A uniform temperature plate with capillary structure and an end sealing welding process thereof

Abstract

The application discloses an end sealing welding process of a uniform temperature plate with a capillary structure, which can effectively reduce the invalid length and improve the welding strength, and the welding sealing reliability is obviously improved. The technical scheme is as follows: an end sealing welding process of a uniform temperature plate with a capillary structure, comprising the following steps: step 1: the end part of the uniform temperature plate with the capillary structure filled with a phase-changeable working medium is sealed by extrusion to obtain a sealed end with a certain invalid length; step 2: the part of the uniform temperature plate away from the sealed end is in heat conduction contact with a temperature control module, so that the vapor pressure of the phase-changeable working medium in the uniform temperature plate reaches a first pressure P1 and is stable; at this time, the environmental pressure is P0, the surface tension of the molten aluminum liquid generates a maximum pressure difference P2 on the heat conduction pipe; the absolute value of P1-P0 is less than P2; step 3: the invalid length part of the sealed end is fused by a welding process, so that the invalid length part of the sealed end is shortened, and the end face of the end part of the sealed end changes from a sharp end to an arc surface. Meanwhile, the application further discloses a uniform temperature plate and belongs to the field of uniform temperature plates.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vapor chamber, more particularly, relates to a vapor chamber with capillary structure and an end sealing welding process thereof. BACKGROUND

[0002] The vapor chamber, also known as superconducting heat spreader, has a cavity inside, and the cavity has a plurality of arrayed or disordered capillary structures, and the cavity is filled with liquid or gaseous working medium which can change heat absorption or heat release.

[0003] The processing process of the vapor chamber is as follows: an open cavity of aluminum alloy or other material is prepared by stretching or welding or other processes, then the cavity is filled with liquid or gaseous working medium, and then the open end of the cavity is sealed by extrusion or welding, and the end is a sealed end.

[0004] Since the extrusion process is used, the problems are as follows: the end is a tapered end, which has a certain invalid length, and the invalid length is about 1.5 times or more of the thickness.

[0005] The existence of the invalid length can cause two problems: first, the sealing end obtained by the extrusion process has insufficient pressure bearing capacity and is easy to damage; second, there is a certain length, although the length is not long, but if the vapor chamber is applied to electronic devices such as mobile phones, tablets and other electronic devices, 1mm long is intolerable.

[0006] In order to solve the problem, we try to process the sealing end by hot melting welding, so that the sealing end with invalid length is hot melted to obtain a sealing end with a rounded end. The problem is that there is always a welding hole in the welding process, that is, the cavity and the atmosphere are connected, which leads to leakage of the phase-changeable working medium, and the welding hole phenomenon is usually accompanied by the situation that the molten aluminum liquid splashes at the welding position. The product cannot be welded, and there is no qualified product.

[0007] Based on this, the technical problem solved by the present application is: how to reduce the invalid length of the sealing end of the vapor chamber, and ensure the welding quality and sealing reliability, and make the operation more simple and feasible. SUMMARY

[0008] The main purpose of the present application is to provide an end sealing welding process of a vapor chamber with capillary structure, which has strong operability, obvious improvement of sealing reliability, and can effectively reduce the invalid length, and the present application also discloses a vapor chamber.

[0009] According to the first aspect of the present application, an end sealing welding process of a vapor chamber with capillary structure is provided, which comprises the following steps:

[0010] Step 1: the end of the uniform temperature plate filled with the phase-changeable working medium and having the capillary structure is sealed by extrusion to obtain a sealed end with a certain dead length;

[0011] Step 2: the part of the uniform temperature plate away from the sealed end is in heat-conducting contact with a temperature control module, so that the vapor pressure of the phase-changeable working medium in the uniform temperature plate reaches a first pressure P1 and stabilizes; at this time, the ambient pressure is P0, and the maximum pressure difference P2 generated by the surface tension of the molten aluminum liquid on the heat pipe;

[0012] The absolute value of P1-P0 is less than P2.

[0013] Step 3: the part of the dead length of the sealed end is fused by a welding process, so that the part of the dead length of the sealed end is shortened and the end face of the end of the sealed end changes from a sharp end to an arc face.

[0014] It should be noted that the uniform temperature plate can be an aluminum alloy or other metals such as copper, aluminum, stainless steel, titanium, etc.

[0015] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, the dead length in step 1 is 1.5 times or more of the product thickness; and the dead length in step 3 is 0.5 times or less of the product thickness.

[0016] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, P2 is less than or equal to 400 Pa when welding an aluminum alloy product with a thickness greater than 2 mm.

[0017] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, the absolute value of P1-P0 is less than 0.5 times P2.

[0018] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, the temperature control module is a constant-temperature water tank or a constant-temperature oil tank or a constant-temperature metal block; one end of the uniform temperature plate away from the sealed end is immersed in the constant-temperature water tank or the constant-temperature oil tank or is pressed against the constant-temperature metal block, and the immersion depth is L1; the height of the phase-changeable working medium filled in the uniform temperature plate is L0; L1 is greater than L0; and the sealed end of the uniform temperature plate is upward.

[0019] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, a heating module is arranged at a position close to the sealed end of the uniform temperature plate, the heating module is in heat-conducting contact with the uniform temperature plate, and the heating temperature T2 of the heating module is higher than the boiling point T1 of the phase-changeable working medium under the first pressure P1.

[0020] In the end-sealing welding process of the uniform temperature plate with the capillary structure described above, the heating temperature T2 is at least 5℃ higher than the boiling point T1.

[0021] In the above-mentioned end-sealing welding process of the heat exchange plate with capillary structure, the ambient pressure is the local atmospheric pressure of the welding site or a constant pressure chamber with a preset pressure.

[0022] In the above-mentioned end-sealing welding process of a heat spreader with capillary structure, the welding process is characterized by being one of argon arc welding, laser welding, or friction welding.

[0023] Finally, a temperature distribution plate with a capillary structure is also disclosed, which is prepared using the process described above.

[0024] One of the above-described technical solutions of the present invention has at least one of the following advantages or beneficial effects:

[0025] 1. The invalid length is shorter;

[0026] 2. The absence of a pressure-sealed area avoids cracking and stress concentration caused by material deformation in the pressure-sealed area;

[0027] 3. The material on both sides of the molten zone does not become thinner, resulting in better sealing strength. Attached Figure Description

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0029] Figure 1 This is a cross-sectional view of the heat spreader before processing in Embodiment 1 of the present invention;

[0030] Figure 2 This is a cross-sectional view of the processed heat spreader in Embodiments 1 and 2 of the present invention;

[0031] Figure 3 This is a schematic diagram of the processing in Embodiment 1 of the present invention;

[0032] Figure 4 These are front views of different samples from Embodiment 1 of the present invention;

[0033] Figure 5 These are magnified front views of different samples from Embodiment 1 of the present invention;

[0034] Figure 6 These are side views of different samples from Embodiment 1 of the present invention;

[0035] Figure 7 These are side cross-sectional views of different samples from Embodiment 1 of the present invention;

[0036] Figure 8 These are embodiments 1 and 2 of the present invention. Figure 2 AA sectional view. Detailed Implementation

[0037] Embodiments of the present application are described below in detail with reference to the drawings, examples of which are shown in the accompanying drawings, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are for the purpose of explaining the present application only, and are not to be understood as limiting the present application.

[0038] In the description of the present application, it needs to be understood that the orientation description, such as the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, which is only for the purpose of describing the present application and simplifying the description, and is not to indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0039] In the description of the present application, several meanings are one or more, and the meaning of multiple is two or more, greater than, less than, more than, etc. are understood as not including the number, above, below, etc. are understood as including the number. If it is described as first, second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the order of indicated technical features.

[0040] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more features.

[0041] In the description of the present application, it needs to be noted that unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, it can be fixed connection or movable connection, or detachable connection or non-detachable connection, or integral connection; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, indirect communication or interaction relationship between two elements.

[0042] The following disclosure provides many different embodiments or examples for implementing different aspects of the present application.

[0043] Example 1

[0044] Referring to Figures 1 to 3 as shown:

[0045] An end sealing welding process of a uniform temperature plate 1 with capillary structure, comprising the following steps:

[0046] Step 1: seal the end of the uniform temperature plate 1 with capillary structure filled with the phase-changeable working medium 5 by extrusion to obtain a sealed end 2 with a certain invalid length L1; the invalid length L1 in step 1 is 1.5 times or more of the thickness of the product; due to the limitation of the extrusion process, the invalid length L1 of the product is generally greater than 4.5 mm, and can be longer;

[0047] Step 2: put the part of the uniform temperature plate 1 away from the sealed end 2 in heat conduction contact with a temperature control module 3, so that the vapor pressure of the phase-changeable working medium in the uniform temperature plate 1 reaches a first pressure P1 and stabilizes; at this time, the environmental pressure is P0, and the maximum pressure difference P2 generated by the surface tension of the molten aluminum liquid on the heat pipe;

[0048] The absolute value of P1-P0 is less than P2;

[0049] Step 3: melt the part of the invalid length L2 of the sealed end 2 by a welding process, so that the part of the invalid length L2 of the sealed end 2 is shortened and the end face of the end of the sealed end 2 changes from a sharp end to an arc face. The invalid length L2 in step 3 is 0.5 times or less of the thickness of the product, and the invalid length L2 can be changed from 4-5 mm to 1.5 mm or less.

[0050] After the uniform temperature plate 1 is processed in this way, the invalid length of the sealed end 2 is shortened, the sealed end 2 becomes round, and the average thickness of the sealed end 2 increases, which can improve the sealing strength and avoid leakage of the cooling medium. At the same time, the stress distribution of the processed sealed end 2 is uniform, and the pressure resistance is better.

[0051] Reference Figures 4-7 , the No. 1 sample is a view of the sealed end of the uniform temperature plate before processing in step 1; the No. 2 sample is a view of the sealed end after processing by a common welding method; and the No. 3 sample is a view of the sealed end after processing in the embodiment.

[0052] It can be seen that the sealed end of the No. 3 sample is more round and thick than that of the No. 2 sample.

[0053] It should be noted that the uniform temperature plate 1 can be an aluminum alloy, or other metals such as copper, aluminum, stainless steel, titanium, etc. In this embodiment, it is an aluminum alloy. The welding process is one of argon arc welding, laser welding, and friction welding.

[0054] The welding process can be selected in many ways, but no matter which one is selected, we need to control the welding temperature to be greater than the melting temperature of the material.

[0055] The environmental pressure generally refers to the atmospheric pressure, but the embodiment can also be placed in a constant pressure container, and when in the constant pressure container, P0 is the pressure of the constant pressure container.

[0056] Therefore, P1 should be adjusted according to the pressure of P0, and the value of P1 is related to the temperature of the heat conducting medium; for example, when the heat conducting medium is at the boiling temperature under the atmospheric pressure, the pressure is the atmospheric pressure. Therefore, the simple operation of the present application is to operate under the atmospheric pressure, and the heating temperature is the boiling temperature of the heat conducting medium under the atmospheric pressure.

[0057] In general, P2 is less than or equal to 400 Pa when welding an aluminum alloy product with a thickness of 2-4 mm. For products with greater thickness, the upper limit of P2 can be smaller, and can be flexibly adjusted according to the thickness of the product.

[0058] In this embodiment, the temperature control module 3 is a constant temperature water tank or a constant temperature oil tank or a constant temperature metal block; one end of the vapor chamber 1 away from the sealed end 2 is immersed in the constant temperature water tank or the constant temperature oil tank or is pressed against the constant temperature metal block, and the immersion depth is L1, and the height of the phase-change working medium filled in the vapor chamber 1 is L0; L1 is greater than L0; and the sealed end 2 of the vapor chamber 1 is upward.

[0059] In this embodiment, it is further optimized that the position of the vapor chamber 1 close to the sealed end 2 is provided with a heating module 4, the heating module 4 is in thermal contact with the vapor chamber 1, and the heating temperature T2 of the heating module 4 is higher than the boiling point T1 of the phase-change working medium under the first pressure P1.

[0060] The purpose of such a setting is that during operation, it is found that sometimes there is a situation of molten liquid splashing. The main reason for the splashing of the molten liquid is that because the vapor chamber 1 has a capillary structure, the heat conducting medium will rise along the capillary structure to the vicinity of the sealed end 2, and once high-temperature welding is performed, the temperature of the sealed end 2 will be instantaneously higher than the boiling point of the heat conducting medium, the heat conducting medium will rapidly boil, a local high pressure will be generated, the weakest position of the molten metal will be broken, and the molten metal liquid will splash.

[0061] In order to solve this problem, the heating module 4 is arranged at the position close to the sealed end 2 of the vapor chamber 1, the heat conducting medium close to the sealed end 2 is heated by the heating module 4 to become a gas, and the situation of instantaneous gasification at the position of the sealed end 2 is avoided.

[0062] The heating module 4 is arranged at a position 1-3 cm away from the sealed end 2, and of course can be arranged at a position farther away from the sealed end 2. Preferably, the heating temperature T2 is at least 5°C higher than the boiling point T1.

[0063] Embodiment 2

[0064] Reference Figure 2 and Figure 8A kind of uniform temperature plate 1, including body 10, the cavity 11 in the body is equipped with, the cavity 11 is filled with phase change working medium 5, the two ends of the body are sealing end 2, 2 sealing ends 2 are the sealing ends of welding fusion zone;The surface of the sealing end is cambered surface.

[0065] Preferably, the surface of the sealing end is about 0.2-0.5 times the thickness of the uniform temperature plate from the cavity.

[0066] Preferably, the cavity is provided with a plurality of capillary structure channels 12.

[0067] Preferably, the capillary structure channel 12 extends along the length direction of the cavity 11.

[0068] Preferably, the capillary structure channel 12 is arranged in an array manner on the inner wall of the cavity.

[0069] Preferably, the body is copper, aluminum, aluminum alloy, stainless steel, titanium or iron.

[0070] Preferably, the boiling point temperature of the phase change working medium under atmospheric pressure is -40-300℃.

[0071] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An end seal welding process of a vapor chamber having a capillary structure, characterized by, The method comprises the following steps: Step 1: sealing the end of the uniform temperature plate filled with the phase-changeable working medium by extrusion, to obtain a sealed end with a certain dead length; Step 2: placing the part of the uniform temperature plate away from the sealed end in heat-conducting contact with a temperature control module, so that the vapor pressure of the phase-changeable working medium in the uniform temperature plate reaches a first pressure P1 and stabilizes; at this time, the ambient pressure is P0, the maximum pressure difference P2 generated by the surface tension of the molten aluminum on the heat pipe, and the P2 is less than or equal to 400 Pa when welding aluminum alloy products with a thickness greater than 2 mm; The absolute value of P1-P0 is less than P2; Step 3: melting the part of the dead length of the sealed end by a welding process, so that the part of the dead length of the sealed end is shortened and the end face of the end of the sealed end changes from a sharp end to an arc surface; The position of the uniform temperature plate close to the sealed end is provided with a heating module, the heating module and the uniform temperature plate are in heat-conducting contact, and the heating temperature T2 of the heating module is higher than the boiling point T1 of the phase-changeable working medium under the first pressure P1, and the heating temperature T2 is at least 5℃ higher than the boiling point T1; The temperature control module is a constant-temperature water tank or a constant-temperature oil tank or a constant-temperature metal block; one end of the uniform temperature plate away from the sealed end is immersed in the constant-temperature water tank or the constant-temperature oil tank or is pressed against the constant-temperature metal block, and the immersion depth is L1, and the height of the phase-changeable working medium filled in the uniform temperature plate is L0; L1 is greater than L0; the sealed end of the uniform temperature plate is upward.

2. The end seal welding process of a vapor chamber with capillary structure according to claim 1, wherein, The dead length in step 1 is 1.5 times or more of the product thickness; the dead length in step 3 is 0.5 times or less of the product thickness.

3. The end seal welding process of a vapor chamber with capillary structure according to claim 1, wherein, The absolute value of P1-P0 is less than 0.5 times of P2.

4. The end seal welding process of a vapor chamber with capillary structure according to any one of claims 1-3, characterized in that, The ambient pressure is the local atmospheric pressure of the welding site or a constant-pressure cabin with a set pre-set pressure.

5. The end seal welding process of a vapor chamber with capillary structure according to any one of claims 1-3, wherein The welding process is one of argon arc welding, laser welding, and friction welding. The welding process is one of argon arc welding, laser welding, and friction welding.

Images