A heat pipe vapor chamber welding process based on heat conduction

Abstract

The application discloses a heat pipe heat sink welding process based on heat conduction and belongs to the technical field of welding. The welding equipment is composed of a vacuum box, a control box, an electromagnetic device, a heating plate, a control box, a vacuum straight-through pipe with a water cooling jacket, a water pipe, a vacuum variable-diameter cross pipe, a gas release valve, a vacuum valve, a condenser, a vacuum bellows, a vacuum pump, a baffle valve, a gas collecting pipe, a smoke hood, a liquid cooling source and a smoke purifier. The application has the advantages that the problems of product performance decline and even scrapping caused by the floating of the heat pipe in the traditional welding process are perfectly solved, the welding quality is improved, the vacuum pump is protected and the service life of the vacuum pump is prolonged, the process is simple and easy to implement, and the production cost can be greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding, in particular to a heat pipe vapor chamber welding process based on heat conduction. BACKGROUND

[0002] The heat pipe vapor chamber is a copper heat pipe embedded in an aluminum substrate by welding. The heat pipe vapor chamber has the advantages of high heat transfer efficiency, low cost, short production cycle, etc., and is suitable for eliminating single-point heat sources and single-point heat sources with high power. However, the current production process is complex, and the yield of the product is relatively low. The reason is that there are a large number of bubbles in the molten filler during the welding process, which causes a large number of voids in the welding layer after welding, and the performance of the product is reduced due to the upward floating of the heat pipe during the welding process, even scrapped, etc.

[0003] Chinese patent (invention patent number: ZL201811606251.9) discloses a "production process of heat pipe-aluminum alloy heat sink", which proposes to design a positioning convex body on the heat pipe-aluminum alloy heat sink. During the process of flattening the heat pipe by the press or any tool, the positioning convex body contacts and extrudes the heat pipe and forms a pressure mark on the heat pipe, so as to clamp the heat pipe. Although this method can avoid the problem of performance reduction or even scrapping of the product due to the upward floating of the heat pipe during the welding process, it still has a problem that cannot be ignored, that is, the internal structure of the heat pipe is damaged during the process of flattening the heat pipe to make it flat, thereby reducing the heat conduction performance of the heat pipe.

[0004] Therefore, how to avoid the problem of a large number of voids in the welding layer due to a large number of bubbles in the molten filler during the welding process, and the problem of performance reduction or even scrapping of the product due to the upward floating of the heat pipe during the welding process, without affecting the heat conduction performance of the heat pipe itself, is a difficult problem that needs to be solved. SUMMARY

[0005] The purpose of the present application is to solve the problems of the prior art, and to provide a heat pipe vapor chamber welding device and process based on heat conduction.

[0006] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A heat pipe vapor chamber welding device based on heat conduction, comprising:

[0008] A vacuum box is provided with a through hole at the top, and a vacuum straight pipe with a water cooling jacket and a vacuum joint at one end is welded at this position. The vacuum box contains one or more heating plates fixed on the bottom surface of the vacuum box.

[0009] A control box is located at the bottom of the vacuum box and contains a plurality of electromagnetic devices and a control box.

[0010] A liquid cooling source, wherein the inlet / outlet of the liquid cooling source is connected to the inlet / outlet of the water cooling jacket via a water pipe;

[0011] The vacuum reducing diameter four-way pipe is a vacuum reducing diameter four-way pipe with vacuum connectors at all four ports. One port of the vacuum reducing diameter four-way pipe is connected to the port of the aforementioned vacuum straight pipe with a vacuum connector. The other port, which is parallel to the plane of the aforementioned port, is connected to one port of the baffle valve. Of the remaining two ports of the vacuum reducing diameter four-way pipe, one port is connected to the vent valve, and the other port is connected to one port of the vacuum valve.

[0012] A vacuum pump, the inlet of which is connected to the outlet of a condenser, and the inlet of the condenser is connected to the other end of the aforementioned vacuum valve. The outlet of the vacuum pump is connected to a gas collection pipe.

[0013] The gas collection pipe is a three-way pipe with a vacuum connector at one port. The port with the vacuum connector is connected to the other port of the baffle valve. The other port, which is parallel to the plane of the first port, is located below the fume hood. The remaining port is connected to the outlet of the vacuum pump through a vacuum bellows.

[0014] A smoke purifier, wherein the smoke hood of the smoke purifier is positioned above the gas collection pipe.

[0015] Furthermore, the axis of the electromagnet in the electromagnetic device is perpendicular to the bottom of the vacuum chamber.

[0016] Furthermore, the control box is used for controlling the electromagnetic device and the heating platform.

[0017] Furthermore, the overlapping surfaces of the vacuum chamber and the control box are made of pure iron, while the remaining surfaces of the vacuum chamber and the control box are made of stainless steel.

[0018] Furthermore, the vacuum valve is a KF / CF vacuum ball valve, a KF / CF vacuum butterfly valve, or a KF / CF vacuum baffle valve.

[0019] Furthermore, the baffle valve is a KF / CF vacuum butterfly valve or a KF / CF vacuum baffle valve.

[0020] Furthermore, the condenser is a heat exchanger.

[0021] A heat pipe vapor chamber welding process based on heat conduction includes the following steps:

[0022] Step 1, nickel plating: plate a layer of nickel onto the surface of the heat pipe and the grooves embedded in the heat pipe.

[0023] Step 2, Assembly: Place the nickel-plated heat pipe into the nickel-plated heat pipe tank, and then evenly coat the heat pipe tank with low-temperature solder.

[0024] Step 3: Place the heat pipe heat spreader into the welding equipment, close the vacuum chamber door, place the assembled heat pipe heat spreader onto the heating plate inside the vacuum chamber, and close the vacuum chamber door.

[0025] Step 4: Turn on the electromagnetic device and power it through the control box to generate an electromagnetic field, so that the nickel-plated heat pipe is firmly attached to the bottom of the heat pipe tank.

[0026] Step 5: Turn on the heating device and control the heating plate through the control box to raise its temperature according to the set temperature curve, so that the low-temperature solder melts.

[0027] Step 6: Close the vacuum valve, open the baffle valve, and turn on the fume purifier to allow the toxic and harmful gases generated when the low-temperature brazing filler metal melts to enter the gas collection pipe smoothly, and then the exhaust gas in the gas collection pipe is sucked away by the fume purifier.

[0028] Step 7: Close the baffle valve, turn on the vacuum pump, and open the vacuum valve. After the low-temperature brazing filler metal has melted for a period of time and there is no obvious visible smoke emission, close the baffle valve, then turn on the vacuum pump, and then open the vacuum valve to evacuate the vacuum chamber. The exhaust gas discharged by the vacuum pump enters the gas collection pipe and is then sucked away by the smoke purifier.

[0029] Step 8: Close the vacuum valve and turn off the vacuum pump. Once the vacuum chamber reaches the specified vacuum level, first close the vacuum valve and then turn off the vacuum pump.

[0030] Step 9, vacuum degassing. In a vacuum environment, due to the pressure difference between the inside and outside of the molten solder, the air bubbles in the molten solder can easily escape until no air bubbles are generated on the surface of the molten solder.

[0031] Step 10: Open the vent valve. After the vacuum venting is completed, open the vent valve to gradually equalize the air pressure inside the vacuum chamber with the air pressure outside the chamber.

[0032] Step 11: Turn off the heating platform. After opening the vent valve, the heating platform can be turned off through the control box.

[0033] Step 12: Close the vent valve and open the baffle valve. When the air pressure inside the vacuum chamber is equal to the air pressure outside the chamber, you can close the vent valve and open the baffle valve.

[0034] Step 13, cooling and solidification: As the heating platform is turned off, the temperature of the heat pipe heat spreader gradually decreases, and the low-temperature brazing filler metal in the molten state gradually cools and solidifies.

[0035] Step 14: Turn off the electromagnetic device. When the temperature of the heat pipe heat exchanger plate drops to a certain temperature and the low-temperature brazing filler metal solidifies, the electromagnetic device can be turned off.

[0036] Step 15: Turn off the fume purifier, open the vacuum chamber door, and take out the workpiece. That is, after turning off the electromagnetic device, immediately turn off the fume purifier, then open the vacuum chamber door and take out the welded heat pipe heat spreader.

[0037] Furthermore, the thickness of the nickel plating layer on the heat pipe is 30µm to 100µm.

[0038] Furthermore, the low-temperature solder is a tin-lead solder, tin-silver-lead solder, tin-bismuth solder, or tin-bismuth-silver solder with a melting point below 200 degrees Celsius.

[0039] The beneficial effects of the above-mentioned technical solution adopted by the present invention are as follows:

[0040] 1. After the copper heat pipe is nickel-plated, it remains firmly fixed in the bottom of the heat pipe groove due to the electromagnetic attraction generated by the electromagnetic field generated after the electromagnetic device is energized. This avoids the need for mechanical fixing methods that affect the thermal performance of the heat pipe in traditional methods. The welding equipment and process proposed in this invention perfectly solve the problems of product performance degradation or even scrapping caused by the heat pipe floating during traditional welding processes.

[0041] 2. This invention adopts a more scientific welding process. The low-temperature brazing filler metal contains a corresponding flux. During the heating process, the flux reduces oxidation, improves the brazing filler metal's wetting ability on the base material, and effectively dissolves or destroys the oxide film on the surface of the workpiece and the brazing filler metal. After the brazing filler metal has completely melted and the flux has evaporated, vacuum degassing is then performed. This not only improves welding quality but also protects the vacuum pump and extends its service life.

[0042] 3. The present invention proposes a heat pipe heat exchanger welding equipment and process based on heat conduction. The process is simple, easy to implement, and can greatly reduce production costs. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a heat pipe heat exchanger welding device based on heat conduction proposed in Embodiment 1 of the present invention.

[0044] In the diagram: 1. Vacuum chamber, 2. Control box, 3. Electromagnetic device, 4. Heating plate, 5. Control box, 6. Vacuum straight pipe with water-cooled jacket, 7. Water pipe, 8. Vacuum reducing four-way pipe, 9. Venting valve, 10. Vacuum valve, 11. Condenser, 12. Vacuum bellows, 13. Vacuum pump, 14. Baffle valve, 15. Gas collection pipe, 16. Fume hood, 17. Liquid cooling source, 18. Smoke purifier. Detailed Implementation

[0045] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Reference Figure 1 As shown, this embodiment of a heat pipe vapor chamber welding device based on heat conduction includes:

[0048] Vacuum chamber 1, with a through hole at the top, and a vacuum straight pipe 6 with a water-cooled jacket and a vacuum connector at one end welded at this position. Vacuum chamber 1 contains one or more heating plates 4, which are fixed to the bottom surface of vacuum chamber 1.

[0049] Control box 2, located at the bottom of vacuum chamber 1, includes four electromagnetic devices 3 and a control box 5;

[0050] Liquid cooling source 17, the inlet / outlet of the liquid cooling source 17 is connected to the inlet / outlet of the water cooling jacket via water pipe 7;

[0051] Vacuum reducing four-way pipe 8, wherein the vacuum reducing four-way pipe 8 is a vacuum reducing four-way pipe with vacuum connectors at all four ports. One end of the vacuum reducing four-way pipe 8 is connected to the port with the vacuum connector of the aforementioned vacuum straight pipe 6, and the other port, which is parallel to the plane of the port, is connected to the port of the baffle valve 14. Of the remaining two ports, one port is connected to the vent valve 9, and the other port is connected to one end of the vacuum valve 10.

[0052] A vacuum pump 13 is provided, with its inlet connected to the outlet of a condenser 11, and the inlet of the condenser 11 connected to the other end of the vacuum valve 10. The outlet of the vacuum pump 13 is connected to a gas collection pipe 15.

[0053] Gas collection pipe 15, the gas collection pipe 15 is a three-way pipe with a vacuum connector at one port, the port with the vacuum connector is connected to the baffle valve 14, the other port parallel to the plane of the port is placed below the fume hood 16, and the remaining port is connected to the outlet of the vacuum pump 13 through the bellows 12.

[0054] The smoke purifier 18 has a smoke hood 16 (with a funnel-shaped structure) positioned above the gas collection pipe.

[0055] Furthermore, the electromagnetic device is perpendicular to the bottom of the vacuum chamber.

[0056] Furthermore, the control box is used for controlling the electromagnetic device and the heating platform.

[0057] Furthermore, the overlapping surfaces of the vacuum chamber and the control box are made of pure iron, while the remaining surfaces of the vacuum chamber and the control box are made of stainless steel.

[0058] Furthermore, the vacuum valve is selected as a KF vacuum ball valve.

[0059] Furthermore, the baffle valve is selected as a KF vacuum baffle valve.

[0060] Furthermore, the condenser is selected from heat exchangers.

[0061] This embodiment of a heat pipe vapor chamber welding process based on heat conduction specifically includes the following steps:

[0062] Step 1, nickel plating: plate a layer of nickel onto the surface of the heat pipe and the grooves embedded in the heat pipe.

[0063] Step 2, Assembly: Place the nickel-plated heat pipe into the nickel-plated heat pipe tank, and then evenly coat the heat pipe tank with low-temperature solder.

[0064] Step 3: Place the heat pipe heat spreader into the welding equipment, close the vacuum chamber door, place the assembled heat pipe heat spreader onto the heating plate inside the vacuum chamber, and close the vacuum chamber door.

[0065] Step 4: Turn on the electromagnetic device and power it through the control box to generate an electromagnetic field, so that the nickel-plated heat pipe is firmly attached to the bottom of the heat pipe tank.

[0066] Step 5: Turn on the heating device and control the heating plate through the control box to raise its temperature according to the set temperature curve, so that the low-temperature solder melts.

[0067] Step 6: Close the vacuum valve, open the baffle valve, and turn on the fume purifier. After turning on the heating device, close the vacuum valve and open the baffle valve to allow the toxic and harmful gases generated when the low-temperature brazing filler melts to enter the gas collection pipe smoothly. Then, the exhaust gas in the gas collection pipe is sucked away by the fume purifier.

[0068] Step 7: Close the baffle valve, turn on the vacuum pump, open the vacuum valve, and after the low-temperature brazing filler metal has melted for a period of time and there is no obvious visible smoke emission, close the baffle valve, then turn on the vacuum pump, and then open the vacuum valve to evacuate the vacuum chamber. The exhaust gas discharged by the vacuum pump enters the gas collection pipe and is then sucked away by the smoke purifier.

[0069] Step 8: Close the vacuum valve and turn off the vacuum pump. Once the vacuum chamber reaches the specified vacuum level, first close the vacuum valve and then turn off the vacuum pump.

[0070] Step 9, vacuum degassing. In a vacuum environment, due to the pressure difference between the inside and outside of the molten solder, the air bubbles in the molten solder can easily escape until no air bubbles are generated on the surface of the molten solder.

[0071] Step 10: Open the vent valve. After the vacuum venting is completed, open the vent valve to gradually equalize the air pressure inside the vacuum chamber with the air pressure outside the chamber.

[0072] Step 11: Turn off the heating platform. After opening the vent valve, the heating platform can be turned off through the control box.

[0073] Step 12: Close the vent valve and open the baffle valve. When the air pressure inside the vacuum chamber is equal to the air pressure outside the chamber, you can close the vent valve and open the baffle valve.

[0074] Step 13, cooling and solidification: As the heating platform is turned off, the temperature of the heat pipe heat spreader gradually decreases, and the low-temperature brazing filler metal in the molten state gradually cools and solidifies.

[0075] Step 14: Turn off the electromagnetic device. When the temperature of the heat pipe heat exchanger plate drops to a certain temperature and the low-temperature brazing filler metal solidifies, the electromagnetic device can be turned off.

[0076] Step 15: Turn off the fume purifier, open the vacuum chamber door, take out the workpiece, turn off the electromagnetic device, then immediately turn off the fume purifier, then open the vacuum chamber door and take out the welded heat pipe heat spreader.

[0077] Furthermore, the nickel plating layer on the heat pipe has a thickness of 50µm.

[0078] Furthermore, the low-temperature solder is a tin-bismuth solder.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A welding process for heat pipe vapor chambers based on heat conduction, characterized in that, A heat pipe vapor chamber welding device based on heat conduction is used. The device includes: a vacuum chamber with a through hole at the top, where a vacuum straight pipe with a water-cooled jacket and a vacuum connector at one end is welded; one or more heating plates fixed to the bottom of the vacuum chamber; a control box located at the bottom of the vacuum chamber, containing multiple electromagnetic devices and a control housing; a liquid cooling source with its inlet / outlet connected to the inlet / outlet of the water-cooled jacket via water pipes; and a vacuum reducing four-way pipe with vacuum connectors at all four ports. One end of the reducing four-way pipe is connected to the vacuum straight pipe with a vacuum connector, and the other port, parallel to the plane of that port, is connected to a port of a baffle valve. Of the remaining two ports of the four-way pipe, one port is connected to the vent valve, and the other port is connected to one end of the vacuum valve; the vacuum pump has its inlet connected to the outlet of the condenser, the inlet of the condenser connected to the other end of the aforementioned vacuum valve, and its outlet connected to the gas collection pipe; the gas collection pipe is a three-way pipe with a vacuum connector at one port, the port with the vacuum connector connected to the other port of the baffle valve, and the other port, parallel to the plane of the first port, is placed below the fume hood; the remaining port is connected to the outlet of the vacuum pump via a vacuum bellows; the fume hood of the fume hood is placed above the gas collection pipe; a heat pipe heat spreader welding process based on heat conduction specifically includes the following steps: Step 1, nickel plating: plate a layer of nickel onto the surface of the heat pipe and the grooves embedded in the heat pipe. Step 2, Assembly: Place the nickel-plated heat pipe into the nickel-plated heat pipe tank, and then evenly coat the heat pipe tank with low-temperature solder. Step 3: Place the heat pipe heat spreader into the welding equipment, close the vacuum chamber door, place the assembled heat pipe heat spreader onto the heating plate inside the vacuum chamber, and close the vacuum chamber door. Step 4: Turn on the electromagnetic device and power it through the control box to generate an electromagnetic field, so that the nickel-plated heat pipe is firmly attached to the bottom of the heat pipe tank. Step 5: Turn on the heating device and control the heating plate through the control box to raise its temperature according to the set temperature curve, so that the low-temperature solder melts. Step 6: Close the vacuum valve, open the baffle valve, and turn on the fume purifier to allow the toxic and harmful gases generated when the low-temperature brazing filler metal melts to enter the gas collection pipe smoothly, and then the exhaust gas in the gas collection pipe is sucked away by the fume purifier. Step 7: Close the baffle valve, turn on the vacuum pump, and open the vacuum valve. After the low-temperature brazing filler metal has melted for a period of time and there is no obvious visible smoke emission, close the baffle valve, then turn on the vacuum pump, and then open the vacuum valve to evacuate the vacuum chamber. The exhaust gas discharged by the vacuum pump enters the gas collection pipe and is then sucked away by the smoke purifier. Step 8: Close the vacuum valve and turn off the vacuum pump. Once the vacuum chamber reaches the specified vacuum level, first close the vacuum valve and then turn off the vacuum pump. Step 9, vacuum degassing. In a vacuum environment, due to the pressure difference between the inside and outside of the molten solder, the air bubbles in the molten solder can easily escape until no air bubbles are generated on the surface of the molten solder. Step 10: Open the vent valve. After the vacuum venting is completed, open the vent valve to gradually equalize the air pressure inside the vacuum chamber with the air pressure outside the chamber. Step 11: Turn off the heating platform. After opening the vent valve, the heating platform can be turned off through the control box. Step 12: Close the vent valve and open the baffle valve. When the air pressure inside the vacuum chamber is equal to the air pressure outside the chamber, you can close the vent valve and open the baffle valve. Step 13, cooling and solidification: As the heating platform is turned off, the temperature of the heat pipe heat spreader gradually decreases, and the low-temperature brazing filler metal in the molten state gradually cools and solidifies. Step 14: Turn off the electromagnetic device. When the temperature of the heat pipe heat exchanger plate drops to a certain temperature and the low-temperature brazing filler metal solidifies, the electromagnetic device can be turned off. Step 15: Turn off the fume purifier, open the vacuum chamber door, and take out the workpiece. That is, after turning off the electromagnetic device, immediately turn off the fume purifier, then open the vacuum chamber door and take out the welded heat pipe heat spreader.

2. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The thickness of the nickel plating layer on the heat pipe is 30µm to 100µm.

3. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The low-temperature solder is tin-lead solder, tin-silver-lead solder, tin-bismuth solder, or tin-bismuth-silver solder with a melting point below 200 degrees Celsius.

4. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, In the electromagnetic device, the axis of the electromagnet is perpendicular to the bottom of the vacuum chamber.

5. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The control box is used to control the electromagnetic device and the heating platform.

6. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The overlapping surfaces of the vacuum chamber and the control box are made of pure iron, while the remaining surfaces of the vacuum chamber and the control box are made of stainless steel.

7. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The vacuum valve is a KF / CF vacuum ball valve, a KF / CF vacuum butterfly valve, or a KF / CF vacuum baffle valve.

8. The welding process for a heat pipe vapor chamber based on heat conduction according to claim 1, characterized in that, The baffle valve is a KF / CF vacuum butterfly valve or a KF / CF vacuum baffle valve.

9. The welding process for a heat pipe vapor chamber based on thermal conduction according to claim 1, characterized in that, The condenser is a heat exchanger.

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