Flexible heat pipe and flexible heat pipe welding method

Abstract

The embodiment of the invention provides a flexible heat pipe and a flexible heat pipe welding method. The flexible heat pipe welding method comprises the steps that a first welding face of a first shell and a second welding face of a second shell are in opposite contact; a welding head is arranged on the side, away from the first welding face, of the first shell; the first welding face and the second welding face are welded through ultrasonic waves emitted by the welding head; according to the embodiment of the invention, the first shell and the second shell are welded through the ultrasonic waves emitted by the welding head, so that the air tightness of the flexible heat pipe is effectively ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat spreader, more particularly, to a flexible heat pipe and a flexible heat pipe welding method. BACKGROUND

[0002] As a kind of phase-change heat transfer high-efficiency heat transfer device, heat pipe rapidly becomes a mainstream heat dissipation device with the development of consumer electronics products in recent years, and with the rise of folding mobile phone market, the demand for flexible heat pipe with repeated bending requirement is also increasing.

[0003] However, the welding temperature of the welding process for heat pipe in the prior art is too high, which causes damage to the shell of the flexible heat pipe when welding the flexible heat pipe, thereby seriously affecting the air tightness of the flexible heat pipe.

[0004] Therefore, it is necessary to provide a new technical solution to solve the above technical problems. SUMMARY

[0005] An object of the present application is to provide a new technical solution of a flexible heat pipe and a flexible heat pipe welding method.

[0006] According to a first aspect of the present application, a flexible heat pipe welding method is provided, wherein the flexible heat pipe welding method comprises:

[0007] The first welding surface of the first shell and the second welding surface of the second shell are in contact with each other;

[0008] The welding head is arranged on the side of the first shell away from the first welding surface;

[0009] The first welding surface and the second welding surface are welded by the ultrasonic waves emitted by the welding head.

[0010] Optionally, the ultrasonic welding frequency increases as the thickness dimension of the first shell decreases.

[0011] Optionally, the ultrasonic welding frequency ranges from 10 kHz to 50 kHz.

[0012] Optionally, the welding head is provided with a pattern, and the pattern is in contact with the side of the first shell away from the first welding surface.

[0013] Optionally, the pattern comprises at least one of a strip-shaped tooth and a race pattern.

[0014] Optionally, after arranging the welding head on the side of the first shell away from the first welding surface, the method further comprises:

[0015] Another welding head is arranged on the side of the second shell away from the second welding surface;

[0016] wherein the ultrasonic welding frequency of the two welding heads is equal.

[0017] Optionally, the material of the first shell comprises at least one of copper, stainless steel and copper clad plate.

[0018] Optionally, the material of the second shell comprises at least one of copper, stainless steel and copper clad plate.

[0019] Optionally, the material of the first shell comprises copper clad plate, the copper clad plate comprises a first copper layer, a polymer layer and a second copper layer, and the polymer layer is arranged between the first copper layer and the second copper layer.

[0020] Optionally, the copper clad plate is flexible copper clad plate, and the material of the polymer layer is polyimide.

[0021] According to a second aspect of the present application, a flexible heat pipe is provided, wherein the flexible heat pipe is prepared by the flexible heat pipe welding method according to any one of the first aspect.

[0022] According to a flexible heat pipe welding method provided by an embodiment of the present application, the flexible heat pipe welding method comprises: contacting a first welding surface of a first shell and a second welding surface of a second shell; arranging a welding head on a side of the first shell away from the first welding surface; and welding the first welding surface and the second welding surface by ultrasonic waves emitted by the welding head. The first shell and the second shell are welded by the ultrasonic waves emitted by the welding head, so that the air tightness of the flexible heat pipe is effectively ensured.

[0023] Other features of the present application, and their advantages, will become apparent in the non-limiting detailed description of the application, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0025] Figure 1 is a flow chart of the flexible heat pipe welding method in an embodiment of the present application.

[0026] Figure 2 is a structural schematic diagram of a flexible heat pipe in an embodiment of the present application.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 11, first shell; 111, first welding surface; 112, first copper layer; 113, polymer layer; 114, second copper layer; 12, second shell; 121, second welding surface; 13, accommodating cavity. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present application will now be described in detail below with reference to the drawings. Note that the relative arrangement, numerical expressions, and numerical values of components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0030] Embodiments of the present application will be described below in detail, examples of which are shown in the accompanying drawings. The embodiments described below by reference to the drawings are exemplary and are for the purpose of explanation of the present application, and should not be understood as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts are within the scope of the present application.

[0031] Note that like reference numerals and letters represent like items in the drawings below, and thus, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0032] According to one embodiment of the present application, a flexible heat pipe welding method is provided, referring to FIG. 1, Figure 1 As shown, the flexible heat pipe welding method includes the following steps S101-S103:

[0033] S101, the first welding surface 111 of the first shell 11 and the second welding surface 121 of the second shell 12 are in contact with each other;

[0034] S102, the welding head is arranged on the side of the first shell 11 away from the first welding surface 111;

[0035] S103, the first welding surface 111 and the second welding surface 121 are welded by the ultrasonic waves emitted by the welding head.

[0036] Specifically, the first welding surface 111 of the first shell 11 and the second welding surface 121 of the second shell 12 are brought into contact, so that the first shell 11 and the second shell 12 are stacked together. Then, the welding head is arranged on the side of the first shell 11 away from the first welding surface 111, so that the welding head is in contact with the side of the first shell 11 away from the first welding surface 111. Finally, the welding head is driven at a specific frequency and amplitude, so that the high-frequency oscillation energy generated by the welding head is transmitted to the first welding surface 111 and the second welding surface 121 through the first shell 11. When the high-frequency oscillation energy generated by the welding head is transmitted to the first welding surface 111 and the second welding surface 121, the high-frequency oscillation energy drives the first welding surface 111 and the second welding surface 121 to rub quickly and generate heat, so that the first welding surface 111 and the second welding surface 121 are melted and welded together. Since the gas permeability between the first welding surface 111 and the second welding surface 121 after welding is equivalent to that of pure copper material, the air tightness of the flexible heat pipe can be effectively ensured, and the effect of air-tight isolation of the flexible heat pipe is achieved. In addition, since the flexible heat pipe of the embodiment of the present application uses the high-frequency oscillation energy generated by the welding head to weld the first shell 11 and the second shell 12, i.e., uses ultrasonic welding process to weld the first shell 11 and the second shell 12, compared with the traditional high-temperature welding process, the flexible heat pipe will not be damaged, further avoiding the problem of leakage of the working medium in the flexible heat pipe, and effectively ensuring the integrity of the flexible heat pipe.

[0037] Therefore, the flexible heat pipe welded by the flexible heat pipe welding method of the embodiment of the present application not only can effectively ensure the air tightness of the flexible heat pipe, but also can further improve the water tightness of the flexible heat pipe, so that the flexible heat pipe has higher reliability, better use effect and longer service life.

[0038] In addition, in the preparation process of the flexible heat pipe, the shell needs to be processed, the working medium needs to be injected into the containing cavity 13, the containing cavity 13 needs to be vacuumized, and the liquid injection port needs to be sealed, etc.

[0039] The sealing of the liquid injection port directly determines whether the flexible heat pipe can maintain a negative pressure state, and the negative pressure state determines the use performance of the flexible heat pipe. Therefore, the sealing process of the liquid injection port directly affects the quality of the flexible heat pipe when the flexible heat pipe is prepared. In addition, the working medium needs to be injected into the containing cavity 13 and the containing cavity 13 needs to be vacuumized when the flexible heat pipe is prepared, i.e., the working medium needs to be injected into the containing cavity 13 formed between the first shell 11 and the second shell 12, and then the containing cavity 13 needs to be vacuumized to a negative pressure state.

[0040] However, when the liquid injection port is sealed, the outside of the flexible heat pipe is at standard atmospheric pressure, which can cause a large pressure difference on both sides of the liquid injection port, and thus easily cause air leakage. Therefore, when using the traditional welding process, an additional process method is set to avoid air leakage, but setting an additional process method increases the manufacturing cost of the flexible heat pipe.

[0041] Therefore, the flexible heat pipe welding method of the present application seals the liquid injection pipe of the flexible heat pipe, that is, the high-frequency oscillation energy generated by the welding head is used to firmly weld the first shell 11 and the second shell 12 on both sides of the liquid injection port, effectively avoiding the problem that a large pressure difference on both sides of the liquid injection port easily causes air leakage. Moreover, since the flexible heat pipe welding method of the present application does not damage the integrity of the material of the flexible heat pipe itself, the first shell 11 and the second shell 12 on both sides of the liquid injection port also have a complete structure, thereby achieving the effect of air-tightness, achieving the purpose of sealing the flexible heat pipe and maintaining the air-tightness of the flexible heat pipe, effectively ensuring that the inside of the flexible heat pipe can be kept in a negative pressure state for a long time, so that the flexible heat pipe has better use performance.

[0042] Optionally, the ultrasonic welding frequency increases as the thickness dimension of the first shell 11 decreases.

[0043] Specifically, the welding head of the present application is an ultrasonic welding head, and the ultrasonic welding frequency of the ultrasonic welding head increases as the thickness dimension of the first shell 11 decreases, effectively realizing the welding of the first shell 11 with a thinner size and the second shell 12 with a thinner size, expanding the application range of the flexible heat pipe welding method, and effectively ensuring the gas permeability between the first welding surface 111 of the first shell 11 and the second welding surface 121 of the second shell 12, so that the flexible heat pipe welding method can achieve the purpose of sealing the flexible heat pipe and maintaining the air-tightness of the inside of the flexible heat pipe.

[0044] Optionally, the ultrasonic welding frequency ranges from 10 kHz to 50 kHz.

[0045] Specifically, since the higher the ultrasonic welding frequency, the better the welding precision, and the smaller the output power required by the welding head, by setting the ultrasonic welding frequency range to 10 kHz to 50 kHz, the welding quality between the first welding surface 111 of the first shell 11 and the second welding surface 121 of the second shell 12 can be effectively ensured, thereby effectively ensuring the air-tightness of the inside of the flexible heat pipe.

[0046] Optionally, the welding head is provided with a pattern, which is in contact with the side of the first shell 11 away from the first welding surface 111.

[0047] Specifically, by providing the welding head with the pattern, which is in contact with the side of the first shell 11 away from the first welding surface 111, the transmission efficiency of the high-frequency oscillation energy generated by the welding head can be ensured, and the problems of crushing, excessive thinning or poor bonding of the first welding surface 111 and the second welding surface 121 can be prevented, thereby effectively ensuring the welding quality between the first welding surface 111 of the first shell 11 and the second welding surface 121 of the second shell 12.

[0048] In addition, by contacting the pattern with the side of the first shell 11 away from the first welding surface 111, the contact area of the welding head with the side of the first shell 11 away from the first welding surface 111 can be further increased, thereby significantly enhancing the rapid friction heating efficiency and plastic deformation degree between the first welding surface 111 and the second welding surface 121, and significantly improving the welding efficiency of the first shell 11 and the second shell 12.

[0049] In addition, the present application can only provide the pattern on one side of the welding head, so as to more efficiently transmit the high-frequency oscillation energy generated by the welding head to the first welding surface 111 and the second welding surface 121 while reducing the manufacturing cost of the welding head, thereby effectively ensuring the welding quality and welding efficiency between the first shell 11 and the second shell 12.

[0050] Of course, the present application can also provide the pattern on the circumferential side of the welding head, and the person skilled in the art can select according to actual needs, which is not specifically limited herein.

[0051] Optionally, the pattern includes at least one of a strip-shaped tooth and a race pattern.

[0052] Specifically, when the pattern is a strip-shaped tooth, the contact pressure between the welding head and the first shell 11 can be significantly increased, further improving the stability and reliability of the welding head; the sliding or deviation of the first shell 11 and the second shell 12 during welding can be significantly reduced, ensuring the accuracy of the welding position of the first shell 11 and the second shell 12; the formation and flow of the molten pool between the first welding surface 111 and the second welding surface 121 can be better controlled, making the welding process more uniform and stable; welding defects such as slag inclusion and incomplete fusion can be effectively reduced, further improving the welding quality and efficiency between the first shell 11 and the second shell 12.

[0053] When the pattern is a race pattern, the friction between the welding head and the first shell 11 can be increased, so that the welding head can be more stably attached to the first shell 11 during welding; the contact area between the welding head and the first shell 11 can be increased, improving heat transfer and distribution, reducing heat loss during welding, and avoiding overheating or insufficient welding; the generation of welding defects such as pores and cracks can be reduced, further improving the welding quality between the first shell 11 and the second shell 12; the welder can have a more comfortable feel during welding, making the operation smoother, further reducing the labor intensity of the welder, and improving the work efficiency.

[0054] Optionally, before step S101, it further includes:

[0055] A1, surface cleaning of the first shell 11, surface cleaning of the second shell 12.

[0056] Specifically, in step A1, by placing the first shell 11 and the second shell 12 in an acid solution with a concentration of 10%-20% and performing ultrasonic oscillation cleaning for 60s, the resin protective film, oxide layer and impurities on the surface of the first shell 11 and the second shell 12 can be effectively removed, facilitating subsequent welding of the first shell 11 and the second shell 12.

[0057] Of course, the first shell 11 can also be surface cleaned and the second shell 12 can also be surface cleaned by other chemical treatment methods according to actual needs, and those skilled in the art can make selections, which are not specifically limited herein.

[0058] Optionally, after step S102, before step S103, it further includes:

[0059] B1, another welding head is arranged on the side of the second shell 12 away from the second welding surface 121;

[0060] The ultrasonic welding frequencies of the two welding heads are equal.

[0061] Specifically, since the thicknesses of the first shell 11 and the second shell 12 are equal, after the welding head is arranged on the side of the first shell 11 away from the first welding surface 111, another welding head can also be arranged on the side of the second shell 12 away from the second welding surface 121, and then the ultrasonic welding frequencies of the two welding heads are equal, so that the two welding heads can simultaneously weld the first welding surface 111 and the second welding surface 121, thereby further improving the welding efficiency between the first shell 11 and the second shell 12.

[0062] Optionally, the material of the first shell 11 comprises at least one of copper, stainless steel and copper-clad plate.

[0063] Optionally, the material of the second shell 12 comprises at least one of copper, stainless steel and copper-clad plate.

[0064] Specifically, the first shell 11 and the second shell 12 are prepared by copper, stainless steel or copper-clad plate, thereby effectively improving the use performance of the flexible heat pipe.

[0065] Optionally, the material of the first shell 11 comprises copper-clad plate, the copper-clad plate comprises a first copper layer 112, a polymer layer 113 and a second copper layer 114, and the polymer layer 113 is arranged between the first copper layer 112 and the second copper layer 114.

[0066] Specifically, the polymer layer 113 is arranged between the first copper layer 112 and the second copper layer 114, so that the first copper layer 112, the polymer layer 113 and the second copper layer 114 can form the copper-clad plate with a three-layer structure. Furthermore, since the polymer layer 113 has excellent flexibility and bending performance, the copper-clad plate not only has excellent heat conduction performance, but also has excellent flexibility and bending performance, thereby better meeting the repeated bending requirements of consumer electronic products.

[0067] Optionally, the material of the first copper layer 112 comprises at least one of copper foil, aluminum foil and copper-beryllium alloy foil, the material of the polymer layer 113 comprises at least one of polyester, polyimide, polyester-imide, fluorocarbon ethylene, imide fiber and polybutylene terephthalate, and the material of the second copper layer 114 comprises at least one of copper foil, aluminum foil and copper-beryllium alloy foil.

[0068] Optionally, the copper-clad plate is a flexible copper-clad plate, and the material of the polymer layer 113 is polyimide.

[0069] Specifically, with the development of consumer electronics in recent years, the flexible heat pipe has rapidly become a mainstream heat dissipation device, and with the rise of the folding mobile phone market, the demand for flexible heat pipes with repeated bending requirements is also increasing, so in order to meet the folding and heat dissipation requirements of the folding mobile phone, it is preferred to use a flexible copper-clad plate to prepare the first shell 11 and the second shell 12 of the flexible heat pipe.

[0070] In addition, since the copper-clad plate with polyimide as the high molecular layer 113 has excellent heat resistance, dimensional stability, electrical properties, and processing properties, etc., it can better meet the folding and heat dissipation requirements of the folding mobile phone.

[0071] According to another embodiment of the present application, a flexible heat pipe is provided, which is prepared by the flexible heat pipe welding method described in the above embodiments.

[0072] The above embodiments focus on the differences between the various embodiments, and the different optimization features between the various embodiments can be combined to form a more optimal embodiment as long as they are not contradictory. In view of the brevity of the text, it will not be repeated here.

[0073] Although some specific embodiments of the present application have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration and are not intended to limit the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A method of welding a flexible heat pipe, characterized by, The method comprises: placing a first welding surface of a first shell and a second welding surface of a second shell in contact with each other; placing a welding head on a side of the first shell away from the first welding surface; welding the first welding surface and the second welding surface by ultrasonic waves emitted by the welding head.

2. The flexible heat pipe welding method according to claim 1, wherein The ultrasonic welding frequency increases as the thickness of the first shell decreases.

3. The flexible heat pipe welding method according to claim 1, wherein The ultrasonic welding frequency ranges from 10 kHz to 50 kHz.

4. The flexible heat pipe welding method according to claim 1, wherein The welding head is provided with a pattern in contact with the side of the first shell away from the first welding surface.

5. The flexible heat pipe welding method according to claim 4, wherein The pattern comprises at least one of a strip-shaped tooth and a race pattern.

6. The flexible heat pipe welding method according to claim 1, wherein The method further comprises, after placing the welding head on the side of the first shell away from the first welding surface: placing another welding head on a side of the second shell away from the second welding surface; wherein the ultrasonic welding frequencies of the two welding heads are equal.

7. The flexible heat pipe welding method according to claim 1, wherein The material of the first shell comprises at least one of copper, stainless steel and copper-clad plate. The material of the second shell comprises at least one of copper, stainless steel and copper-clad plate.

8. The flexible heat pipe welding method according to claim 1, wherein The material of the first shell comprises a copper-clad plate, which comprises a first copper layer, a polymer layer and a second copper layer, and the polymer layer is arranged between the first copper layer and the second copper layer.

9. The flexible heat pipe welding method according to claim 8, wherein The copper-clad plate is a flexible copper-clad plate, and the material of the polymer layer is polyimide.

10. A flexible heat pipe, characterized by, The flexible heat pipe is prepared by the flexible heat pipe welding method according to any one of claims 1 to 9.

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