EP-4739016-A1 - ELECTRONIC DEVICE, VAPOR CHAMBER AND PREPARATION METHOD THEREFOR

Abstract

An electronic device, a vapor chamber, and a preparation method therefor are disclosed, and relate to the field of electronic devices, to improve heat dissipation performance of the vapor chamber. A specific solution is as follows: The vapor chamber includes a first metal layer, a second metal layer, and a capillary structure. The first metal layer includes a first body part and a first edge part. The second metal layer includes a second body part and a second edge part. A surface of the first edge part is connected to a surface of the second edge part to form a connection layer. A quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer accounts for 70% or more. The small crystal grains at the connection layer can prevent impurities that affect a capillary force of the capillary structure in an accommodation cavity from entering the accommodation cavity, so that the vapor chamber has good heat dissipation performance. The vapor chamber may include a metal cover and the connection layer, is mainly formed by metal crystal grains with small grain sizes, and may feature high strength and high stiffness macroscopically; or may include a part of non-metal materials, features high flexibility, and satisfies heat dissipation requirements of different electronic products.

Inventors

• CHEN, Qiu
• HUANG, YU
• JIN, LINFANG
• LIU, Yonglu
• LUO, YANG

Assignees

• Huawei Technologies Co., Ltd.

Dates

Publication Date

20260506

Application Date

20241012

Claims (15)

1. A vapor chamber, wherein the vapor chamber comprises: a first cover, comprising a first metal layer, wherein the first metal layer comprises a first body part and a first edge part disposed around a periphery of the first body part; a second cover, comprising a second metal layer, wherein the second metal layer comprises a second body part and a second edge part disposed around a periphery of the second body part, a surface of the first edge part is connected to a surface of the second edge part to form a connection layer, and the first body part and the second body part jointly enclose an accommodation cavity; and a capillary structure, located in the accommodation cavity and connected to the first body part, wherein in a direction perpendicular to a thickness direction of the connection layer, a quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer having a length of at least 5 mm accounts for 70% or more of a total quantity of crystal grains.
2. The vapor chamber according to claim 1, wherein the quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer accounts for 70% or more of the total quantity of crystal grains.
3. The vapor chamber according to claim 1 or 2, wherein a material of the first metal layer is a first metal material, the first edge part has a first surface and a second surface that are disposed opposite to each other, the second surface is connected to the surface of the second edge part, and a mass percentage of the first metal material is greater than or equal to 95% at a location that is in the first edge part and that is at a distance greater than or equal to 3 µm from the first surface.
4. The vapor chamber according to any one of claims 1 to 3, wherein the first cover further comprises a support layer, and the support layer is connected to a side that is of the first metal layer and that is away from the second metal layer.
5. The vapor chamber according to claim 4, wherein a material of the support layer comprises at least one of titanium and an alloy thereof, aluminum and an alloy thereof, magnesium and an alloy thereof, and steel.
6. The vapor chamber according to any one of claims 1 to 5, wherein the first cover further comprises a polymer layer, and the polymer layer is connected to the side that is of the first metal layer and that is away from the second metal layer.
7. The vapor chamber according to any one of claims 1 to 6, wherein the material of the first metal layer comprises at least one of copper and an alloy thereof, or aluminum and an alloy thereof.
8. The vapor chamber according to any one of claims 1 to 7, wherein a thickness of the first metal layer ranges from 5 µm to 80 µm.
9. The vapor chamber according to any one of claims 1 to 8, wherein the vapor chamber further comprises a plurality of protrusions that are spaced from each other in the accommodation cavity, and one end of each of the plurality of protrusions is connected to the second body part, and the other end is a free end.
10. The vapor chamber according to any one of claims 1 to 9, wherein the capillary structure is connected to the first body part to form an integrated component.
11. A method for preparing a vapor chamber, wherein the method for preparing the vapor chamber comprises: providing a first cover, a second cover, and a capillary structure, wherein the first cover comprises a first metal layer, and the first metal layer comprises a first body part and a first edge part disposed around a periphery of the first body part; the second cover comprises a second metal layer, and the second metal layer comprises a second body part and a second edge part disposed around a periphery of the second body part; and the capillary structure is connected to the first body part; and performing first thermal processing on the first cover, the capillary structure, and the second cover that are sequentially stacked, to connect the first edge part to the second edge part, wherein in the first thermal processing, a temperature ranges from 150°C to 400°C, pressure is greater than or equal to 30 MPa, and time is greater than or equal to 30 min to 100 min.
12. The method for preparing the vapor chamber according to claim 11, wherein before a step of performing the first thermal processing on the first cover, the capillary structure, and the second cover that are sequentially stacked, the method further comprises: performing second thermal processing on the first cover and the capillary structure, to connect the capillary structure to the first body part, wherein in the second thermal processing, a temperature ranges from 150°C to 400°C, pressure is greater than or equal to 5 MPa, and time is greater than or equal to 30 min.
13. The method for preparing the vapor chamber according to claim 11 or 12, wherein before the step of performing the first thermal processing on the first cover, the capillary structure, and the second cover that are sequentially stacked, the method further comprises: stacking the first cover, the capillary structure, and the second cover, and filling nanoparticles between the first edge part and the second edge part.
14. An electronic device, wherein the electronic device comprises a printed circuit board and the vapor chamber according to any one of claims 1 to 10, and the first cover is connected to the printed circuit board.
15. The electronic device according to claim 14, wherein the electronic device further comprises a middle frame; the vapor chamber, the middle frame, and the printed circuit board are sequentially stacked; and a through hole that penetrates the middle frame in a thickness direction of the middle frame is disposed on the middle frame, and the first cover passes through the through hole and is connected to the printed circuit board.

Description

This application claims priority to Chinese Patent Application No. 202410009564.5, filed with the China National Intellectual Property Administration on January 2, 2024 and entitled "ELECTRONIC DEVICE, VAPOR CHAMBER, AND PREPARATION METHOD THEREFOR", which is incorporated herein by reference in its entirety. TECHNICAL FIELD Embodiments of this application relate to the field of electronic devices, and in particular, to an electronic device, a vapor chamber, and a preparation method therefor. BACKGROUND An electronic device (for example, a mobile phone) generates heat during operating. If the heat is accumulated inside the electronic device for a long time, a temperature of the electronic product increases, affecting user experience and even causing a fault. Currently, a vapor chamber (Vapor Chamber, VC) is used to dissipate heat on the electronic device. The vapor chamber is a vacuum cavity with a capillary structure on an inner wall and injected with a working medium (namely, working medium). Currently, heat dissipation performance of the vapor chamber becomes an important factor affecting heat dissipation performance of the electronic device. Therefore, how to improve the heat dissipation performance of the vapor chamber is an urgent problem to be resolved for the vapor chamber. SUMMARY Embodiments of this application provide an electronic device, a vapor chamber, and a preparation method therefor, to improve heat dissipation performance of the vapor chamber. To achieve the foregoing objective, the following technical solutions are used in this application. According to a first aspect, an embodiment of this application provides a vapor chamber. The vapor chamber includes a first cover, a second cover, and a capillary structure. The first cover includes a first metal layer, and the first metal layer includes a first body part and a first edge part disposed around a periphery of the first body part. The second cover includes a second metal layer, and the second metal layer includes a second body part and a second edge part disposed around a periphery of the second body part. A surface of the first edge part is connected to a surface of the second edge part to form a connection layer, and the first body part and the second body part jointly enclose an accommodation cavity. The capillary structure is located in the accommodation cavity and is connected to the first body part. In a direction perpendicular to a thickness direction of the connection layer, a quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer having a length of at least 5 mm accounts for 70% or more of a total quantity of crystal grains. Therefore, there is an advantage of small crystal grain size at a joint between the first cover and the second cover. The small crystal grain is conducive to uniform stress between the first edge part and the second edge part, so that mechanical properties of the first edge part and the second edge part are good. In addition, a size of a crystal grain in the first edge part is small, so that another crystal grain structure on a side that is of the first metal layer and that is away from the accommodation cavity cannot pass through the first edge part and enter the accommodation cavity, to avoid a case that heat dissipation performance of the vapor chamber deteriorates because a capillary force of the capillary structure in the accommodation cavity is affected by the another crystal grain structure. Similarly, a size of a crystal grain in the second edge part is small, so that another crystal grain structure on a side that is of the second metal layer and that is away from the accommodation cavity cannot affect the capillary force of the capillary structure in the accommodation cavity. A better capillary force of the capillary structure indicates better heat dissipation performance of the vapor chamber, thereby effectively improving the heat dissipation performance of the vapor chamber. With reference to the first aspect, in some possible implementations, the quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer accounts for 70% or more of the total quantity of crystal grains. Therefore, there is an advantage of good mechanical property at the entire joint between the first cover and the second cover. With reference to the first aspect, in some implementations, the quantity of crystal grains whose grain sizes are less than or equal to 50 µm at the connection layer accounts for 90% or more of the total quantity of crystal grains. Therefore, there is an advantage of good mechanical property at the entire joint between the first cover and the second cover. With reference to the first aspect, in some possible implementations, a material of the first metal layer is a first metal material, the first edge part has a first surface and a second surface that are disposed opposite to each other, the second surface is connected to