High-porosity copper fiber vapor chamber

Abstract

The utility model discloses a high porosity copper fiber vapor chamber, which comprises an upper shell and a lower shell, a wick and a support column are arranged between the upper shell and the lower shell, the support column is a copper column with uniform specification, and the wick is made of high porosity copper fiber. And the porosity of the copper fiber is 10%-65%. The diameter of the copper column is 5mm. The copper fibers are prepared through a thread throwing method, the porosity of the copper fibers can be higher than that of cold-drawn copper wires, and the heat exchange efficiency of the vapor chamber is higher. The structure of the vapor chamber is synergistically simplified, copper columns of multiple specifications are unified into copper columns of small specifications, and good heat dissipation efficiency can still be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electronic components, especially to a high porosity copper fiber vapor chamber. BACKGROUND

[0002] With the continuous development of electronic industry, electronic equipment is developing rapidly towards miniaturization and integration. The increase of component power consumption and the reduction of component size make the heat flow density of electronic equipment higher and higher. The heat flow density of some products has exceeded 200W / cm 2 . The operation of electronic equipment at high temperature will lead to the reduction of reliability and service life.

[0003] In the current consumer electronics field, the heat dissipation schemes mainly include heat pipes, graphene heat conduction films, graphite sheets and vapor chambers. As a two-phase heat sink driven by capillary tubes, the vapor chamber has become a research hotspot in the current heat dissipation field. Compared with other heat dissipation schemes, the vapor chamber has many advantages, including strong heat conduction performance, good temperature equalization effect, excellent corrosion resistance, high heat dissipation power, ability to adapt to various structures and light weight.

[0004] With the popularization and application of 5G technology, the processing capacity and performance requirements of mobile devices are becoming higher and higher, so the heat dissipation problem becomes particularly important. As a high-efficiency heat dissipation solution, the vapor chamber can effectively handle the heat generated by high heat flow density devices and ensure the normal operation of the devices. Therefore, the position of the vapor chamber in the 5G smartphone market is continuously improving, and the market demand is continuously growing, showing a broad development prospect. Analysis shows that as the mainstream heat dissipation scheme of 5G smartphones, the market demand for vapor chambers has been continuously released in recent years, the market penetration rate has been continuously improved, and the industry development prospect is good. In the future, with the continuous development of domestic 5G smartphones and tablet computers towards high power, thin and light and high performance, ultra-thin, high-quality and high-end vapor chambers will become the mainstream development trend of the industry.

[0005] In the vapor chamber, the wick is an important component. It plays a role in accelerating the evaporation efficiency of the liquid working medium at the evaporation end, and improves the condensation efficiency of the vapor at the condensation end. The wick at the evaporation end and the condensation end together promotes the evaporation-condensation cycle of the vapor chamber. Some types of wick structure can generate strong capillary pressure to drive the condensation working medium to flow back from the condensation end to the evaporation end, thereby improving the evaporation-condensation cycle capacity of the vapor chamber. Therefore, the structure of the wick has an important influence on the heat transfer performance of the vapor chamber.

[0006] At present, the commonly used wicks of ultra-thin vapor chambers include micro-groove type, powder sintering type, foam metal type, wire mesh sintering type and composite structure type, etc. Figure 1It is a kind of now widely used hot plate, including upper shell, lower shell, upper and lower shell is equipped with braided copper mesh as liquid absorption core, the braided copper mesh is generally woven by cold-drawn steel wire, and the porosity is relatively low, generally about 5%, and different specifications of copper column are also provided as support column. Such hot plate structure is relatively complex, and the overall heat dissipation efficiency is low due to the limited heat dissipation of cold-drawn steel wire. Practical new type content

[0007] The technical problem to be solved by the present application is to provide a hot plate with a simpler structure, and the copper fiber prepared by the spinning method is used as the heat transfer medium, and the overall heat transfer efficiency is higher.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is:

[0009] A high-porosity copper fiber hot plate, comprising an upper shell and a lower shell, a liquid absorption core and a support column are arranged between the upper shell and the lower shell, characterized in that the support column is a copper column with uniform specifications, and the liquid absorption core is a high-porosity copper fiber.

[0010] Further, the porosity of the copper fiber is 10% to 65%, and the diameter of the copper column is 5mm.

[0011] The beneficial effects that can be achieved by the present application are:

[0012] 1. The copper fiber in the present application is prepared by the spinning method, which can achieve higher porosity than cold-drawn copper wire, and the heat exchange efficiency of the hot plate is higher.

[0013] 2. The structure of the hot plate is simplified in the present application, and the copper columns of multiple specifications are unified into one specification, and still can achieve good heat dissipation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, and the drawings in the following description are only some embodiments of the present application, wherein:

[0015] Figure 1 It is a schematic diagram of the internal structure of the hot plate in the prior art;

[0016] Figure 2 It is a schematic diagram of the internal structure of the hot plate of the present application.

[0017] Figure 3 It is a schematic diagram of the appearance of the hot plate of the present application. DETAILED DESCRIPTION

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. The structures, proportions, sizes, etc., shown in the drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives of the present invention, should still fall within the scope of the technical content disclosed in the present invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are only for clarity of description and are not intended to limit the scope of the present invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the present invention.

[0019] See Figure 2 , Figure 3 This is a schematic diagram of the internal structure of a heat spreader plate according to an embodiment of the present invention. It includes an upper shell 1 and a lower shell 2, with several copper pillars 3 arranged between the upper and lower shells as support pillars. In this embodiment, the diameter of the copper pillars is 5 mm, and a uniform specification can be used, saving on manufacturing process. The liquid absorption core in this embodiment is made of pure copper as raw material, prepared by the wire spinning method, and then stamped and sintered. It is evenly distributed on the upper and lower shells and arranged around the copper pillars.

[0020] The process of preparing copper fibers by the specific spinning method is as follows. Pure copper is placed in a crucible extraction device to prepare flexible and uniform copper fibers. Then, granular pure copper raw material is placed in a specially designed cylindrical glass crucible. The glass crucible has a circular hole with a diameter of 0.5 mm at the bottom and is open at the top for placing the sample. The top has a flange for fixing and positioning when the crucible is installed in the device. The crucible with the raw material in it is placed in the crucible melting extraction device and fixed in the vacuum chamber of the crucible melting extraction device. The crucible is located above the graphite spinning roller and in the center of the heating coil. The upper end of the crucible is connected to an argon source. After the crucible is fixed to the device, the water cooling device connected to the heating coil and the graphite spinning roller is started. The vacuum chamber is evacuated, then filled with argon, and at the same time, an external buffer tank is filled with argon, so that the gas pressure in the buffer tank is greater than that in the vacuum chamber. The graphite roller power is started to rotate along the horizontal axis, and the heating coil is started to melt the raw material in the crucible by induction heating. After waiting for the pure copper raw material to fully melt and have sufficient fluidity, the gas path from the buffer tank to the crucible is opened and quickly closed to generate a downward pressure in the crucible to push the molten material onto the graphite roller. The material will quickly cool when it contacts the surface of the graphite roller and be spun out to the side by the rapidly rotating graphite roller, allowing the material to further cool into copper fibers.

[0021] Further, the process of punching copper fibers to prepare shaped products is as follows: a set of aluminum alloy molds is prepared, which is divided into an upper cover, a base and a shell. The combination of the three parts is the mold, and the internal space is the shape of the vapor chamber wick. The internal cavity of this aluminum alloy mold is used to control the shape of the metal fibers after pressing. In addition, the mold base is provided with a plurality of protruding cylinders to reserve space for placing support columns. To avoid interference, the mold upper cover is also designed with corresponding through holes for displacement during pressing. This aluminum alloy mold can be further designed to be suitable for batch production on a punch press. By adding a pop-up design to the base, the mold can be removed from the punch press without affecting the production cycle. After the aluminum alloy mold is prepared, the weight of the copper fibers is measured, and the specified weight of the fibers is placed in the mold combination of the shell and the base, and the mold top cover is placed. The semi-finished product can reach the specified thickness by mechanical pressing on the punch press. The thickness of the semi-finished product after pressing on the punch press can also become more uniform.

[0022] Further, the process of sintering the semi-finished block into a porous flexible solid is as follows: a set of graphite molds is prepared, which is divided into an upper cover, a base and an outer shell, and the combination of the three parts is the mold, and the internal space is the shape of the wick. Since the metal fibers need to be sintered after being pressed into a shape to improve the integrity and strength of the porous metal fibers, the graphite mold can be used to hold the sample in a high temperature environment to assist in sintering. The base and the outer shell of the graphite mold are combined, then the pressed pure copper wick semi-finished product is placed in, then the upper cover of the graphite mold is placed, and then the combination is placed in a vacuum sintering furnace.

[0023] Further, the central part of the vacuum sintering furnace is a horizontally placed quartz tube, and the transparent quartz tube can facilitate the operator to observe the sample state after loading the sample. The left and right ends of the quartz tube are connected with airtight covers, the left cover is provided with a vacuum valve, the vacuum valve is connected with a vacuum gauge and an argon gas supply source, and the right cover is connected with two vacuum valves, which are connected with a vacuum pump and the atmosphere respectively. Since the sintering process of metal fibers involves high temperature, which may cause oxidation of pure copper, the sintering metal needs to be carried out in an inert gas protected environment to melt the contact surface of the fibers and make the fibers become continuous porous fiber structure. Therefore, a vacuum tube type sintering furnace is used in the preparation process of the present application. The device can be heated to 1200 DEG C in an argon environment, which meets the sintering temperature requirement of pure copper fibers. The sintering process is as follows: after the sample is placed, all the gas paths connected with the atmosphere are closed, and the vacuum pump is opened to perform vacuumizing. After vacuumizing, the vacuum pump valve is closed. Argon gas is injected into the vacuum sintering furnace until a slight positive pressure is formed. Then the argon flow of the inlet is reduced, and the outlet to the atmosphere is slightly opened, so that the vacuum sintering furnace will not be broken due to the cold contraction and thermal expansion of the gas during sintering and cooling. Thereafter, the sintering device together with the semi-finished product therein is heated, and the temperature is maintained for a specified time and then the furnace is cooled to room temperature. Then the annealing furnace is closed and the sample is taken out, and a porous flexible pure copper fiber wick finished product can be prepared. After detection, the porosity of the copper fibers obtained by the above process can reach 10% to 65%, which is much higher than the porosity of 5% of conventional cold-drawn copper mesh.

[0024] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-porosity copper fiber vapor chamber comprising an upper case and a lower case, a wick and a support column being provided between the upper case and the lower case, characterized in that, The support column is a copper column with uniform specifications, and the liquid absorption core is a copper fiber with high porosity.

2. The high porosity copper fiber vapor chamber of claim 1, wherein, The porosity of the copper fiber is 10% to 65%.

3. The high porosity copper fiber vapor chamber of claim 1, wherein, The diameter of the copper column is 5 millimeters.

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