, and the density per unit area has become higher and higher, and its performance has been continuously enhanced. Under these factors, the total heat generation of electronic components is Almost every year, taking the central processing unit as an example, the central processing unit currently developed has an operating efficiency of several billion megahertz (GHz), and the high heat generated by it has been rapidly dissipated by conventional heat sinks. If there is no good heat dissipation method to eliminate the heat generated by the electronic components, these excessive temperatures will cause electronic components to generate electron liberation and thermal stress, resulting in a decrease in overall stability and a shortened life of the electronic components. How to eliminate this heat to avoid overheating of electronic components has always been a problem that cannot be ignored.

However, the future semiconductor package will tend to be higher power and higher density. In contrast, the thermal energy dissipation is a problem that developers must continue to face in the future, and the high-density energy emitted by electronic components at work. The high-density heat brought about by the high power density, the current heat dissipation method is based on copper or aluminum as the base material of the heat spreader (Heat Spreader), or further buried the heat pipe (Heat Pipe) into the foundation. Within the material, to speed up the heat diffusion, but the cost of this practice has also increased considerably. With the advancement and improvement of electronic components, the density per unit area is becoming higher and higher, so that the heat diffusion rate must be accelerated, and the thermal conductivity of copper and aluminum is about 400 watts/meter Kelvin ( W/mk) and 200 watts/meter Kelvin (W/mk) are gradually being used in electronic components with increasing heat generation, and the density of copper and aluminum is about 8.9 g/cm3. (g/cm ³ ) and 2.7 g/cm ³ (g/cm ³ ), so when the electronic component is combined with a heat sink made of copper or aluminum, the weight of the heat sink tends to cause a stress on the electronic component. It is easy to damage the structure of the electronic component for a long time, and the life of the electronic component is shortened or damaged.

Since the heat sink made of copper and aluminum as the base material has the above problems, The development of new heat-dissipating materials has become a very important part. At present, diamonds have excellent properties in nature, such as excellent penetration from deep ultraviolet light to far infrared rays, highest surface acoustic wave velocity, highest thermal conductivity, highest physical hardness, high radiation resistance, good chemical inertness and excellent insulation. Sex properties, etc., have been widely applied to conventional cutting tools and abrasive materials. Recently, with the development of Chemical Vapor Deposition (CVD) technology, diamonds have become good electrical conductors and thermal conductors. Diamonds have a thermal conductivity of up to 2,000 watts per meter Kelvin at room temperature (W/ Mk), and in this way extend the diamond application to the heat dissipation structure of the semiconductor and optoelectronic industries.

In addition, the previous methods for manufacturing diamond and metal composite heat sinks can be divided into three types, as outlined below. First, the use of diamond microparticles (or powder) bonded with organic materials, such as epoxy resin or acrylic resin, paraffin wax or eucalyptus oil, but due to the poor wettability and bonding properties of diamonds, it fails to show Its thermal conductivity and thermal diffusivity have not been widely adopted. Second, it is a polycrystalline diamond film by chemical vapor deposition (CVD), which has a large area but a limited thickness (less than 0.5 mm), so it cannot effectively derive the heat of the wafer, and the cost is high. Does not meet the cost-effectiveness of heat dissipation of electronic components. Thirdly, in order to prevent oxidation or graphitization of the diamond microparticles (or powder) during the penetration of the molten metal during sintering, the sintering temperature should be lower than 1100 ° C, and must be in the high vacuum 10 ^-3 ~ 10 ^-5 tor (orr) and high pressure greater than 5GPa to avoid damage to the diamond due to the expansion of the graphitized volume and brittle fracture, and the poor bonding force affects the thermal conductivity of the finished product, and the process equipment and production costs are extremely high, Does not meet the economic benefits of production.

In view of the lack of the above-mentioned diamond composite fins (soaked fins), it is necessary to understand In the trend of globalization, low-cost and low-profit, in the 3C electronics industry, optoelectronics industry, etc., in addition to the need to strengthen the improvement of manufacturing technology and cost-effective control and actively develop high-performance Under the principle of electronic heat dissipating material, the present invention specially develops a competitive and feasible diamond microparticle and metal material heat sink and a manufacturing method thereof, which not only solves the above disadvantages, but also the diamond microparticles combined with the metal material can conform to a certain degree. The requirement of the thermal stock test does not cause the diamond microparticles to fall off the heat sink of the metal.

The main object of the present invention is to provide a heat sink and a method for preparing the same, which is laminated and integrated into two metal layers by a plurality of diamond microparticles in a press-fit manner and with a predetermined high pressure and high temperature. In order to improve the cooling effect.

To achieve the above object, a heat sink according to the present invention comprises: a first metal layer, a diamond layer, and a second metal layer. The diamond layer is evenly distributed on the first metal layer. The second metal layer is over the first metal layer and the diamond layer is sandwiched therein. The method is characterized in that the second metal layer and the first metal layer are hot-pressed and fused by a predetermined high pressure and high temperature for a predetermined time by a pressing device (for example, a hydraulic cylinder), and the first The thickness of a metal layer is thinner than the thickness of the second metal layer, and the overall thickness after pressing is preferably between 0.1 mm and 1 mm.

1, 1a, 1b‧‧‧ heat sink

1a’‧‧‧Small heat sink

11‧‧‧First metal layer

12‧‧‧Diamond layer

13‧‧‧Second metal layer

2‧‧‧Metal strips

3‧‧‧Pressure device

4‧‧‧Cutter

5‧‧‧Working platform

7‧‧‧vacuum pump

8‧‧‧Preset metal

9‧‧‧ diamond particles

1 is a schematic cross-sectional view showing a first preferred embodiment of a heat sink according to the present invention.

2A to 2D are schematic diagrams showing the steps of a manufacturing method of the first preferred embodiment of the heat sink of the present invention.

Figure 3 is a cross-sectional view showing a second preferred embodiment of the heat sink of the present invention.

4A to 4F are schematic diagrams showing the steps of a manufacturing method of a second preferred embodiment of the heat sink of the present invention.

5A-5C are schematic diagrams showing the steps of a manufacturing method of a third preferred embodiment of the heat sink of the present invention.

In order to more clearly describe the heat sink of the present invention and the method of manufacturing the same, the following will be described in detail in conjunction with the drawings.

Referring to FIG. 1, FIG. 1 is a cross-sectional view showing a first preferred embodiment of the heat sink of the present invention. The heat sink 1 includes a first metal layer 11 and a diamond layer 12, And a second metal layer 13. The diamond layer 12 uniformly distributes a plurality of diamond particles 9 (powder-shaped diamond particles) on the upper surface of the first metal layer 11. The second metal layer 13 is located above the upper surface of the first metal layer 11 having the diamond layer 12, and the diamond layer 12 is sandwiched therein. Then, the second metal layer 13 and the first metal layer 11 are subjected to a predetermined high-pressure, high-temperature process condition through a pressing device (such as but not limited to a hydraulic cylinder) for a predetermined period of time. The method is mutually thermocompression-bonded to make the heat sink 1 an integrated structure. The thickness of the first metal layer 11 is thinner than the thickness of the second metal layer 13, and the overall thickness of the heat sink 1 after pressing is preferably between 0.1 mm and 1 mm.

Please refer to Figure 2A~Figure 2D and shown in Figure 1, Figure 2A~2D It is a schematic diagram of the steps of the manufacturing method of the first preferred embodiment of the heat sink of the present invention. The method for manufacturing the heat sink 1 of the first preferred embodiment of the present invention includes the following steps: Step 1, as shown in FIG. 2A, preparing a first metal layer 11 on a working platform 5; Step 2 As shown in FIG. 2B, a predetermined amount of diamond particles 9 (ie, diamond microparticles, or diamond powder) is evenly distributed on the first metal layer 11 to form a thin layer of diamond micro. Granular layer; in the first embodiment of the method for manufacturing the heat sink 1 of the present invention, during the processing, the present invention performs a vacuuming operation of the processing environment in which the first metal layer 11 is located by a vacuum pump 7; Step 3, as shown in FIG. 2C, a second metal layer 13 is overlaid on the first metal layer 11, and the diamond particles 9 are covered therein; and step four, as shown in FIG. The second metal layer 13 and the first metal layer 11 are mutually heat-compressed by a predetermined high voltage and high temperature through a pressing device (for example, but not limited to the hydraulic cylinder 3) for a predetermined time. , the second metal layer 13 and the first metal layer 11 form a diamond layer 12; In this step, the vacuum pump 7 continuously vacuums the processing environment in which the first metal layer 11, the diamond particles 9 and the second metal layer 13 are located, so as to avoid air during the hot press fusion process. Covered between the first and second metal layers 11, 13 or between a plurality of diamond microparticles. Thereby, the entire heat sink 1 of the present invention can be completed.

In the first preferred embodiment of the present invention, the thickness of the first metal layer 11 is thinner than the thickness of the second metal layer 13, and the overall thickness H is preferably between 0.1 mm and 1 mm after pressing. The overall thickness H of the heat sink 1 is preferably between 0.2 mm and 0.6 mm.

In the first preferred embodiment of the present invention, the first metal layer 11 has a thickness h1 range. Preferably, it is between 0.03 mm and 0.07 mm; wherein the thickness h1 of the first metal layer 11 is preferably between 0.04 mm and 0.06 mm.

In the first preferred embodiment of the present invention, the second metal layer 13 has a thickness h2 range. Preferably, the thickness of the second metal layer 13 is between 0.09 mm and 0.11 mm.

In the first preferred embodiment of the present invention, the thickness of the diamond layer 12 is preferably in the range of h3. Between 0.06 mm and 0.15 mm; wherein the thickness h3 of the diamond layer 12 is preferably between 0.09 mm and 0.11 mm.

It is worth mentioning that in the process of hot pressing fusion described in step four, there will be A portion of the metal layer material is flashed from the peripheral edge, and therefore, the overall thickness H of the manufactured heat sink 1 is actually slightly smaller than the sum of the thicknesses of the first metal layer 11, the diamond layer 12, and the second metal layer 13. Point, that is, there will actually be a result of H < (h1 + h2 + h3).

In the first preferred embodiment of the present invention, the first metal layer 11 and the second metal The material of layer 13 may be one of copper, aluminum, copper alloy, aluminum alloy, silver, gold, or other highly thermally conductive metal. In the first preferred embodiment of the present invention, the materials of the first metal layer 11 and the second metal layer 13 are respectively copper metal.

In the first preferred embodiment of the present invention, the hot pressing fusion process described in the fourth step The process temperature is applied to the first metal layer 11 and the second metal layer 13 at a high temperature ranging from 300 ° C to 900 ° C when the diamond layer 12 is pressed.

In the first preferred embodiment of the present invention, the pressurizing device (hydraulic cylinder) 3 of the hot press fusion process described in the fourth step is pressurized for the first metal layer 11 and the second metal layer. 13 applies a high pressure ranging from 15 kgw/cm ² to 25 kgw/cm ² when the diamond layer 12 is pressed.

In the first preferred embodiment of the present invention, the hot pressing fusion process described in the fourth step The high temperature and high pressure duration of the first metal layer 11 and the second metal layer 13 are preferably in the range of 8 to 15 minutes.

That is, in the first preferred embodiment of the present invention, the first metal layer 11 and the second metal layer 13 are respectively made of a metal plate made of copper, and a high temperature of 300 ° C to 900 ° C is applied. The first metal layer 11 of the copper material and the second metal layer 13 are heated and softened (the melting point of the copper material is 1085 ° C, so the melt will not soften during the hot press fusion process), and at the same time, the vacuum pump 7 During the continuous vacuuming, the first metal layer 11, the diamond particles 9, and the second metal layer are sequentially stacked on the working platform 5 through the pressing device (hydraulic cylinder) 3. 13 is further applied by pressing at a high pressure of 20 kgw/cm ² or more, and after substantially a period of more than 10 minutes, the first and second metal layers 11 and 13 are hot-pressed and integrated into one body and diamond particles are simultaneously 9 is formed between the first and second metal layers 11 and 13 to form the diamond layer 12, so that the diamond particles 12 are not easily used by the diamond layer 12 when performing a thermal stock test. The heat sink 1 is detached.

In addition, since the thickness of the first metal layer 11 is greater than the thickness of the second metal layer 13 The heat sink 1 of the present invention is preferably more suitable for use in general micro appliances (such as smart phones, tablet computers, etc.). The electronic component is required to dissipate heat, and the relatively thin first metal layer 11 is in contact with a heat source (CPU central processing unit, LED chip), and the diamond layer 12 is pressed through the center to have excellent thermal conductivity. The heat generated by the heat source is quickly transmitted to the second metal layer 13, so that the heat dissipation efficiency of the heat sink 1 as a whole is greatly improved.

In other preferred embodiments of the invention described below, most of the components are phased The same components and structures will not be described below, and the same components will be given the same names and numbers directly, and the same components will be given the same name but an additional number after the original number. The letters are distinguished and will not be described in detail.

Please refer to FIG. 3, which is a cross section of the second preferred embodiment of the heat sink of the present invention. schematic diagram. Since the second preferred embodiment of the heat sink of the present invention is substantially similar to the first preferred embodiment shown in FIG. 2, the same components and structures will not be described below. The heat sink of the second preferred embodiment of the present invention is different from the foregoing first preferred embodiment in that the heat sink 1a further includes a plurality of metal strips 2. The metal strips 2 are disposed on the first metal layer 11 in a parallel array, and further divide the diamond layer 12 into a plurality of sections. The material of the metal strip 2 may be one of copper, aluminum, copper alloy, aluminum alloy or other high thermal conductivity metal. In the second preferred embodiment of the present invention, the metal strip 2 is made of copper metal.

Referring to FIG. 4A to FIG. 4F, FIG. 4A to FIG. 4F are schematic diagrams showing the steps of the manufacturing method of the second preferred embodiment of the heat sink of the present invention. The manufacturing method of the heat sink 1a of the second preferred embodiment of the present invention includes the following steps: Step 1, as shown in FIG. 4A, preparing a first metal layer 11 to be placed in a working level. On the stage 5; in step A, as shown in FIG. 4B, a plurality of metal strips 2 are disposed on the first metal layer 11 in a parallel array; in step two, as shown in FIG. 4C, a pre- A set of diamond particles 9 (i.e., diamond microparticles, or diamond powder) is evenly distributed on the upper surface of the first metal layer 11 and in a region between the plurality of metal strips 2 to form a thin layer. The diamond microparticle layer; during the processing, the vacuum evacuation pump 7 is used to evacuate the processing environment in which the first metal layer 11 is located; step 3, as shown in FIG. a second metal layer 13 is overlaid on the first metal layer 11 and the diamond particles 9 are covered therein; and in step 4, as shown in FIG. 4E, the first metal layer is passed through a pressurizing device (hydraulic cylinder) 3 The second metal layer 13 and the first metal layer 11 are hot-pressed and fused by a predetermined high voltage and high temperature for a predetermined time, so that the second metal layer 13 and the first metal layer 11 form a diamond layer. In this step, the vacuum pump 7 still continuously faces the first metal layer 11, a plurality of metal strips 2, and drills The processing environment in which the particles 9 and the second metal layer 13 are located is subjected to a vacuum operation to prevent air from being coated on the first and second metal layers 11, 13 or most of the diamond microparticles during the hot press fusion process. And step 5, as shown in FIG. 4F, a whole piece of heat sink 1a can be manufactured by the steps of FIG. 4A to FIG. 4E, and then a cutter 4 is used to be parallel to the metal strip 2 The long side direction is used to cut a plurality of heat sinks of a smaller size into the center of each of the metal strips 2, respectively. .

That is, the diamond layer 12 is divided into a plurality of segments by the metal strip 2, and the heat sink 1a is guided to the center of the respective metal strip 2 along the longitudinal direction of the metal strip 2 by the cutter 4. Cutting, respectively, the heat sink 1a is cut into a plurality of small heat sinks 1a', and each of the small heat sinks 1a' has a stripped metal strip 2 on both sides thereof, which can be further used for The diamond particles 9 in the diamond layer 12 are prevented from falling off the edge of the cut during the thermal shock test.

Referring to FIG. 5A to FIG. 5C, FIG. 5A to FIG. 5C are schematic diagrams showing the steps of the manufacturing method of the third preferred embodiment of the heat sink of the present invention. The method for manufacturing the heat sink 1b according to the third preferred embodiment of the present invention includes the following steps: Step 1, as shown in FIG. 5A, preparing a first metal layer 11 on a working platform 5; Step 2, as shown in FIG. 5B, a predetermined amount of diamond particles 9 are evenly distributed on the first metal layer 11; and step 3, as shown in FIG. 5C, is passed through chemical vapor deposition (Chemical Vapor). Deposition, CVD) deposits a predetermined metal 8 on the first metal layer 11 and encapsulates the diamond particles 9 in the center of the first metal layer 11 and the predetermined metal 8.

In the third preferred embodiment of the present invention, the thickness of the first metal layer 11 is thinner than the thickness of the predetermined metal 8 after deposition, and the overall thickness of the heat sink 1b after deposition is preferably 0.1 mm. ~1mm between. The material of the first metal layer 11 and the predetermined metal 8 may be one of copper, aluminum, copper alloy, aluminum alloy or other high thermal conductivity metal.

The above-mentioned embodiments are not intended to limit the scope of application of the present invention, and the scope of the present invention should be based on the technical spirit defined by the content of the patent application scope of the present invention and the scope thereof. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

1‧‧‧ Heat sink

11‧‧‧First metal layer

12‧‧‧Diamond layer

13‧‧‧Second metal layer

9‧‧‧ diamond particles

Claims (10)

A method for manufacturing a heat sink, comprising the steps of: preparing a first metal layer on a working platform; and step 2, distributing a predetermined amount of diamond particles on the first metal layer Step three, superposing a second metal layer on the first metal layer and covering the diamond particles therein; and step four, using the vacuum pump to the first metal layer on the working platform, The working environment of the diamond particles and the second metal layer is evacuated, and the second metal layer and the first metal layer are subjected to a predetermined high pressure and high temperature for a predetermined time by a pressing device. The thermocompression fusion causes the second metal layer to form a diamond layer with the center of the first metal layer. The method for manufacturing a heat sink according to claim 1, wherein the thickness of the first metal layer is thinner than the thickness of the second metal layer, and the overall thickness after pressing is preferably between 0.1 mm and 1 mm. The thickness of the first metal layer is preferably between 0.03 mm and 0.07 mm; wherein the thickness of the second metal layer is preferably between 0.06 mm and 0.15 mm; wherein the thickness of the diamond layer is preferably in the range of Between 0.06mm and 0.15mm. The method for manufacturing a heat sink according to claim 1, wherein the step 4 applies a high temperature ranging from 300 ° C to 900 ° C when the first metal layer and the second metal layer are pressed together; Step 4: applying a high pressure ranging from 15 kgw/cm ² to 25 kgw/cm ² when the first metal layer and the second metal layer are pressed; wherein, step 4 is for the first metal layer and the second metal The preset time of the lamination is preferably in the range of 8 to 15 minutes; wherein the material of the first metal layer and the second metal layer may be copper or a copper alloy. The method for manufacturing a heat sink according to claim 1, further comprising a step A, wherein the step A is to arrange a plurality of metal strips on the first metal layer in a parallel array. The method for manufacturing a heat sink according to claim 4, further comprising the step 5, wherein the step 5 is performed by using a cutter parallel to the longitudinal direction of the metal strip to the center of each of the metal strips. Cut. A heat sink comprising: a first metal layer; a diamond layer uniformly distributing a plurality of diamond particles on the first metal layer; and a second metal layer overlying the first metal layer and sandwiching the diamond layer therein; And in the environment of vacuuming by a vacuum pump, the second metal layer and the first metal layer are hot-pressed and fused by a predetermined high pressure and high temperature through a pressing device for a predetermined time. The heat sink of claim 6, wherein the thickness of the first metal layer is thinner than the thickness of the second metal layer, and the thickness of the heat sink after pressing is preferably between 0.1 mm and 1 mm. The thickness of the first metal layer is preferably between 0.03 mm and 0.07 mm; wherein the thickness of the second metal layer is preferably between 0.06 mm and 0.15 mm; wherein the thickness of the diamond layer is preferably in the range of Between 0.06mm and 0.15mm. The heat sink according to claim 6, wherein the first metal layer and the second metal layer are respectively applied with a high temperature ranging from 300 ° C to 900 ° C during pressing, wherein a metal layer and the second metal layer are subjected to a high pressure ranging from 15 kgw/cm ² to 25 kgw/cm ² when pressed; wherein, a predetermined time for the first metal layer and the second metal are laminated The range is 8 to 15 minutes. A method for manufacturing a heat sink, comprising the steps of: preparing a first metal layer on a working platform; and step 2, distributing a predetermined amount of diamond particles on the first metal layer And step 3, depositing a predetermined metal on the first metal layer by a chemical vapor deposition (CVD) technique, and coating the diamond particle on the first metal layer and the preset Between metal. The method for manufacturing a heat sink according to claim 9, wherein the thickness of the first metal layer is thinner than the thickness of the predetermined metal after deposition, and the overall thickness of the heat sink is preferably after deposition. Between 0.1mm~1mm.