A novel phase change material encapsulation structure for electronic temperature control

Abstract

The application discloses a novel phase change material packaging structure for electronic device temperature control, which comprises a base and a metal heat dissipation structure, a closed space is formed in the base, the closed space comprises a filling space and an expansion space, the expansion space is located at the top of the closed space, the filling space is used for filling phase change material, and the expansion space is used after the phase change material expands; an connecting groove is arranged on the outer side of the base, the connecting groove is located at the top end or the bottom end of the base, the depth of the connecting groove is smaller than the thickness of the base, and the connecting groove is used for connecting a heat source; the metal heat dissipation structure is connected in the base, the metal heat dissipation structure is in the shape of a tree branch, the root of the metal heat dissipation structure is connected with the base at the connecting groove, and the branch of the metal heat dissipation structure is connected with the phase change material; the metal heat dissipation structure is in the shape of a tree branch, the forming material of the metal heat dissipation structure is metal material, and finally, the metal heat dissipation structure can reduce the use amount of metal material and improve the heat storage capacity of the packaging structure per unit volume under the same heat exchange efficiency.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation technology for electronic devices and electronic components, and specifically to a novel phase change material packaging structure for temperature control of electronic devices. Background Technology

[0002] With the rapid development of advanced information technologies, such as cloud computing and big data, the widespread use of high-performance chips and large-scale and very-large-scale integrated circuits has placed higher demands on the performance and operational stability of electronic devices. According to relevant statistics, 55% of electronic device failures are caused by operating temperatures exceeding specified limits. Passive phase change temperature control technology, which has developed rapidly in recent years, is one effective way to solve this problem. However, this application has a significant drawback: the thermal conductivity of the material itself is very low. How to improve the phase change heat transfer rate of such phase change material packaging is a major research direction and hot topic in the development of new phase change temperature control technologies for electronic devices. Therefore, a new temperature control technology is urgently needed to meet the packaging requirements of future high-performance electronic devices.

[0003] Currently, the main approach to improving the heat transfer performance of phase change materials is to uniformly fill the phase change materials with nanomaterials or metal structures with high thermal conductivity to increase their overall thermal conductivity. However, the influence of liquid phase material convection heat transfer related to the metal structure during the phase change process is ignored. Summary of the Invention

[0004] The purpose of this invention is to provide a novel phase change material packaging structure for temperature control of electronic devices, so as to solve the problem of poor heat transfer performance of packaging structures in the prior art.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] A novel phase change material encapsulation structure for temperature control of electronic devices includes a base and a metal heat dissipation structure. A closed space is formed within the base, and the closed space includes a filling space and an expansion space. The expansion space is located at the top of the closed space. The filling space is used to fill the phase change material, and the expansion space is used after the phase change material expands.

[0007] The outer side of the base is provided with a connecting groove, which is located at the top or bottom of the base. The depth of the connecting groove is less than the thickness of the base. The connecting groove is used to connect a heat source. The metal heat dissipation structure is connected inside the base. The shape of the metal heat dissipation structure is tree-like. The root of the metal heat dissipation structure is connected to the base at the connecting groove, and the branches of the metal heat dissipation structure are connected to the phase change material.

[0008] Furthermore, the cross-sectional area ratio of the metal heat dissipation structure can be adjusted.

[0009] Furthermore, the cross-sectional area ratio of the metal heat dissipation structure is 12.5%.

[0010] Furthermore, the cross-sectional area ratio of the metal heat dissipation structure is 15%.

[0011] Furthermore, the cross-sectional area ratio of the metal heat dissipation structure is 20%.

[0012] Furthermore, the heat source and the connecting groove are connected by a transition fit.

[0013] Furthermore, thermally conductive silicone grease or thermally conductive adhesive is filled between the heat source and the connecting groove.

[0014] Furthermore, the metal heat dissipation structure and the base are integrally formed.

[0015] Furthermore, the metal heat dissipation structure is manufactured using 3D printing technology.

[0016] Furthermore, the material of the metal heat dissipation structure is a silicon-magnesium alloy.

[0017] According to the above technical solution, the embodiments of the present invention have at least the following effects:

[0018] 1. The packaging structure of the present invention has a tree-like shape for the metal heat dissipation structure, and its forming material is metal material. Ultimately, it can reduce the amount of metal material used and increase the heat storage per unit volume of the packaging structure under the same heat exchange efficiency.

[0019] 2. This invention reduces the proportion of existing metal heat dissipation structures and increases the volume and mass ratio of phase change materials in the packaging structure. The tree shape of the metal heat dissipation structure is optimized by the SIMP method. Experimental results show that, under the same heat exchange efficiency, the metal mass required by the optimized metal heat dissipation structure can be reduced by up to half compared with the traditional plate-fin metal heat dissipation structure. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a packaging structure in the prior art;

[0021] Figure 2 This is a schematic diagram of a packaging structure in the prior art;

[0022] Figure 3 This is a schematic diagram of the base and its internal metal heat dissipation structure in a specific embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the first form of the encapsulation structure in a specific embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the second form of the encapsulation structure in a specific embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the third form of the encapsulation structure in a specific embodiment of the present invention.

[0026] The components include: 1. Heat source; 2. Filling space; 3. Base; 4. Metal heat dissipation structure; 5. Phase change material; and 6. Expansion space. Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0028] It should be noted that in the description of this invention, the terms "front," "rear," "left," "right," "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "front," "rear," "left," "right," "upper," and "lower" used in the description of this invention refer to the directions shown in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0029] This invention proposes a novel phase change material (PCM) encapsulation structure for temperature control of electronic devices to meet the needs of future electronic device packaging designs. This method fully considers the design freedom advantages provided by advanced manufacturing technologies and the deterministic design capabilities of structural topology optimization methods, effectively enabling the development of a new generation of lightweight and efficient PCM temperature control technology for electronic devices. Its advantages include high heat exchange efficiency, a rational and efficient heat conduction path, and enhanced heat transfer through the promotion of natural convection.

[0030] like Figures 3 to 6 As shown, a novel phase change material encapsulation structure for temperature control of electronic devices includes a base 3 and a metal heat dissipation structure 4. A closed space is formed inside the base 3. The closed space includes a filling space 2 and an expansion space 6. The expansion space 6 is located at the top of the closed space. The filling space 2 is used to fill the phase change material 5, and the expansion space 6 is used after the phase change material 5 expands.

[0031] A connecting groove is provided on the outer side of the base 3. The connecting groove is located at the top or bottom of the base 3. The depth of the connecting groove is less than the thickness of the base 3. The connecting groove is used to connect the heat source 1. The metal heat dissipation structure 4 is connected inside the base 3. The shape of the metal heat dissipation structure 4 is tree-like. The root of the metal heat dissipation structure 4 is connected to the base 3 at the connecting groove. The branches of the metal heat dissipation structure 4 are connected to the phase change material 5.

[0032] In the structure, the metal heat dissipation structure 4 is shaped like a tree branch, and its forming material is metal. Ultimately, it can reduce the amount of metal material used and increase the heat storage per unit volume of the encapsulation structure while maintaining the same heat exchange efficiency.

[0033] The dendritic metal heat dissipation structure 4 can significantly improve the thermal diffusion efficiency of the overall packaging structure and simultaneously enhance convective heat transfer, thereby reducing the volume fraction of the metal heat dissipation structure 4 in the overall packaging structure and increasing the phase change heat storage volume of the package. Specifically, under the same heat transfer efficiency, the metal mass (or volume) required by the dendritic metal heat dissipation structure 4 is only half that of the traditional plate-fin metal heat dissipation structure; adjusting the volume ratio of the branches of the metal heat dissipation structure 4, i.e., the cross-sectional area ratio of the metal heat dissipation structure 4, can directly affect the thermal diffusion efficiency and convective heat transfer effect of the packaging structure.

[0034] Specifically, within a given cross-sectional area ratio of the metal heat dissipation structure 4, the enhancement effect on convective heat transfer becomes more pronounced as the cross-sectional area ratio of the metal heat dissipation structure 4 increases. Taking wax-based phase change materials as an example, the heat transfer effect is more excellent when the cross-sectional area ratio of the metal heat dissipation structure 4 is between 10% and 20%.

[0035] Experimental data shows that, when using wax-based phase change materials, compared to the traditional straight-fin metal heat dissipation structure 2, the metal heat dissipation structure 4 with optimized thermal conductivity topology can improve the safe operating time at a temperature range of 3-15 times within the 10%-20% cross-sectional area ratio of the metal heat dissipation structure (the specific value depends on the safe operating temperature and the phase change temperature of the phase change material). Currently, metal cross-sectional area ratios of 12.5%, 15%, and 20% are considered suitable.

[0036] Specifically, experimental analysis shows that the thermal conductivity of the metal heat dissipation structure 4 plays a crucial role in the thermal response under high thermal load shocks. However, excessive heat dissipation fins do not necessarily improve the heat transfer performance of the metal heat dissipation structure. The base 3, which contacts the heat source (chip) 1, is not limited to being below the metal heat dissipation structure 4; it can also be placed at the top, depending on the location of the heat source 1. Based on experimental results, when the heat source 1 is located below the metal heat dissipation structure 4, the enhanced convective heat transfer under gravity is more pronounced, and the phase change material melts at a faster rate.

[0037] The enhanced heat transfer effect is due to the improved heat conduction efficiency of the heat dissipation structure and the enhanced convective heat transfer caused by the complex shape of the structure itself. This is reflected in the fact that the complex shape can optimize the heat conduction path and suppress temperature non-uniformity, thereby effectively reducing the temperature of the heat source.

[0038] In a further embodiment of the present invention, the outer periphery of the base 3 is wrapped with heat-insulating material to ensure the heat storage effect within the encapsulation structure. The shape of the base 3 is not limited to the square box structure shown in the figure of this embodiment; it can be any shape such as trapezoidal, columnar, or frustum-shaped. The base 3 serves a fixing function, both fixing the heat exchanger workpiece and fixing the metal heat dissipation structure 4 on it.

[0039] In a further embodiment of the present invention, the metal heat dissipation structure 4 and the base 3 are integrally formed. This integral forming enhances the effect of heat absorption by the base 3 and its conduction to the metal heat dissipation structure 4. After the heat is conducted to the metal heat dissipation structure 4 via the base 3, a portion of the heat will be carried away by the metal heat dissipation structure 4 through convection heat transfer.

[0040] In a further embodiment of the present invention, the metal heat dissipation structure 4 is specially processed. Depending on the complexity of its structure, it can be formed by 3D metal printing technology (using silicon-magnesium metal alloy powder) or by electrical discharge wire cutting, but is not limited to these two processing methods.

[0041] In a further embodiment of the present invention, the metal heat sink 3 and the surface of the heat source 1 should be connected as closely as possible. The two can be connected by a plug-in joint or by thermal fusion. For plug-in joints, a tight connection must be ensured; specifically, a transition fit connection can be used. To prevent insufficient heat conduction, the gaps between the joints should be filled with a heat dissipation component with high thermal conductivity and relatively good fluidity, such as a heat dissipation pad, thermal grease, thermal paste, or liquid metal, etc., to enhance thermal conductivity.

[0042] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A phase change material encapsulation structure for temperature control of electronic devices, characterized in that, It includes a base (3) and a metal heat dissipation structure (4). The base (3) forms a closed space. The closed space includes a filling space (2) and an expansion space (6). The expansion space (6) is located at the top of the closed space. The filling space (2) is used to fill the phase change material (5). The expansion space (6) is used after the phase change material (5) expands. The outer side of the base (3) is provided with a connecting groove, which is located at the top or bottom of the base (3). The depth of the connecting groove is less than the thickness of the base (3). The connecting groove is used to connect the heat source (1). The metal heat dissipation structure (4) is connected inside the base (3). The shape of the metal heat dissipation structure (4) is tree-like. The root of the metal heat dissipation structure (4) is connected to the base (3) at the connecting groove, and the branches of the metal heat dissipation structure (4) are connected to the phase change material (5). The cross-sectional area ratio of the metal heat dissipation structure (4) is 12.5%, 15%, or 20%. The heat source (1) and the connecting groove are connected by a transition fit.

2. The phase change material encapsulation structure according to claim 1, characterized in that, The gap between the heat source (1) and the connecting groove is filled with thermally conductive silicone grease or thermally conductive adhesive.

3. The phase change material encapsulation structure according to claim 1, characterized in that, The metal heat dissipation structure (4) and the base (3) are integrally formed.

4. The phase change material encapsulation structure according to claim 1, characterized in that, The metal heat dissipation structure is manufactured using 3D printing technology.

5. The phase change material encapsulation structure according to any one of claims 1 or 4, characterized in that, The material of the metal heat dissipation structure is a silicon-magnesium alloy.

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