Packaging structure

Abstract

Some embodiments of the present application provide a package structure comprising: a first element; a second element over the first element; the heat conduction structure is positioned between the first element and the second element, and comprises a non-solid heat conduction layer; and a dam structure surrounding the non-solid thermally conductive layer, the dam structure including a plurality of gaps. The packaging structure provided by the utility model has a better heat dissipation effect under the condition of preventing the non-solid heat conduction layer from overflowing.

Description

Technical Field

[0001] An embodiment of the present application relates to a packaging structure. Background Art

[0002] For the existing packaging structure 10, see Figures 1A to 1C ,in, Figure 1A shows a cross-sectional view of the package structure 10, and Figure 1B to Figure 1C An electron microscope image of an existing packaging structure 10 is shown, wherein: Figure 1A The cross-sectional view is shown along Figure 1B and Figure 1C Line AA of package structure 10. Figures 1A to 1C As can be seen in FIG, a heat dissipation material 11 (eg, TIM (thermal interface material)) is usually provided on the package structure 10, and in the design of the heat dissipation material 11 such as TIM, an overflow C problem usually occurs. Figures 1D to 1F , Figures 1D to 1F A package structure 10 ′ is shown with a dam structure 12 , and Figure 1E and Figure 1F They are shown respectively Figure 1D The electron microscope image of the package structure 10'. Figures 1D to 1F It can be seen that in order to reduce the overflow problem of heat dissipation materials 11 such as TIM, a dam structure 12, such as a metal part or a high-strength polymer part (for example, a molding compound (CPD)), is usually set at the edge of the back surface of the packaging structure 10' to reduce the overflow C problem of heat dissipation materials 11 such as TIM. Figure 1D Shown along Figure 1E and Figure 1F A cross-sectional view of the package structure 10' along line AA', from Figure 1D It can be clearly seen in FIG. 1 that the heat dissipation material 11 disposed between the electronic components 13 and 14 is blocked by the dam structure 12 (wherein L represents the heat dissipation direction of the electronic components 13 and 14). Figure 1E and Figure 1F As shown, due to the higher density of the dam structure 12, in a thermal environment (for example, when the packaging structure 10' is in operation), the dam structure 12 is squeezed and cracked due to thermal expansion (a larger space can accommodate the expansion of the dam structure 12), resulting in the inability to improve the overflow effect of limiting the heat dissipation material 11 such as TIM.

[0003] It can be seen that in the existing packaging structures 10 and 10', the heat dissipation material 11 (cooling material) such as TIM cannot be controlled in the selected area, resulting in the overflow C problem, and the dam structure 12 for releasing heat without any passage also causes the dam area to fail. Therefore, the problem of preparing the heat dissipation material 11 (such as TIM) of the packaging structures 10 and 10' at this stage is that the overflow C problem of the heat dissipation material 11 cannot be completely avoided regardless of whether the dam structure 12 is used for containment, and the use of the dam structure 12 for containment is also prone to damage the fence (dam structure 12) due to expansion. Utility Model Content

[0004] The packaging structure provided in the present application can solve the problem that the existing packaging structure cannot limit the overflow of heat dissipation materials such as TIM because the existing dam structure has a high density and is prone to rupture due to expansion of the dam structure in a thermal environment, by reducing the density of the dam structure.

[0005] Some embodiments of the present application provide a packaging structure, comprising: a first element; a second element located above the first element; and a heat-conducting structure located between the first element and the second element, wherein the heat-conducting structure comprises: a non-solid heat-conducting layer; a dam structure surrounding the non-solid heat-conducting layer, the dam structure comprising a plurality of gaps.

[0006] In some embodiments, the dam structure is composed of a plurality of branch structures grown on the first element, wherein the branch structures include a main body connected to the first element and a plurality of strip-shaped branches branching from the main body.

[0007] In some embodiments, some of the plurality of strip-shaped branches are embedded in the non-solid heat conductive layer.

[0008] In some embodiments, the dam structure is annular in shape when viewed from above.

[0009] In some embodiments, the annular shape is a rectangular shape or a circular shape.

[0010] In some embodiments, the plurality of gaps exist between the bodies, between the bodies and the plurality of strip-shaped branches, or between the plurality of strip-shaped branches.

[0011] In some embodiments, the non-solid heat conductive layer extends into a gap of the dam structure adjacent to the non-solid heat conductive layer.

[0012] In some embodiments, the packaging structure further includes: a columnar structure surrounded by the dam structure.

[0013] In some embodiments, the columnar structure includes a first column connected to the first element and a second column connected to the second element, wherein the first column is in contact with the second column.

[0014] In some embodiments, the first pillar is spaced apart from the second element by the non-solid thermally conductive layer, and the second pillar is spaced apart from the first element by the non-solid thermally conductive layer.

[0015] In some embodiments, the non-solid heat conductive layer is liquid metal.

[0016] In some embodiments, the branch-like structure includes a first main body connected to the first element and a plurality of first strip-like branches branching from the first main body, and includes a second main body connected to the first element and a plurality of second strip-like branches branching from the second main body, wherein the first strip-like branches are in contact with the second strip-like branches.

[0017] In some embodiments, the branch structure includes a first body connected to the first element and a plurality of first strip branches branching from the first body, and includes a second body connected to the first element and a plurality of second strip branches branching from the second body, wherein the second strip branches are farther away from the non-solid thermal conductive layer relative to the first strip branches, and wherein the first strip branches are embedded in the non-solid thermal conductive layer, and the second strip branches are separated from the non-solid thermal conductive layer.

[0018] In some embodiments, the columnar structure is connected to the first element and is spaced apart from the second element by the non-solid thermally conductive layer.

[0019] In some embodiments, the columnar structure is a nanowire structure.

[0020] In some embodiments, an outermost wall of the dam structure is recessed from outermost walls of the first element and the second element.

[0021] In some embodiments, the first element is vertically aligned with the second element.

[0022] Other embodiments of the present application provide a packaging structure, comprising: a first element; a heat-conducting structure located on the first element, wherein the heat-conducting structure comprises: a non-solid heat-conducting layer; a dam structure surrounding the non-solid heat-conducting layer; and a second element located above the heat-conducting structure, wherein a portion of the non-solid heat-conducting layer is embedded in the dam structure.

[0023] In some embodiments, the dam structure includes a plurality of gaps, and the non-solid thermally conductive layer extends into the gaps.

[0024] In some embodiments, the dam structure is composed of a plurality of branch structures grown on the first element, wherein the branch structures include a main body connected to the first element and a plurality of strip-shaped branches branching from the main body.

[0025] The packaging structure provided in the present application has a better heat dissipation effect while preventing overflow of the non-solid heat-conducting layer, and can be applied to heat dissipation of various components, such as 2.5D / 3D... packaging structures, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] When read in conjunction with the accompanying drawings, various aspects of the present invention can be best understood from the following detailed description. It should be noted that, in accordance with standard practice in the industry, the various components are not drawn to scale. In fact, for the sake of clarity of discussion, the size of the various components can be arbitrarily increased or reduced.

[0027] Figures 1A to 1F The package structure in the prior art is shown.

[0028] Figure 2 and Figure 2A A packaging structure according to some embodiments of the present application is shown.

[0029] FIG. 3A to FIG. 3C A dam structure according to some embodiments of the present application is shown.

[0030] FIG. 4A to FIG. 4D A top view of a packaging structure according to some embodiments of the present application is shown.

[0031] Figure 5 , FIG. 5A to FIG. 5B Other packaging structures according to other embodiments are shown.

[0032] FIG. 6A to FIG. 6B The simulation results of heat dissipation of the packaging structure in the prior art and the packaging structure of the present application are shown.

[0033] Figures 7 to 9 The process flow of the packaging structure according to some embodiments of the present application is shown. DETAILED DESCRIPTION

[0034] The following disclosure provides many different embodiments or examples for realizing different features of the present invention. Specific examples of components and arrangements are described below to simplify the present invention. Of course, these are merely examples and are not intended to limit the present invention. In addition, when "approximately", "about", "substantially", etc. are used to describe a numerical value or a numerical range, unless otherwise specified, the term is intended to cover a numerical value within ±10% of the described numerical value. For example, the term "about 5nm" covers a size range from 4.5nm to 5.5nm.

[0035] The packaging structure of the present application reduces the density of the dam structure by setting a microstructure of the dam structure, grabs the liquid metal or limits the metal position concept through the dendrite structure, and uses nanowires to increase the bonding strength of the upper and lower components and further grab the liquid metal. In addition, the packaging structure provided by the present application can pattern the dam structure of the dendrite microstructure, and the relative positions of the nanowires and the dendrite microstructure can be designed according to the heat source to improve the heat dissipation efficiency.

[0036] Specifically, see Figure 2 , Figure 2 FIG. 1 shows a package structure 100 according to some embodiments of the present application. Figure 2 As shown, the packaging structure 100 includes: a first element 104; a second element 105 located above the first element 104; and a heat-conducting structure 101 located between the first element and the second element. Specifically, the heat-conducting structure 101 includes: a non-solid heat-conducting layer 102 and a dam structure 103 surrounding the non-solid heat-conducting layer 102. In some embodiments, the dam structure 103 includes a plurality of gaps V (such as Figure 3A In some embodiments, the non-solid thermal conductive layer 102 is liquid metal. In some embodiments, the non-solid thermal conductive layer 102 is made of TIM material. In some embodiments, the first component 104 and the second component 105 are electronic components, such as but not limited to electronic integrated circuit components, photonic integrated circuit components, etc. Figure 2 In the package structure 100 shown, the outermost wall 103s of the dam structure 103 is recessed from the outermost wall 104s of the first element 104 and the outermost wall 105s of the second element 105. In further embodiments, the first element 104 is vertically aligned with the second element 105. In some other embodiments, the first element 104 is not aligned with the second element 105.

[0037] Next, if Figure 3A As shown, the dam structure 103 is composed of a plurality of branch structures 1031 grown on the first element 104, and in a further embodiment, the branch structure 1031 includes a main body 1031A connected to the first element 104 and a plurality of strip branches 1031B branching from the main body 1031A. Further, some of the plurality of strip branches 1031B are embedded in the non-solid heat conductive layer 102, such as the strip branches 1031B close to the non-solid heat conductive layer 102. In some embodiments, the non-solid heat conductive layer 102 extends into the gap V of the dam structure 103 close to the non-solid heat conductive layer 102. Further, as shown in FIG. Figure 3A As shown, the branch structure 1031 may be a dendrite structure such as a branch-like structure or a branch-like structure. Figure 3AAs can be seen from the figure, a plurality of gaps V exist between the main bodies 1031A, between the main body 1031A and a plurality of strip-shaped branches 1031B, or between a plurality of strip-shaped branches 1031B. Figure 3A As shown, the branch structure 1031 includes a first body 1031A1 connected to the first element 104 and a plurality of first strip branches 1031B1 branched from the first body 1031A1, and includes a second body 1031A2 connected to the first element 104 and a plurality of second strip branches 1031B2 branched from the second body 1031A2, wherein the first strip branches 1031B1 are in contact with the second strip branches 1031B2. In some other embodiments, the second strip branches 1031B2 are farther away from the non-solid heat-conducting layer 102 relative to the first strip branches 1031B1, and wherein the first strip branches 1031B1 are embedded in the non-solid heat-conducting layer 102, and the second strip branches 1031B2 are separated from the non-solid heat-conducting layer 102. In some embodiments, the dam structure 103 includes a metal such as copper, nickel, or a copper alloy.

[0038] Figure 3B and Figure 3C Shows Figure 3A The scanning electron microscope image of the dendrite structure 1031 is shown, wherein Figure 3B A loosely distributed dendritic structure 1031 is shown, and Figure 3C The densely distributed dendritic structure 1031 is shown. Figure 3C As can be seen in FIG. 1 , in the packaging structure 100 provided in the present application, by using the dense branch structure (dendritic structure) 1031 as the dam structure 103, since the branch structure 1031 has a gap V, the gap V can be formed by a mixture of blind holes and through holes, so that the dense structure of the branch structure 1031 as the dam structure 103 can also release some heat from the internal cooling system, as shown in FIG. Figure 2 Heat dissipation direction L' is shown. Return to Figure 3B , Figure 3B The loose structure of the branch-like structure 1031 can fix the material of the non-solid heat-conducting layer 102 within a desired pattern. This is because the loose structure of the branch-like structure 1031 can assist in coating and fixing the non-solid heat-conducting layer 102 (liquid heat dissipation material) on the first element 104 .

[0039] Therefore, in the package structure 100 provided in the present application, by using the dendritic or dendritic dense microstructure of the dendritic structure 1031 as the dam structure 103 (i.e., fence or fence) for preparing and patterning the non-solid thermal conductive layer 102 (such as the heat dissipation material of TIM), the gap V therein includes through holes and blind holes, which can effectively dredge the excessive heat in the process, so that the dam structure 103 that blocks the non-solid thermal conductive layer 102 will not be destroyed due to thermal expansion and cause the non-solid thermal conductive layer 102 to overflow. The loose structure of the dam structure 103 can assist the non-solid thermal conductive layer 102 to be coated and fixed on the first element 104. Therefore, in the package structure 100 of the present application, the dam structure 103 with the dendritic or dendritic dense microstructure of the dendritic structure 1031 effectively solves the problem of overflow of the non-solid thermal conductive layer 102 of the package structure 100 in a thermal environment. In addition, as described in further detail below, the density of the branch structure 1031 can be adjusted by the electroplating conditions, that is, the density of the branch structure 1031 can be controlled by the electroplating conditions.

[0040] Next, see FIG. 4A to FIG. 4D , FIG. 4A to FIG. 4D Shown along Figure 2 FIG. 1 is a top view of the package structure 100 along line B1 - B1 ′. In the top view, a heat conducting structure 101 disposed on the first element 104 and including a non-solid heat conducting layer 102 and a dam structure 103 surrounding the non-solid heat conducting layer 102 is shown in detail. FIG. 4A to FIG. 4C As can be seen from the figure, the dam structure 103 may be in a ring shape when viewed from above. Specifically, it may be as follows Figure 4A and Figure 4C The single rectangular shape or multiple rectangular shapes shown can also be as shown Figure 4D The circular shape shown. See above Figures 1A to 1F As described, in the prior art, molding compound (CPD) and the like are usually used as dam structures for blocking heat dissipation materials (or cooling materials), but the dam structures are often damaged due to thermal expansion in a hot environment. However, the dam structure 103 with a branch structure 1031 provided in the present application is not only not damaged due to thermal expansion, but also further transfers the heat of a device such as the first element 104 vertically upward to the outside of the package structure 100 or transfers it outward to the outside of the package structure 100 through a portion 103o of the dam structure 103. Therefore, the branch structure 1031 is a barrier that blocks the non-solid heat-conducting layer 102 within the desired pattern. It can be seen that the dam structure 103 (used as a fence or fence) with a special structure of the branch structure 1031 can be used to pattern the non-solid heat-conducting layer 102, the dam structure 103 can be formulated according to requirements, and assists the heat inside the package structure 100 to be conducted outward (upward (i.e., in the direction toward the second element 105)).

[0041] Back to reference Figure 2 The package structure 100 further includes a columnar structure 106 surrounded by the dam structure 103. Specifically, in some embodiments, the columnar structure 106 includes a first column 106A connected to the first element 104 and a second column 106B connected to the second element 105, wherein the first column 106A is in contact with the second column 106B. Figure 2A It can be further seen that the first column 106A is separated from the second element 105 by the non-solid heat conductive layer 102, and the second column 106B is separated from the first element 104 by the non-solid heat conductive layer 102. In some embodiments, only the first column 106A / 106B may be provided as the columnar structure 106, such as Figure 2A As shown in the package structure 100', in Figure 2A In the case shown, the columnar structure 106 is connected to the first element 104 and is separated from the second element 105 by the non-solid heat conductive layer 102. In some embodiments, the columnar structure 106 can be a nanometer or micrometer-scale structure, and in some specific embodiments, the columnar structure 106 is a nanowire structure. In some embodiments, the columnar structure 106 can also have a branch structure similar to the branch structure 1031, and the branch structure can also be a dendrite structure such as a dendrite-like structure or a dendrite structure.

[0042] See below Figures 5 to 5A , which respectively show the Figure 2 and Figure 2A The corresponding package structures 1000 and 1000' are provided without the dam structure 103, and Figure 5B Shown along Figure 5 A top view of the package structure 1000 taken along line B2-B2' is shown. Figures 2 to 2A , Figure 4A as well as Figures 5 to 5B It can be seen that the use of such nano- or micro-scale columnar structures 106 allows the non-solid heat-conducting layer 102 (ie, cooling material) to be interposed between the corresponding intervening layers (ie, the first element 104 and the second element 105), as shown in FIG. Figure 2A and Figure 5A In addition, the nano- or micro-scale columnar structure 106 can be used to fix the non-solid heat-conducting layer 102, and if the non-solid heat-conducting layer 102 is to be patterned, it can be as shown in FIG. Figure 5B As shown, Figures 2 to 2A , Figure 4A As shown, the branch structure 1031 is used as the dam structure 103. In this case, if the non-solid thermal conductive layer 102 does not need to be patterned, the non-solid thermal conductive layer 102 can be locked in the dam structure 103, as shown in FIG. Figure 4AIn some embodiments, the non-solid heat-conducting layer 102 may be liquid metal or the like. Figure 2 as well as Figure 5 As can be seen in the figure, the package structures 100 and 1000 can enhance the interposer (i.e., the first element 104 and the second element 105) bonding from both sides because the columnar structure 106 is formed on opposite sides of the interposer (i.e., the first element 104 and the second element 105). In addition, the structure of the non-solid thermal conductive layer 102 for fixing the cooling system can also be a uniform columnar structure 106, such as by using a template, such as a polymer, anodized aluminum oxide (AAO) template, etc. to form the columnar structure 106. Finally, special structures such as the columnar structure 106 of the packaging structure 100 / 100' and the corresponding packaging structure 1000 / 1000' provided in the present application can also assist in the bonding strength between the intermediate layers (such as the first element 104 and the second element 105), that is, special structures such as the columnar structure 106 are configured to increase the fixing strength of the relative position between the first element 104 and the second element 105, and therefore the use of the dam structure 103 and the dam structure 103 and the columnar structure 106 allows the non-solid thermal conductive layer 102 to be more effectively fixed at a specific position.

[0043] In addition, the present application also provides a packaging structure 100, see Figure 2 The package structure 100 includes: a first element 104; and a heat-conducting structure 101 located on the first element 104. In an embodiment, the heat-conducting structure includes: a non-solid heat-conducting layer 102 and a dam structure 103 surrounding the non-solid heat-conducting layer 102. The package structure 100 also includes a second element 105 located above the heat-conducting structure 101, wherein a portion of the non-solid heat-conducting layer 102 is embedded in the dam structure 103. See further Figure 3A The dam structure 103 includes a plurality of gaps V, into which the non-solid heat-conducting layer 102 extends. Further, the dam structure 103 is composed of a plurality of branch structures 1031 grown on the first element 104, and the branch structures include a main body 1031A connected to the first element 104 and a plurality of strip-shaped branches 1031B branched from the main body 1031A.

[0044] Further, Figure 1D The package structure 10 '(Leg_1) and Figure 2 The heat dissipation (cooling) effect of the package structure 100 (Leg_2) shown in FIG. 1 is simulated, that is, the temperature of the package structure 10' and the package structure 100 are measured under the same conditions. The measurement results are shown in Table 1 and Table 2. Fig. 6A and Figure 6B As shown:

[0045] Table 1 Figure 1DThe package structure 10 '(Leg_1) and Figure 2 The simulation results (°C) of the package structure 100 (Leg_2) are shown (wherein Tj_1, Tj_2, Tj_3, and Tj_4 respectively represent the different component / chip temperatures from the bottom layer to the top layer of the package structure 10' (Leg_1) and the package structure 100 (Leg_2), where Tj represents the component / chip temperature, and numbers 1 to 4 represent different components / chips from the bottom layer to the top layer).

[0046] Tj_1 Tj_2 Tj_3 Tj_4 Leg_1 121.52 111.60 89.16 53.72 Leg_2 99.39 88.70 77.75 58.92

[0047] From Table 1 above and Fig. 6A and Figure 6B It can be seen from the table that the Theta JC of the package structure 100 (Leg_2) is lower than the Theta JC of the package structure 10' (Leg_1). Therefore, the package structure 100 (Leg_2) provided by the present application has a better heat dissipation effect while preventing overflow. In addition, it can be seen from the table 1 that the temperature difference of the package structure 100 (Leg_2) is lower than that of the package structure 10' (Leg_1) by 20°C, and the heat dissipation effect of the package structure 100 (Leg_2) relative to the package structure 10' (Leg_1) is: TJ_1 = 121.52 -> 99.39, which is about 22% improvement, TJ_2 = 111.6 -> 88.7, which is about 20%, and TJ_3 = 89.16 -> 77.75, which is about 15% improvement. However, since the upward heat transfer channel of the chip stack below TJ4 has been opened, the temperature of the improved structure will be higher than that before the improvement, but the temperature is still much lower than the maximum operating temperature of the general chip (125°C), so the overall improvement is effective. Therefore, the special structure provided in the present application (dam structure 103 or a combination of dam structure 103 and columnar structure 106) combined with the non-solid thermal conductive layer 102 of the heat dissipation material effectively enhances the heat dissipation effect of the corresponding packaging structure 100 (Leg_2), thereby improving the heat dissipation effect by about 22%.

[0048] Figures 7 and 8 is a schematic diagram of a process of forming a dam structure 103 according to an embodiment of the present application.

[0049] refer to Figure 7 and Figure 8As shown, first, through the electroplating process P, for example, through the electroplating process on the first element 104, a branch structure 1031 of a metal structure is grown, and the branch structure 1031 includes a main body 1031A connected to the first element 104 and a plurality of strip branches 1031B branching from the main body 1031A, thereby forming a dam structure 103 having the branch structure 1031. Further, the density of the branch structure 1031 can be adjusted by the conditions of the electroplating process P, that is, the density of the branch structure 1031 can be controlled by the conditions of the electroplating process P. In this embodiment, the dam structure 103 is made of copper. In addition, Fig. 9 Shows Figure 8 The SEM image of the dendrite structure 1031 is shown in FIG. Figure 8 and Fig. 9 It can be seen from the figure that the dam structure 103 is a dendrite structure having a dendrite-like structure or a dendrite structure. After the dam structure 103 is formed, a non-solid heat-conducting layer 102 and a corresponding columnar structure 106 are formed by a method commonly used in the art. The columnar structure 106 can also be formed into a nanowire structure by an electroplating process, or can be formed into a structure similar to the dam structure 103. Finally, the second element 105 is bonded to the first element 104 to obtain Figure 2 The package structure 100 is shown.

[0050] The features of several embodiments are summarized above so that those skilled in the art can better understand aspects of the present invention. Those skilled in the art should understand that they can easily use the present invention as a basis to design or modify other processes and structures for implementing the same purpose and / or achieving the same advantages as the embodiments described herein. Those skilled in the art should also appreciate that such equivalent constructions do not deviate from the spirit and scope of the present invention, and that they can make various changes, substitutions, and modifications herein without departing from the spirit and scope of the present invention.

Claims

1. A packaging structure, characterized in that: include: first element; a second element, located above the first element; as well as A heat-conducting structure is located between the first element and the second element, wherein the heat-conducting structure comprises: Non-solid thermally conductive layer; A dam structure surrounds the non-solid heat conductive layer, and the dam structure includes a plurality of gaps.

2. The packaging structure according to claim 1, characterized in that: The dam structure is composed of a plurality of branch structures grown on the first element, wherein the branch structures include a main body connected to the first element and a plurality of strip-shaped branches branching from the main body.

3. The packaging structure according to claim 2, characterized in that: Some of the plurality of strip-shaped branches are embedded in the non-solid heat-conducting layer.

4. The packaging structure according to claim 2, characterized in that: The plurality of gaps exist between the bodies, between the bodies and the plurality of strip-shaped branches, or between the plurality of strip-shaped branches.

5. The packaging structure according to claim 1, characterized in that: The non-solid heat-conducting layer extends into a gap of the dam structure close to the non-solid heat-conducting layer.

6. The packaging structure according to claim 1, characterized in that: Also includes: A columnar structure is surrounded by the dam structure.

7. The packaging structure according to claim 6, characterized in that: The columnar structure includes a first column connected to the first element and a second column connected to the second element, wherein the first column is in contact with the second column.

8. The packaging structure according to claim 7, characterized in that: The first column is spaced apart from the second element by the non-solid thermally conductive layer, and the second column is spaced apart from the first element by the non-solid thermally conductive layer.

9. The packaging structure according to claim 2, characterized in that: The branch structure includes a first body connected to the first element and a plurality of first strip-shaped branches branching from the first body, and includes a second body connected to the first element and a plurality of second strip-shaped branches branching from the second body, wherein the first strip-shaped branches are in contact with the second strip-shaped branches.

10. The packaging structure according to claim 2, characterized in that: The branch structure includes a first body connected to the first element and a plurality of first strip branches branching from the first body, and includes a second body connected to the first element and a plurality of second strip branches branching from the second body, wherein the second strip branches are farther away from the non-solid heat-conducting layer than the first strip branches, and wherein the first strip branches are embedded in the non-solid heat-conducting layer, and the second strip branches are separated from the non-solid heat-conducting layer.

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