Heat pipe lapping mechanism of 3D uniform temperature plate

Abstract

The utility model discloses a kind of heat pipe lap joint mechanism of 3D uniform temperature plate, including upper cover and heat pipe arranged on upper cover, upper cover is equipped with and is inserted into hole, and step part is equipped on the periphery of and is inserted into hole, heat pipe includes tube body and the butt joint portion corresponding arranged in the bottom of tube body, butt joint portion is sealingly connected with step part.The utility model has low production cost, and welding also cannot destroy internal capillary, contact thermal resistance is low, stability is high, heat transfer loss is low, and adaptability is strong.

Description

Technical Field

[0001] This utility model relates to the field of radiator technology, and in particular to a heat pipe overlapping mechanism for a 3D heat spreader. Background Technology

[0002] There are currently two types of heat pipe welding for 3D vapor chambers: one is direct insertion, where copper paste overflows into the inner cavity and capillary after welding, posing a risk of welding damage and capillary destruction; the other is flipped tubes, which use diffusion welding on the top cover, resulting in excessively high manufacturing costs.

[0003] The existing heat pipe overlapping solutions for 3D vapor chambers have the following main technical defects: 1. High contact thermal resistance: Traditional overlapping often uses direct bonding of flat surfaces or transition through diffusion welding. The overlapping surface is prone to gaps due to processing errors and lacks effective heat-conducting medium filling, resulting in a contact thermal resistance as high as 0.15-0.2℃ / W, which seriously restricts heat dissipation efficiency. 2. Poor structural stability: There is no dedicated positioning structure at the joint, and it is only fixed by screws or jigs. It is prone to displacement due to vibration and temperature changes, which can lead to separation of the joint surface or uneven pressure, resulting in heat dissipation failure. Large heat transfer efficiency loss: When multiple 3DVC heat pipes are connected, steam is prone to forming eddies or stagnation in the overlapping area, which increases the resistance to steam flow. The maximum heat transfer capacity (Qmax) is reduced by 20%-30% compared to a single heat pipe, and the synergistic heat dissipation effect cannot be achieved. Poor adaptability: Existing overlapping structures are mostly designed for 3D vapor chamber heat pipes of fixed size, which cannot flexibly adapt to 3D vapor chamber heat pipes of different diameters and lengths, and are difficult to be compatible with the compact installation space of small-area chips.

[0004] Therefore, developing a 3D vapor chamber heat pipe overlapping structure and method with low contact thermal resistance, high stability, low heat transfer loss and strong adaptability has become a key requirement in the field of multi-chip module heat dissipation. Utility Model Content

[0005] The technical problem to be solved by this utility model embodiment is to provide a heat pipe overlapping mechanism for a 3D heat spreader to achieve low contact thermal resistance, high stability, low heat transfer loss, and strong adaptability.

[0006] To solve the above-mentioned technical problems, this utility model embodiment proposes a heat pipe overlapping mechanism for a 3D heat spreader, including an upper cover and a heat pipe disposed on the upper cover. The upper cover is provided with a mating hole, and a step portion is provided on the outer periphery of the mating hole. The heat pipe includes a pipe body and a corresponding docking portion disposed at the bottom of the pipe body. The docking portion and the step portion are sealed together.

[0007] Furthermore, the stepped portion is annular, and the stepped portion is located on the inner side of the mating portion, with the outer diameter of the stepped portion matching the inner diameter of the mating portion.

[0008] Furthermore, the outer periphery of the top of the stepped section and the inner wall of the top of the connecting section are respectively curved surfaces.

[0009] Furthermore, the outer side of the bottom end of the step and the inner side of the bottom end of the mating part are respectively R-angles.

[0010] Furthermore, the bottom of the mating part is sealed and welded to the top cover.

[0011] Furthermore, the bottom of the mating part and the top cover are sealed by high-frequency welding ring welding process or welding ring brazing.

[0012] Furthermore, the inner wall of the tube is provided with heat pipe capillaries, and the bottom of the upper cover and the inner wall of the stepped portion are provided with upper cover capillaries, with the heat pipe capillaries overlapping the upper cover capillaries.

[0013] Furthermore, the mating part and the stepped part are connected by an interference fit.

[0014] Furthermore, the inner diameter of the mating part is larger than the inner diameter of the tube body.

[0015] Furthermore, the heat pipe is formed by expanding an oxygen-free copper rod.

[0016] The beneficial effects of this utility model are as follows: (1) Extremely low contact thermal resistance: The stepped docking part and the stepped part of this utility model cooperate to ensure accurate positioning, which can reduce the contact thermal resistance to below 0.05℃ / W and greatly improve the heat conduction efficiency; (2) High structural stability: The fixing method of the joint and the step can adapt to vibration and thermal expansion and contraction, and maintain reliable overlap even in harsh environments, avoiding heat dissipation failure; (3) Low heat transfer loss: The steam confluence channel avoids stagnation and eddies, and the Qmax attenuation rate is ≤5%, realizing the superposition of the heat transfer capacity of multiple heat pipes; (4) Strong adaptability: This utility model has a compact structure and is applicable to all 3D heat exchange plates; (5) Good processability: All components of this utility model can be processed using mature technology (CNC, pipe expansion, etc.), the overlapping method is simple and easy to implement, no special equipment is required, it is convenient for mass production and on-site maintenance, and the cost is low. Attached Figure Description

[0017] Figure 1 This is a structural diagram of the heat pipe overlapping mechanism of the 3D heat spreader in an embodiment of this utility model.

[0018] Figure 2 This is a three-dimensional structural diagram of the heat pipe according to an embodiment of the present invention.

[0019] Figure 3 This is a front view of the heat pipe according to an embodiment of the present invention.

[0020] Figure 4 yes Figure 3 Sectional view at point AA.

[0021] Figure 5 yes Figure 4 Enlarged view of point B in the middle.

[0022] Figure 6 This is a cross-sectional view of the lower cover and the upper cover of an embodiment of this utility model.

[0023] Explanation of icon numbers 10. Top cover, 11. Insertion hole, 12. Stepped section, 13. Top cover capillary, 20. Heat pipe, 21. Pipe body, 22. Connecting section, 23. Heat pipe capillary, 30. Bottom cover, 40. Steam chamber. Detailed Implementation

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicators will also change accordingly.

[0026] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0027] Please refer to Figures 1-6 The heat pipe overlapping mechanism of the 3D vapor chamber in this embodiment includes an upper cover and heat pipes disposed on the upper cover. The upper cover has interlocking holes. The 3D vapor chamber also includes a lower cover, which is welded to the upper cover, forming a vapor chamber between the lower and upper covers. The heat pipes communicate with the vapor chamber through the interlocking holes. This part is a conventional technical solution in the art and will not be described in detail here.

[0028] The heat pipe has a stepped portion on the outer periphery of the insertion hole. The upper cover and the insertion hole on the upper cover, along with the stepped portion, can be integrally forged / stamped. The heat pipe includes a pipe body and a corresponding mating portion located at the bottom of the pipe body. The inner diameter of the mating portion is larger than the inner diameter of the pipe body, i.e., the mating portion is flared, covering the stepped portion. The mating portion and the stepped portion are sealed together, with the inner surface of the mating portion and the outer surface of the stepped portion tightly fitted. The mating portion is fitted over the stepped portion. Preferably, the mating portion and the stepped portion are connected by an interference fit. In specific implementations, the heat pipe can be formed by expanding oxygen-free copper rods (99.99% purity).

[0029] In one implementation, the step portion is annular and is located inside the docking portion. The outer diameter of the step portion matches the inner diameter of the docking portion, that is, the outer diameter of the step portion is equal to or slightly larger than the inner diameter of the docking portion.

[0030] In one implementation, the outer periphery of the top of the stepped portion and the inner wall of the top of the mating portion are respectively curved surfaces, which facilitates the assembly of the heat pipe and improves the sealing performance.

[0031] As one implementation method, the outer side of the bottom end of the stepped portion and the inner side of the bottom end of the mating portion are respectively R-angles, which further facilitates the assembly of the heat pipe and improves the sealing performance.

[0032] As one implementation method, the bottom of the mating part is sealed and welded to the top cover. Preferably, a high-frequency welding ring welding process or welding ring brazing is used for sealing welding. In specific implementation, solder is added so that the solder ring is formed around the bottom of the mating part, and then the heat pipe is welded to the top cover.

[0033] In one implementation, a heat pipe capillary is provided on the inner wall of the tube, and an upper cover capillary is provided on the bottom of the upper cover and the inner wall of the stepped portion, with the heat pipe capillary overlapping the upper cover capillary. In a specific implementation, the heat pipe capillary is made of sintered copper powder, or the heat pipe can be directly implemented using a grooved tube.

[0034] After the 3D vapor chamber is prepared, a sealing test can be performed: helium mass spectrometry is used to detect leaks in the vapor chamber of the 3D vapor chamber to ensure that the leakage rate is ≤1×10⁻ 9 Pa・m³ / s; Inject a working fluid (such as deionized water or ethanol) into the working fluid compensation chamber, the injection volume being 80% of the compensation chamber volume, and then seal the compensation chamber.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A heat pipe overlapping mechanism for a 3D heat spreader, comprising a top cover and heat pipes disposed on the top cover, wherein the top cover is provided with interlocking holes, characterized in that, The heat pipe has a stepped portion on the outer periphery of the socket, and includes a pipe body and a corresponding connecting portion at the bottom of the pipe body. The connecting portion and the stepped portion are sealed together.

2. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 1, characterized in that, The stepped part is ring-shaped and is located on the inner side of the mating part. The outer diameter of the stepped part matches the inner diameter of the mating part.

3. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 2, characterized in that, The outer perimeter of the top of the stepped section and the inner wall of the top of the connecting section are curved surfaces.

4. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 2, characterized in that, The outer side of the bottom end of the stepped section and the inner side of the bottom end of the connecting section correspond to the R angle.

5. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 2, characterized in that, The bottom of the mating part is sealed and welded to the top cover.

6. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 5, characterized in that, The bottom of the mating part and the top cover are sealed by high-frequency welding ring welding process or welding ring brazing.

7. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 1, characterized in that, The inner wall of the tube is provided with heat pipe capillary, and the bottom of the upper cover and the inner wall of the stepped part are provided with upper cover capillary. The heat pipe capillary overlaps with the upper cover capillary.

8. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 1, characterized in that, The mating part and the stepped part are connected by an interference fit.

9. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 1, characterized in that, The inner diameter of the mating part is larger than the inner diameter of the pipe body.

10. The heat pipe overlapping mechanism of the 3D heat spreader as described in claim 1, characterized in that, The heat pipe is formed by expanding oxygen-free copper rods.

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