Chip packaging structure of flexible circuit board and manufacturing method

Abstract

The invention discloses a chip packaging structure of a flexible circuit board and a manufacturing method. The packaging structure comprises the flexible circuit board; the chip is located on the flexible circuit board; the first heat dissipation layer is located on the flexible circuit board, and the first heat dissipation layer is arranged around the chip; the packaging body is located on the side face of the chip, and the packaging body is located between the first heat dissipation layer and the chip; wherein the chip is connected with the flexible circuit board, and the reliability of connection between the chip and the flexible circuit board is enhanced through the encapsulation body. The encapsulation body includes a hydrophilic material, and the first heat dissipation layer includes a hydrophobic material. The first heat dissipation layer plays a role of a dam body to limit the flow of the epoxy resin forming the encapsulation body, so that the encapsulation body is more uniform. The consistency and stability of the product are improved, and the heat dissipation performance and reliability of the product are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of microelectronic devices, and more specifically, to a chip packaging structure of a flexible circuit board and a manufacturing method thereof. Background Art

[0002] In recent years, various electronic products have gradually tended to be thinner, smaller and lighter, and in response to such demands, various technical solutions have been developed to install semiconductor chips at high density in a small area of ​​electronic products, such as the use of flexible circuit boards.

[0003] The display device usually includes a display panel, a flexible circuit board and a display driver chip. After the display driver chip is bonded to the flexible circuit board, it is usually necessary to coat the epoxy resin to form an encapsulation to enhance the connection strength between the display driver chip and the flexible circuit board, and provide insulation and external protection capabilities. However, during the packaging process, uneven coating of the epoxy resin will lead to inconsistent thickness of the encapsulation, which in turn affects the uniformity of heat dissipation and causes heat accumulation in some areas of the chip. Furthermore, the epoxy resin has a certain fluidity. If it is not properly handled, it will also cause the epoxy resin to flow to other areas such as the back of the flexible circuit board, affecting the performance of the flexible circuit board.

[0004] Therefore, there is an urgent need to design a chip packaging structure for a flexible circuit board to limit the flow of the encapsulation material, improve the uniformity of the encapsulation body, and enhance the consistency and stability of the product. Summary of the invention

[0005] The purpose of the present invention is to provide a packaging structure and manufacturing method for a flexible circuit board, so as to solve the problems existing in the prior art such as poor product consistency, uneven encapsulation material and even overflow to the back of the flexible circuit board, improve the consistency and stability of the product, and enhance the heat dissipation performance and reliability of the product.

[0006] According to one aspect of the present invention, the present invention provides a chip packaging structure of a flexible circuit board, comprising: a flexible circuit board; a chip located on the flexible circuit board; a first heat dissipation layer located on the flexible circuit board, the first heat dissipation layer being arranged around the chip; an encapsulation body located on the flexible circuit board, the encapsulation body surrounding the chip, the encapsulation body being located between the first heat dissipation layer and the chip; wherein the chip is bonded to the flexible circuit board, and the reliability of the connection between the chip and the flexible circuit board is enhanced by the encapsulation body.

[0007] Optionally, the encapsulation body comprises a hydrophilic material, and the first heat dissipation layer comprises a surface energy not greater than 100 mJ / m 2 The hydrophobic material of the first heat dissipation layer limits the accumulation of the material forming the encapsulation body near the first heat dissipation layer through the hydrophobicity of the first heat dissipation layer.

[0008] Optionally, a height of the first heat dissipation layer is not greater than a height of the chip.

[0009] Optionally, a top surface of the first heat dissipation layer is lower than a top surface of the chip, a longitudinal section of the first heat dissipation layer comprises a rectangle, and a longitudinal section of the encapsulation body comprises a trapezoid or a triangle.

[0010] Optionally, the distances between different side surfaces of the chip and the corresponding first heat dissipation layer are the same.

[0011] Optionally, the first heat dissipation layer further includes metal particles.

[0012] Optionally, a second heat dissipation layer is further included, wherein the second heat dissipation layer is located between the first heat dissipation layer and the chip, and the encapsulation body is located on the second heat dissipation layer.

[0013] Optionally, a height of the second heat dissipation layer is not greater than a height of the first heat dissipation layer.

[0014] Optionally, the encapsulation body and the second heat dissipation layer both include hydrophilic materials, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 hydrophobic material.

[0015] Optionally, the packaging structure is used in a display device.

[0016] According to another aspect of the present invention, a method for manufacturing a flexible circuit board packaging structure is provided, comprising: bonding a chip to a flexible circuit board; providing a first heat dissipation layer; providing an encapsulation body; wherein the first heat dissipation layer is located on the flexible circuit board, and the first heat dissipation layer is provided around the chip; the encapsulation body is located between the first heat dissipation layer and the chip to enhance the reliability of the connection between the chip and the flexible circuit board.

[0017] Optionally, the encapsulation body comprises a hydrophilic material, and the first heat dissipation layer comprises a surface energy not greater than 100 mJ / m 2 hydrophobic material.

[0018] Optionally, the first heat dissipation layer is formed in the solder resist area of ​​the flexible circuit board by a screen printing process, and the first heat dissipation layer is used to limit the encapsulation body.

[0019] Optionally, a top surface of the first heat dissipation layer is lower than a top surface of the chip.

[0020] Optionally, the distances between different side surfaces of the chip and the corresponding first heat dissipation layer are the same.

[0021] Optionally, after setting the first heat dissipation layer and before setting the encapsulation body, it also includes: setting a second heat dissipation layer; wherein the second heat dissipation layer is located on the flexible circuit board, the second heat dissipation layer is located between the first heat dissipation layer and the chip, and the encapsulation body is located on the second heat dissipation layer.

[0022] Optionally, a height of the second heat dissipation layer is not greater than a height of the first heat dissipation layer.

[0023] Optionally, the encapsulation body and the second heat dissipation layer both include hydrophilic materials, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 hydrophobic material.

[0024] The chip packaging structure of the flexible circuit board provided in the embodiment of the present invention can effectively prevent the encapsulation material from overflowing from the range of the first heat dissipation layer, restrict the flow of the encapsulation material, make the formed encapsulation body more uniform, and effectively enhance the consistency and stability of the packaging structure.

[0025] Furthermore, the encapsulation material forming the encapsulation body can be a hydrophilic material, and the first heat dissipation layer can be a hydrophobic material. The different characteristics of the two can also be used to further limit the shape of the encapsulation body. For example, the first heat dissipation layer can also contain nano-metal particles to obtain better heat dissipation performance and electromagnetic protection capabilities.

[0026] The manufacturing method of the packaging structure provided in the embodiment of the present invention involves a processing technology that is mature and reliable, and is simple and easy to implement. The above-mentioned packaging structure can be easily obtained, thereby limiting the flow of the encapsulation material, improving the uniformity of the encapsulation body, avoiding heat accumulation in individual areas of the chip due to uneven encapsulation, and improving the reliability and stability of the product. The manufacturing method can not only meet various needs, but also has a simple process and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0028] Figure 1 A schematic diagram showing a chip packaging structure of a flexible circuit board;

[0029] Figure 2 Schematic diagram showing epoxy resin on the surface of different materials;

[0030] Figure 3 A schematic diagram showing a chip packaging structure of a flexible circuit board according to a first embodiment of the present invention;

[0031] Figure 4 A partial enlarged schematic diagram of a chip packaging structure of a flexible circuit board according to a first embodiment of the present invention is shown;

[0032] Figure 5 A schematic diagram showing the manufacturing process of the chip packaging structure of the flexible circuit board according to the first embodiment of the present invention is shown;

[0033] Figures 6 to 8 A schematic diagram showing various stages in the manufacturing process of the chip packaging structure of the flexible circuit board according to the first embodiment of the present invention;

[0034] Fig. 9 A schematic diagram showing a chip packaging structure of a flexible circuit board according to a second embodiment of the present invention;

[0035] Fig.10 A schematic diagram showing a chip packaging structure of a flexible circuit board according to a third embodiment of the present invention is shown. DETAILED DESCRIPTION

[0036] The present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, the same elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown. For the sake of simplicity, the semiconductor structure obtained after several steps can be described in one figure.

[0037] It should be understood that when describing a structure, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Furthermore, if the device is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0038] If the purpose is to describe the situation of being directly on another layer or another area, this article will use the expression "directly on..." or "on... and adjacent to...".

[0039] Many specific details of some embodiments of the present invention are described below, such as device structures, materials, dimensions, processing techniques and technologies, so that the present invention can be more clearly understood. However, as those skilled in the art will appreciate, the present invention may be implemented without following these specific details.

[0040] The present invention may be embodied in various forms, some examples of which will be described below.

[0041] Figure 1The schematic diagram of the chip packaging structure of the flexible circuit board is shown; the packaging structure includes: a flexible circuit board 100, a chip 200 and an encapsulation body 300, wherein the chip 200 is, for example, a display driver chip, and the flexible circuit board 100 is used as a carrier of the chip 200. The pins of the chip 200 are bonded to the corresponding inner leads on the flexible circuit board 100 by thermal compression (inner lead bonding). In order to enhance the bonding strength and stability between the chip 200 and the flexible circuit board 100, the chip 200 is usually coated with epoxy resin to form the encapsulation body 300. Figure 1 Taking the cross-sectional view shown as an example, the encapsulation 300 formed after the epoxy resin is cured forms a triangular support on the side of the chip 200. Due to process conditions, the sizes of the encapsulation 300 formed by the epoxy resin on different sides of the chip 200 are not the same. Specifically, since the width L1 of the encapsulation on the left side of the chip 200 is different from the width L2 of the encapsulation on the right side of the chip 200, there are differences in the strength and heat dissipation capacity of the two sides of the chip 200, which in turn affects the bonding strength between the chip 200 and the flexible circuit board 100, resulting in heat accumulation in some areas of the chip 200, affecting the consistency and stability of the product.

[0042] Figure 2 Schematic diagram of epoxy resin on the surface of different materials; due to the hydrophilicity and hydrophobicity of epoxy resin itself, it has different contact angles on the surface of different materials, and thus forms different forms. Specifically, polytetrafluoroethylene, polyvinyl chloride, glass, aluminum and frosted steel have different surface energies, and there is a close relationship between surface energy and hydrophilicity. Generally speaking, the higher the surface energy, the stronger the hydrophilicity of the material tends to be, and the smaller the contact angle of water on its surface; refer to Figure 2 As shown in FIG. 1 , the morphology of epoxy resin on surfaces such as polytetrafluoroethylene, polyvinyl chloride, glass, aluminum and frosted steel gradually changes from a nearly spherical shape to an arc shape that better fits the surface of the material. The surface energies of polytetrafluoroethylene, polyvinyl chloride, glass, aluminum and frosted steel increase from small to large.

[0043] The following table lists the surface energy of some materials Material <![CDATA[Surface energy (mJ / m 2 ) <!-- 3 -->]]> Polytetrafluoroethylene 18 Acrylic resin 38 Epoxy resin 43 Polyurethane 43 Modified epoxy resin 52 Polyimide 50 Silicone-filled epoxy resin 60-80 Composite materials of silicon dioxide and silicon 287 tin 526 silver 890 copper 1103

[0044] The greater the hydrophilicity of the encapsulation material, the easier it is to overflow to the area that does not need to be encapsulated during encapsulation. In order to prevent its excessive fluidity from overflowing to the back of the chip or other nearby areas, the encapsulation material of this application can be selected with a surface energy of 50mJ / m 2 -70mJ / m 2 materials.

[0045] According to the characteristics of epoxy resin, the present invention proposes a new chip packaging structure of a flexible circuit board to limit the flow of epoxy resin (encapsulation material), improve the uniformity of the encapsulation body 300 formed after the epoxy resin is cured, and enhance the consistency and stability of the product.

[0046] Figure 3 The schematic diagram of the chip packaging structure of the flexible circuit board of the first embodiment of the present invention is shown; the chip packaging structure of the flexible circuit board of the first embodiment includes: a flexible circuit board 100, a chip 200, a first heat dissipation layer 410 and an encapsulation body 300. After the chip 200 is bonded to the flexible circuit board 100, before the epoxy resin is coated to form the encapsulation body 300, the first heat dissipation layer 410 is arranged on the flexible circuit board 100, wherein the first heat dissipation layer 410 is arranged around the chip 200, there is a preset distance between the first heat dissipation layer 410 and the chip 200, and the thickness h of the first heat dissipation layer 410 is not greater than the thickness H of the chip 200; the encapsulation body 300 is located between the first heat dissipation layer 410 and the chip 200. By providing the first heat dissipation layer 410, the flow range of the epoxy resin (encapsulation material) forming the encapsulation body 300 is limited, and the epoxy resin can be effectively prevented from overflowing to the back of the flexible circuit board 100.

[0047] Furthermore, the first heat dissipation layer 410 is a hydrophobic heat dissipation layer. For example, the surface energy of the first heat dissipation layer 410 is not greater than 100 mJ / m 2 The encapsulation material forming the encapsulation body 300 is, for example, a hydrophilic epoxy resin. Specifically, since the first heat dissipation layer 410 is a hydrophobic heat dissipation layer, the contact angle between the hydrophilic epoxy resin and the first heat dissipation layer 410 is large, so that the hydrophilic epoxy resin is difficult to accumulate near the first heat dissipation layer 410, thereby making the encapsulation body 300 formed by curing the epoxy resin more uniform, such as Figure 3 As shown in the cross-sectional view, the width L1 of the encapsulant 300 on the left side of the chip 200 is substantially the same as the width L2 of the encapsulant 300 on the right side of the chip 200. This design can also effectively prevent the epoxy resin from flowing to the back side of the chip 200, thereby improving the consistency and stability of the product.

[0048] Figure 4 A partial enlarged schematic diagram of the chip packaging structure of the flexible circuit board according to the first embodiment of the present invention is shown; the first heat dissipation layer 410 is not formed of a single material, and the first heat dissipation layer 410 also includes nano-metal particles 401 (such as nano-silver particles, etc.) to further enhance the heat dissipation capability and provide electromagnetic protection capability.

[0049] Figure 5 The schematic diagram of the manufacturing process of the chip packaging structure of the flexible circuit board according to the first embodiment of the present invention is shown. Figures 6 to 8 The schematic diagram of each stage in the manufacturing process of the chip packaging structure of the flexible circuit board according to the first embodiment of the present invention is shown below. Figure 6-8 The manufacturing process of this structure is described.

[0050] The manufacturing process of the chip packaging structure of the flexible circuit board includes the following steps:

[0051] In step S10: the chip is bonded to the flexible circuit board; this step is similar to Figure 6 Correspondingly, the chip 200 is joined to the flexible circuit board 100 by heat pressing. The chip packaging structure of the flexible circuit board is used for a display device, for example. The chip 200 is a display driver chip, for example. The chip 200 is located on the flexible circuit board 100, and one end of the flexible circuit board 100 is connected to the display panel of the display device.

[0052] In step S20: a first heat dissipation layer is provided; this step is similar to Figure 7 Correspondingly, for example, a first heat dissipation layer 410 is arranged on the flexible circuit board 100 by screen printing technology. The first heat dissipation layer 410 is arranged around the chip 200, and the height of the first heat dissipation layer 410 does not exceed the height of the chip 200. The first heat dissipation layer 410 is, for example, a hydrophobic heat dissipation layer.

[0053] In step S30: set up the encapsulation body; this step is similar to Figure 8 Correspondingly, the gap between the first heat dissipation layer 410 and the chip 200 is filled with encapsulation material, for example, hydrophilic epoxy resin is used. The first heat dissipation layer 410 can play a role similar to a dam, which can effectively limit the flow of the encapsulation material and prevent it from overflowing to the outside of the first heat dissipation layer 410. Furthermore, the first heat dissipation layer 410 is different from an ordinary dam in that due to the hydrophobicity of the first heat dissipation layer 410, the hydrophilic epoxy resin will have a larger contact angle with it, which can effectively prevent the hydrophilic epoxy resin from accumulating in the first heat dissipation layer 410, so that the hydrophilic epoxy resin forms a uniform encapsulation body 300.

[0054] Fig. 9 The schematic diagram of the chip packaging structure of the flexible circuit board according to the second embodiment of the present invention is shown; the second embodiment is similar to the first embodiment, except that the second embodiment further provides a second heat dissipation layer 420 between the first heat dissipation layer 410 and the chip 200, and the height of the second heat dissipation layer 420 is less than the height of the first heat dissipation layer 410. Specifically, after the chip 200 is bonded to the flexible circuit board 100, before encapsulation with an encapsulation material, a first heat dissipation layer 410 is formed on the solder resist layer around the chip 200 by a printing process. Since the solder resist layer is usually a hydrophobic material, it is not conducive to the adhesion of the encapsulation material. Therefore, a hydrophilic material is used to fill the gap between the chip 200 and the first heat dissipation layer 410 to form the second heat dissipation layer 420, and then an encapsulation material such as a hydrophilic epoxy resin is coated to form an encapsulation body 300.

[0055] In the second embodiment, the first heat dissipation layer 410 is, for example, a hydrophobic heat dissipation layer, the second heat dissipation layer 420 is, for example, a hydrophilic heat dissipation layer, and the epoxy resin forming the encapsulation body 300 is, for example, a hydrophilic epoxy resin. Specifically, the surface energy of the first heat dissipation layer 410 is, for example, less than the surface energy of the second heat dissipation layer 420, and the surface energy of the first heat dissipation layer 410 is, for example, not greater than 100 mJ / m 2 , which is hydrophobic; the surface energy of the second heat dissipation layer 420 is, for example, not less than 200 mJ / m 2 , and its surface is hydrophilic. The epoxy resin has hydrophobicity and hydrophilicity corresponding to the different surface energies of the first heat dissipation layer 410 and the second heat dissipation layer 420. The contact angle between the epoxy resin and the second heat dissipation layer 420 is smaller than the contact angle between the epoxy resin and the first heat dissipation layer 410. Therefore, the epoxy resin will be closer to the second heat dissipation layer 420 and its flow is also restricted by the first heat dissipation layer 410, so that the encapsulation body 300 formed by curing the epoxy resin is more uniform and flat.

[0056] Fig.10 A schematic diagram of a chip packaging structure of a flexible circuit board according to a third embodiment of the present invention is shown; the third embodiment is similar to the second embodiment, except that the height of the first heat dissipation layer 410 in the third embodiment is lower, and the height of the first heat dissipation layer 410 is the same as the height of the second heat dissipation layer 420. The first heat dissipation layer 410 is, for example, a hydrophobic heat dissipation layer, and the second heat dissipation layer 420 is, for example, a hydrophilic heat dissipation layer. The epoxy resin forming the encapsulation body 300 is, for example, a hydrophilic epoxy resin. The first heat dissipation layer 410 and the second heat dissipation layer 420 in the third embodiment can also make the encapsulation body 300 formed by curing the epoxy resin more uniform.

[0057] The chip packaging structure of the flexible circuit board provided in the embodiment of the present invention can effectively prevent the encapsulation material from overflowing from the range of the first heat dissipation layer, restrict the flow of the encapsulation material, make the formed encapsulation body more uniform, and effectively enhance the consistency and stability of the packaging structure.

[0058] Furthermore, the encapsulation material forming the encapsulation body can be a hydrophilic material, and the first heat dissipation layer can be a hydrophobic material. The different characteristics of the two can also be used to further limit the shape of the encapsulation body. For example, the first heat dissipation layer can also contain nano-metal particles to obtain better heat dissipation performance and electromagnetic protection capabilities.

[0059] The manufacturing method of the packaging structure provided in the embodiment of the present invention involves a processing technology that is mature and reliable, and is simple and easy to implement. The above-mentioned packaging structure can be easily obtained, thereby limiting the flow of the encapsulation material, improving the uniformity of the encapsulation body, avoiding heat accumulation in individual areas of the chip due to uneven encapsulation, and improving the reliability and stability of the product. The manufacturing method can not only meet various needs, but also has a simple process and high production efficiency.

[0060] In the above description, the technical details of the patterning and etching of each device are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0061] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A chip packaging structure of a flexible circuit board, characterized in that: include: Flexible circuit boards; A chip, located on the flexible circuit board; A first heat dissipation layer is located on the flexible circuit board, and the first heat dissipation layer is arranged around the chip; An encapsulation body, located on the flexible circuit board, surrounding the chip, and located between the first heat dissipation layer and the chip; The chip is bonded to the flexible circuit board, and the encapsulation body enhances the reliability of the connection between the chip and the flexible circuit board.

2. The packaging structure according to claim 1, characterized in that: The encapsulation body includes a hydrophilic material, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 The hydrophobic material of the first heat dissipation layer limits the accumulation of the material forming the encapsulation body near the first heat dissipation layer through the hydrophobicity of the first heat dissipation layer.

3. The packaging structure according to claim 1, characterized in that: The height of the first heat dissipation layer is not greater than the height of the chip.

4. The packaging structure according to claim 1, characterized in that: The top surface of the first heat dissipation layer is lower than the top surface of the chip, the longitudinal section of the first heat dissipation layer comprises a rectangle, and the longitudinal section of the encapsulation body comprises a trapezoid or a triangle.

5. The packaging structure according to claim 1, characterized in that: The distances between different side surfaces of the chip and the corresponding first heat dissipation layer are the same.

6. The packaging structure according to claim 1, characterized in that: The first heat dissipation layer also includes metal particles.

7. The packaging structure according to claim 1, characterized in that: The device further comprises a second heat dissipation layer, wherein the second heat dissipation layer is located between the first heat dissipation layer and the chip, and the encapsulation body is located on the second heat dissipation layer.

8. The packaging structure according to claim 7, characterized in that: A height of the second heat dissipation layer is not greater than a height of the first heat dissipation layer.

9. The packaging structure according to claim 7, characterized in that: The encapsulation body and the second heat dissipation layer both include hydrophilic materials, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 hydrophobic material.

10. The packaging structure according to claim 1, characterized in that: The packaging structure is used in a display device.

11. A method for manufacturing a flexible circuit board packaging structure, characterized in that: include: Bonding the chip to the flexible circuit board; Providing a first heat dissipation layer; Setting an enclosure; The first heat dissipation layer is located on the flexible circuit board, and the first heat dissipation layer is arranged around the chip; the encapsulation body is located between the first heat dissipation layer and the chip to enhance the reliability of the connection between the chip and the flexible circuit board.

12. The manufacturing method according to claim 11, characterized in that: The encapsulation body includes a hydrophilic material, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 hydrophobic material.

13. The manufacturing method according to claim 12, characterized in that: The first heat dissipation layer is formed on the solder resist area of ​​the flexible circuit board by a screen printing process, and the first heat dissipation layer is used to limit the encapsulation body.

14. The manufacturing method according to claim 11, characterized in that: The top surface of the first heat dissipation layer is lower than the top surface of the chip.

15. The manufacturing method according to claim 11, characterized in that: The distances between different side surfaces of the chip and the corresponding first heat dissipation layer are the same.

16. The manufacturing method according to claim 11, characterized in that: After setting the first heat dissipation layer and before setting the encapsulation body, it also includes: setting a second heat dissipation layer; wherein the second heat dissipation layer is located on the flexible circuit board, the second heat dissipation layer is located between the first heat dissipation layer and the chip, and the encapsulation body is located on the second heat dissipation layer.

17. The manufacturing method according to claim 16, characterized in that: A height of the second heat dissipation layer is not greater than a height of the first heat dissipation layer.

18. The manufacturing method according to claim 16, characterized in that: The encapsulation body and the second heat dissipation layer both include hydrophilic materials, and the first heat dissipation layer includes a surface energy not greater than 100 mJ / m 2 hydrophobic material.

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