Diamond microchannel heat sink and preparation method thereof

Abstract

The present invention provides a diamond microchannel heat sink and a preparation method thereof, and relates to the technical field of heat dissipation of high heat flux density chips. In this scheme, a metal wire or an active metal wire with active abrasive particles fixed thereon is used as a wire saw cutting tool, and a multi-wire cutting machine tool is used as a processing device. By making the wire net quickly form a wire bow, the active abrasive wire saw or active metal wire is used to scratch the diamond matrix at a high wire speed, reciprocatingly, and dryly under pressure conditions. The diamond surface undergoes a phase change to generate amorphous carbon, graphite, or carbide under the action of the active abrasive particles or active metal wires, and then the phase change products are removed by the mechanical action of the active abrasive particles or active metal wires, thereby exposing a fresh diamond surface. The above process is repeated in this way to achieve efficient and high-quality processing of the diamond microchannel heat sink.

Description

Technical Field

[0001] The present invention relates to the technical field of high heat flux density chip heat dissipation, and in particular to a diamond microchannel heat sink and a preparation method thereof. Background Art

[0002] The rapid development of emerging fields such as artificial intelligence, 5G communications, and new energy vehicles has driven electronic devices to develop towards miniaturization, integration, and high power, resulting in a significant increase in chip heat flux density, with local heat flux density even exceeding 1000W / cm², a rapid increase in power consumption, and increasingly severe chip heating problems. Within the limited volume of the chip, how to smoothly discharge the heat generated by high integration and high energy density has become one of the most challenging issues in 3D packaging of high heat flux density chips.

[0003] The heat dissipation coefficient of traditional air-cooled radiators is too low to meet the heat dissipation requirements of high heat flux density electronic devices. Microchannel radiators (hydraulic channel diameter is less than 1mm) use a microchannel structure as a heat exchanger. The flowing liquid working medium contacts the microchannel wall surface, and then quickly removes the heat of the electronic device. It has the advantages of small size and large heat dissipation specific surface area. It is an advanced cooling method to solve the heat dissipation problem of ultra-high heat flux density electronic chips. In addition to its excellent thermal conductivity, diamond is also the hardest material in nature and has extremely strong chemical stability. These properties make it difficult to process diamond microchannel radiators using conventional mechanical processing methods or chemical processes.

[0004] The magazine Diamond & Related Materials, 2013, Vol. 34, pp. 19-24, reported a method of processing diamond microchannels using plasma etching technology. This method is a process that uses the interaction between plasma (i.e., ionized gas) and the material surface to remove or modify the material surface. The equipment required is expensive, the process is complex, the processing efficiency is extremely low, and there is a risk of gas contamination.

[0005] Chinese patents CN101071756B, CN110557936B, CN113337806B, CN114758996, etc. use chemical vapor deposition to grow diamond microchannels, but this method needs to be combined with plasma etching or deep reactive ion etching or masking to assist in preparation. In addition, after the diamond microchannel is grown, the top surface of the microchannel needs to be further ground and polished to meet the requirements of connecting chips and other heat sink materials. The preparation of diamond microchannels by chemical vapor deposition has high requirements on processing equipment, complex processes, low processing efficiency, and high costs.

[0006] Chinese patents CN108682662B, CN113267082B, CN114242598A, and CN118507440A disclose methods for processing diamond microchannels using lasers, but the overall processing efficiency of this method is relatively high, but the processing capacity is easily attenuated with the distance of the focal length, and the processing section is inevitably conical. In addition, the laser processing temperature is very high, and the surface of the diamond microchannel after processing will be severely graphitized, and thermal cracks will also be easily generated. The thermal conductivity of the generated graphite layer is much lower than that of diamond, which will seriously reduce the performance of the diamond microchannel radiator. Even after pickling, the surface of the diamond microchannel after laser processing cannot be cleaned of graphite, and the surface graphite layer needs to be removed by plasma etching method, which further increases the production cost. Summary of the invention

[0007] The invention discloses a method for preparing a diamond microchannel radiator to solve the above-mentioned problems.

[0008] The present invention adopts the following scheme:

[0009] A method for preparing a diamond microchannel heat sink comprises: a liquid flow cavity with a coolant inlet and an outlet and a diamond microchannel substrate suitable for being installed in the liquid flow cavity. The preparation of the diamond microchannel substrate comprises the following steps:

[0010] S1: Prepare active abrasive wire saw, fix active abrasive grains on the core wire by brazing, sintering or electroplating; or use active pure metal wire as wire saw cutting tool;

[0011] S2: The wire saw is mounted on a multi-wire cutting machine workbench, and the wire groove spacing is adjusted according to the structural parameters of the microchannel to form a wire saw wire network;

[0012] S3: Select a diamond substrate, and select glass, sapphire or resin block as auxiliary support according to its thickness for bonding, and then install the bonded body together on the workbench of the wire saw multi-wire cutting machine tool, so that the diamond substrate and the wire saw wire mesh are in a position to be in contact;

[0013] S4: adjusting and setting the wire tension, wire speed, the speed at which the diamond substrate is fed to quickly form a specified wire bow height, the feeding speed of the diamond substrate after forming the specified wire bow, the reciprocating cycle of the wire saw and the feeding trajectory of the diamond substrate;

[0014] S5: Run the processing program to make the wire saw wire mesh perform periodic reciprocating motion under the drive system of the machine tool, and the worktable quickly feeds a predetermined distance and then stops feeding to form a specified wire bow height; the active abrasive grains fixed on the wire saw wire mesh perform high-speed, reciprocating, and dry scratching on the diamond matrix, so that the active abrasive grains fixed on the wire saw interact with the diamond under pressure and temperature conditions to generate amorphous carbon, graphite and carbide, and the generated amorphous carbon, graphite and carbide are then removed by the mechanical action of the active abrasive grains, and this step is repeated to achieve microchannel processing of the diamond matrix;

[0015] S6: After the processing program is completed, the diamond substrate is taken out, cleaned in an ultrasonic alcohol bath, and dried in an oven to obtain the final diamond microchannel substrate;

[0016] S7: The diamond microchannel substrate is embedded in the liquid flow cavity, and the two are bonded and sealed by bonding. Water pipes are connected to the coolant inlet and outlet, and connected to a water pump to form a liquid convection circulation loop, and finally a complete U-shaped cross-section diamond microchannel radiator is obtained.

[0017] Furthermore, the active abrasive grains include active pure metal abrasive grains, or hard abrasive grains, or plated hard abrasive grains encapsulating active pure metal, or a combination of active pure metal abrasive grains, plated hard abrasive grains encapsulating active pure metal, and hard abrasive grains.

[0018] Furthermore, the active metal wire includes one of nickel wire, steel wire, tungsten wire, molybdenum wire and titanium wire.

[0019] Furthermore, the active pure metal abrasive includes a combination of one or more of iron, cobalt, nickel, chromium, titanium, vanadium, tungsten, molybdenum, manganese, aluminum, zirconium, lanthanum, and cerium pure metal abrasives; the hard abrasive includes a mixture of one or more of diamond, cubic boron nitride, silicon carbide, silicon oxide, aluminum oxide, copper oxide, titanium oxide, iron oxide, cerium oxide, etc.

[0020] Furthermore, when the active abrasive wire saw is prepared by brazing in step S1, the process includes the following steps:

[0021] S11: Pre-treat the tungsten wire to remove oil stains and oxide layer;

[0022] S12: Coat a layer of glue on the surface of the tungsten wire; then use an electrostatic coating device to coat the active abrasive and metal binder on the surface of the tungsten wire respectively, the electrostatic voltage used is 1~30kV, the distance between the upper and lower plates is 1~8cm, and the wire speed of the tungsten wire is 2~4cm / s;

[0023] S13: placing the tungsten wire coated with active abrasive and metal binder into a protective atmosphere tubular furnace at a furnace temperature of 650-950° C. for heat treatment; cooling the tungsten wire after it is taken out of the furnace to obtain an active abrasive wire saw.

[0024] Furthermore, when active pure metal abrasive grains are fixed on the surface of the tungsten wire, the formula of the metal binder includes 0-5% by mass of Ni, 0-20% by mass of Sn, 0-10% by mass of P, and the rest is Cu.

[0025] Furthermore, when active pure metal abrasive grains and diamonds are simultaneously consolidated on the surface of the tungsten wire, the formula of the metal binder includes 20-80 mass percent of Cu, 0.5-10 mass percent of Ti, 0-0.5 mass percent of Ga, and the rest is Sn.

[0026] Furthermore, when the coated hard abrasive grains are solidified on the surface of the tungsten wire, the coated hard abrasive grains are formed by plating a Ni layer on the surface of the diamond; the formula of the metal binder includes 15-25 mass percent of Cu, 15-20 mass percent of Zn, 0-6 mass percent of Sn, and the rest is Ag.

[0027] Furthermore, the height of the wire bow is 0.1 mm to 50 mm.

[0028] The present invention also provides a diamond microchannel heat sink, which is prepared by any one of the above-mentioned methods for preparing a diamond microchannel heat sink.

[0029] Beneficial effects:

[0030] 1. Diamond microchannel processing is achieved through the chemical and mechanical composite action of active abrasive grains or active metal wires on the surface of the wire saw and the diamond matrix. The phase change layer on the surface of the microchannel processing will be continuously removed, and finally there will be less phase change products remaining on the surface of the diamond microchannel, which will hardly deteriorate the thermal conductivity of the diamond itself, and there is no need to post-process the diamond microchannel radiator after processing;

[0031] 2. Compared with conventional wire saw processing methods, the interaction between active abrasive particles or active metal wires and diamond substrates is accelerated by quickly forming a wire bow;

[0032] 3. The wire saw processing method can easily control the structure and morphology of the diamond microchannel, and can easily process microchannels with ultra-large aspect ratios, and can also realize the processing of microchannel recessed structures;

[0033] 4. All the microchannels with large aspect ratio in the same direction can be processed in batches in a single pass. The process is simple, the equipment requirements are low, the cost is low, the processing efficiency is high, and it is easy to mass produce;

[0034] 5. There is no waste liquid or waste gas pollution in the processing process, which is green, environmentally friendly and has low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 An exploded schematic diagram of a diamond microchannel heat sink;

[0036] Figure 2 It is a schematic diagram of the assembly of a diamond microchannel heat sink;

[0037] Figure 3 A schematic diagram of a diamond microchannel substrate of a diamond microchannel heat sink;

[0038] Figure 4 A schematic cross-sectional view of a diamond microchannel substrate of a diamond microchannel heat sink;

[0039] Figure 5 Schematic diagram of reciprocating multi-wire cutting of diamond microchannel substrate wire saw. v fy , v fz is the feed speed in different axes, v s Indicates line speed;

[0040] Figure 6 Schematic diagram of rapid formation of wire bow for machining diamond microchannel substrate. δ is the line bow height;

[0041] Figure 7 is a schematic diagram of the active pure metal abrasive wire saw in Example 3;

[0042] Figure 8 A schematic diagram of a wire saw comprising hard abrasive grains and active pure metal abrasive grains used in multi-wire cutting in Example 4;

[0043] Fig. 9 Schematic diagram of a coated hard abrasive wire saw wrapped with active pure metal used in multi-wire cutting in Example 5;

[0044] Fig.10 A top view of a diamond microchannel machined by an abrasive wire saw wrapped with nickel metal in Example 6;

[0045] Fig.11 Side view of diamond microchannel machined by abrasive wire saw with nickel metal wrapped in Example 6.

[0046] Icon: diamond microchannel substrate 1, liquid flow chamber 2, inlet 201, outlet 202, workbench 3, diamond substrate 4, wire roller 5, wire mesh 6, active pure metal abrasive 7, core wire 8, metal binder 9, hard abrasive 10, metal coating 11, coated hard abrasive 12. DETAILED DESCRIPTION

[0047] Example 1

[0048] Combination Figures 1 to 4As shown, this embodiment provides a diamond microchannel heat sink, comprising a liquid flow chamber 2 with a coolant inlet 201 and an outlet 202, and a diamond microchannel substrate 1 suitable for installation in the liquid flow chamber 2, wherein a plurality of groove-shaped microchannels are arranged in parallel array on the diamond microchannel substrate 1, and the aspect ratio of the microchannel is 0.1-50. The coolant inlet 201 and the outlet 202 are respectively suitable for external water pipes, and the water pipes are connected to a water pump to form a circulation loop of liquid convection, and finally a complete U-shaped cross-section diamond microchannel heat sink is obtained.

[0049] Example 2

[0050] This embodiment provides a method for preparing a diamond microchannel heat sink, comprising: a liquid flow chamber 2 with a coolant inlet 201 and an outlet 202 and a diamond microchannel substrate 1 suitable for being installed in the liquid flow chamber 2. The preparation of the diamond microchannel substrate 1 comprises the following steps:

[0051] S1: preparing an active abrasive wire saw, fixing active abrasive grains on a core wire 8 by brazing, sintering or electroplating; the core wire 8 is made of tungsten wire;

[0052] S2: installing the wire saw on the multi-wire cutting machine table 3, and adjusting the wire groove spacing according to the structural parameters of the microchannel to form a wire saw wire network 6;

[0053] S3: Select a diamond substrate 4, and select glass or sapphire or resin block as an auxiliary support according to its thickness for bonding, and then install the bonded body together on the workbench 3 of the wire saw multi-wire cutting machine tool, so that the diamond substrate 4 and the wire saw wire mesh 6 are in a position to be in contact;

[0054] S4: adjusting and setting the wire tension, wire speed, the speed at which the diamond substrate 4 is fed to quickly form a specified wire bow height, the feeding speed of the diamond substrate 4 after forming the specified wire bow, the wire saw reciprocating cycle and the feeding trajectory of the diamond substrate 4 of the multi-wire cutting machine;

[0055] S5: Run the processing program to make the wire saw wire mesh 6 perform periodic reciprocating motion under the drive of the machine tool drive system, and the workbench 3 quickly feeds a predetermined distance and then stops feeding to form a specified wire bow height; the active abrasive particles fixed on the wire saw wire mesh 6 are scratched on the diamond substrate 4 at high speed, reciprocatingly, and dryly, so that the active abrasive particles fixed on the wire saw interact with the diamond under pressure and temperature conditions to generate amorphous carbon, graphite and carbide, and the generated amorphous carbon, graphite and carbide are then removed by the mechanical action of the active abrasive particles, and this step is repeated to achieve microchannel processing of the diamond substrate 4; the pressure is generated by the wire bow acting on the diamond substrate, generally in the range of 0.1~10N; the temperature is generated during the high-speed, reciprocating, dry scratching of the active abrasive particles on the diamond substrate, generally in the range of 25~350℃;

[0056] S6: After the processing program is completed, the diamond substrate 4 is taken out, placed in an ultrasonic alcohol bath for cleaning, and placed in an oven for drying to obtain the final diamond microchannel substrate 1;

[0057] S7: Embed the diamond microchannel substrate 1 into the liquid flow cavity 2, achieve the bonding and sealing of the two by brazing, connect water pipes to the coolant inlet and outlet, connect to a water pump, form a liquid convection circulation loop, and finally obtain a complete U-shaped cross-section diamond microchannel radiator.

[0058] In this embodiment, before processing, the relative positions of the wire mesh 6 and the diamond matrix 4 are adjusted to form a wire bow of a certain value in advance, or the wire mesh 6 wire saw is operated at high speed, and the wire mesh 6 is quickly formed into a wire bow of a certain value through the processing program. The method of quickly forming a wire bow can accelerate the interaction between the abrasive grains and the diamond matrix 4. The height of the wire bow is 0.1 mm to 50 mm. When forming the wire bow, the speed of the diamond matrix 4 is 4 to 15 mm / min, the wire speed of the wire mesh 6 wire saw is 5 to 50 m / s, and the wire tension of the wire mesh 6 wire saw is 1 to 50 N.

[0059] In this embodiment, the active abrasive grains include active pure metal abrasive grains 7, or hard abrasive grains 10, or coated hard abrasive grains 12 wrapped with active pure metal, or a combination of active pure metal abrasive grains 7, coated hard abrasive grains 12 wrapped with active pure metal, and hard abrasive grains 10, wherein the coated hard abrasive grains 12 are formed by coating the hard abrasive grains 10 with active pure metal. The active pure metal abrasive grains 7 include a combination of one or more pure metal abrasive grains of iron, cobalt, nickel, chromium, titanium, vanadium, tungsten, molybdenum, manganese, aluminum, zirconium, lanthanum, and cerium. The hard abrasive grains 10 include a mixture of one or more of diamond, cubic boron nitride, silicon carbide, silicon oxide, aluminum oxide, copper oxide, titanium oxide, iron oxide, and cerium oxide. The particle size of the active abrasive grains is between 5 and 50 μm. The core wire 8 is an active metal wire, and the active metal wire can be one of nickel wire, steel wire, tungsten wire, molybdenum wire, and titanium wire, including but not limited to these.

[0060] When the active abrasive wire saw is prepared by brazing in step S1, the following process is included:

[0061] S11: pre-treating the tungsten wire to remove oil stains and an oxide layer; the diameter of the tungsten wire is between 30 μm and 200 μm;

[0062] S12: coating a layer of glue on the surface of the tungsten wire; and then coating the active abrasive and the metal binder 9 on the surface of the tungsten wire respectively through an electrostatic coating device, wherein the particle size of the metal binder 9 is between 200 and 600 meshes; the electrostatic voltage used is 1 to 30 kV, the distance between the upper and lower plates is 1 to 8 cm, and the wire travel speed of the tungsten wire is 2 to 5 cm / s;

[0063] S13: placing the tungsten wire coated with active abrasive and metal binder 9 into a protective atmosphere tubular furnace at a furnace temperature of 650-950° C. for heat treatment; cooling the tungsten wire after it is taken out of the furnace to obtain an active abrasive wire saw.

[0064] In this embodiment, the wire groove spacing of the wire mesh 6 wire saw is 250 μm-300 μm.

[0065] Example 3

[0066] The specific dimensions of the diamond microchannel substrate 1 structure prepared in this embodiment are L=D=5mm, H=1mm; the microchannel structure dimensions are h=750μm, a=60μm, b=300μm, and the microchannel aspect ratio is 12.5. Figures 5 to 7 , including the following steps:

[0067] S1: Prepare active abrasive wire saw by brazing method, such as Figure 7As shown; the active abrasive grains are pure metal iron abrasive grains 7; the active abrasive grain wire saw core wire 8 is tungsten wire; specifically, the tungsten wire with a diameter of 46 μm is pre-treated to remove oil stains and an oxide layer; a layer of glue is coated on the surface of the tungsten wire; and then the active pure metal iron abrasive grains with an average particle size of 10 μm and a metal binder 9 with a particle size of 400 mesh are coated by an electrostatic coating device, wherein the formula of the metal binder 9 includes 0-5% Ni, 0-20% Sn, and 0- 10% P, the rest is Cu, formed by mixing; active pure metal iron abrasive grains and metal binder 9 are coated on the surface of tungsten wire respectively, the electrostatic voltage used is 15kV, the distance between the upper and lower plates is 5cm, and the wire speed of tungsten wire is 3.5cm / s; the tungsten wire coated with active abrasive grains and metal binder 9 enters a protective atmosphere tubular furnace with a furnace temperature of 650℃ for heat treatment; after being taken out of the furnace and cooled, a pure metal iron abrasive brazed wire saw is obtained; the diameter of the wire saw finally obtained is 60μm;

[0068] S2: Selecting a wire roller 5 with a wire groove spacing of 300 μm to form a wire saw wire mesh 6 according to the structural parameters of the microchannel;

[0069] S3: According to the thickness of the diamond substrate 4, glass, sapphire or resin block is selected as an auxiliary support for bonding to form a bonded body, and then the bonded body is mounted together on the workbench 3 of the multi-wire cutting machine tool;

[0070] S4: operating the control panel of the multi-wire cutting machine tool so that the diamond substrate 4 and the wire saw wire mesh 6 are in a position to be in contact;

[0071] S5: Set the wire tension to 30N and the wire speed to 30N on the multi-wire cutting machine control panel. v s ) 20m / s, the speed at which the diamond substrate 4 is fed to quickly form a specified wire bow height ( v fz ) is 8mm / min, and the feed speed of the diamond substrate 4 after forming the specified wire bow ( v fz ) is set to 0, the reciprocating cycle of the wire saw ( T r ) 100s and diamond substrate 4 feed trajectory;

[0072] S6: Run the processing program: The wire saw wire mesh 6 is driven by the machine tool drive system to perform periodic reciprocating motion, and the workbench 3 quickly feeds 8mm and then stops feeding to form a specified wire bow height. δ= 8mm, the fixed active iron abrasive wire saw on the wire mesh 6 performs high-speed, reciprocating, dry scratching on the diamond substrate 4, and the active abrasive on the wire saw interacts with the diamond under certain pressure and temperature conditions to generate amorphous carbon, graphite and iron carbide, and the above phase change products are then removed by the mechanical action of the abrasive, and the above process is repeated to achieve efficient processing of the diamond microchannel substrate 1; in this embodiment, the pressure is measured to be 2N; the temperature is about 50°C;

[0073] S7: After the processing program is completed, the binder is removed to take out the diamond substrate 4, which is placed in an ultrasonic alcohol bath for cleaning for 5 minutes and placed in a 50° C. oven for drying for 30 minutes to obtain the final diamond microchannel substrate 1;

[0074] S8: Embed the diamond microchannel substrate 1 into the liquid flow cavity 2, achieve the bonding and sealing of the two by brazing, connect water pipes to the coolant inlet 201 and outlet 202, and connect them to a water pump to form a liquid convection circulation loop, and finally obtain a complete U-shaped cross-section diamond microchannel radiator.

[0075] Example 4

[0076] Combination Figures 1 to 4 The specific dimensions of the diamond microchannel substrate 1 structure prepared in this embodiment are L=D=10mm, H=500μm; the microchannel structure dimensions are h=360μm, a=120μm, b=300μm, and the microchannel aspect ratio is 3.

[0077] Combination Figure 5 , 6 8, comprising the following steps: the preparation steps include the following:

[0078] S1: Prepare active abrasive wire saw, such as Figure 8 As shown, the active pure metal abrasive grains 7 and diamonds are simultaneously consolidated on the surface of the tungsten wire, and are prepared by brazing; the active pure metal abrasive grains 7 are pure metal iron abrasive grains; the tungsten wire with a diameter of 100 μm is pre-treated to remove oil stains and an oxide layer; a layer of glue is coated on the surface of the tungsten wire; and then a mixture of pure metal iron abrasive grains and diamond abrasive grains with an average particle size of 20 μm and a metal binder 9 with a particle size of 400 meshes are coated by an electrostatic coating device, wherein the formula of the metal binder 9 includes 20 to 80 mass percent of Cu, 0.5 to 10% Ti, 0-0.5% Ga, and the rest Sn; then active pure metal abrasive 7, diamond, and metal binder 9 are coated on the surface of the tungsten wire respectively, the electrostatic voltage used is 25kV, the distance between the upper and lower plates is 2.5cm, and the wire speed of the tungsten wire is 5cm / s; the tungsten wire coated with active pure metal abrasive 7, diamond, and metal binder 9 is placed in a protective atmosphere tubular furnace with a furnace temperature of 850℃ for heat treatment; after being taken out of the furnace and cooled, a pure metal iron abrasive brazed wire saw is obtained; the final wire saw has a diameter of 120μm;

[0079] S2: Selecting a wire roller 5 with a wire groove spacing of 300 μm to form a wire saw wire mesh 6 according to the structural parameters of the microchannel;

[0080] S3: According to the thickness of the diamond substrate 4, glass, sapphire or resin block is selected as an auxiliary support for bonding, and then the above-mentioned bonded bodies are installed together on the workbench 3 of the wire saw multi-wire cutting machine tool;

[0081] S4: operating the control panel of the multi-wire cutting machine tool so that the diamond substrate 4 and the wire saw wire mesh 6 are in a position to be in contact;

[0082] S5: Set the wire tension to 40N and the wire speed to 40N on the multi-wire cutting machine control panel. v s ) 30m / s, the speed at which the diamond substrate 4 feeds quickly to form a specified wire bow height ( v fz ) is 4 mm / min, and the feed speed of the diamond substrate 4 after forming the specified wire bow ( v fz ) is set to 0, the reciprocating cycle of the wire saw ( T r ) 100s and diamond substrate 4 feed trajectory;

[0083] S6: Run the processing program: The wire saw wire mesh 6 is driven by the machine tool drive system to perform periodic reciprocating motion, and the workbench 3 quickly feeds 4mm and then stops feeding to form a specified wire bow height δ =4mm, the fixed active abrasive wire saw on the wire mesh 6 performs high-speed, reciprocating, dry scratching on the diamond substrate 4, and the active abrasive on the wire saw interacts with the diamond under certain pressure and temperature conditions to generate amorphous carbon, graphite and iron carbide, and the above phase change products are then removed by the mechanical action of the abrasive, and the above process is repeated to achieve efficient processing of the diamond microchannel substrate 1; the pressure in this embodiment is measured to be 1.5N; the temperature is about 40°C;

[0084] S7: After the processing program is completed, the binder is removed to take out the diamond substrate 4, which is placed in an ultrasonic alcohol bath for cleaning for 5 minutes and placed in a 50° C. oven for drying for 30 minutes to obtain the final diamond microchannel substrate 1;

[0085] S8: Embed the diamond microchannel substrate 1 into the liquid flow cavity 2, achieve the bonding and sealing of the two by brazing, connect water pipes to the coolant inlet 201 and outlet 202, and connect them to a water pump to form a liquid convection circulation loop, and finally obtain a complete U-shaped cross-section diamond microchannel radiator.

[0086] Example 5

[0087] Combination Figure 1-4 The specific dimensions of the diamond microchannel substrate 1 structure prepared in this embodiment are L=D=15mm, H=1000μm; the microchannel structure dimensions are h=750μm, a=250μm, b=450μm, and the microchannel aspect ratio is 3. Figure 5 , 6 9, comprising the following steps: The active abrasive multi-wire cutting preparation method of the heat sink comprises the following steps:

[0088] S1: Prepare active abrasive wire saw by brazing method; Fig. 9 As shown, a tungsten wire is used as a core wire 8; a coated hard abrasive grain 12 is consolidated on the surface of the tungsten wire. Specifically, the coated hard abrasive grain 12 forms a metal coating 11 on the surface of the diamond by adopting an existing process, such as a Ni coating; the formula of the metal binder 9 includes 15-25% Cu, 15-20% Zn, 0-6% Sn, and the rest is Ag; a tungsten wire with a diameter of 180 μm is pre-treated to remove oil and oxide layer; a layer of glue is coated on the surface of the tungsten wire; and then the tungsten wire is electroplated by static electricity. The electro-coating device coats the plated hard abrasive grains 12 with an average particle size of 30 μm and the metal binder 9 with a particle size of 400 mesh on the surface of the tungsten wire, respectively, with an electrostatic voltage of 30 kV, a distance between the upper and lower plates of 2.5 cm, and a wire running speed of 2.5 cm / s; the tungsten wire coated with the plated hard abrasive grains 12 and the binder is placed in a protective atmosphere tubular furnace at a furnace temperature of 700°C for heat treatment; after being taken out of the furnace and cooled, a pure metal iron abrasive brazed wire saw is obtained; the diameter of the wire saw finally obtained is 250 μm;

[0089] S2: Selecting a wire roller 5 with a wire groove spacing of 300 μm to form a wire saw wire mesh 6 according to the structural parameters of the microchannel;

[0090] S3: According to the thickness of the diamond substrate 4, glass, sapphire or resin block is selected as an auxiliary support for bonding to form a bonded body, and then the bonded body is mounted together on the workbench 3 of the multi-wire cutting machine tool;

[0091] S4: operating the control panel of the multi-wire cutting machine tool so that the diamond substrate 4 and the wire saw wire mesh 6 are in a position to be in contact;

[0092] S5: Set the wire tension to 40N and the wire speed to 40N on the multi-wire cutting machine control panel. v s ) 5m / s, the speed at which the diamond substrate 4 is fed to quickly form a specified wire bow height ( v fz ) is 4 mm / min, and the feed speed of the diamond substrate 4 after forming the specified wire bow ( v fz ) is set to 0, the reciprocating cycle of the wire saw ( Tr ) 100s and diamond substrate 4 feed trajectory;

[0093] S6: Run the processing program: The wire saw wire mesh 6 is driven by the machine tool drive system to perform periodic reciprocating motion, and the workbench 3 quickly feeds 4mm and then stops feeding to form a specified wire bow height δ =4mm, the fixed active abrasive wire saw on the wire mesh 6 performs high-speed, reciprocating, dry scratching on the diamond substrate 4, and the active abrasive on the wire saw interacts with the diamond under pressure and temperature conditions to generate amorphous carbon, graphite and carbide, and the above phase change products are then removed by the mechanical action of the abrasive, and the above process is repeated to achieve efficient processing of the diamond microchannel substrate 1; in this embodiment, the pressure is measured to be 1.5N; the temperature is about 30°C;

[0094] S7: After the processing program is completed, the binder is removed to take out the diamond substrate 4, which is placed in an ultrasonic alcohol bath for cleaning for 5 minutes and placed in a 50° C. oven for drying for 30 minutes to obtain the final diamond microchannel substrate 1;

[0095] S8: Embed the diamond microchannel substrate 1 into the liquid flow cavity 2, achieve the bonding and sealing of the two by brazing, connect water pipes to the coolant inlet 201 and outlet 202, connect to a water pump, form a circulation loop for liquid convection, and finally obtain a complete U-shaped cross-section diamond microchannel radiator.

[0096] Example 6

[0097] Combination Figure 1-4 The specific dimensions of the diamond microchannel substrate 1 structure prepared in this embodiment are L=D=10mm, H=1000μm; the microchannel structure dimensions are h=750μm, a=250μm, b=450μm, and the microchannel aspect ratio is 3. Figure 5 , 6 9. The active abrasive multi-wire cutting preparation method of the heat sink comprises the following steps:

[0098] S1, using a steel wire with a wire diameter of 180 μm as a core wire 8 and diamond abrasive grains 12 wrapped with a nickel metal coating as active abrasive grains, and preparing an electroplated active diamond abrasive grain wire saw by electroplating;

[0099] S2, selecting a wire roller 5 with a wire groove spacing of 300 μm according to the structural parameters of the microchannel to form a wire saw wire mesh 6;

[0100] S3, according to the thickness of the diamond substrate 4, select glass or sapphire or resin block as auxiliary support for bonding to form a bonded body, and then install the above bonded body together on the workbench 3 of the multi-wire cutting machine tool;

[0101] S4, operating the control panel of the multi-wire cutting machine tool so that the diamond substrate 4 and the wire saw wire mesh 6 are in a position to be in contact;

[0102] S5. Set the wire tension to 30N and the wire speed to 30N on the multi-wire cutting machine control panel. v s ) 15m / s, the speed at which the diamond substrate 4 feeds quickly to form a specified wire bow height ( v fz ) is 6mm / min, and the feed speed of the diamond substrate 4 after forming the specified wire bow ( v fz ) is set to 0, the reciprocating cycle of the wire saw ( T r ) 100s and diamond substrate 4 feed trajectory;

[0103] S6, run the processing program: the wire saw wire net 6 is driven by the machine tool drive system to perform periodic reciprocating motion, the workbench 3 quickly feeds 6mm and then stops feeding, forming a specified wire bow height δ =6mm, the electroplated diamond wire saw on the wire mesh 6 performs high-speed, reciprocating, dry scratching on the diamond substrate 4, and the active abrasive particles wrapped with nickel metal on the wire saw interact with the diamond under pressure and temperature conditions to generate amorphous carbon, graphite and carbide, and the above phase change products are then removed by the mechanical action of the abrasive particles, and the above process is repeated to achieve efficient processing of the diamond microchannel substrate 1; in this embodiment, the pressure is measured to be 1.5N; the temperature is about 35°C;

[0104] S7, after the processing program is completed, remove the binder to take out the diamond substrate 4, place it in an ultrasonic alcohol bath for cleaning for 5 minutes, and place it in a 50° C. oven for drying for 30 minutes to obtain the final diamond microchannel substrate 1; Fig.10 and Fig.11 Top view and side view of the processed diamond microchannel.

[0105] S8. Embed the diamond microchannel substrate 1 into the liquid flow cavity 2, achieve the bonding and sealing of the two by brazing, connect water pipes to the cooling liquid inlet 201 and outlet 202, connect to a water pump, form a circulation loop for liquid convection, and finally obtain a complete U-shaped cross-section diamond microchannel radiator.

[0106] In the above embodiment, a wire saw with active abrasive particles fixed thereon is used as a cutting tool, and a multi-wire cutting machine is used as a processing equipment. By making the wire mesh 6 quickly form a wire bow, the active abrasive wire saw is used to dryly scratch the diamond substrate 4 at a high wire speed in a reciprocating manner under pressure. Under the action of the active abrasive particles, the diamond surface undergoes a phase change to generate amorphous carbon, graphite or carbide, and then the phase change products are removed by the mechanical action of the active abrasive particles to expose a fresh diamond surface. The above process is repeated in this way to achieve efficient and high-quality processing of the diamond microchannel heat sink.

[0107] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0108] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. A method for preparing a diamond microchannel heat sink, characterized in that: include: A liquid flow chamber with a coolant inlet and an outlet and a diamond microchannel substrate suitable for being installed in the liquid flow chamber, wherein the preparation of the diamond microchannel substrate comprises the following steps: S1: Prepare active abrasive wire saw, fix active abrasive grains on the core wire by brazing, sintering or electroplating; or use active metal wire as wire saw cutting tool; S2: The wire saw is mounted on a multi-wire cutting machine workbench, and the wire groove spacing is adjusted according to the structural parameters of the microchannel to form a wire saw wire network; S3: Select a diamond substrate, and select glass or sapphire or resin block as auxiliary support according to its thickness to form a laminated body, and then install the laminated body on the workbench of the wire saw multi-wire cutting machine tool, so that the diamond substrate and the wire saw wire net are in a position to be in contact; S4: adjusting and setting the wire tension, wire speed, the speed at which the diamond substrate is fed to quickly form a specified wire bow height, the feeding speed of the diamond substrate after forming the specified wire bow, the reciprocating cycle of the wire saw and the feeding trajectory of the diamond substrate; S5: Run the processing program to make the wire saw wire mesh perform periodic reciprocating motion under the drive system of the machine tool, and the worktable quickly feeds a predetermined distance and then stops feeding to form a specified wire bow height; the active abrasive grains fixed on the wire saw wire mesh perform high-speed, reciprocating, and dry scratching on the diamond matrix, so that the active abrasive grains fixed on the wire saw interact with the diamond under pressure and temperature conditions to generate amorphous carbon, graphite and carbide, and the generated amorphous carbon, graphite and carbide are then removed by the mechanical action of the active abrasive grains, and this step is repeated to achieve microchannel processing of the diamond matrix; S6: After the processing program is completed, the diamond substrate is taken out, cleaned in an ultrasonic alcohol bath, and dried in an oven to obtain the final diamond microchannel substrate; S7: The diamond microchannel substrate is embedded in the liquid flow cavity, and the two are bonded and sealed by bonding. Water pipes are connected to the coolant inlet and outlet and connected to a water pump to form a liquid convection circulation loop, and finally a complete U-shaped cross-section diamond microchannel radiator is obtained.

2. The method for preparing a diamond microchannel heat sink according to claim 1, characterized in that: The active abrasive grains include active pure metal abrasive grains, or hard abrasive grains, or coated hard abrasive grains encapsulating active pure metal, or a combination of active pure metal abrasive grains, coated hard abrasive grains encapsulating active pure metal, and hard abrasive grains.

3. The method for preparing a diamond microchannel heat sink according to claim 1, characterized in that: The active metal wire includes one of nickel wire, steel wire, tungsten wire, molybdenum wire and titanium wire.

4. The method for preparing a diamond microchannel heat sink according to claim 2, characterized in that: The active pure metal abrasive includes a combination of one or more of iron, cobalt, nickel, chromium, titanium, vanadium, tungsten, molybdenum, manganese, aluminum, zirconium, lanthanum, and cerium pure metal abrasives; the hard abrasive includes a mixture of one or more of diamond, cubic boron nitride, silicon carbide, silicon oxide, aluminum oxide, copper oxide, titanium oxide, iron oxide, and cerium oxide.

5. The method for preparing a diamond microchannel heat sink according to claim 4, characterized in that: When the active abrasive wire saw is prepared by brazing, step S1 includes the following process: S11: Pre-treat the tungsten wire to remove oil stains and oxide layer; S12: Coat a layer of glue on the surface of the tungsten wire; then use an electrostatic coating device to coat the active abrasive and metal binder on the surface of the tungsten wire respectively, the electrostatic voltage used is 1~30kV, the distance between the upper and lower plates is 1~8cm, and the wire speed of the tungsten wire is 2~4cm / s; S13: placing the tungsten wire coated with active abrasive and metal binder into a protective atmosphere tubular furnace at a furnace temperature of 650-950° C. for heat treatment; cooling the tungsten wire after it is taken out of the furnace to obtain an active abrasive wire saw.

6. The method for preparing a diamond microchannel heat sink according to claim 5, characterized in that: When the active pure metal abrasive grains are fixed on the surface of the tungsten wire, the formula of the metal binder includes 0-5% by mass of Ni, 0-20% by mass of Sn, 0-10% by mass of P, and the rest is Cu.

7. The method for preparing a diamond microchannel heat sink according to claim 5, characterized in that: When active pure metal abrasive grains and diamonds are simultaneously consolidated on the surface of the tungsten wire, the formula of the metal binder includes 20-80 mass percent of Cu, 0.5-10 mass percent of Ti, 0-0.5 mass percent of Ga, and the rest of Sn.

8. The method for preparing a diamond microchannel heat sink according to claim 6, characterized in that: When the coated hard abrasive grains are consolidated on the surface of the tungsten wire, the coated hard abrasive grains are formed by coating a Ni layer on the surface of the diamond; the formula of the metal binder includes 15-25 mass percent of Cu, 15-20 mass percent of Zn, 0-6 mass percent of Sn, and the rest is Ag.

9. The method for preparing a diamond microchannel heat sink according to claim 1, characterized in that: The height of the wire bow is 0.1mm~50mm.

10. A diamond microchannel heat sink, characterized in that: The diamond microchannel heat sink is prepared by the preparation method of the diamond microchannel heat sink according to any one of claims 1 to 9.

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