Package structure

Abstract

The utility model provides a packaging structure comprising an electronic component, the top surface of which comprises a central area and a peripheral area surrounding the central area; the upper cover is arranged above the electronic element, and the upper cover comprises a dendritic metal structure facing the electronic element; a heat dissipation cured layer disposed in the peripheral region and contacting the dendritic metal structure; the heat conduction layer is arranged in the central area, and the dendritic metal structure and the heat dissipation curing layer surround the heat conduction layer in a top view. The utility model aims to provide the packaging structure so as to improve the heat dissipation effect of the packaging structure.

Description

Technical Field

[0001] The utility model relates to a packaging structure. Background Art

[0002] With the improvement of computing power, electronic products have more intensive functions, increasing power, and the heat generated will also increase. The heat dissipation capacity has become a problem to be solved. At present, thermal interface materials (TIM) are often used as a medium for heat dissipation, and among them, the heat dissipation gel material of liquid metal on the market has a more significant effect. Liquid metal increases the heat conduction area through the volume change generated by heating, increases the thermal conductivity, and at the same time, due to the volume change, exhaust holes are designed in the past to allow the liquid metal to exhaust when the volume changes.

[0003] At present, thermal paste is used as a framework to set the liquid metal therein, and the framework of the thermal paste is provided with exhaust holes to allow the liquid metal to exhaust during phase change. However, after the reliability test of this structure, the phenomenon of liquid metal overflowing at the exhaust holes is very obvious. The coverage ratio of the overflowed liquid metal decreases (for example, less than 90%), and the cost of liquid metal is high, resulting in low feasibility. Summary of the Utility Model

[0004] Aiming at the problems existing in the related art, the purpose of the utility model is to provide a packaging structure to improve the heat dissipation effect of the packaging structure.

[0005] To achieve the above purpose, the utility model provides a packaging structure, including: an electronic component, the top surface of the electronic component includes a central area and a peripheral area surrounding the central area; an upper cover, arranged above the electronic component, and the upper cover includes a dendritic metal structure arranged facing the electronic component; a heat dissipation curing layer, arranged in the peripheral area and in contact with the dendritic metal structure; a heat conduction layer, arranged in the central area, and in a top view, the dendritic metal structure and the heat dissipation curing layer surround the heat conduction layer.

[0006] In some embodiments, the dendritic metal structure defines a gap between the upper cover and the heat dissipation curing layer, and the gap is used for the exhaust of the heat conduction layer.

[0007] In some embodiments, the heat conduction layer is distributed into the gap.

[0008] In some embodiments, the heat conduction layer is liquid metal.

[0009] In some embodiments, the dendritic metal structure is only arranged above the peripheral area.

[0010] In some embodiments, the packaging structure further includes: a substrate, the electronic component is arranged on the substrate, and the upper cover covers the substrate.

[0011] In some embodiments, the encapsulation structure further includes: an encapsulation layer, adhered between the upper cover and the substrate, and surrounding the electronic component in a top view.

[0012] In some embodiments, the substrate is a printed circuit board.

[0013] In some embodiments, the upper cover includes a groove, and a dendritic metal structure is disposed around the groove.

[0014] In some embodiments, the heat dissipation and curing layer is spaced apart from the surface of the groove of the upper cover.

[0015] In some embodiments, the dendritic metal structure spaces apart the heat dissipation and curing layer from the surface of the groove of the upper cover.

[0016] In some embodiments, the heat dissipation and curing layer forms a continuous retaining wall surrounding the heat conduction layer.

[0017] In some embodiments, the heat dissipation and curing layer is heat dissipation paste.

[0018] In some embodiments, the top surface of the heat conduction layer contacts the upper cover.

[0019] In some embodiments, the side wall of the heat conduction layer contacts the dendritic metal structure and the heat dissipation and curing layer.

[0020] Embodiments of the present application further provide an encapsulation structure, including: an electronic component, the top surface of the electronic component including a central region and a peripheral region surrounding the central region; an upper cover, disposed above the electronic component, and the upper cover including a dendritic metal structure disposed facing the electronic component; a heat dissipation and curing layer, disposed between the peripheral region and the upper cover and contacting the dendritic metal structure; a heat conduction layer, disposed between the central region and the upper cover, and the dendritic metal structure and the heat dissipation and curing layer surround the heat conduction layer.

[0021] In some embodiments, the bottom surface and the top surface of the heat conduction layer contact the central region and the upper cover respectively.

[0022] In some embodiments, the bottom surface and the top surface of the heat dissipation and curing layer contact the peripheral region and the dendritic metal structure respectively.

[0023] In some embodiments, the dendritic metal structure defines a void between the upper cover and the heat dissipation and curing layer, and a part of the heat conduction layer extends into the void.

[0024] In some embodiments, the part of the heat conduction layer extending into the void contacts the top surface of the heat dissipation and curing layer.

[0025] The beneficial technical effects of the present utility model are as follows:

[0026] The dendritic metal structure of the embodiment of the present application can be used to exhaust gas during the phase change of the heat-conducting layer. Therefore, the heat-dissipating and curing layer does not need to be provided with exhaust holes, and the heat-conducting layer will not overflow from the exhaust holes of the heat-dissipating and curing layer. Therefore, the heat-dissipating area of the heat-conducting layer covering the electronic components will not be reduced, and the heat-dissipating effect of the packaging structure is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Shows a top view of the upper cover according to an embodiment of the present application.

[0028] Figure 2 Shows along Figure 1 The cross-sectional view taken along line AA.

[0029] Figure 3 And Figure 4 Shows the formation of the dendritic metal structure, Figure 3 Is a bottom view, Figure 4 Is along Figure 3 The cross-sectional view taken along line BB.

[0030] Figure 5 Shows the substrate and the electronic components on the substrate.

[0031] Figure 6 Shows the application of the heat-conducting layer on the central area.

[0032] Figure 7 Shows the application of the encapsulation layer around the top surface of the substrate.

[0033] Figure 8 Shows the encapsulation layer bonding the upper cover and the substrate.

[0034] Figure 9 Shows the cross-sectional view of the packaging structure according to an embodiment of the present application

[0035] Figure 10 Shows the packaging structures according to different embodiments of the present application.

[0036] Figure 11 And Figure 12 Shows the schematic diagram of the heat dissipation principle of the heat-conducting layer

[0037] Figure 13 Shows that a part of the heat-conducting layer may enter the voids of the dendritic metal structure, obtaining Figure 14 The packaging structure shown.

[0038] Figure 15 Shows an embodiment of the prior art where the heat-dissipating paste designed with exhaust holes serves as a retaining wall for the liquid metal.

[0039] Figure 16 Shows the electron microscope images of two prior art embodiments after curing.

[0040] Figure 17 shows the control group.

[0041] Figure 18 and Figure 19 respectively show the electron micrographs of the control group and the experimental group in the initial stage.

[0042] Figure 20 and Figure 21 respectively show the electron micrographs of the control group C and the experimental group D after five times of mass reflux. Detailed implementation manners

[0043] To better understand the spirit of the embodiments of the present application, the following further describes it in conjunction with some preferred embodiments of the present application.

[0044] The embodiments of the present application will be described in detail below. Throughout the specification of the present application, components that are the same or similar and have the same or similar functions are denoted by like reference numerals. The embodiments of the drawings described herein are illustrative, diagrammatic, and are used to provide a basic understanding of the present application. The embodiments of the present application should not be construed as a limitation of the present application.

[0045] As used herein, the terms "substantially", "essentially", "substantially" and "about" are used to describe and account for small variations. When used in conjunction with an event or situation, the terms can refer to instances in which the event or situation occurs exactly and instances in which the event or situation occurs very nearly.

[0046] In this specification, unless specifically specified or limited otherwise, relative terms such as: "central", "longitudinal", "lateral", "front", "rear", "right", "left", "inner", "outer", "lower", "higher", "horizontal", "vertical", "above", "below", "upper", "lower", "top", "bottom" and their derivative terms (such as "horizontally", "downwardly", "upwardly", etc.) should be construed as referring to the directions described in the discussion or depicted in the drawings. These relative terms are only for convenience of description and do not require the present application to be constructed or operated in a specific direction.

[0047] For ease of description, "first", "second", "third", etc. may be used herein to distinguish different components of a figure or a series of figures. "First", "second", "third", etc. are not intended to describe the corresponding components.

[0048] Figures 1 to 9 shows the formation process of the encapsulation structure 100 according to the embodiment of the present application. Figure 1The top view of the upper cover 20 according to an embodiment of the present application is shown. Figure 2 The sectional view taken along Figure 1 line AA is shown, where the upper cover 20 is provided with a groove 26.

[0049] Figure 3 and Figure 4 The dendritic metal structure 22 formed around the groove 26 (e.g., by electroplating process) is shown. Figure 3 The bottom view is shown. Figure 4 The sectional view taken along Figure 3 line BB is shown, and voids 24 are present in the dendritic metal structure 22.

[0050] Figure 5 The substrate 50 and the electronic component 10 on the substrate 50 are shown. The top surface of the electronic component 10 includes a central region 12 and a peripheral region 14 surrounding the central region 12. The heat dissipation curing layer 30 is coated on the peripheral region 14 and forms a continuous frame. The substrate 50 is, for example, a printed circuit board (PCB), and the heat dissipation curing layer 30 is heat dissipation paste, such as SE4450 thermal conductive adhesive.

[0051] Figure 6 The heat conductive layer 40 is shown coated on the central region 12, and the heat dissipation curing layer 30 forms a complete circle of retaining wall surrounding the heat conductive layer 40.

[0052] Figure 7 The encapsulation layer 60 is shown coated around the top surface of the substrate 50. The encapsulation layer 60 surrounds the electronic component 10 in the top view. Figure 8 The covering of Figure 3 and Figure 4 the upper cover 20 shown on the Figure 7 substrate 50 shown is shown. The encapsulation layer 60 adheres the upper cover 20 and the substrate 50, and the encapsulated structure 100 is obtained after baking in an oven.

[0053] Figure 9 The sectional view of the encapsulated structure 100 according to an embodiment of the present application is shown. The upper cover 20 is disposed above the electronic component 10 and includes the dendritic metal structure 22 disposed facing the electronic component 10; the heat dissipation curing layer 30 is disposed in the peripheral region 14 and contacts the dendritic metal structure 22; in the top view, the dendritic metal structure 22 and the heat dissipation curing layer 30 surround the heat conductive layer 40. The dendritic metal structure 22 in the embodiment of the present application can be used for exhausting gas when the heat conductive layer 40 undergoes a phase change. Therefore, the heat dissipation curing layer 30 does not need to be provided with exhaust holes, and the heat conductive layer 40 will not overflow from the exhaust holes of the heat dissipation curing layer 30. Therefore, the heat dissipation area of the heat conductive layer 40 covering the electronic component 10 will not be reduced, and the heat dissipation effect of the encapsulated structure 100 is improved.

[0054] The dendritic metal structure 22 is only disposed above the peripheral region 14. The dendritic metal structure 22 separates the heat dissipation curing layer 30 from the surface of the groove 26 of the upper cover 20. The top surface of the heat conducting layer 40 contacts the upper cover 20, and the side wall of the heat conducting layer 40 contacts the dendritic metal structure 22 and the heat dissipation curing layer 30.

[0055] Figure 10 The encapsulation structure 100 according to different embodiments of the present application is shown. Among them, the heat conducting layer 40 and the heat dissipation curing layer 30 cover the top surface of the electronic component 10. The positions of the heat conducting layer 40 and the heat dissipation curing layer 30 can be designed according to the size of the heat generating area of the electronic component 10. As long as it is ensured that the heat dissipation curing layer 30 surrounds the heat conducting layer 40 and the dendritic metal structure 22 corresponds to the heat dissipation curing layer 30 to ensure exhaust, the heat dissipation effect of the encapsulation structure 100 can be ensured.

[0056] Figure 11 and Figure 12 The schematic diagram of the heat dissipation principle of the heat conducting layer 40 is shown. The heat conducting layer 40 is, for example, a liquid metal, including a silicon matrix 42 and liquid metal particles 44. Below the heat conducting layer 40 is the electronic component 10. The electronic component 10 is, for example, a central processing unit (CPU), a graphics processing unit (GPU), a memory, etc. Above the heat conducting layer 40 is the upper cover 20 as a heat dissipation member. The heat conducting layer 40 starts from Figure 11 After being compressed and cured as shown, it becomes Figure 12 The structure shown forms a heat conducting path 46 for circulating heat.

[0057] The dendritic metal structure 22 defines a gap 24 between the upper cover 20 and the heat dissipation curing layer 30. The gap 24 is used for exhausting air from the heat conducting layer 40. As shown in Figure 13 During compression and curing, part of the heat conducting layer 40 may enter the gap 24 of the dendritic metal structure 22 to obtain the encapsulation structure 100 shown in Figure 14 It can be understood that the heat conducting layer 40 does not necessarily fill the gap 24 and may only fill part of the gap 24.

[0058] Continue to refer to Figure 9, an embodiment of the present application further provides a packaging structure 100, including: an electronic component 10, the top surface of the electronic component 10 includes a central region 12 and a peripheral region 14 surrounding the central region 12; an upper cover 20, disposed above the electronic component 10, and the upper cover 20 includes a dendritic metal structure 22 disposed facing the electronic component 10; a heat-dissipating curing layer 30, disposed between the peripheral region 14 and the upper cover 20 and contacting the dendritic metal structure 22; a heat-conducting layer 40, disposed between the central region 12 and the upper cover 20, and the dendritic metal structure 22 and the heat-dissipating curing layer 30 surround the heat-conducting layer 40. The bottom surface and the top surface of the heat-conducting layer 40 contact the central region 12 and the upper cover 20 respectively. The bottom surface and the top surface of the heat-dissipating curing layer 30 contact the peripheral region 14 and the dendritic metal structure 22 respectively.

[0059] See Figure 14 , the dendritic metal structure 22 defines a void 24 located between the upper cover 20 and the heat-dissipating curing layer 30, and a portion of the heat-conducting layer 40 extends into the void 24. The portion of the heat-conducting layer 40 extending into the void 24 contacts the top surface of the heat-dissipating curing layer 30.

[0060] Figure 15 An embodiment of the prior art design of the thermal paste 1 with exhaust holes 4 as a retaining wall for the liquid metal 2 is shown, where the liquid metal 2 is in the form before curing. Figure 16 Electron micrographs obtained by using a C-SAM (SAT) after curing for two embodiments of the prior art are shown. Figure 16 The mass of the liquid metal 2 in the embodiment of the left half is 65 mg. Figure 16 The mass of the liquid metal 2 in the right half is 35 mg. The liquid metal 2 in both embodiments overflows from the exhaust holes 4 of the thermal paste 1 (see arrow 3), resulting in a coverage area of the liquid metal 2 in the area surrounded by the thermal paste 1 being less than 90%.

[0061] In addition, a control group C as shown is also provided. Figure 17 In the control group C, only the dendritic metal structure 22 is used as a retaining wall, and the heat-dissipating curing layer 30 is not used. In the present application Figure 9 The embodiment shown is used as the experimental group D. Figure 18 And Figure 19 Electron micrographs of the control group C and the experimental group D at the initial stage (150 °C, 10 min) are shown respectively. Figure 20 And Figure 21 Electron micrographs of the control group C and the experimental group D after five times of mass reflow (MR, Mass Reflow) (260 °C, 10 min * 5) are shown respectively. It can be seen that the control group overflows as shown by the dashed box 190 in Figure 19 , while there is no overflow phenomenon in the experimental group D of the present application, and the coverage area of the heat-conducting layer 40 is greater than 90%, and even can be greater than 95%.

[0062] Embodiments of the present application provide a packaging structure 100 for reducing overflow exhaust of liquid metal, which relates to fields such as Thermal Enhancement, Embedded structure, Ball Grid Array (BGA), Package on Package (PoP), TIM, Liquid Metal, etc. Embodiments of the present application use a plated dendritic metal structure 22 combined with a heat dissipation curing layer 30 as a retaining wall to improve the exhaust phenomenon of the heat conduction layer 40, enhance the strength of the retaining wall, block the overflow of the heat conduction layer 40, reduce the problem of uneven coverage of the heat conduction layer 40, and improve the coverage rate of the heat dissipation curing layer 30. Although it slightly increases the manufacturing process and cost, it can significantly increase the chip heat generation density, and the thermal conductivity of the packaging structure is greater than 10 W / mK. Embodiments of the present application can be used to solve the problem of excessive chip temperature caused by high-density heat sources now and in the future, and improve its overheating problem.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An encapsulation structure, characterized in that, Comprising: An electronic component, the top surface of the electronic component comprising a central region and a peripheral region surrounding the central region; An upper cover, disposed above the electronic component, and the upper cover comprising a dendritic metal structure disposed facing the electronic component; A heat dissipation and curing layer, disposed in the peripheral region and in contact with the dendritic metal structure; A heat conducting layer, disposed in the central region, and in a top view, the dendritic metal structure and the heat dissipation and curing layer surround the heat conducting layer.

2. The encapsulation structure according to claim 1, wherein The dendritic metal structure defines a gap between the upper cover and the heat dissipation and curing layer, and the gap is used for exhausting gas of the heat conducting layer.

3. The encapsulation structure according to claim 2, characterized in that The heat conducting layer extends into the gap.

4. The encapsulation structure according to claim 1, wherein The heat conducting layer is a liquid metal.

5. The encapsulation structure according to claim 1, characterized in that, The dendritic metal structure is only disposed above the peripheral region.

6. The encapsulation structure according to claim 1, wherein Further comprising: A substrate, the electronic component is disposed on the substrate, and the upper cover covers the substrate.

7. The encapsulation structure according to claim 6, wherein Further comprising: A packaging layer, bonded between the upper cover and the substrate, and surrounding the electronic component in a top view.

8. The encapsulation structure according to claim 1, wherein The upper cover comprises a groove, and the dendritic metal structure is disposed around the groove.

9. The encapsulation structure according to claim 8, wherein, The dendritic metal structure separates the heat dissipation and curing layer from the surface of the groove of the upper cover.

10. The encapsulation structure according to claim 1, wherein The heat dissipation and curing layer forms an integral retaining wall surrounding the heat conducting layer.

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