Edge covering structure of heat conduction pad and chip packaging structure

Abstract

The utility model relates to the technical field of chip packaging, and discloses an edge covering structure of a heat conduction pad and a chip packaging structure, the chip packaging structure comprises a heating source, a substrate, an electronic component, a radiator and a heat conduction structure; the heating source and the electronic components are arranged on the substrate, and the electronic components are distributed around the heating source; the heat conduction structure is arranged between the radiator and the heating source and is in thermal contact with the heating source and the radiator. The heat conduction structure is a thermal interface material, and the electronic component is covered with an insulation protection layer to protect the electronic component and prevent the thermal interface material from causing short circuit of the electronic component, or the heat conduction structure comprises a heat conduction pad, and the circumferential surface of the heat conduction pad is provided with a first insulation layer.

Description

TECHNICAL FIELD

[0001] The utility model relates to chip packaging technical field, especially a kind of edge covering structure of heat-conducting pad and chip packaging structure. BACKGROUND

[0002] With the advent of AI era, electronic chip working frequency is increasing, electronic products gradually develop towards lightweight and high integration, which leads to a substantial increase in the heat generation of equipment. The thermal conductivity of heat-conducting structures such as heat-conducting pads is increasingly required, among which, heat-conducting pads have high compressibility, softness and elasticity, and can provide various thickness and size options, and are favored in the selection of heat-conducting structures of electronic devices.

[0003] High-thermal-conductivity heat-conducting fillers are needed for heat-conducting structures. Since high-thermal-conductivity heat-conducting fillers used to make high-thermal-conductivity heat-conducting structures all have electrical conductivity, those with thermal conductivity higher than 15 W / m·K can conduct electricity. During assembly and use, there is a risk that heat-conducting fillers come into contact with surrounding components, and there is a risk that electrically conductive particles on the surface fall onto components, and there is a risk of slagging and cracking, all of which can cause short circuits between components and result in major failures. SUMMARY

[0004] The utility model discloses an edge covering structure of heat-conducting pad and chip packaging structure for solving the problem that heat-conducting pads can cause short circuits of surrounding electronic components.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical scheme:

[0006] In a first aspect, a chip packaging structure is provided, which includes a heat source, a substrate, an electronic component, a heat sink and a heat-conducting structure. The heat source and the electronic component are both arranged on the substrate, and the electronic component is distributed around the heat source. The heat-conducting structure is arranged between the heat sink and the heat source and is in thermal contact with the heat source and the heat sink, respectively. The heat-conducting structure is a thermal interface material, and the electronic component is covered with an insulating protective layer to protect the electronic component from short circuits caused by the thermal interface material. Alternatively, the heat-conducting structure includes a heat-conducting pad, which has a first thermal contact surface and a second thermal contact surface arranged oppositely, and a circumferential surface connecting the first thermal contact surface and the second thermal contact surface. The circumferential surface is provided with a first insulating layer to prevent the circumferential surface of the heat-conducting pad from contacting the electronic components around the heat source. At the same time, the problem of short circuits and damage to the electronic components caused by electrically conductive particles or slag falling on the electronic components can be avoided.

[0007] Optionally, the first insulating layer has a cross-section in a "U" shape, and the edge portion of the thermal pad is located in the opening of the "U" shape.

[0008] Optionally, the first thermal contact surface and the second thermal contact surface are both covered with a second insulating layer, and the tensile strength of the first insulating layer is greater than the tensile strength of the second insulating layer.

[0009] Optionally, the tensile strength of the first insulating layer is greater than or equal to 100 kpa, and the tensile strength of the second insulating layer is greater than or equal to 1 kpa.

[0010] Optionally, the thickness of the first insulating layer is greater than the thickness of the second insulating layer.

[0011] Optionally, the thickness of the first insulating layer is between 5 um and 100 um, and the thickness of the second insulating layer is between 500 nm and 1 um.

[0012] Optionally, the first insulating layer is a coating layer or a cladding layer, and the second insulating layer is a thin film formed on the circumferential surface by chemical vapor deposition.

[0013] Optionally, the material of the first insulating layer is one or more of silicone rubber, acrylic resin, polyurethane, and polyimide film; and the material of the second insulating layer is one or more of polymethyl methacrylate, polytetrafluoroethylene, and thermoplastic elastomer.

[0014] Optionally, the insulating protective layer is a cured glue, a resin, a thin film, or a tape.

[0015] Optionally, the height of the insulating protective layer is lower than the surface of the heat sink for contacting the thermal interface material.

[0016] Optionally, the thickness of the insulating protective layer is between 10 um and 5 mm.

[0017] Optionally, a ring-shaped enclosure structure is further provided between the heat sink and the substrate, the heat source is located in the space enclosed by the ring-shaped enclosure structure, and at least part of the electronic components are located outside the space enclosed by the ring-shaped enclosure structure; wherein the material stress generated by the ring-shaped enclosure structure after being compressed is less than the material stress generated by the thermal interface material after being compressed.

[0018] Optionally, the material stress generated by the ring-shaped enclosure structure after being compressed by 20% is less than or equal to 40 psi.

[0019] Optionally, the material of the ring-shaped enclosure structure is foam, adhesive tape, rubber pad, or plastic pad.

[0020] In a second aspect, a structure of a heat-conducting pad is provided, which comprises: a heat-conducting pad having a first thermal contact surface and a second thermal contact surface arranged oppositely, and a circumferential surface connecting the first thermal contact surface and the second thermal contact surface, wherein the circumferential surface is provided with a first insulating layer.

[0021] In the structure of the heat-conducting pad, the first thermal contact surface and the second thermal contact surface are used as functional areas to contact a heat source and a heat sink respectively; the first insulating layer coated on the circumferential surface can prevent the circumferential surface of the heat-conducting pad from contacting electronic components around the heat source, and can also prevent the circumferential surface from contacting conductive particles or falling scraps to cause short circuit and damage of the electronic components.

[0022] Optionally, the first insulating layer has a "U" shaped structure in cross section, and the edge portion of the heat-conducting pad is located in the opening of the "U" shaped structure.

[0023] Optionally, the first thermal contact surface and the second thermal contact surface are both covered with a second insulating layer, and the tensile strength of the first insulating layer is greater than that of the second insulating layer.

[0024] Optionally, the tensile strength of the first insulating layer is greater than or equal to 100 kpa, and the tensile strength of the second insulating layer is greater than or equal to 1 kpa.

[0025] Optionally, the thickness of the first insulating layer is greater than that of the second insulating layer.

[0026] Optionally, the thickness of the first insulating layer is between 5 um and 100 um, and the thickness of the second insulating layer is between 500 nm and 1 um.

[0027] Optionally, the first insulating layer is a coating layer or a cladding layer, and the second insulating layer is a thin film formed on the circumferential surface by chemical vapor deposition.

[0028] Optionally, the material of the first insulating layer is one or more of silicone rubber, acrylic resin, polyurethane and polyimide film; and the material of the second insulating layer is one or more of polymethyl methacrylate, polytetrafluoroethylene and thermoplastic elastomer. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A structure diagram of a chip packaging structure provided by an embodiment of the present application;

[0030] Figure 2 A structure diagram of a structure of a heat-conducting pad provided by an embodiment of the present application;

[0031] Figure 3 A structure diagram of a structure of a heat-conducting pad provided by an embodiment of the present application;Figure 2 A top view of the edge wrapping structure of the heat-conductive pad shown in the figure;

[0032] Figure 4 For Figure 2 An exemplary variation of the edge wrapping structure of the heat-conductive pad shown in the figure;

[0033] Figure 5 For Figure 2 Another exemplary variation of the edge wrapping structure of the heat-conductive pad shown in the figure;

[0034] Figure 6 A structural schematic diagram of another chip packaging structure provided by the embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] As Figure 1 shown, the embodiment of the present application provides a chip packaging structure, which comprises: a heat source 200, a substrate 400, an electronic component 401, a heat sink 300 and a heat-conductive structure 100'; the heat source 200 and the electronic component 401 are both arranged on the substrate 400, and the electronic component 401 is distributed around the heat source 200; the heat-conductive structure 100 is arranged between the heat sink 300 and the heat source 200, and is in thermal contact with the heat source 200 and the heat sink 300, respectively. Wherein, the above-mentioned heat source 200 can be a bare die, or other types of chips, or other structures that need to be cooled. Wherein, the bare die (the plural form of die can be dice, dies or die) is also called bare chip, bare die, die, or die, which is a small piece of integrated circuit body made of semiconductor material, and the intended function of the integrated circuit is to realize on this small piece of semiconductor.

[0037] The heat-conductive structure needs to use high-thermal-conductivity heat-conductive fillers. Since the high-thermal-conductivity heat-conductive fillers that can be used to make high-thermal-conductivity heat-conductive structures all have electrical conductivity, and the thermal conductivity is higher than 15 W / m·K, they can conduct electricity. In the process of assembly and use, the heat-conductive fillers have the risk of contacting the surrounding components, the conductive particles on the surface have the risk of falling onto the components, and there is also the risk of falling slag and cracking, which can all cause short circuits between components and cause major failures.

[0038] To solve the above technical problems, as shown in FIG. 2, an embodiment of the present application provides a heat-conducting pad edge structure 100, that is Figure 1 The heat-conducting structure 100' in the above heat-conducting pad edge structure can be a heat-conducting pad with an edge. It comprises a heat-conducting pad 101, the heat-conducting pad 101 having a first thermal contact surface S1 and a second thermal contact surface S2 arranged oppositely, and a circumferential surface S3 connecting the first thermal contact surface S1 and the second thermal contact surface S2, wherein the circumferential surface S3 is provided with a first insulating layer T1. The material of the heat-conducting pad 101 can be graphene, carbon fiber, metal, etc.

[0039] In the above heat-conducting pad edge structure, the first thermal contact surface S1 and the second thermal contact surface S2 serve as functional areas and are used for thermal contact with a heat source 200 (see Figure 1 ) and a heat sink 300 (see Figure 1 ) respectively; the circumferential surface S3 serves as a non-functional area, and by coating the circumferential surface S3 with the first insulating layer T1, the circumferential surface S3 of the heat-conducting pad 101 can be prevented from contacting electronic components 401 (see Figure 1 ) around the heat source 200, thereby avoiding short circuit of the electronic components 401, and also avoiding the problem of short circuit damage caused by conductive particles or slag falling on the above electronic components 401.

[0040] The form of the circumferential surface S3 provided with the first insulating layer T1 can be various, for example:

[0041] Referring to Figure 2 , the cross section of the first insulating layer T1 can be in a "U" shape structure, and the edge portion of the heat-conducting pad 101 is located in the opening of the above "U" shape structure. For example, the heat-conducting pad 101 can comprise a main covering layer a and two side wings b, and the two side wings b are connected to the two ends of the main covering layer a one by one respectively, wherein one side wing a extends along the edge of the first thermal contact surface S1, and the other side wing b extends along the edge of the second thermal contact surface S2.

[0042] In addition to the first insulating layer T1 provided on the circumferential surface S3, the first thermal contact surface S1 and the second thermal contact surface S2 can also be coated with a second insulating layer T2. During the assembly process of the heat-conducting pad edge structure 100, the first insulating layer T1 and the second insulating layer T2 can make the heat-conducting pad 101 achieve the effect of overall insulation, thereby avoiding conductive particles and slag from falling on the electronic components 401, and further reducing the risk of short circuit of the electronic components 401. Wherein, each side wing b is spaced apart from the heat-conducting pad 101 by the edge portion of the corresponding second insulating layer T2, but the two side wings b can also be in direct contact with the first thermal contact surface S1 and the second thermal contact surface S2 one by one respectively.

[0043] Figure 3 It is indicated that Figure 2Top view of the edge structure 100 of the heat-conducting pad shown, reference Figure 2 The side wings b extend along the edge of the second insulating layer T2 and enclose a notch area, forming a "hui" (Chinese character for "return") shaped structure.

[0044] Among them, combining Figure 1 and Figure 3 it can be seen that the heat source 200 and the radiator 300 can be pressed on the corresponding side wings b to clamp the edge part of the heat-conducting pad 101 to avoid suspension. Otherwise, when the heat-conducting pad 101 is pressed, the above-mentioned edge part is likely to break and fall off.

[0045] However, the heat source 200 and the radiator 300 can be assembled in the notch area enclosed by the corresponding side wings b and directly contact the second insulating layer T2 to avoid the thermal resistance of the second insulating layer T2 affecting the heat flow between the heat source 200 and the radiator 300.

[0046] By the above method, the contact area between the first insulating layer T1 and the heat-conducting pad 101 or the second insulating layer T2 can be increased. On the one hand, the first insulating layer T1 can be more firmly combined with the heat-conducting pad 101. On the other hand, the first insulating layer T1 can physically protect the first heat contact surface S1 and the second heat contact surface S2 of the heat-conducting pad 101 to prevent knocking and chipping.

[0047] In addition, the first insulating layer T1 can also only retain the main covering layer a without setting two side wings b, and can also play an insulating role on the circumferential surface S3 of the heat-conducting pad 101 to prevent the electronic component 401 from conducting and causing a short circuit.

[0048] As Figure 4 shown, the present application provides Figure 2 an exemplary deformation of the edge structure of the heat-conducting pad shown. The main covering layer a can simultaneously cover the cross-sections of the two side wings b. By connecting with the cross-sections of the side wings b, the possibility of the first insulating layer T1 falling off can be reduced to a certain extent. [[ID=2,7]]

[0049] As Figure 5 shown, the present application provides Figure 2 another exemplary deformation of the edge structure of the heat-conducting pad shown. The main covering layer a is sandwiched between the two side wings b, and the two side wings b cover the top and bottom surfaces of the main covering layer a. Among them, the top surface of the main covering layer a refers to the cross-section corresponding to the second heat contact surface S2, and the bottom surface refers to the cross-section corresponding to the first heat contact surface S1. It can also reduce the possibility of the first insulating layer T1 falling off to a certain extent. By removing the two side wings b, the surfaces of the two second insulating layers T2 can be made flatter, avoiding generating a gap between the heat source 200 and the radiator 300, and improving the heat dissipation effect of the heat source 200.

[0050] In a specific embodiment, the tensile strength of the first insulating layer T1 is greater than the tensile strength of the second insulating layer T2. During assembly, the edge position of the edge-wrapped structure 100 is prone to contact with the electronic component 401. The first insulating layer T1 has a greater tensile strength, which helps to avoid damage to the first insulating layer T1 and can withstand shocks during application. The first thermal contact surface S1 and the second thermal contact surface S2 are less likely to be knocked. The second insulating layer T2 does not need a greater tensile strength, and increasing the tensile strength by increasing the thickness or changing the material often simultaneously reduces the thermal conductivity, which is not conducive to the heat of the heat source 200 being transferred to the heat sink 300 through the second insulating layer T2.

[0051] In a specific embodiment, the tensile strength of the first insulating layer T1 is greater than or equal to 100 kpa, for example, it can be 100 kpa, 120 kpa, 130 kpa, 140 kpa, and 150 kpa, etc. If the tensile strength is too small, it will be difficult to effectively withstand the impact during assembly and the vibration in the application scenario. The tensile strength of the second insulating layer T2 is greater than or equal to 1 kpa, for example, it can be 1 kpa, 3 kpa, 5 kpa, and 10 kpa, etc. If the tensile strength is too small, it may fall off during assembly by contacting the heat source 200 and the heat sink 300. If the tensile strength is too large, it may cause the heat dissipation performance between the heat source 200 and the heat sink 300 to deteriorate. Therefore, the tensile strength of the second insulating layer T2 needs to be balanced to meet both functions.

[0052] In a specific embodiment, the thickness of the first insulating layer T1 is greater than the thickness of the second insulating layer T2. The first insulating layer T1 has a greater thickness, which is conducive to fully isolating the circumferential surface S3 from the electronic component 401, fully insulating the two, and physically protecting against possible impacts. The second insulating layer T2 is smaller, which is conducive to the heat of the heat source 200 being transferred to the heat sink 300, facilitating rapid heat dissipation of the heat source 200.

[0053] In a specific embodiment, the thickness of the first insulating layer T1 is between 5um and 100um, for example, it can be 5um, 10um, 15um, 20um, 32um, 47um, 62um, 77um, 90um and 100um, etc. If the thickness is too small, it is difficult to fully insulate the circumferential surface S3 from the electronic component 401. If the thickness is too large, it can cause physical interference with the electronic component 401, the edge of the heat-conducting pad 101 is raised, resulting in poor contact between the heat source 200 and the heat-conducting pad 101, air gap is generated, affecting the heat dissipation efficiency; the thickness of the second insulating layer T2 is between 500nm and 1um, for example, it can be 500nm, 600nm, 700nm, 800nm, 900nm and 1000nm, etc. If the thickness is too small, it is easy to break, and the conductive particles and slag are easy to fall on the electronic component 401, causing short circuit problem. If the thickness is too large, it will increase the thermal resistance between the heat source 200 and the heat sink 300, and the heat dissipation effect will be poor.

[0054] In a specific embodiment, the first insulating layer T1 is a coating layer or a cladding layer. By coating the insulating material on the first thermal contact surface S1, the coating layer or the cladding layer has a larger thickness than the chemical vapor deposition thin film, which is beneficial to improve the insulation and reduce the risk of short circuit of the electronic component 401. The second insulating layer T2 is a thin film formed on the circumferential surface S3 by chemical vapor deposition. Chemical vapor deposition can form a thin film that meets the above thickness requirements, has lower insulation and better heat conduction performance, and is beneficial to the full heat dissipation of the heat source 200.

[0055] For example, the material of the first insulating layer T1 is one or more of silicone rubber, acrylic resin, polyurethane and polyimide film. These materials have high insulation, can avoid short circuit between electronic components 401 caused by conduction between heat-conducting pad 101 and electronic components 401, and have high tensile strength, which can meet the physical protection requirements. The material of the second insulating layer T2 is one or more of polymethyl methacrylate, polytetrafluoroethylene and thermoplastic elastomer. These materials have lower insulation, which is beneficial to the heat dissipation of the heat source.

[0056] As shown in the chip packaging structure, Figure 1 In another possible implementation, the heat-conducting structure 100' can be a thermal interface material. The thermal interface material can include a heat-conducting silicone grease, or can be a wrapped edge structure of the heat-conducting pad as described above, but is not limited to the above examples. The present application provides another chip packaging structure, as shown in Figure 6As shown in the figure, the electronic component 401 is covered by the insulation protective layer 402, which protects the electronic component 401 and prevents the thermal interface material from causing short circuit of the electronic component 401. For example, the insulation protective layer 402 can be a cured glue, resin, film or tape, which has low cost and good insulation property. The insulation protective layer 402 does not cover the heat source 200 to avoid affecting heat dissipation.

[0057] In a specific embodiment, the height of the insulation protective layer 402 can be lower than the surface of the heat sink 300 for contacting the thermal interface material (e.g. the surface of the boss 301 of the heat sink 300 facing the heat source 200) to prevent tilting of the heat sink 300 and causing gap between the heat sink 300 and the heat source 200, which affects heat dissipation of the heat source 200.

[0058] In a specific embodiment, the thickness of the insulation protective layer 402 can be between 10 um and 5 mm, for example, 10 um, 20 um, 30 um, 50 um, 100 um, 500 um, 800 um, 1 mm, 2 mm, 3 mm, 4 mm and 5 mm, etc. If the thickness is too small, the insulation effect can be poor and the electronic component 401 can be at risk of short circuit. If the thickness is too large, the electronic component 401 can have difficulty in heat dissipation.

[0059] In a specific embodiment, the heat sink 300 and the substrate 400 are further provided with a ring-shaped barrier structure 500, one side of the ring-shaped barrier structure 500 is in contact with the substrate 400 and the other side is in contact with the heat sink 300. The heat source 200 is located in the space surrounded by the ring-shaped barrier structure 500, and at least part of the electronic component 401 can be located outside the space surrounded by the ring-shaped barrier structure 500, for example, part of the electronic component 401 can be located outside the space surrounded by the ring-shaped barrier structure 500, or all of the electronic component 401 can be located outside the space surrounded by the ring-shaped barrier structure 500. The ring-shaped barrier structure 500 prevents the conductive particles or falling slag of the thermal interface material from falling onto the electronic component 401 outside the ring-shaped barrier structure 500, thereby preventing short circuit of the electronic component 401. The material stress of the ring-shaped barrier structure 500 after compression is less than the material stress of the thermal interface material after compression. Otherwise, when the heat sink 300 is assembled, the rebound force of the ring-shaped barrier structure 500 can not compress the thermal interface material sufficiently, which causes gap between the thermal interface material and the heat sink 300 or the heat source 200, thereby affecting heat dissipation efficiency of the heat source 200.

[0060] In one specific embodiment, the annular containment structure 500 is compressed by 20% and the resulting material stress is less than or equal to 40 psi, for example, it can be 40 psi, 37 psi, 35 psi, 31 psi, 27 psi, 25 psi, 22 psi, 18 psi, 15 psi, 12 psi, 10 psi, 9 psi, 8 psi, 7 psi, 6 psi, and 5 psi, etc. If the resulting material stress is too large, the rebound force of the annular containment structure 500 will not be able to fully compress the thermal interface material, resulting in a gap between the thermal interface material and the heat sink 300 or the heat source 200, affecting the heat dissipation efficiency of the heat source 200. For example, the material of the annular containment structure 500 is a soft insulating layer such as foam, adhesive tape, rubber pad, or plastic pad, etc. The material stress generated when these materials are compressed can meet the above requirements.

[0061] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application also intends to include these modifications and variations.

Claims

1. A chip package structure, characterized by, The application relates to a heat dissipation structure, which comprises a heat source, a substrate, electronic components, a heat sink and a heat conducting structure. The heat source and the electronic components are arranged on the substrate, and the electronic components are distributed around the heat source. The heat conducting structure is arranged between the heat sink and the heat source and is in thermal contact with the heat source and the heat sink respectively. The heat conducting structure is a thermal interface material, the electronic components are covered with an insulating protective layer, or the heat conducting structure comprises a heat conducting pad, the heat conducting pad has a first thermal contact surface and a second thermal contact surface arranged oppositely and a circumferential surface connecting the first thermal contact surface and the second thermal contact surface, and the circumferential surface is provided with a first insulating layer. The first thermal contact surface and the second thermal contact surface are both covered with a second insulating layer, and the tensile strength of the first insulating layer is greater than that of the second insulating layer. The cross section of the first insulating layer is in a "U" shape structure, and the edge part of the heat conducting pad is located in the opening of the "U" shape structure.

2. The chip package structure of claim 1, wherein, The tensile strength of the first insulating layer is greater than or equal to 100 kpa, and the tensile strength of the second insulating layer is greater than or equal to 1 kpa.

3. The chip package structure of claim 1, wherein, The thickness of the first insulating layer is greater than that of the second insulating layer.

4. The chip package structure of claim 1, wherein, The thickness of the first insulating layer is between 5 um and 100 um, and the thickness of the second insulating layer is between 500 nm and 1 um.

5. The chip package structure of claim 4, wherein, The first insulating layer is a coating layer or a cladding layer, and the second insulating layer is a thin film formed on the circumferential surface through chemical vapor deposition.

6. The chip package structure of any one of claims 1 to 5, wherein, The material of the first insulating layer is one of silicone rubber, acrylic resin, polyurethane and polyimide film.

7. The chip package structure of claim 6, wherein, The material of the second insulating layer is one of polymethyl methacrylate, polytetrafluoroethylene and thermoplastic elastomer. The insulating protective layer is solidified glue, resin, a thin film or adhesive tape.

8. The chip package structure of claim 1, wherein, The height of the insulating protective layer is lower than the surface of the heat sink used for contacting the thermal interface material.

9. The chip package structure of claim 1, wherein, The thickness of the insulating protective layer is between 10 um and 5 mm.

10. The chip package structure of claim 9, wherein, An annular enclosing structure is further arranged between the heat sink and the substrate, the heat source is located in the space enclosed by the annular enclosing structure, and at least part of the electronic components are located outside the space enclosed by the annular enclosing structure.

11. The chip package structure of claim 1, wherein, The material stress of the annular enclosing structure after compression is less than the material stress of the thermal interface material after compression. The material stress of the annular enclosing structure is less than or equal to 40 psi after being compressed by 20%.

12. The chip package structure of claim 11, wherein, The material of the annular enclosing structure is foam, adhesive tape, rubber pad or plastic pad.

13. The chip package structure of claim 12, wherein, The application relates to a heat conducting pad, which comprises a first thermal contact surface and a second thermal contact surface arranged oppositely and a circumferential surface connecting the first thermal contact surface and the second thermal contact surface, wherein the circumferential surface is provided with a first insulating layer.

14. A structure of a heat conductive pad, characterized by, The first thermal contact surface and the second thermal contact surface are both covered with a second insulating layer, and the tensile strength of the first insulating layer is greater than that of the second insulating layer. The cross section of the first insulating layer is in a "U" shape structure, and the edge part of the heat conducting pad is located in the opening of the "U" shape structure. ​ 15. The edge-wrapped construction of a thermal pad of claim 14, wherein, ​ 16. The edge-wrapped construction of a thermal pad of claim 14, wherein, The tensile strength of the first insulation layer is greater than or equal to 100 kPa, and the tensile strength of the second insulation layer is greater than or equal to 1 kPa.

17. The edge-wrapped construction of a thermal pad of claim 14, wherein, The thickness of the first insulation layer is greater than the thickness of the second insulation layer.

18. The edge-wrapped construction of a thermal pad of claim 17, wherein, The thickness of the first insulation layer is between 5 um and 100 um, and the thickness of the second insulation layer is between 500 nm and 1 um.

19. The edge-wrapped construction of a thermal pad according to any one of claims 14 to 18, wherein, The first insulation layer is a coating layer or a cladding layer, and the second insulation layer is a thin film formed on the circumferential surface by chemical vapor deposition.

20. The edge-wrapped construction of a thermal pad of claim 19, wherein, The material of the first insulation layer is one of silicone rubber, acrylic resin, polyurethane, and polyimide film. The material of the second insulation layer is one of polymethyl methacrylate, polytetrafluoroethylene, and thermoplastic elastomer.

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