CN113889440A - Heat conduction structure, manufacturing method thereof, heat conduction system, chip packaging structure and electronic equipment - Google Patents

Heat conduction structure, manufacturing method thereof, heat conduction system, chip packaging structure and electronic equipment Download PDF

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Publication number
CN113889440A
CN113889440A CN202010625164.9A CN202010625164A CN113889440A CN 113889440 A CN113889440 A CN 113889440A CN 202010625164 A CN202010625164 A CN 202010625164A CN 113889440 A CN113889440 A CN 113889440A
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heat
organic material
heat conduction
heat conducting
conducting structure
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徐焰
王奋成
赵仁哲
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Huawei Technologies Co Ltd
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Huawei Technologies Co Ltd
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Priority to CN202010625164.9A priority Critical patent/CN113889440A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/367—Cooling facilitated by shape of device
    • H01L23/3672—Foil-like cooling fins or heat sinks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/367—Cooling facilitated by shape of device
    • H01L23/3675—Cooling facilitated by shape of device characterised by the shape of the housing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3735—Laminates or multilayers, e.g. direct bond copper ceramic substrates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3737—Organic materials with or without a thermoconductive filler

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Ceramic Engineering (AREA)
  • Cooling Or The Like Of Electrical Apparatus (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)

Abstract

The embodiment of the application provides a heat conduction structure, a manufacturing method thereof, a heat conduction system, a chip packaging structure and electronic equipment. The second organic material in the heat conduction structure diffuses towards the outer surface of the heat conduction structure, and the second organic material diffusing outwards forms an adhesive layer between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator, and the adhesive layer connects the heat conduction structure with the heating element and/or connects the heat conduction structure with the radiator, so that the heat conduction structure is ensured to be in close contact with the surface of the heating element/radiator, and the problem that the heating element is over-heated due to the fact that the heat conduction structure is layered with the interface between the heating element/radiator in the using process is avoided; in addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the heating element and between the heat conduction structure and the radiator, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, and the application thermal resistance of the heat conduction structure is reduced.

Description

Heat conduction structure, manufacturing method thereof, heat conduction system, chip packaging structure and electronic equipment
Technical Field
The embodiment of the application relates to the technical field of heat conduction, in particular to a heat conduction structure, a manufacturing method thereof, a heat conduction system, a chip packaging structure and electronic equipment.
Background
As electronic devices continue to integrate more powerful functions into smaller components, temperature control has become one of the most important challenges in design, i.e. how to effectively remove more heat generated by larger unit power under the condition of compact architecture and smaller operating space is a problem to be solved.
At present, the heat that the chip produced mainly realizes the heat dissipation to the chip for the radiator through the heat conduction pad transmission, specifically does, sets up the heat conduction pad on the chip, and the another side that the heat conduction pad deviates from the chip is connected with the radiator, and wherein, adopt the adhesive linkage to link to each other between chip and heat conduction pad and the radiator.
However, in the application process of the heat conduction pad, along with the temperature change, the bonding force between the chip and the heat conduction pad and between the heat conduction pad and the heat sink is reduced, and the heat conduction pad and the chip and/or between the heat conduction pad and the heat sink are easily layered, so that the chip junction temperature is too high due to the fact that the heat on the chip cannot be timely dissipated.
Disclosure of Invention
The embodiment of the application provides a heat conduction structure, a manufacturing method thereof, a heat conduction system, a chip packaging structure and electronic equipment, which improve the bonding strength between the heat conduction structure and a heating element as well as a radiator, reduce the thermal contact resistance between the heat conduction structure and the heating element as well as the radiator, improve the heat conduction effect of the heat conduction structure, and solve the problem that the chip junction temperature is too high due to the fact that layering is easy to occur between the existing heat conduction pad and a chip and/or a radiator.
A first aspect of the embodiments of the present application provides a heat conduction structure, configured to transfer heat generated by a heat generating component to a heat sink, including:
the heat conduction film and the medium layers are alternately arranged;
one ends of the plurality of heat-conducting films face the heat generating element, and the other ends of the plurality of heat-conducting films face the heat sink;
the dielectric layer at least comprises: a first organic material and a second organic material located in the first organic material;
the first organic material is used for bonding two adjacent heat conduction films;
the second organic material is used for the heat conduction structure is in when predetermineeing the temperature or predetermineeing under the pressure the surface diffusion of heat conduction structure, and the outward diffusion the second organic material is at least in the heat conduction structure with between the heating element and/or be in the heat conduction structure with form the adhesive linkage between the radiator, the adhesive linkage be used for with the heat conduction structure with the heating element links to each other and/or will the heat conduction structure with the radiator links to each other.
The heat conducting structure provided by the embodiment of the application is characterized in that the heat conducting films and the medium layers are alternately arranged, one end of the heat conducting film faces the heating element, the other end of the heat conducting film faces the radiator, the medium layer at least comprises a first organic material and a second organic material positioned in the first organic material, the second organic material is diffused towards the outer surface of the heat conducting structure at a preset temperature or a preset pressure, the second organic material diffused outwards forms an adhesive layer at least between the heat conducting structure and the heating element and/or between the heat conducting structure and the radiator, the adhesive layer connects the heat conducting structure with the heating element and/or between the heat conducting structure and the radiator, and the close contact between the heat conducting structure and the surface of the heating element/radiator is ensured, therefore, the problem that the heating element is over-temperature due to the fact that the heat conducting structure is layered with the interface between the heating element and the radiator in the using process is solved. In addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the heating element and between the heat conduction structure and the radiator, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, and the application thermal resistance of the heat conduction structure is reduced.
Furthermore, the second organic material may be filled in local micro-holes or gaps between the heat conducting structure and the heat generating element and/or the heat conducting structure and the heat sink, so that the contact area between the generated adhesive layer and the heat generating element/heat sink is increased and the adhesive force is greater.
In one possible implementation, the preset temperature is greater than or equal to 35 ℃.
In one possible implementation, the preset pressure is greater than or equal to 5 psi.
In one possible implementation, the second organic material that diffuses out forms an adhesive layer having van der waals, chemical bonding, or biting forces at least between the heat conducting structure and the heat generating element and/or between the heat conducting structure and the heat sink. Therefore, the purpose of tight combination between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator is achieved, the higher the temperature of the heating element is, the more the second organic material in the heat conduction structure diffuses outwards, and the combination force between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator is larger, so that the problem of layering caused by overhigh temperature between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator is avoided.
In one possible implementation, the second organic material diffuses through the bulk of the first organic material at the predetermined temperature or the predetermined pressure.
In one possible implementation, the first organic material is solid or semi-solid and the second organic material is liquid or semi-solid.
In a possible implementation manner, the adhesion between the adhesive layer and the heat sink, and/or the adhesion between the adhesive layer and the heat generating element is greater than the cohesion of the dielectric layer. Therefore, even if the heat conduction structure is stretched and damaged, the bonding state between the heat conduction structure and the heating element/radiator is still kept, firm bonding force between the heat conduction structure and the heating element/radiator is guaranteed, and the problem of layering between the heat conduction structure and the heating element/radiator is avoided.
In one possible implementation manner, the second organic material is a material that undergoes a dehydration condensation reaction or a polymerization reaction with the heat generating element and/or with at least a partial region of the heat sink on the outer surface of the heat conducting structure facing the heat conducting structure under a preset reaction condition, where the preset reaction condition includes a reaction temperature, a reaction humidity or a reaction medium, the reaction temperature is greater than or equal to 35 ℃, and the reaction humidity is greater than or equal to 10%. Therefore, chemical bond binding force is generated at the joint between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator, and the temperature of layering caused by the fact that the bonding strength is reduced when the temperature is increased due to the fact that the existing heat conduction pad and the heating element/radiator are bonded through the glue layer is avoided.
In one possible implementation, the reaction temperature is greater than or equal to 35 ℃.
In one possible implementation, the reaction humidity is greater than or equal to 10%.
In one possible implementation, the second organic material includes a liquid material containing reactive hydroxyl groups and a liquid material containing hydrolyzable groups. Thus, the liquid material containing the hydrolyzable group in the second organic material provides a hydrolyzable group, the hydrolyzable group undergoes a hydrolysis reaction to obtain a hydroxyl group, and after the hydroxyl group is sufficiently active, the second organic material undergoes a dehydration condensation reaction at the metal surface between the heat conductive structure and the heat generating element and/or between the heat conductive structure and the heat sink under an accelerating factor such as high temperature, moisture or metal surface to form the adhesive layer. The metal surface of the heating element and the bonding layer can form chemical bond bonding, the metal surface of the radiator and the bonding layer form chemical bond bonding, and the metal surface of the radiator and the bonding layer form interface bonding similar to chelation, so that chemical bonding force is formed between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator, bonding is firmer, and layering is not easy to occur.
In one possible implementation, the liquid material of the reactive hydroxyl groups includes a polyol. The polyol thus provides hydroxyl groups which are hydrolyzed such that the liquid of the hydrolyzable groups has hydroxyl functionality, and after sufficient activity of the hydroxyl groups has been achieved, the liquid material containing hydroxyl functionality undergoes a dehydration condensation reaction to form the adhesive layer under accelerated conditions of elevated temperature, moisture or metal surfaces.
In one possible implementation, the liquid material containing hydrolyzable groups is a silane coupling agent. After the silane coupling agent is hydrolyzed, when the hydroxyl in the second organic material reaches enough activity, the silane coupling agent undergoes a dehydration condensation reaction to form an adhesive layer.
In one possible implementation, the polyol is at least one of butanetriol, pentaerythritol, glycerol, trimethylolethane, xylitol, or sorbitol, and the silane coupling agent is a trialkoxysilane, or the silane coupling agent is octyltriethoxysilane.
In one possible implementation, the adhesive layer formed after the second organic material is polymerized has pressure-sensitive characteristics. The adhesive layer thus produced effects adhesion between the heat conducting structure and the heat generating element and/or between the heat conducting structure and the heat sink under pressure.
In one possible implementation, the second organic material is an unsaturated acrylic material. Such that the second organic material may be polymerized under predetermined reaction conditions to form the adhesive layer.
In a possible implementation manner, the unsaturated acrylic material is an acrylic material containing an ester functional group, or the unsaturated acrylic material is an acrylic material containing a strong hydrophilic group such as a carboxyl group and a hydroxyl group.
In a possible implementation manner, an included angle formed between one surface of the heat conducting film facing the dielectric layer and the thickness direction of the heat conducting structure is greater than 0 ℃ and less than or equal to 45 ℃.
Or an included angle formed between one surface of the heat conduction film facing the medium layer and one surface of the heat conduction film departing from the medium layer and the thickness direction of the heat conduction structure is greater than 0 ℃ and less than or equal to 45 ℃. The heat conduction membrane compressive deformation absorbs stress, so that the compressive stress of the heat conduction structure is obviously reduced, the plane size of the heat conduction structure is not obviously expanded when the heat conduction structure 1 is compressed by external force, and the short circuit risk caused by the expansion of the 100-size of the heat conduction structure is avoided.
In one possible implementation, the first organic material is a polyorganosiloxane oil containing at least an unsaturated siloxane. The first organic material contains unsaturated bonds, and the reactive functional groups can be activated under the modes of heating, illumination and the like, so that the unsaturated bonds can generate addition polymerization reaction to realize curing.
In one possible implementation, the first organic material includes a vinyl silicone oil and a hydrogen-containing silicone oil, and both the vinyl silicone oil and the hydrogen-terminated silicone oil have a molecular weight of less than 15000. Thus, the vinyl silicone oil and the hydrogen-containing silicone oil can generate addition reaction, so that the first organic material is cured to form the organic silicon elastic material.
In one possible implementation, the hydrogen-containing silicone oil includes at least one of a terminal hydrogen silicone oil and a side hydrogen silicone oil.
In one possible implementation, the first organic material is an organic chemical containing acrylic, polyurethane, epoxy, or polyimide.
In one possible implementation, the first organic material includes 4-hydroxybutyl acrylate and divinyl adipate.
In one possible implementation manner, the second organic material diffused outwards accounts for less than or equal to 50% of the dielectric layer by weight.
In one possible implementation, the weight percentage of the second organic material in the first organic material is lower than 50%.
In one possible implementation, the thickness of the adhesive layer is less than or equal to 1 μm.
In one possible implementation, the thickness of the heat conducting structure is greater than or equal to 0.1mm and less than or equal to 5 mm.
In one possible implementation manner, a thermal conductivity of the heat conducting structure in a first direction is greater than a thermal conductivity of the heat conducting structure in a second direction, and a thermal conductivity of the heat conducting structure in a third direction is greater than a thermal conductivity of the heat conducting structure in the second direction, where the first direction is a direction perpendicular to a surface of the heat generating element facing the heat conducting structure, the second direction is a direction perpendicular to a surface of the heat conducting film facing the dielectric layer, and the third direction is a direction perpendicular to the first direction and the second direction. When the heating element and the radiator are located on two sides of the heat conduction structure along the first direction (namely the Z direction), the heat conduction coefficient of the heat conduction structure in the first direction is large, so that the heat generated by the heating element is quickly transferred to the radiator by the heat conduction structure, and the purpose of quickly radiating the heating element is achieved.
In one possible implementation, a ratio of a thermal conductivity of the thermally conductive structure in the first direction to a thermal conductivity of the thermally conductive structure in the second direction is greater than or equal to 5.
In one possible implementation, the thermal conductivity of the thermally conductive structure in the first direction is higher than or equal to 35W/mk.
In one possible implementation, the thickness of each of the thermally conductive films is greater than or equal to 7 μm and less than or equal to 200 μm.
In one possible implementation, the thermally conductive membrane is a compressible thermally conductive membrane. Therefore, when the heat conduction structure bears compressive stress, the stress can be transmitted to the internal heat conduction film, and the compressive stress can be reduced by absorbing the stress through the compressive deformation of the heat conduction film. After the heat conduction structure is compressed, the plane size of the heat conduction structure is not obviously expanded, the density of the corresponding heat conduction structure is increased, and the risk of short circuit caused by the expansion of the plane size when the heat conduction structure is compressed is avoided.
In one possible implementation manner, the density of the compressible heat conduction membrane is 1.2-1.95 g/cm3。
In one possible implementation, the thermally conductive film is a graphene film or a graphite film. Thus, when the heat conduction membrane is a graphene membrane, the graphene membrane has compressibility, and the heat conduction membrane is ensured to be compressible.
A second aspect of the present application provides a heat conducting system, comprising a heat generating element and the above heat conducting structure, wherein the heat conducting structure is used for transferring heat from the heat generating element. Through including above-mentioned heat conduction structure like this, the second organic material in the heat conduction structure outdiffusion forms the adhesive linkage that has van der Waals' force, chemical bond cohesion or bite power between heating element and heat conduction structure, and the adhesive linkage realizes heating element and heat conduction structure closely linking to each other, avoids the problem that the layering appears between heating element and the heat conduction structure.
In a possible implementation manner, the heat dissipation device further includes a heat sink, and the heat conduction structure is located between the heat generating element and the heat sink, and the heat conduction structure is used for transferring heat from the heat generating element to the heat sink. The second organic material in the heat conducting structure diffuses outwards between the heating element and the heat conducting structure and between the heating element and the radiator to form an adhesive layer with Van der Waals force, chemical bond bonding force or biting force, and the adhesive layer tightly connects the heating element and the heat conducting structure and the radiator.
A third aspect of the present application provides a chip package structure, at least including: the heat conducting structure is arranged between the chip and the packaging heat radiating cover;
and the heat conduction structure is at the temperature of predetermineeing or predetermineeing under the pressure, the second organic material in the heat conduction structure outdiffuses to the heat conduction structure with between the chip and/or the heat conduction structure with between the encapsulation heat dissipation lid and form the adhesive linkage, the heat conduction structure with between the chip and/or the heat conduction structure with between the encapsulation heat dissipation lid pass through the adhesive linkage links to each other.
Through including above-mentioned heat conduction structure in chip package structure, realized forming the adhesive linkage between heat conduction structure and chip and the heat conduction structure and/or between heat conduction structure and the encapsulation heat dissipation lid, the adhesive linkage generates the in-process and forms the chemical cohesion with the heat conduction structure and chip and/or the heat conduction structure and encapsulates the junction between the heat dissipation lid, has ensured that heat conduction structure and chip/encapsulation heat dissipation lid surface maintain inseparable bonding to the problem that the layering appears in the interface between heat conduction structure and chip/encapsulation heat dissipation lid in the use and leads to the chip overtemperature has been avoided. In addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the chip and/or between the heat conduction structure and the packaging heat dissipation cover, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, the application thermal resistance of the heat conduction structure is reduced, and the purpose of good heat dissipation of the chip is achieved.
In one possible implementation manner, the method further includes: the fixed frame is positioned between the packaging carrier plate and the packaging heat dissipation cover, a cavity is enclosed by the fixed frame, the packaging carrier plate and the packaging heat dissipation cover, and the chip and the heat conduction structure are positioned in the cavity.
In a possible implementation mode, fixed frame with it links to each other to encapsulate through the elastic fastener fastening between the heat dissipation lid, and after being connected between fixed frame and the encapsulation heat dissipation lid like this, fixed frame and encapsulation have compressible surplus between the heat dissipation lid, can realize exerting pressure to the heat conduction structure after exerting the effort to the encapsulation heat dissipation lid like this, the heat conduction structure second organic material outdiffusion takes place chemical reaction and forms the adhesive linkage under the pressure effect.
Alternatively, the fixing frame and the package heat-dissipating cover are integrated. When the packaging is finished, water vapor is prevented from entering a cavity formed by the packaging carrier plate, the packaging radiating cover and the fixed frame from the assembly gap between the fixed frame and the packaging radiating cover and influencing a chip.
In one possible implementation, the fixing frame and the package carrier are firmly connected.
A fourth aspect of the embodiments of the present application provides an electronic device, including at least: the chip packaging structure described in any of the above. The second organic material is diffused between the heat conduction structure and the chip and/or between the heat conduction structure and the packaging heat dissipation cover by the heat generated by the operation of the chip, the second organic material diffused outwards is subjected to chemical reaction to form an adhesive layer, and the heat conduction structure and the chip and/or the heat conduction structure and the packaging heat dissipation cover are connected by the adhesive layer. Therefore, heat generated by the chip is transferred to the packaging heat dissipation cover through the heat conduction structure, and the packaging heat dissipation cover is in contact with the shell of the electronic equipment to transfer the heat out of the electronic equipment. In addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the chip and/or between the heat conduction structure and the packaging heat dissipation cover, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, the application thermal resistance of the heat conduction structure is reduced, and the purpose of good heat dissipation of the chip in the electronic equipment is achieved.
A fifth aspect of an embodiment of the present application provides an electronic device, including at least: the shell and establish heating element, radiator and the last arbitrary heat conduction structure in the shell, the heat conduction structure is located heating element with between the radiator, the radiator contacts with the shell.
Thus, under high temperature or pressure, the second organic material in the heat conducting structure diffuses between the heating element and the heat conducting structure and/or between the radiator and the heat conducting structure, when reaction conditions are reached, the second organic material performs chemical reaction, so that an adhesive layer with van der Waals force, chemical bond bonding force or occlusion force is generated at the joint between the heating element and the heat conducting structure and/or between the radiator and the heat conducting structure, close contact between the heat conducting structure and the surface of the heating element/radiator is ensured, and the problem that the temperature of the heating element in the electronic equipment is over-high due to the fact that the heat conducting structure is layered with the interface between the heating element/radiator in the using process is avoided. In addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the heating element and between the heat conduction structure and the radiator, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, and the application thermal resistance of the heat conduction structure is reduced. The heat generated by the heating element in the electronic equipment is dissipated outwards in time, and the phenomenon that the heating element cannot work normally due to overhigh temperature of the heating element is avoided. Furthermore, the second organic material diffusing outward can fill the local micropores between the heat conducting structure and the heat generating element and between the heat conducting structure and the heat sink, so that the contact area between the formed bonding layer and the heat generating element/heat sink is increased, and the bonding force is larger.
In one possible implementation, the heat sink is in contact with the housing. Therefore, heat generated by the heating element is transferred to the radiator through the heat conduction structure, and the radiator radiates the heat to the outside of the electronic equipment through the shell of the electronic equipment, so that the purpose of radiating the heating element in the electronic equipment is achieved.
A fifth aspect of the embodiments of the present application provides a method for manufacturing a heat conducting structure, where the method includes:
providing a plurality of heat conducting films, wherein each heat conducting film is provided with a first surface and a second surface opposite to the first surface;
forming a dielectric layer on the first surface and the second surface of each of the thermal conductive films, the dielectric layer including a first organic material and a second organic material located in the first organic material;
laminating and pressing the plurality of heat conducting films with the medium layers to form a block structure;
and cutting the block structure to obtain the heat conduction structure.
In a possible implementation manner, the cutting the block structure to obtain the heat conducting structure includes:
cutting the blocky structure along a cutting direction, wherein an included angle is formed between the direction perpendicular to the heat-conducting film and the cutting direction, and the included angle is greater than or equal to 0 degree and less than or equal to 45 degrees.
In one possible implementation, the forming a dielectric layer on the first surface and the second surface of each of the thermal conductive films includes:
providing a first organic material and a second organic material, and mixing the second organic material in the first organic material to form an organic slurry;
coating the organic slurry on the first surface and the second surface of each of the heat conductive films to form the dielectric layer.
In one possible implementation, the providing the first organic material and the second organic material to form an organic paste includes:
providing vinyl silicone oil, hydrogen-terminated silicone oil, lateral hydrogen silicone oil and a catalyst;
mixing the vinyl silicone oil, the hydrogen-terminated silicone oil, the side hydrogen silicone oil and the catalyst to prepare the first organic material;
providing butanetriol and octyltriethoxysilane;
mixing said butanetriol and said octyltriethoxysilane to produce said second organic material;
mixing the first organic material and the second organic material to form the organic slurry;
alternatively, the providing the first organic material and the second organic material to form an organic paste includes:
providing a first organic material comprising 4-hydroxybutyl acrylate and divinyl adipate;
providing a second organic material comprising 2-ethylhexyl acrylate;
providing an initiator, wherein the initiator comprises a photopolymerization initiator and a thermal initiator;
mixing the 4-hydroxybutyl acrylate, the divinyl adipate, the 2-ethylhexyl acrylate, the photopolymerization initiator and the thermal initiator to prepare the organic slurry.
Drawings
Fig. 1 is an assembly view of a heat conducting structure, a heat generating element and a heat sink according to an embodiment of the present disclosure;
FIG. 2 is a schematic cross-sectional view taken along the line A-A in FIG. 1;
fig. 3 is a schematic view illustrating the out-diffusion of a second organic material in a thermal conductive structure according to an embodiment of the present disclosure;
fig. 4 is a schematic cross-sectional view illustrating a heat conducting structure, a heat generating element and a heat sink according to an embodiment of the present disclosure after being assembled;
FIG. 5 is a schematic cross-sectional view of a heat conducting structure according to another embodiment of the present application;
fig. 6 is a schematic flow chart illustrating a method for fabricating a heat conducting structure according to another embodiment of the present disclosure;
FIG. 7A is a schematic structural diagram of a plurality of thermally conductive films according to another embodiment of the present disclosure;
fig. 7B is a schematic structural diagram of a plurality of thermally conductive films formed with dielectric layers on two sides according to another embodiment of the present disclosure;
fig. 7C is a schematic diagram of a block structure formed by laminating a plurality of thermal conductive films having dielectric layers formed thereon according to another embodiment of the present application;
FIG. 7D is a schematic diagram of the block structure cut in FIG. 7C;
FIG. 7E is a schematic structural diagram of the resulting thermally conductive structure;
fig. 8A is a schematic cross-sectional view illustrating a chip package structure according to another embodiment of the present application;
fig. 8B is a schematic cross-sectional view illustrating a chip package structure according to another embodiment of the present application;
fig. 9 is a schematic perspective view of an electronic device according to another embodiment of the present application;
fig. 10 is a schematic view of a disassembled structure of an electronic device according to another embodiment of the present application;
fig. 11 is a schematic diagram of another disassembled structure of an electronic device according to another embodiment of the present application;
fig. 12 is a schematic diagram illustrating an addition reaction of components in a first organic material in a thermally conductive structure according to an embodiment of the disclosure.
Description of reference numerals:
100-a thermally conductive structure; 10-a thermally conductive film; 20-a dielectric layer; 21-a first organic material; 22-a second organic material; 221-an adhesive layer;
200-a heating element; 201-chip; 300-a heat sink; 301-encapsulating a heat sink cover;
400-chip package structure; 401 — a fixed frame; 402-a package carrier; 403-a first pad; 404-a second pad; 405-a resilient fastener;
500-mobile phone; 510-a housing; 501-display screen; 502-rear cover; 5021-inner surface; 520-circuit board.
Detailed Description
The terminology used in the description of the embodiments of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the application, as the embodiments of the present application will be described in detail below with reference to the accompanying drawings.
Application of thermal resistance: and guiding the comprehensive thermal resistance of the thermal material in application. The application thermal resistance can be considered to be formed by the thermal resistance of the heat conduction material body and the interface contact thermal resistance of the heat conduction material and two contact surfaces. The bulk thermal resistance of the heat conduction material is mainly determined by the heat conduction coefficient and the application thickness of the heat conduction material, and the interface thermal resistance is comprehensively influenced by a plurality of factors such as the self characteristics, the pressure, the roughness and the like of the heat conduction material.
The embodiment of the application provides a heat conduction structure, wherein a dielectric layer is at least arranged between adjacent heat conduction films, the dielectric layer at least comprises a first organic material and a second organic material positioned in the first organic material, the second organic material is diffused towards the outer surface of the heat conduction structure at a preset temperature or a preset pressure, the second organic material diffused outwards forms an adhesive layer between the heat conduction structure and a heating element and/or between the heat conduction structure and a radiator, and the adhesive layer connects the heat conduction structure with the heating element and/or the heat conduction structure with the radiator, so that the close contact between the heat conduction structure and the surface of the heating element/radiator is ensured, and the problem that the heating element is over-heated due to the fact that the interface between the heat conduction structure and the heating element/radiator is layered in the using process is avoided; in addition, the second organic material which diffuses outwards can be filled in local micropores between the heat conduction structure and the heating element and/or between the heat conduction structure and the radiator, so that the micro wettability of the heat conduction structure is improved, the interface contact thermal resistance is reduced, and the application thermal resistance of the heat conduction structure is reduced.
The following describes in detail a heat conducting structure provided in an embodiment of the present application with reference to the drawings and the embodiments.
Example one
The heat conducting structure 100 provided in the embodiment of the present application can transfer heat generated by the heat generating component 200 to the heat sink 300, as shown in fig. 1, the heat conducting structure 100 is located between the heat generating component 200 and the heat sink 300, after the heat conducting structure 100 is assembled according to an arrow in fig. 1, one surface of the heat conducting structure 100 is in contact with the heat generating component 200, and the other surface of the heat conducting structure 100 can be in contact with the heat sink 300, so that heat generated by the heat generating component 200 is transferred to the heat sink 300 through the heat conducting structure 100, thereby achieving heat dissipation of the heat generating component 200.
The heating element 200 may be a chip or an electronic component that generates heat, and in the embodiment of the present application, the heating element 200 is taken as an example for description. The heat sink 300 may be a heat dissipation plate, for example, the heat dissipation plate may be an aluminum plate, or the heat sink 300 may also be a heat dissipation member such as a heat pipe, a heat dissipation fin, a graphene sheet, or the like, which can absorb heat.
Referring to fig. 1, the heat conductive structure 100 may include: the heat-conducting film comprises a plurality of heat-conducting films 10 and one or more medium layers 20, wherein the heat-conducting films 10 and the medium layers 20 are alternately arranged, for example, as shown in fig. 1, the plurality of heat-conducting films 10 and the plurality of medium layers 20 are alternately arranged in sequence along the X direction (for example, the medium layers 20, the heat-conducting films 10, and the medium layers 20). Of course, in some other examples, the plurality of heat conductive films 10 and the plurality of medium layers 20 may be alternately arranged along the Y direction. When the plurality of heat-conducting films 10 and the plurality of medium layers 20 are alternately arranged, as shown in fig. 1, the plurality of heat-conducting films 10 and the plurality of medium layers 20 are vertically arranged.
For example, as shown in fig. 1, the heat conducting structure 100 is located between the heat generating element 200 and the heat sink 300 in the Z direction, the bottom end of the heat conducting films 10 faces the heat generating element 200, and the top end of the heat conducting films 10 faces the heat sink 300. Of course, in some other examples, the heat conducting structure 100 may also be located between the heat generating element 200 and the heat sink 300 in the Y direction, with the left ends of the plurality of heat conducting films 20 facing the heat generating element 200 and the right ends of the plurality of heat conducting films 20 facing the heat sink 300.
It should be noted that, when the plurality of heat conductive films 10 and the dielectric layers 20 are alternately arranged to form the heat conductive structure, one or more of the dielectric layers 20 may be located between two adjacent heat conductive films 10, or as shown in fig. 1, a plurality of heat conductive films 10 are located between two adjacent dielectric layers 20.
In the embodiment of the present application, referring to fig. 2, the dielectric layer 20 may at least include: a first organic material 21 and a second organic material 22 disposed in the first organic material 21, for example, as shown in fig. 1, the second organic material 22 being mixed in the first organic material 21. The first organic material 21 bonds two adjacent heat conductive films 10, and the plurality of heat conductive films 10 form an integral structure by the first organic material 21.
The dielectric layer 20 may further include a functional assistant, and the functional assistant may be, for example, a nano filler for improving the adhesive strength.
It should be noted that the second organic material 22 is located in the first organic material 21, where the second organic material 22 is located completely in the first organic material 21, or a part of the second organic material 22 is located in the first organic material 21, and a part of the second organic material 22 is exposed outside the first organic material 21.
It should be noted that, the first organic material 21 bonds the two adjacent thermal conductive films 10, specifically, the first organic material 21 becomes solid or gel after being cured to connect the two adjacent thermal conductive films 10, wherein during the curing process of the first organic material 21, the second organic material 22 does not participate in the curing reaction, for example, the second organic material 22 still remains in a liquid state or a gel state during the curing process of the first organic material 21.
Wherein, the second organic material 22 in the first organic material 21 is diffused towards the outer surface of the heat conducting structure 100 at a predetermined temperature or a predetermined pressure in the heat conducting structure 100, for example, the second organic material 22 is diffused through the first organic material 21 at a high temperature (for example, greater than or equal to 35 ℃) or under a pressure (the diffusion direction is shown by the dotted arrows in fig. 3) towards both end surfaces of the heat conducting structure 100, so that the heat conducting structure 100 has the second organic material 22 on both sides towards the heat generating element 200 and/or towards the heat sink 300.
Wherein the out-diffused second organic material 22 forms the adhesive layer 221 (see fig. 4) at least between the heat conductive structure 100 and the heat generating element 200 and/or between the heat conductive structure 100 and the heat sink 300 when a preset reaction condition (a preset reaction condition such as high temperature, moisture, metal surface, etc.) is satisfied, for example, the out-diffused second organic material 22 may form the adhesive layer 221 between the heat conductive structure 100 and the heat generating element 200, or the out-diffused second organic material 22 may form the adhesive layer 221 between the heat conductive structure 100 and the heat sink 300, or, as shown in fig. 4, the out-diffused second organic material 22 may form the adhesive layer 221 between the heat conductive structure 100 and the heat sink 300 and between the heat conductive structure 100 and the heat sink 300.
It should be noted that, when the out-diffused second organic material 22 may form the adhesive layer 221 between the heat conducting structure 100 and the heat generating element 200, and the adhesive layer 221 connects the heat conducting structure 100 and the heat generating element 200, at this time, the heat conducting structure 100 and the heat sink 300 may be connected by using an adhesive layer, for example, so that a delamination phenomenon is not likely to occur between the heat conducting structure 100 and the heat generating element 200, thereby solving a problem that a chip temperature is too high due to an easy delamination between an existing heat conducting pad and a chip.
Or, when the second organic material 22 diffusing outward may form the adhesive layer 221 between the heat conducting structure 100 and the heat sink 300, the adhesive layer 221 connects the heat conducting structure 100 and the heat sink 300, and at this time, the heat conducting structure 100 and the heat generating element 200 may be connected by using an adhesive layer, thereby solving the problem that the chip is too hot due to the fact that the chip heat cannot be timely dissipated outward due to the easy delamination between the heat conducting pad and the heat sink.
In the embodiment of the present application, since the heating element 200 generates heat during operation, when the heat conductive structure 100 is located between the heat generating element 200 and the heat sink 300, the temperature of the junction between the heat generating element 200 and the heat conductive structure 100 is higher than the temperature of the junction between the heat conductive structure 100 and the heat sink 300, the second organic material 22 in the heat conductive structure 100 is first diffused to the junction between the heat generating element 200 and the heat conductive structure 100 when subjected to high temperature out-diffusion, this ensures that the second organic material 22, which is diffused outward, forms the adhesive layer 221 at the junction between the heat generating element 200 and the heat conductive structure 100, and as the amount of heat generated by the heat generating element 200 increases, the second organic material 22 is diffused between the heat sink 300 and the heat conductive structure 100, and the second organic material 22, which is diffused between the heat sink 300 and the heat conductive structure 100, forms the adhesive layer 221, and the adhesive layer 221 bonds the heat sink 300 and the heat conductive structure 100. And the more heat generated by the heat generating element 200, the more the second organic material 22 is diffused outward, and the more the adhesive layer 221 is generated, so that the adhesion between the heat generating element 200 and the heat conducting structure 100 and between the heat sink 300 and the heat conducting structure 100 is more secure.
In the embodiment of the present application, the out-diffused second organic material 22 may chemically react to form the adhesive layer 221 when a predetermined reaction condition is satisfied. That is, the first organic material 22 generates the adhesive layer 221 by a chemical reaction between the heat conducting structure 100 and the heat generating element 200 and/or the heat conducting structure 100 and the heat sink 300, and during the generation of the adhesive layer 221, since the second organic material 22 is in contact with the surface of the heat generating element 200 and/or the heat sink 300 facing the heat conducting structure 100, a chemical bonding force is generated between the generated adhesive layer 221 and the surface of the heat generating element 200 and/or the heat sink 300 facing the heat conducting structure 100, so that the bonding between the heat conducting structure 100 and the heat generating element 200 and/or the bonding between the heat conducting structure 100 and the heat sink 300 is tighter and less prone to delamination, and the second organic material 22 diffuses outward more as the temperature generated by the heat generating element 200 is higher, so that the bonding between the heat conducting structure 100 and the heat generating element 200 and/or the heat conducting structure 100 and the heat sink 300 is firmer.
It should be noted that the out-diffusion of the second organic material 22 specifically means that the second organic material 22 moves out through the first organic material 21.
Therefore, the heat conducting structure 100 provided in the embodiment of the present application is in a liquid state or a semi-solid state when not under a high temperature (e.g., greater than or equal to 35 ℃) or a pressure, and the second organic material 22 in the heat conducting structure 100 is located inside the first organic material 21, and the reaction condition is not met, and when the heat conducting structure 100 is applied between the heat generating element 200 and the heat sink 300 and the connection between the heat conducting structure 100 and the heat generating element 200 and the heat sink 300 is required, a diffusion condition (e.g., a high temperature or a pressure applied to the heat conducting structure 100 through the heat generating element 200 and the heat sink 300) is provided, so that the second organic material 22 in the heat conducting structure 100 diffuses outward under the high temperature or the pressure, and the diffused second organic material 22 is located between the heat conducting structure 100 and the heat generating element 200 and/or between the heat generating element 200 and the heat sink 300.
When the reaction conditions are satisfied, and the reaction conditions, such as high temperature, moisture, metal surface, and other acceleration factors, are met, the diffused second organic material 22 will undergo a chemical reaction, and a bonding layer with a chemical bonding force is formed at the joint between the heat conducting structure 100 and the heat generating element 200 and/or between the heat conducting structure 100 and the heat sink 300. Compared with the prior art in which the heat conducting pad is directly bonded to the heating element 200/the heat sink 300 through an adhesive layer, in the embodiment of the present application, a chemical bonding force is formed at a bonding position between the heat conducting structure 100 and the heating element 200 and/or between the heat conducting structure 100 and the heat sink 300, so that the heat conducting structure 100 and the heating element 200 and/or between the heat conducting structure 100 and the heat sink 300 are tightly connected through the generated bonding layer, and when the temperature changes, the heat conducting structure 100 and the heating element 200 and/or between the heat conducting structure 100 and the heat sink 300 are not easily layered.
In some examples, as the temperature of the heat generating element 200 increases, the second organic material 22 in the heat conducting structure 100 may continue to diffuse outward to form an adhesive layer with chemical bonding force, so that the connection between the heat conducting structure 100 and the heat generating element 200 and between the heat conducting structure 100 and the heat sink 300 may be more secure instead when the temperature changes.
Therefore, when the heat conducting structure 100 provided in the embodiment of the present application is disposed between the heat generating element 200 and the heat sink 300, a purpose of generating a chemical bonding force between the heat conducting structure 100 and the heat generating element 200 and/or between the heat conducting structure 100 and the heat sink 300 is achieved, a close contact between the heat conducting structure 100 and the surfaces of the heat generating element 200/the heat sink 300 is ensured, and a problem that the heat generating element 200 is over-heated due to a delamination of an interface between the heat conducting structure 100 and the heat generating element 200/the heat sink 300 during a use process is avoided.
In addition, the second organic material 22 diffusing outward may be filled in local micro-holes or gaps between the heat conducting structure 100 and the heat generating element 200 and/or between the heat conducting structure 100 and the heat sink 300, so as to improve micro-wettability of the heat conducting structure 100, thereby reducing interface contact thermal resistance, reducing application thermal resistance of the heat conducting structure 100, and improving the heat conducting effect of the heat conducting structure 100, and the second organic material 22 may be filled in local micro-holes or gaps between the heat conducting structure 100 and the heat generating element 200 and/or between the heat conducting structure 100 and the heat sink 300, so that the contact area between the generated bonding layer 221 and the heat generating element 200/heat sink 300 is increased, and the bonding force is larger.
It should be noted that, due to the dispersed distribution of the second organic material 22 in the first organic material 21, the second organic material 22 that diffuses out is locally distributed on the surface of the heat conducting structure 100 in a granular or dot shape, for example, as shown in fig. 3, partial areas of both surfaces of the heat conducting structure 100 have the second organic material 22 that diffuses out, so a plurality of adhesive layers 221 distributed at intervals are formed between the heat conducting structure 100 and the heat generating element 200 and the heat sink 300 (i.e., the adhesive layers are not covered on the whole surface of the heat conducting structure 100). Of course, in some other examples, the out-diffused second organic material 22 is present over the entire surface of the heat conductive structure 100, so the adhesive layer is formed to entirely cover one surface of the heat conductive structure 100. In fig. 4, the adhesive layer 221 formed for the purpose of description is granular or dot-shaped, so that there is a gap between the heat generating element 200 and the heat sink 300 in fig. 4 and the two surfaces of the heat conducting structure 100, but in an actual product, both the heat generating element 200 and the heat sink 300 are in close contact with the heat conducting structure 100, and there is no gap.
In the embodiment of the present application, the preset temperature may be greater than or equal to 35 ℃, and the preset pressure may be greater than or equal to psi, for example, the preset pressure may be greater than or equal to 5psi and less than or equal to 150psi, for example, the preset pressure may be 10 to 60 psi. Alternatively, the preset pressure may be 50 psi.
It should be noted that, when the second organic material 22 in the heat conducting structure 100 diffuses outwards under the pressure, the first organic material 21 needs to form an elastic solid substance after curing, and the heat conducting film 10 is a compressible heat conducting film 10. Thus, the heat conductive structure 100 has compressibility, the heat conductive structure 100 is compressed under pressure, the second organic material 22 is pressed to diffuse outward, and after the pressure is removed, the solid substance formed by the heat conductive film 10 and the first organic material 21 after curing can return to an original state.
The thickness of the diffused second organic material 22 is often on the order of nanometers, so the formed adhesive layer 221 is a molecular-level adhesive, which means that the thickness of the diffused second organic material 22 is a single molecule or a few molecules on the surface of the heat conducting structure 100, and can form a chemical bond with the contact surface, for example, the thickness of the adhesive layer is less than 1 μm.
In the embodiment of the present application, it should be noted that the first organic material 21 is formed into a generally solid state after being cured, and the second organic material 22 diffuses out from the molecular gap of the solid substance after being cured by the first organic material 21 under the action of high temperature or pressure. Therefore, the diffusion of the second organic material 22 is facilitated, the first organic material 21 may be a material with a low cross-linking density and a large mesh in a molecular chain mesh structure, so that the gaps between molecules in the cured first organic material 21 are large, and the second organic material 22 (for example, a small molecular material may be selected) is easy to move in the cured first organic material 21 to achieve the purpose of outward diffusion.
In the embodiment of the present application, the second organic material 22 that diffuses out forms an adhesive layer 221 having van der waals, chemical bonding, or biting force at least between the heat conductive structure 100 and the heat generating element 200 and/or between the heat conductive structure 100 and the heat spreader 300. For example, after the second organic material 22 diffuses out, the adhesive layer 221 is disposed between the heat conducting structure 100 and the heat generating component 200, and during the formation of the adhesive layer 221, a bonding force such as van der waals force, chemical bonding force or biting force is formed at the bonding position between the heat conducting structure 100 and the heat generating component 200, so as to achieve the purpose of generating a chemical bonding force between the heat conducting structure 100 and the heat generating component 200 and/or between the heat conducting structure 100 and the heat sink 300, and the higher the temperature of the heat generating component 200 is, the more the second organic material 22 diffuses out in the heat conducting structure 100, so that the bonding force between the heat conducting structure 100 and the heat generating component 200 and/or between the heat conducting structure 100 and the heat sink 300 is larger, thereby avoiding the problem of delamination between the heat conducting structure 100 and the heat generating component 200 and/or between the heat conducting structure 100 and the heat sink 300 due to the excessively high temperature.
Or, after the second organic material 22 diffuses outward, the adhesive layer 221 is formed between the heat conducting structure 100 and the heat sink 300, and in the process of generating the adhesive layer 221, a bonding force such as van der waals force, chemical bonding force or bite force is formed at the bonding position between the heat conducting structure 100 and the heat generating element 200, so that the purpose of generating a chemical bonding force between the heat conducting structure 100 and the heat sink 300 is achieved, and the problem of delamination between the heat conducting structure 100 and the heat sink 300 due to an excessively high temperature is avoided.
Or after the second organic material 22 diffuses outward, the adhesive layers 221 are formed between the heat conducting structure 100 and the heat sink 300 and between the heat conducting structure 100 and the heat sink 300, and in the process of generating the adhesive layers 221, chemical bonding forces such as van der waals force, chemical bonding force, or biting force are formed at the bonding positions between the heat conducting structure 100 and the heat generating element 200 and between the heat conducting structure 100 and the heat sink 300, so that the delamination phenomenon is not likely to occur between the heat conducting structure 100 and the heat generating element 200 and between the heat conducting structure 100 and the heat sink 300.
The second organic material 22, which is specifically diffused outward, diffuses into the uneven micropores or micro gaps on the surface of the heat generating element 200 facing the heat conducting structure 100 and/or the surface of the heat spreader 300 facing the heat conducting structure 100, so that the generated adhesive layer 221 forms an interlocking mechanical bonding force with the surface of the heat generating element 200 facing the heat conducting structure 100 and/or with the surface of the heat spreader 300 facing the heat conducting structure 100.
The van der waals force is an intermolecular bonding force generated between the molecules in the second organic material 22 that diffuse outward and the side of the heat generating element 200 facing the heat conductive structure 100 and/or the side of the heat spreader 300 facing the heat conductive structure 100.
The chemical bonding force is a chemical bonding force in which molecules in the second organic material 22 that diffuse outward chemically react with molecules on a side of the heat generating element 200 facing the heat conducting structure 100 and/or a side of the heat spreader 300 facing the heat conducting structure 100 to form chemical bonds.
In the embodiment of the present application, the second organic material 22 diffuses through the bulk of the first organic material 21 at a predetermined temperature or a predetermined pressure. The bulk of the first organic material 21 refers to the material remaining within the dielectric layer 20 after the second organic material 22 is removed. Wherein the molecular structure of the first organic material 21 may be a lattice structure through which molecules of the second organic material 22 diffuse at a predetermined temperature or the predetermined pressure.
In one possible implementation, the first organic material 21 is in a solid or semi-solid state and the second organic material 22 is in a liquid or semi-solid state. For example, where the first organic material 21 is in a solid state, the second organic material 22 is a liquid, such that the second organic material 22 can flow at an elevated temperature or pressure to facilitate diffusion from the first organic material 21 through the outside. Alternatively, when the first organic material 21 is in a solid state, the second organic material 22 may be in a semisolid state, or the first organic material 21 may be in a semisolid state, and the second organic material 22 may flow in the first organic material 21 so that the second organic material 22 is in a liquid state, whereby the second organic material 22 can be diffused out.
Of course, in some other examples, the first organic material 21 may also be in a gel state and the second organic material 22 may also be in a gel state, for example, the first organic material 21 is in a gel state and the second organic material 22 is in a semisolid state, or the first organic material 21 is in a semisolid state and the second organic material 22 is in a gel state.
In some examples, the second organic material 22 may also be an organic material that undergoes a phase change such that the second organic material 22 is in a solid state when a predetermined temperature is not reached, e.g., a low temperature, and becomes in a liquid state when a high temperature (e.g., 40-105℃.) and diffuses out through the first organic material 21 under temperature or pressure.
In one possible implementation, the adhesion between the adhesive layer 221 and the heat spreader 300, and/or the adhesion between the adhesive layer 221 and the heat generating element 200 are greater than the cohesion of the dielectric layer 20 (cohesion refers to the breaking strength of the cured organic material against tensile deformation). For example, the adhesion between the adhesive layer 221 and the heat spreader 300 is greater than the cohesion of the dielectric layer 20, or the adhesion between the adhesive layer 221 and the heat generating element 200 is greater than the cohesion of the dielectric layer 20, or both the adhesion between the adhesive layer 221 and the heat spreader 300 and the adhesion between the adhesive layer 221 and the heat generating element 200 are greater than the cohesion of the dielectric layer 20. This ensures that the heat-conducting structure 100 and the heat-generating component 200/heat sink 300 are still adhered even if the heat-conducting structure 100 is damaged by stretching, thereby ensuring a strong adhesion between the heat-conducting structure 100 and the heat-generating component 200/heat sink 300 and avoiding the delamination between the heat-conducting structure 100 and the heat-generating component 200/heat sink 300.
In the embodiment of the present application, the second organic material 22 is a material that undergoes a dehydration condensation reaction or a polymerization reaction with the heat generating element 200 and/or with at least a partial region of the outer surface of the heat spreader 300 facing the heat conducting structure 100 under the preset reaction condition, that is, the second organic material 22 may undergo a dehydration condensation reaction or a polymerization reaction between the heat generating structure 200 and the heat conducting structure 100 and/or between the heat spreader 300 and the heat conducting structure 100 when the preset reaction condition is satisfied.
The second organic material 22 is described in detail below as being capable of performing a dehydration condensation reaction between the heat generating structure 200 and the heat conductive structure 100 and/or the heat spreader 300 and the heat conductive structure 100 under a predetermined reaction condition.
The preset reaction conditions may include: a reaction temperature, a reaction humidity or a reaction medium, wherein the reaction temperature may be, for example, 35 ℃ or higher and the reaction humidity is 10% or higher (i.e., moisture is present during the reaction). The reaction medium is the surface material that the second organic material 22 contacts when reacting. In the embodiment of the present application, the reaction medium may be a metal material, that is, the surface contacted when the second organic material 22 reacts is a metal surface, and the metal surface usually has hydroxyl groups (the metal surface is oxidized in air to generate metal oxide, and the metal oxide reacts with water vapor in air to generate hydroxyl groups), so that a chemical bond can be formed between the hydroxyl groups and the second organic material 22.
In the embodiment of the present application, the surfaces of the heat generating element 200 and the heat sink 300 are often metal surfaces, so when the second organic material 22 diffuses between the heat conducting structure 100 and the heat generating element 200 and/or between the heat conducting structure 100 and the heat sink 300, the metal surfaces of the heat generating element 200 and the heat sink 300 provide a reaction condition for a chemical reaction of the second organic material 22, and the second organic material 22 chemically reacts and forms a chemical bond on the metal surfaces of the heat generating element 200 and the heat sink 300, so that a chemical bond bonding force is generated between the interfaces of the heat conducting structure 100 and the heat generating element 200/the heat sink 300, thereby improving the current situation that the interface between the existing heat conducting pad and the heat generating element 200/the heat sink 300 is not chemically bonded, and the bonding force is small.
In the embodiment of the present application, in order to realize the dehydration condensation reaction of the second organic material 22, the second organic material 22 may include a liquid material containing a reactive hydroxyl group and a liquid material containing a hydrolyzable group, that is, the second organic material 22 is in a liquid state. Wherein the liquid material containing the hydrolyzable group in the second organic material 22 provides a hydrolyzable group, the hydrolyzable group undergoes a hydrolysis reaction to obtain a hydroxyl group, and after the hydroxyl group is sufficiently active, the second organic material 22 undergoes a dehydration condensation reaction under an accelerating factor such as high temperature, moisture or metal surface to form the adhesive layer 221.
In the process of forming the adhesive layer 221, a chemical bond is formed between the heat conducting structure 100 and the heating element 200/heat sink 300 (the surface of the heating element 200/heat sink 300 is a metal surface), wherein when the heating element 200 is a chip, the surface of the chip has hydroxyl groups, which can form a chemical bond with the second organic material 22, and a chemical bond between the metal surface of the heat sink 300 and the second organic material 22 and an interface adhesive bonding similar to a chelating effect between the metal surface of the heat sink 300 and the formed adhesive layer 221 are formed, so that a chemical bonding force is formed between the heat conducting structure 100 and the heating element 200 and the heat sink 300, the adhesive bonding is more secure, and delamination is not likely to occur.
In one possible implementation, the liquid material containing active hydroxyl groups can be a polyol, which is an alcohol containing two or more hydroxyl groups in the molecule and has the general formula CnH2n+2-x (OH) x (x.gtoreq.3). The liquid material containing hydrolyzable groups may be a silane coupling agent.
The polyhydric alcohol may be at least one of butanetriol, pentaerythritol, glycerol, trimethylolethane, xylitol, and sorbitol, for example, the polyhydric alcohol may be butanetriol, and the butanetriol may be 1,2,4 butanetriol. The silane coupling agent may be a trialkoxysilane, or the silane coupling agent may be octyltriethoxysilane.
Where the first organic material 21 includes butanetriol and octyltriethoxysilane, it is possible to select 0.5 parts of butanetriol and 0.3 parts of octyltriethoxysilane, and mix them together to form the second organic material 22. of course, in some other examples, butanetriol and octyltriethoxysilane are mixed in selected amounts including, but not limited to, 0.5 parts and 0.3 parts.
In one possible implementation, the first organic material 21 may be a polyorganosiloxane oil containing at least unsaturated siloxane, such that the first organic material 21 contains unsaturated bonds, and the reactive functional group can be activated by heating or light irradiation, so that the unsaturated bonds undergo addition polymerization to cure.
It should be noted that, in order to avoid the first organic material 21 from diffusing out of the second organic material 22 at a high temperature during the heating and curing process, in the embodiment of the present application, the temperature for heating and curing the first organic material 21 may be lower than the temperature for diffusing out of the second organic material 22, or different curing manners may be used for the first organic material 21 and the second organic material 22, for example, the first organic material 21 is cured by UV light.
In one possible implementation, the polyorganosiloxane oil containing unsaturated siloxane may be vinyl silicone oil, the first organic material 21 further includes hydrogen-containing silicone oil in order to realize addition polymerization, and the molecular weight of both the vinyl silicone oil and the hydrogen-containing silicone oil is less than 15000, and a catalyst may be selected in order to accelerate the curing reaction, and the catalyst may be a Pt-based catalyst, wherein the formula of the vinyl silicone oil may be the following formula (1):
Figure RE-GDA0002727248810000131
the hydrogen-containing silicone oil comprises at least one of hydrogen-terminated silicone oil and side hydrogen-terminated silicone oil, in the embodiment of the application, the hydrogen-terminated silicone oil is used as the hydrogen-terminated silicone oil, and the molecular formula of the hydrogen-terminated silicone oil can be the following molecular formula (2):
Figure RE-GDA0002727248810000132
the curing process of the first organic material 21 proceeds with the following addition reaction:
Figure RE-GDA0002727248810000133
the viscosity of the vinyl silicone oil and the hydrogen-terminated silicone oil may be 50 to 10000cps (1cps ═ 1mPa · s)), and for example, the vinyl silicone oil may be a vinyl silicone oil having a viscosity of 50mPa · s, and the hydrogen-terminated silicone oil may be a hydrogen-terminated silicone oil having a viscosity of 50mPa · s. During preparation, 50 parts of vinyl silicone oil, 40 parts of hydrogen terminated silicone oil and a trace amount of catalyst can be selected and uniformly mixed, and the mixture is heated and cured for 30min at 120 ℃ to form an organic silicon elastic bonding material, namely a first organic material 21, and the organic silicon elastic bonding material bonds the heat-conducting film 10.
When the second organic material 22 is mixed with the first organic material 21, the second organic material 22 is added to the first organic material 21 and mixed before the first organic material 21 is cured. And the curing modes of the first organic material 21 and the second organic material 22 are different, so that the second organic material 22 does not participate in the curing of the first organic material 21 in the curing process of the first organic material 21, and thus after the first organic material 21 is cured, the second organic material 22 can still keep liquid flowability, and the second organic material 22 can be diffused outwards under high temperature or pressure.
In another possible implementation manner, the hydrogen-containing silicone oil includes a hydrogen-terminated silicone oil and a hydrogen-terminated silicone oil, that is, the first organic material 21 may include a vinyl silicone oil, a catalyst, a hydrogen-terminated silicone oil, and a hydrogen-terminated silicone oil, wherein the hydrogen-terminated silicone oil may be the hydrogen-terminated silicone oil of the above formula (2), the hydrogen-terminated silicone oil may be the hydrogen-terminated silicone oil of the following formula (3):
Figure RE-GDA0002727248810000134
the vinyl silicone oil (1), the hydrogen-terminated silicone oil (2), and the side hydrogen silicone oil (3) in the first organic material 21 undergo an addition reaction in the curing process as shown in fig. 12, wherein (1) in the addition reaction shown in fig. 12 represents formula (1), i.e., vinyl silicone oil, (2) represents formula (2), i.e., hydrogen-terminated silicone oil, and (3) represents formula (3), i.e., hydrogen-containing silicone oil.
In one possible implementation, when the second organic material 22 is mixed in the first organic material 21, the weight percentage of the second organic material 22 in the first organic material 21 is less than 50%, for example, when the organic material is configured, 100 parts of the first organic material 21 may be selected and less than 50 parts of the second organic material 22 may be selected, so as to ensure that the weight percentage of the second organic material 22 in the first organic material 21 is less than 50%, for example, the weight percentage of the second organic material 22 in the first organic material 21 may be less than 25%, or the weight percentage of the second organic material 22 in the first organic material 21 may be less than 10%, so as to ensure that the compressibility and resilience of the thermal conductive structure 100 after the first organic material 21 is cured are more than 50%.
In one possible implementation, the second organic material 22 that diffuses out is less than or equal to 50% by weight of the dielectric layer 20. For example, the out-diffused second organic material 22 may comprise 10% by weight of the dielectric layer 20. The amount of the second organic material 22 diffusing out can be specifically realized by controlling the temperature or the pressure.
In one possible implementation, the thickness H (shown in fig. 2) of the heat conducting structure 100 is greater than or equal to 0.1mm and less than or equal to 5 mm. For example, the thickness H of the heat conducting structure 100 may be 0.1mm, or the thickness H of the heat conducting structure 100 may be 2mm, or the thickness H of the heat conducting structure 100 may be any value of 0.2 to 0.5 mm.
In one possible implementation manner, the thermal conductivity of the heat conducting structure 100 in the first direction is greater than the thermal conductivity of the heat conducting structure 100 in the second direction, and the thermal conductivity of the heat conducting structure 100 in the third direction is greater than the thermal conductivity of the heat conducting structure 100 in the second direction, where the first direction is a direction perpendicular to a face of the heat generating element 200 or the heat sink 300 facing the heat conducting structure 100, in some examples, since a face of the heat generating element 200 or the heat sink 300 facing the heat conducting structure 100 tends to be non-planar, in this embodiment, the first direction may be a direction perpendicular to a forward projection of the face of the heat generating element 200 or the heat sink 300 facing the heat conducting structure 100, for example, the first direction may be a Z direction in fig. 1. The second direction is a direction perpendicular to a side of the heat conductive film 10 facing the medium layer 20, and in some examples, a side of the heat conductive film 10 facing the medium layer 20 is a slope or a non-vertical surface, so in this embodiment, the second direction may specifically be a direction perpendicular to an orthographic projection of the side of the heat conductive film 10 facing the medium layer 20, for example, the second direction may be an X direction in fig. 1, and the third direction may be a direction perpendicular to both the first direction and the second direction, for example, the third direction may be a Y direction in fig. 1. When the heating element 200 and the heat sink 300 are located on two sides of the heat conducting structure 100 along the first direction (i.e., the Z direction), the heat conducting structure 100 ensures that the heat generated by the heating element 200 is quickly transferred to the heat sink 300 due to the large heat conductivity coefficient of the heat conducting structure 100 in the first direction, so as to achieve the purpose of quickly dissipating heat from the heating element 200. The thermal conductivity of the heat conducting structure 100 in the first direction is equivalent to the thermal conductivity of the heat conducting structure 100 in the third direction, so that the heating element 200 and the heat sink 300 can also be located on two sides of the heat conducting structure 100 along the third direction (i.e., the Y direction), and the thermal conductivity of the heat conducting structure 100 in the third direction is relatively large, so that the purpose of rapidly dissipating heat of the heating element 200 in the third direction is achieved.
In one possible implementation, the thermal conductivity of the thermally conductive structure 100 in the first direction is higher than or equal to 35W/mk. For example, the thermal conductivity of the thermal conductive structure 100 in the first direction may be 50W/mk.
Wherein a ratio of a thermal conductivity of the thermal conductive structure 100 in the first direction to a thermal conductivity of the thermal conductive structure 100 in the second direction is greater than or equal to 5. For example, the ratio of the thermal conductivity of the thermal conductive structure 100 in the first direction to the thermal conductivity of the thermal conductive structure 100 in the second direction may be any value from 10 to 40.
In a possible implementation manner, the thicknesses of the respective heat conduction films 10 may be the same, so as to ensure that the two ends of the plurality of heat conduction films 10 are respectively located on the same plane, so that when the heat conduction structure 100 is in contact with the surfaces of the heat generating component 200 and the heat sink 300, the distance between the two ends of each heat conduction film 10 and the heat generating component 200 and the heat sink 300 is the same, and the heat conduction structure 100 is ensured to achieve uniform heat conduction effect on the heat generating component 200. Of course, in some other examples, the thickness of each thermal conductive film 10 may not be the same.
Here, the thickness L (see fig. 2) of each of the thermal conductive films 10 is greater than or equal to 7 μm and less than or equal to 200 μm, and for example, the thickness L of the thermal conductive film 10 may be 50 μm, or the thickness L of the thermal conductive film 10 may be 100 μm. In practical application, the thickness L of the heat-conducting film 10 is 15-50 μm.
In one possible implementation, when the density of the heat-conducting film 10 is 1.95-2.05 g/cm3In this embodiment, in order to achieve the purpose that the second organic material 22 diffuses outwards under pressure in the heat conductive structure 100, the heat conductive film 10 is compressible, and the density of the heat conductive film 10 may be 1.2-1.95 g/cm3. For example, the thermally conductive film 10 may have a density of 1.5g/cm3Or the density of the heat conductive film 10 may be 1.8g/cm3. In practical use, the density of the heat-conducting film 10 is 1.5-1.8 g/cm3. The density is 1.2-1.95 g/cm3The thermal conductive film 10 is made compressible so that the second organic material 22 is easily diffused outward when pressed by the pressure of the thermal conductive film 10.
In a possible implementation manner, the thermal conductive film 10 may be a graphene film, which is compressible, and after the thermal conductive structure 100 is manufactured, when the thermal conductive structure 100 bears a compressive stress, the stress may be transmitted to the graphene film inside, and the compressive stress may be reduced by absorbing the stress through compressive deformation of the graphene film. And after the heat conducting structure 100 is compressed, the plane size of the heat conducting structure 100 is not significantly expanded, and the density of the corresponding heat conducting structure 100 is increased. In the prior art, the heat conducting filler is solid, and the manufactured heat conducting pad can be obviously expanded on four sides after being compressed, namely, the thickness of the heat conducting pad is thinned after being compressed and the size of the heat conducting pad is increased because the density is kept unchanged. However, after the heat conducting structure 100 provided in the embodiment of the present application is compressed and thinned, the actual density of the heat conducting structure 100 is increased, and the size of the heat conducting pad is not increased significantly.
The graphene film is a film layer formed by stacking multiple layers of graphene, and for example, the graphene film can be manufactured by taking graphene micro-sheets with nanometer-scale thickness as raw materials.
Wherein, when the thermally conductive film 10 is a graphene film, the thickness of the graphene film may be greater than or equal to 15 μm and less than or equal to 50 μm. The interval between the plurality of thermal conductive films 10 may vary from nano-scale to micro-scale, such that when the dielectric layer 20 is filled between two adjacent thermal conductive films 10, the thickness D (see fig. 2) of the formed dielectric layer 20 may be from nano-scale to micro-scale, for example, 1nm to 100 μm, and in order to achieve a higher performance thermal conductivity, the thickness D of the dielectric layer 20 formed between two adjacent thermal conductive films 10 may be less than 1 μm. The thickness of the dielectric layer 20 can be controlled by the viscosity of the first organic material 21 and the lamination pressure during the fabrication process. In practical cases, the vertically aligned graphene film generally has an irregular twisted shape, i.e., the thickness of the dielectric layer 20 has a non-uniform shape.
When the thermally conductive film 10 is a graphene film, the graphene film may be made of single-layer graphene nanoplatelets or few-layer graphene nanoplatelets (few layers usually means within 10 layers), and microscopically, the graphene film is formed by stacking multiple graphene nanoplatelets. The multilayer graphene nanoplatelets are typically stacked in a non-AB stack. The AB stacking means that the upper graphene micro-sheets and the lower graphene micro-sheets are arranged and stacked in a staggered mode to form a graphene film, and the non-AB stacking means that the upper graphene micro-sheets and the lower graphene micro-sheets are arranged in a non-staggered mode to form the graphene film.
For example, graphene films can be made as follows: monolayer graphene oxide nanoplatelets having a D50 size of 20 μm (i.e., the longitudinal dimension of the graphene nanoplatelets is 20 μm) were used, wherein D50 refers to the cumulative percent particle size distribution of the graphene nanoplateletsWhen the particle size reaches 50%, 500mg of single-layer graphene oxide micro-sheets are weighed and dispersed in 20ml of deionized water to prepare a solution. The aqueous graphene oxide solution was coated on a substrate (e.g., a high-temperature-resistant graphite film) having a width of 100mm to obtain a graphene oxide film having a width of 100mm and a thickness of about 25 μm. And (3) putting the graphene oxide film into an oven, and drying for 24h at 60 ℃. Putting the dried graphene oxide film into a high-temperature graphitization furnace, introducing argon as protective gas, wherein the flow rate is 100cm3And/min, calcining at 2600 deg.C for 20min for high-temperature reduction reaction. After the reduction reaction is finished, naturally cooling to room temperature, and controlling the density of the graphene heat conduction film 10 to be about 1.6g/cm through the pressure of pressing3. The plane thermal conductivity coefficient of the graphene film is 1100W/mk by adopting a laser flash method, and the thickness of the graphene film is 20 mu m.
In the examples of the present application, a thickness of 20 μm, 100 mm. times.100 mm, and a density of 1.6g/cm were used3The graphene film with the thermal conductivity of 1100W/mk is used as the thermal conductive film 10 to be vertically arranged. The heat conducting structure 100 of 0.2mm × 30mm × 30mm is manufactured by referring to the above organic material formulation. The thermal resistance of the thermal pad was measured to be 0.07 deg.C-cm at 40psi using ASTM D5470 method, Taiwan Ridge LW9389 apparatus2and/W. Testing the thermal resistance under different thicknesses, and calculating that the contact thermal resistance of the heat conduction structure 100 is only 0.03-0.035 ℃ -cm2and/W. The compressibility of the thermally conductive structure 100 was tested using a universal mechanical tester, with a 50% compression at 40 psi.
The heat conducting pad of 0.2mm × 30mm × 30mm is attached to a chip with a die size of 30 × 30mm, the chip is exposed, the package size is 55 × 55mm, and the typical working heat consumption is 300W. The radiator 300 is installed on the chip through spring screws, the fastening force of the radiator 300 is 40psi, the radiator 300 is fastened with the screws on the single plate where the chip is located, the surface temperature of the chip is 100 degrees through a fan speed regulation control mode, the radiator 300 is disassembled after continuous work for 500 hours, the heat conducting pad can be found to have no obvious change in size, and the size is increased within the range of 2mm in unilateral expansion. The heat conducting structure 100 after the heat spreader 300 is disassembled is in a cohesive failure state, the heat spreader 300 and the chip have partial heat conducting pads on both sides, and a point-like organic matter can be observed on the chip and the heat spreader 300 at a local position. Therefore, the second organic material 22 system extends to the interface of the thermally conductive structure 100 and the heat dissipating interface, forming a localized chemical bond. The adhesion force of the second organic material 22 to the heat dissipation contact surface is greater than the cohesion force of the first organic material 21, that is, the adhesion force between the adhesion layer 221 and the heat spreader 300 and the adhesion layer 221 and the chip is greater than the cohesion force of the first organic material 21 after curing, so when the heat spreader 300 is disassembled, the heat spreader 300 has the point-shaped adhesion layer 221, and the heat conduction structure 100 is subjected to cohesive failure.
Therefore, the heat conducting structure 100 provided in the embodiment of the present application realizes lower contact thermal resistance (by more than 50%), maintains reliable contact between the heat conducting structure 100 and a heat dissipation contact surface when a gap changes, and avoids the problem that the interface delamination of the heat conducting structure 100 causes the over-temperature of the heating element 200. The problem of short circuit caused after the heat conduction structure 100 expands in size and overflows to the edge of the heating element 200 (such as a chip) can be avoided, the heat conduction structure 100 achieves ultralow application thermal resistance, and the application thermal resistance is reduced by more than one time compared with the existing optimal heat conduction pad.
Alternatively, in another possible implementation, the heat conductive film 10 may also be a graphite film, for example, an artificial graphite film. The artificial graphite film is formed by stacking multiple layers of graphene in an AB stacking mode (AB stacking means that upper graphene micro-sheets and lower graphene micro-sheets are arranged and stacked in a staggered mode). The artificial graphite film is prepared by taking a polyimide film as a raw material, realizing the incompressible heat-conducting film 10 through high-temperature graphitization under the condition of pressing, wherein the density of the heat-conducting film 10 can be more than or equal to 2.0g/cm3And is less than or equal to 2.1g/cm3。
When the heat conductive film 10 is a graphite film, a thicker graphite film is likely to be internally cracked when it is pressed after being placed vertically, so that a graphite film having a smaller thickness is used, and therefore, the thickness of the graphite film may be less than or equal to 25 μm, for example, 17 μm. The graphite film can have a density greater than or equal to 1.51.9g/cm3And less than or equal to 1.9g/cm3The density can be adjusted by adjusting the pressureControlling the process conditions.
In the examples of the present application, a thickness of 12 μm and a density of 1.75g/cm were used3And graphite films with plane thermal conductivity of 1100W/mk are used as raw materials and are vertically arranged. Referring to the above organic material formula (i.e. the first organic material 21 is composed of vinyl silicone oil, hydrogen terminated silicone oil and side hydrogen silicone oil, and the second organic material 22 is composed of butanetriol and octyl triethoxysilane) and its process steps, the heat conducting structure 100 with 0.2mm × 30mm × 30mm is made. The thermal resistance of the thermally conductive structure 100 at 40psi was measured to be 0.08 deg.C-cm using a Taiwan Riling LW9389 apparatus2and/W. The compressibility of the thermally conductive structure 100 was tested using a universal mechanical tester with a compression of 35% at 40 psi.
In one possible implementation manner, as shown in fig. 5, each of the thermal conductive films 10 is inclined, for example, an angle a formed between a surface of the thermal conductive film 10 facing the dielectric layer 20 and a thickness direction (i.e., a z direction in fig. 5) of the thermal conductive structure 100 is greater than 0 ° and less than or equal to 45 °, and for example, an angle a formed between a surface of the thermal conductive film 10 facing the dielectric layer 20 and the thickness direction of the thermal conductive structure 100 may be 30 °. Or, in some examples, when the heat conduction films 10 and the medium layers 20 are alternately arranged, the medium layer 20 is located between two adjacent heat conduction films 10, so that an included angle a between one surface of the heat conduction film 10 facing the medium layer 20 and one surface of the heat conduction film 10 facing away from the medium layer 20 and the thickness direction of the heat conduction structure 100 is greater than 0 ° and less than or equal to 45 °.
Through setting heat conduction membrane 10 to the slope form, heat conduction membrane 10 compressive deformation absorbs stress like this to show the compressive stress who reduces heat conduction structure 100, when making heat conduction structure 100 receive external force compression, heat conduction structure 100's plane size does not obviously expand, thereby has avoided heat conduction structure 100 size expansion and has caused the short circuit risk. The heat conducting film 10 is designed to be inclined, and can be realized by a cutting process.
Example two
The differences from the above embodiment are: in the embodiment of the present application, the second organic material 22 is a material that can undergo a polymerization reaction under a predetermined reaction condition between the heat generating structure 200 and the heat conducting structure 100 and/or between the heat conducting structure 100 and the heat sink 300. The adhesive layer 221 formed by polymerizing the second organic material 22 has pressure-sensitive characteristics. That is, the adhesive layer 221 is formed as an adhesive agent sensitive to pressure, so that the heat conducting structure 100 and the heat generating element 200 and/or the heat sink 300 of the heat conducting structure 100 are closely adhered by the adhesive layer 221 formed by applying pressure to the heat generating element 200 and the heat sink 300.
The polymerization reaction of the second organic material 22 between the heat generating structure 200 and the heat conducting structure 100 and/or between the heat conducting structure 100 and the heat sink 300 will be described in detail below.
Wherein, to achieve that the second organic material 22 undergoes a polymerization reaction when the reaction conditions are met, the second organic material 22 may be, for example, an unsaturated acrylic material. The unsaturated acrylic material may undergo polymerization.
In the embodiment of the present application, the unsaturated acrylic material may be, for example, an acrylic material containing an ester functional group, or the unsaturated acrylic material may be an acrylic material containing a hydrophilic group, for example, the unsaturated acrylic material may also be an acrylic material containing a strong hydrophilic group such as a carboxyl group, a hydroxyl group, and the like.
In embodiments of the present application, the acrylic material containing an ester functional group may include: 2-ethylhexyl acrylate, 4-hydroxybutyl acrylate, i.e. the second organic material 22 may be 2-ethylhexyl acrylate, or the second organic material 22 may be 4-hydroxybutyl acrylate, 2-ethylhexyl acrylate is mixed in the first organic material 21.
In the embodiment of the present application, the first organic material 21 may be an organic chemical containing acrylic, polyurethane, epoxy, or polyimide. For example, in the embodiment of the present application, the first organic material 21 may include 4-hydroxybutyl acrylate and divinyl adipate, and the 4-hydroxybutyl acrylate and the divinyl adipate are specifically cured by an initiator (e.g., a photoinitiator, a thermal initiator, etc.).
Therefore, in the embodiment of the present application, the first organic material 21 and the second organic material 22 are changed from silicone to acrylic system, so that the cured substance of the first organic material 21 is in a solid or gel state, so that the heat conductive structure 100 is a flexible heat conductive pad. And the second organic material 22 can diffuse to the outer surface of the heat conducting structure 100 to polymerize and form the adhesive with pressure sensitive property
During configuration, the following steps can be selected: 60 parts of 4-hydroxybutyl acrylate, 25 parts of 2-ethylhexyl acrylate, 15 parts of divinyl adipate, 1 part of acetophenone photopolymerization initiator and 0.02 part of organic peroxide thermal initiator are mixed to prepare organic slurry, the organic slurry is filled between two adjacent heat-conducting films 10 to form a dielectric layer 20 with the thickness of 5 microns, the dielectric layer is cured by UV light, the first organic material 21 becomes an adhesive with pressure-sensitive characteristics, and the adhesive bonds the heat-conducting films 10 to form an integral structure.
The reaction mechanism of the free radical polymerization reaction between monomers under UV illumination is as follows:
Figure RE-GDA0002727248810000181
in the mixed organic slurry of the first organic material 21 and the second organic material 22 described above, a part of 2-ethylhexyl acrylate is not completely involved in radical polymerization initiated under UV light (for example, the amount of 2-ethylhexyl acrylate is large, a part is involved in radical polymerization, and the remaining part of 2-ethylhexyl acrylate is mixed in the first organic material 21). The 2-ethylhexyl acrylate component that does not participate in the polymerization reaction can be spread to the surface of the heat conducting structure 100 and the micropores of the heat conducting structure 100 and the heat dissipating contact surface under the action of pressure or high temperature. The out-diffused 2-ethylhexyl acrylate can undergo self-polymerization at high temperature in the presence of a thermal initiator to form the adhesive layer 221 with pressure sensitivity, and the adhesive layer 221 forms a mutually engaged bonding force with the metal surfaces of the heating element 200 and the heat spreader 300, so that the heat conducting structure 100 can be well and tightly bonded with the heating element 200 and the heat spreader 300.
The heat conductive structure 100 having a thickness of 0.2mm was compressed to 0.18mm using ASTM D5470 method, Taiwan Ridge LW9389 apparatus, test application thermal resistance of 0.17 deg.C-cm2and/W. Maintaining heat conductionThe thickness of the pad and other test conditions are unchanged, the heat conducting pad is continuously heated for 168 hours to monitor the change of the thermal resistance, the gradual reduction of the application thermal resistance can be observed, and the application thermal resistance can be reduced to 0.13-cm2and/W. It is shown that the thermal contact resistance of the thermal conductive structure 100 is significantly reduced under continuous pressurization and high temperature, therefore, the thermal conductive structure 100 provided by the present application diffuses outward through the second organic material 22 and performs a polymerization reaction to form the adhesive layer 221 with chemical bonding force, and the second organic material 22 diffuses outward into the micro grooves on the surfaces of the heating element 200 and the heat sink 300, so that the thermal conductive structure 100 and the heating element 200 and the heat sink 300 are in close contact with each other, thereby reducing the thermal contact resistance of the thermal conductive structure 100, reducing the application thermal resistance of the thermal conductive structure 100, and improving the thermal conductivity of the thermal conductive structure 100.
In the embodiment of the present invention, since the adhesive layer 221 has pressure-sensitive characteristics, even if a crack occurs locally inside the heat conductive structure 100, the adhesive function is still achieved after the stress is recovered, and a certain healing recovery effect is achieved.
EXAMPLE III
The embodiment of the present application further provides a manufacturing method of the heat conducting structure 100, as shown in fig. 6, the method includes the following steps:
s101, providing a plurality of heat conduction films 10, wherein each heat conduction film 10 is provided with a first surface 11 and a second surface 12 opposite to the first surface 11;
referring to fig. 7A, 4 heat conductive films 10 are provided. Of course, in some other examples, the number of thermally conductive films 10 includes, but is not limited to, 4. The thermally conductive film 10 may be a graphene film or an artificial graphite film.
When the heat conducting film 10 is a graphene film, the preparation method is as follows: using a monolayer graphene oxide nanoplatelet with a D50 size of 20 μm (i.e., the longitudinal dimension of the graphene nanoplatelet is 20 μm), 500mg of the monolayer graphene oxide nanoplatelet is weighed and dispersed in 20ml of deionized water to prepare a solution. The aqueous graphene oxide solution was coated on a substrate (e.g., a high-temperature-resistant graphite film) having a width of 100mm to obtain a graphene oxide film having a width of 100mm and a thickness of about 25 μm. And (3) putting the graphene oxide film into an oven, and drying for 24h at 60 ℃. After dryingThe graphene oxide film is put into a high-temperature graphitization furnace, argon is introduced as protective gas, and the flow is 100cm3And/min, calcining at 2600 deg.C for 20min for high-temperature reduction reaction. After the reduction reaction is finished, naturally cooling to room temperature, and controlling the density of the graphene heat conduction film 10 to be about 1.6g/cm through the pressure of pressing3. The plane thermal conductivity coefficient of the graphene film is 1100W/mk by adopting a laser flash method, and the thickness of the graphene film is 20 mu m.
When the heat-conducting film 10 is an artificial graphite film, the manufacturing method comprises the following steps: the multilayer graphene is formed by stacking in an AB stacking mode (AB stacking means that upper graphene micro-sheets and lower graphene micro-sheets are arranged and stacked in a staggered mode) to form the incompressible heat-conducting film 10, and the density of the heat-conducting film 10 can be greater than or equal to 2.0g/cm3And is less than or equal to 2.1g/cm3。
S102, forming a medium layer 20 on the first surface 11 and the second surface 12 of each heat conduction film 10, wherein the medium layer 20 comprises a first organic material 21 and a second organic material 22 located in the first organic material 21;
in the embodiment of the present application, the second organic material 22 may be mixed with the first organic material 21 to form an organic slurry, and as shown in fig. 7B, the organic slurry may be applied to both sides of the thermally conductive film 10 to form the dielectric layer 20. For the composition of the first organic material 21 and the second organic material 22, reference may be made to the first embodiment and the second embodiment, and details of the embodiments of the present application are not repeated.
S103, laminating and pressing the plurality of heat-conducting films 10 with the medium layers 20 to form a block-shaped structure;
as shown in fig. 7C, 4 heat conductive films 10 with dielectric layers 20 are stacked and pressed to form a block with a height of 100mm and a size of 100 × 100mm, the block is cured by UV light or heating at 120 ℃ for 30min, and after the first organic material 21 is cured, an integral structure is formed between the plurality of heat conductive films 10 and the dielectric layers 20. It should be noted that during the curing process by heating at 120 ℃ for 30min, there may be a case where a portion of the second organic material 22 diffuses out at a high temperature, but a portion of the second organic material 22 still exists in the first organic material 21. The second organic material 22 is present in the first organic material 21 thus cured, and the second organic material 22 may be in a liquid state or a semisolid state.
And S104, cutting the block structure to obtain the heat conduction structure 100.
Referring to fig. 7D, the block structure obtained in step 103 is cut, for example, into a thermal pad with a thickness of 0.2 mm. Wherein, after the step 104, the method further comprises: the above-mentioned 0.2mm thermal pad is subjected to polishing treatment and then cut into small pieces, for example, 30 × 30mm in size, to obtain a 0.2mm × 30mm × 30mm thermal conductive structure 100 (see fig. 7E).
Among them, in this application embodiment, cut the block structure and make heat conduction structure 100, include: the block-shaped structure is cut along a cutting direction, and an angle is formed between a direction perpendicular to the heat conductive film 10 (i.e., a direction of a solid-line arrow in fig. 7D) and the cutting direction (i.e., a direction of a dotted-line arrow in fig. 7D), and the angle is greater than or equal to 0 ° and less than or equal to 45 °. That is, the heat conductive film 10 in the heat conductive structure 100 is inclined with respect to the thickness direction of the heat conductive structure 100 by oblique cutting, as shown in fig. 7D, the heat conductive film is cut obliquely along the dotted arrow, for example, the included angle between the cutting direction and the direction perpendicular to the heat conductive film 10 may be 5 °, and in the heat conductive structure 100 obtained by cutting, the included angle between the surface of the heat conductive film 10 facing the dielectric layer 20 and the thickness direction of the heat conductive structure 100 is 5 °.
In the embodiment of the present application, forming the dielectric layer 20 on the first surface 11 and the second surface 12 of each of the thermal conductive films 10 includes: providing a first organic material 21 and a second organic material 22, and mixing the second organic material 22 in the first organic material 21 to form an organic slurry; the first surface 11 and the second surface 12 of each of the thermally conductive films 10 are coated with an organic paste to form a dielectric layer 20.
Wherein a first organic material 21 is provided comprising:
providing vinyl silicone oil, hydrogen-terminated silicone oil, hydrogen-containing silicone oil and a catalyst; for example, when disposed, 50 parts of vinyl silicone oil, 40 parts of hydrogen-terminated silicone oil, and 10 parts of side hydrogen silicone oil may be provided, and the vinyl silicone oil, the hydrogen-terminated silicone oil, the side hydrogen silicone oil, and the catalyst may be mixed to prepare the first organic material 21. The vinyl silicone oil, the hydrogen-terminated silicone oil and the side hydrogen silicone oil can be selected from the group consisting of vinyl silicone oil, hydrogen-terminated silicone oil and side hydrogen silicone oil, wherein the viscosity of the vinyl silicone oil, the hydrogen-terminated silicone oil and the side hydrogen silicone oil is 50-10000 cps, and 1cps is 1 mPas, and for example, the vinyl silicone oil, the hydrogen-terminated silicone oil and the side hydrogen silicone oil can be selected from the group consisting of vinyl silicone oil, hydrogen-terminated silicone oil and side hydrogen silicone oil.
Providing a second organic material 22 comprising: butanetriol and octyltriethoxysilane are provided, for example, 0.5 parts butanetriol, 0.3 parts octyltriethoxysilane are provided. Butanetriol and octyltriethoxysilane were mixed to produce the second organic material 22. The first organic material 21 formed of butanetriol and octyltriethoxysilane may be mixed into the first organic material 21 by encapsulation.
Alternatively, in another possible implementation, providing the first organic material 21 and the second organic material 22 to form an organic paste includes: providing a first organic material 21, the first organic material 21 comprising 4-hydroxybutyl acrylate and divinyl adipate; providing a second organic material 22, the second organic material 22 comprising 2-ethylhexyl acrylate; providing an initiator, wherein the initiator comprises a photopolymerization initiator and a thermal initiator; in the compounding process, 50 parts of 4-hydroxybutyl acrylate, 15 parts of divinyl adipate, 25 parts of 2-ethylhexyl acrylate, 1 part of photopolymerization initiator and 0.02 part of thermal initiator can be mixed to prepare the organic slurry.
Of course, in some other examples, the second organic material 22 may also be infiltrated and diffused into the first organic material 21 after the first organic material 21 is cured, for example, the first organic material 21 may be cured to form a solid or gel-state substance, and then the second organic material 22 with a nanometer-scale thickness is disposed on the first organic material 21 of the prepared heat conducting structure 100, and the second organic material 22 may be infiltrated and diffused into the cured first organic material 21. Note that, when the second organic material 22 diffuses into the cured first organic material 21, the viscosity of the second organic material 22 needs to be low.
Example four
The embodiment of the present application further provides a heat conduction system, which may include a heat generating element 200 and the heat conduction structure described in any of the above embodiments, where the heat conduction structure is used to transfer heat from the heat generating element 200. By including the above heat conducting structure 100, the second organic material 22 in the heat conducting structure 100 diffuses out to form the adhesive layer 221 having van der waals force, chemical bonding force or biting force between the heat generating element 200 and the heat conducting structure 100, and the adhesive layer 221 tightly connects the heat generating element 200 and the heat conducting structure 100, thereby avoiding the delamination between the heat generating element 200 and the heat conducting structure 100.
In one possible implementation, the heat conducting system further includes a heat sink 300, the heat conducting structure 100 is located between the heat generating element 200 and the heat sink 300, and the heat conducting structure 100 is used for transferring heat from the heat generating element 200 to the heat sink 300. The second organic material 22 in the heat conducting structure 100 is diffused outwardly to form the adhesive layer 221 having van der waals force, chemical bonding force or biting force between the heat generating element 200 and the heat conducting structure 100 and between the heat generating element 200 and the heat sink 300, and the adhesive layer 221 tightly connects the heat generating element 200 and the heat conducting structure 100 and between the heat conducting structure 100 and the heat sink 300.
EXAMPLE five
An embodiment of the present application further provides a chip package structure 400, as shown in fig. 8A, including at least: a chip 201 disposed on a package carrier 402 (which may be a circuit board or a package board, for example), a package heat dissipation cover 301, and any of the above-mentioned heat conducting structures 100, where the heat conducting structure 100 is located between the chip 201 and the package heat dissipation cover 301.
And under a preset temperature or a preset pressure, the second organic material 22 in the heat conducting structure 100 diffuses between the heat conducting structure 100 and the chip 201 and/or between the heat conducting structure 100 and the package heat dissipation cover 301, and the second organic material 22 diffusing outward undergoes a chemical reaction to form an adhesive layer 221, and the adhesive layer 221 connects the heat conducting structure 100 and the chip 201 and/or the heat conducting structure 100 and the package heat dissipation cover 301.
By including the heat conducting structure 100, the adhesive layer 221 is formed between the heat conducting structure 100 and the chip 201 and/or between the heat conducting structure 100 and the package heat dissipation cover 301, and a chemical bonding force is formed at the bonding position between the heat conducting structure 100 and the chip 201 and/or between the heat conducting structure 100 and the package heat dissipation cover 301 in the generation process of the adhesive layer 221, so that the surface of the heat conducting structure 100 and the surface of the chip 201/package heat dissipation cover 301 are maintained to be tightly bonded, and the problem that the chip 201 is over-heated due to the fact that the interface between the heat conducting structure 100 and the chip 201/package heat dissipation cover 301 is layered in the use process is avoided. In addition, the second organic material 22 diffusing outward may be filled in local micro-holes between the heat conducting structure 100 and the chip 201 and/or between the heat conducting structure 100 and the package heat dissipation cover 301, so as to improve micro-wettability of the heat conducting structure 100, thereby reducing interface contact thermal resistance, reducing application thermal resistance of the heat conducting structure 100, and achieving the purpose of good heat dissipation of the chip 201.
In one possible implementation manner, the method further includes: the fixing frame 401, the fixing frame 401 is located between the package carrier 402 and the package heat dissipation cover 301, the fixing frame 401, the package carrier 402 and the package heat dissipation cover 301 enclose a package cavity, and the chip 201 and the heat conducting structure 100 are located in the package cavity. For example, one end of the fixing frame 401 is connected to the package carrier 402, the other end of the fixing frame 401 is connected to the package heat sink cover 301, and the inner surfaces of the fixing frame 401, the package carrier 402 and the package heat sink cover 301 enclose a cavity. In this way, the heat generated by the chip 201 is transferred to the package heat dissipation cover 301 through the heat conduction structure 100, so that the heat generated by the chip 201 in the cavity is transferred to the outside of the cavity, thereby achieving the heat dissipation effect on the chip 201. In this embodiment, the package heat dissipation cover 301 may be a package cover made of an aluminum plate.
In a possible implementation manner, referring to fig. 8A, the bottom end of the fixing frame 401 is connected to the package carrier 402 by clamping, welding or adhesive bonding, the top end of the fixing frame 401 is fastened to the package heat dissipation cover 301 by the elastic fastener 405, that is, after the fixing frame 401 is connected to the package heat dissipation cover 301, a compressible margin is provided between the fixing frame 401 and the package heat dissipation cover 301, so that a force is applied to the package heat dissipation cover 301 to apply a pressure to the heat conducting structure 100, and the second organic material 22 diffuses outward under the pressure of the heat conducting structure 100 and reacts chemically to form the adhesive layer 221.
In this embodiment, the elastic fastening member 405 may specifically be an elastic fastening member such as an elastic buckle or a spring screw, and the fixing frame 401 is provided with a plurality of threaded holes, for example, 8 threaded holes may be provided, and 8 spring screws and the threaded holes may be used to cooperate to connect the encapsulation heat dissipation cover 301 to the fixing frame 401.
Of course, in some other examples, the fixing frame 401 and the package carrier 301 are fastened together, for example, the fixing frame 401 and the package carrier 301 are fastened together by using screws, clamping, or welding.
In another possible implementation, referring to fig. 8B, the package heat sink cover 301 and the fixing frame 401 may be integrally formed, for example, the package heat sink cover 301 and the fixing frame 401 may be formed by stamping using an aluminum plate. Thus, the cover body formed by the package heat sink 301 and the fixing frame 401 is connected with the package carrier 402 to form a cavity. The chip 201 and the package carrier 402 may be connected by a first pad 403, a second pad 404 is disposed on a surface of the package carrier 402 opposite to the first pad, and the chip 201 is connected to the circuit board by the first pad and the second pad 404. Set up to be integrative through encapsulation cooling cap 301 and fixed frame 401, link to each other encapsulation support plate 402 and fixed frame 401 during encapsulation like this and can accomplish the encapsulation, encapsulation efficiency promotes, and fixed frame 401 is integrative with encapsulation cooling cap 301, does not have the assembly gap between fixed frame 401 and the encapsulation cooling cap 301 like this, so after the encapsulation is accomplished, avoided steam to enter into encapsulation support plate 402 from the assembly gap between fixed frame 401 and the encapsulation cooling cap 301, encapsulation cooling cap 301 and fixed frame 402 enclose the cavity in and cause the influence to chip 201.
In the embodiment of the present application, the heat conducting structure 100 may be a heat conducting structure 100 with a thickness of 0.1-0.4mm, for example, the heat conducting structure 100 with a thickness of 0.2mm is placed on a chip 201 with a die size of 30 × 30 mm.
EXAMPLE six
The embodiment of the present application further provides an electronic device, which may include, but is not limited to, a mobile or fixed terminal having a heating element 200, such as a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, an intercom, a netbook, a point of sale (POS), a Personal Digital Assistant (PDA), a wearable device, a virtual reality device, a wireless usb disk, a bluetooth sound/earphone, or a vehicle-mounted front-end, a car recorder, and a security device.
In a possible implementation manner, taking the mobile phone 500 as the above-mentioned electronic device for example, the electronic device may at least include: the chip package structure 400 (see fig. 10) according to the fourth embodiment.
Referring to fig. 9 and 10, the electronic device may further include a display screen 501 and a rear cover 502, the display screen 501 and the rear cover 502 enclose a housing 510, the chip package structure 400 and the circuit board 520 are located in the housing 510, and the chip package structure 400 may be disposed on the circuit board 520 in the electronic device. For example, the package carrier 402 in the chip package structure 400 may be electrically connected to the circuit board 520 through the second pads 404, and the package heat dissipation cover 301 in the chip package structure 400 may be in contact with the housing 510 of the electronic device (e.g., the inner surface 5021 of the back cover 502), so that heat of the package heat dissipation cover 301 may be dissipated to the outside of the electronic device through the housing 510 of the electronic device, thereby achieving good heat dissipation of the chip 201 in the electronic device.
In another possible implementation manner, an electronic device provided in this embodiment of the present application, as shown in fig. 9 and fig. 11, at least includes: the heat sink includes a housing 510, and a heat generating element 200, a heat sink 300 and any one of the above heat conducting structures 100 disposed in the housing 510, wherein the heat conducting structure 100 is located between the heat generating element 200 and the heat sink 300. The heat generating element 200 may be a memory, a CPU, or the like, or the heat generating element 200 may be another electronic element that generates heat during operation.
When the electronic device is mounted, the heat conducting structure 100 is disposed on the heat generating element 200, the heat sink 300 is covered on the heat conducting structure 100, and the other end of the heat sink 300 can contact with the housing 510 of the electronic device, for example, the other end of the heat sink 300 can contact with the inner surface 5021 of the back cover 502, or when the electronic device has a middle frame, the heat sink 300 can contact with the middle frame, so that under high temperature or pressure, the second organic material 22 in the heat conducting structure 100 diffuses between the heat generating element 200 and the heat conducting structure 100 and/or between the heat sink 300 and the heat conducting structure 100, and when the reaction condition is reached, the second organic material 22 reacts chemically, so that the bonding layer 221 having van der waals force, chemical bonding force or biting force is generated at the bonding position between the heat generating element 200 and the heat conducting structure 100 and/or between the heat sink 300 and the heat conducting structure 100, thereby ensuring that the heat conducting structure 100 is in close contact with the surfaces of the heat generating element 200/heat sink 300, the problem that the heat-generating element 200 is over-heated due to the delamination of the heat-conducting structure 100 from the interface between the heat-generating element 200 and the heat sink 300 during the use process is avoided.
In addition, the second organic material 22 diffusing outward may be filled in the local micro-pores between the heat conducting structure 100 and the heating element 200, and between the heat conducting structure 100 and the heat sink 300, so as to improve the micro-wettability of the heat conducting structure 100, thereby reducing the interface contact thermal resistance and reducing the application thermal resistance of the heat conducting structure 100. The heat generated by the heating element 200 in the electronic device is dissipated outwards in time, and the problem that the heating element 200 cannot work normally due to overhigh temperature of the heating element 200 is avoided. Furthermore, the second organic material 22 diffusing outward may fill local micro-pores between the heat conducting structure 100 and the heat generating element 200 and between the heat conducting structure 100 and the heat spreader 300, so that the contact area between the adhesive layer 221 formed in this way and the heat generating element 200/heat spreader 300 is increased and the adhesive force is greater.
In this embodiment of the application, taking the mobile phone 500 as the above-mentioned electronic device for example, referring to fig. 9 and 11, the housing 510 may include a display screen 501 and a rear cover 502, and the display screen 501 and the rear cover 502 enclose the housing 510 having a cavity therein. The heat generating element 200 may be disposed on the circuit board 520, and the heat sink 300 may contact the inner surface 5021 of the rear cover 502, so that heat generated by the heat generating element 200 is transferred to the heat sink 300 through the heat conducting structure 100, and the heat sink 300 dissipates the heat to the outside of the electronic device through the rear cover 502.
Of course, in some examples, when the rear cover 502 and/or the middle frame of the electronic device are made of a metal material, the rear cover 502 and/or the middle frame may serve as the heat sink 300, that is, the heat generating element 200 may be disposed on the circuit board 520, one surface of the heat conducting structure 100 covers the heat generating element 200, and the other surface of the heat conducting structure 100 may be pressed against the inner surface of the rear cover 502 or the middle frame of the electronic device, so that heat generated by the heat generating element 200 is transferred to the rear cover 502 or the middle frame of the electronic device through the heat conducting structure 100, thereby achieving the purpose of dissipating heat outwards.
Alternatively, in some examples, due to the limitation of the layout of components in the electronic device, the heat sink 300 may not contact the back cover 502 or the middle frame of the electronic device, so that the heat sink 300 may be connected to the back cover 502 or the middle frame of the electronic device through a heat conductive metal, so that the heat on the heat sink 300 may be transferred to the back cover 502 or the middle frame of the electronic device through a heat conductive structure.
It is to be understood that the illustrated structure of the embodiment of the present application does not specifically limit the handset 500. In other embodiments of the present application, handset 500 may include more or fewer components than shown, or some components may be combined, some components may be split, or a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.
In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, a fixed connection, an indirect connection via an intermediary, a connection between two elements, or an interaction between two elements. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the embodiments of the application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the embodiments of the present application, and are not limited thereto; although the embodiments of the present application have been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (45)

1. A heat conductive structure for transferring heat generated from a heat generating component to a heat sink, comprising: the heat conduction film and the medium layers are alternately arranged;
one end of the heat conducting film faces the heating element, and the other end of the heat conducting film faces the radiator;
the dielectric layer at least comprises: a first organic material and a second organic material located in the first organic material;
the first organic material is used for bonding two adjacent heat conduction films;
the second organic material is used for the heat conduction structure is in when presetting the temperature or presetting pressure orientation the surface diffusion of heat conduction structure, and the outward diffusion the second organic material is in the heat conduction structure with between the heating element and/or be in the heat conduction structure with form the adhesive linkage between the radiator, the adhesive linkage be used for with the heat conduction structure with the heating element links to each other and/or the heat conduction structure with the radiator links to each other.
2. The heat conducting structure according to claim 1,
the preset temperature is greater than or equal to 35 ℃.
3. The heat conducting structure according to claim 1,
the predetermined pressure is greater than or equal to 5 psi.
4. A heat conducting structure according to any one of claims 1 to 3, wherein the second organic material diffused outwardly forms an adhesive layer having van der waals force, chemical bonding force or biting force between the heat conducting structure and the heat generating element and/or between the heat conducting structure and the heat sink.
5. The structure of any one of claims 1 to 4, wherein the second organic material diffuses through the bulk of the first organic material at the predetermined temperature or the predetermined pressure.
6. The structure according to any one of claims 1 to 5, wherein the first organic material is in a solid state and the second organic material is in a liquid or semisolid state.
7. The structure of any one of claims 1 to 6, wherein the adhesion between the adhesive layer and the heat sink, and/or the adhesion between the adhesive layer and the heat generating element, is greater than the cohesion of the dielectric layer.
8. The heat transfer structure of any one of claims 1 to 7, wherein the second organic material is a material that undergoes a dehydration condensation reaction or a polymerization reaction with the heat generating element and/or with at least a partial region of the outer surface of the heat sink facing the heat transfer structure under a predetermined reaction condition; wherein the preset reaction condition comprises reaction temperature, reaction humidity or reaction medium.
9. The structure of claim 8, wherein the reaction temperature is greater than or equal to 35 ℃.
10. The structure of claim 8, wherein the reaction humidity is greater than or equal to 10%.
11. The heat transfer structure of claim 8, wherein the second organic material comprises a liquid material containing active hydroxyl groups and a liquid material containing hydrolyzable groups.
12. The structure of claim 11, wherein the liquid reactive hydroxyl material comprises a polyol.
13. The heat conductive structure according to claim 12, wherein the liquid material containing a hydrolyzable group is a silane coupling agent.
14. The structure according to claim 13, wherein the polyhydric alcohol is at least one of butanetriol, pentaerythritol, glycerol, trimethylolethane, xylitol, or sorbitol, and the silane coupling agent is trialkoxysilane, or the silane coupling agent is octyltriethoxysilane.
15. The structure of claim 8, wherein the adhesive layer formed by polymerizing the second organic material has pressure-sensitive characteristics.
16. The structure of claim 8 or 15, wherein the second organic material is an unsaturated acrylic material.
17. The structure of claim 16, wherein the unsaturated acrylic material is an acrylic material containing an ester functional group, or the unsaturated acrylic material is an acrylic material containing a hydrophilic group.
18. The structure of any one of claims 1 to 17, wherein an angle formed between a surface of the thermal conductive film facing the dielectric layer and a thickness direction of the thermal conductive structure is greater than 0 ° and less than or equal to 45 °, or
The included angle formed between the surface of the heat-conducting film facing the medium layer and the surface of the heat-conducting film departing from the medium layer and the thickness direction of the heat-conducting structure is larger than 0 degree and smaller than or equal to 45 degrees.
19. The structure according to any one of claims 1 to 18, wherein the first organic material is a polyorganosiloxane oil containing at least an unsaturated siloxane.
20. The heat conducting structure according to claim 19, wherein the first organic material comprises a vinyl silicone oil and a hydrogen-containing silicone oil, both having a molecular weight of less than 15000.
21. The heat transfer structure of claim 20, wherein the hydrogen-containing silicone oil comprises at least one of a terminal hydrogen silicone oil and a side hydrogen silicone oil.
22. The structure of any one of claims 1 to 21, wherein the first organic material is an organic chemistry comprising acrylic, polyurethane, epoxy, or polyimide.
23. The structure of claim 22, wherein the first organic material comprises 4-hydroxybutyl acrylate and divinyl adipate.
24. The structure of any one of claims 1 to 23, wherein the second organic material that diffuses out is less than or equal to 50% by weight of the dielectric layer.
25. The structure of any one of claims 1 to 24, wherein the second organic material is present in the first organic material in an amount of less than 50% by weight.
26. The structure of any one of claims 1 to 25, wherein the adhesive layer has a thickness of 1 μm or less.
27. The structure of any one of claims 1 to 26, wherein the thickness of the structure is greater than or equal to 0.1mm and less than or equal to 5 mm.
28. The structure of any one of claims 1-27, wherein the thermal conductivity of the structure in a first direction is greater than the thermal conductivity of the structure in a second direction, and the thermal conductivity of the structure in a third direction is greater than the thermal conductivity of the structure in the second direction, wherein the first direction is perpendicular to a side of the heat-generating component facing the structure, the second direction is perpendicular to a side of the film facing the dielectric layer, and the third direction is perpendicular to both the first direction and the second direction.
29. The structure of claim 28, wherein the ratio of the thermal conductivity of the thermally conductive structure in the first direction to the thermal conductivity of the thermally conductive structure in the second direction is greater than or equal to 5.
30. The structure of claim 28 or 29, wherein the thermal conductivity of the structure in the first direction is higher than or equal to 35W/mk.
31. The heat conductive structure according to any one of claims 1 to 30, wherein the thickness of each of the heat conductive films is greater than or equal to 7 μm and less than or equal to 200 μm.
32. The structure of any one of claims 1 to 31, wherein the thermally conductive membrane is a compressible thermally conductive membrane.
33. The structure of any one of claims 1 to 32, wherein the thermally conductive film is a graphene film or a graphite film.
34. A heat transfer system comprising a heat generating component and the heat transfer structure of any of claims 1 to 33, the heat transfer structure being configured to transfer heat from the heat generating component.
35. The heat conducting system of claim 34, further comprising a heat sink, the heat conducting structure being located between the heat generating component and the heat sink, the heat conducting structure being configured to transfer heat from the heat generating component to the heat sink.
36. A chip package structure, comprising at least: a chip disposed on a package carrier, a package heat-dissipating cap, and the heat-conducting structure of any of claims 1-33, the heat-conducting structure being located between the chip and the package heat-dissipating cap;
and the heat conduction structure is at the temperature of predetermineeing or predetermineeing under the pressure, the second organic material in the heat conduction structure outdiffuses to the heat conduction structure with between the chip and/or the heat conduction structure with between the encapsulation heat dissipation lid and form the adhesive linkage, the heat conduction structure with between the chip and/or the heat conduction structure with between the encapsulation heat dissipation lid pass through the adhesive linkage links to each other.
37. The chip package structure according to claim 36, further comprising: the fixed frame is positioned between the packaging carrier plate and the packaging heat dissipation cover, a cavity is enclosed by the fixed frame, the packaging carrier plate and the packaging heat dissipation cover, and the chip and the heat conduction structure are positioned in the cavity.
38. The chip package structure according to claim 37, wherein the fixing frame is fastened to the package heat sink cover by an elastic fastener, or the fixing frame is integrated with the package heat sink cover.
39. The chip package structure according to claim 37, wherein the fixing frame is tightly connected to the package carrier.
40. An electronic device, characterized in that it comprises at least: the chip package structure of any one of the preceding claims 36-39.
41. An electronic device, characterized in that it comprises at least: a housing and a heat generating component, a heat sink and the heat conducting structure of any of the preceding claims 1-33 disposed within the housing, the heat conducting structure being located between the heat generating component and the heat sink.
42. The electronic device of claim 41, wherein the heat sink is in contact with the housing.
43. A method of making a thermally conductive structure, the method comprising:
providing a plurality of heat conducting films, wherein each heat conducting film is provided with a first surface and a second surface opposite to the first surface;
forming a dielectric layer on the first surface and the second surface of each of the thermal conductive films, the dielectric layer including a first organic material and a second organic material located in the first organic material;
laminating and pressing the plurality of heat conducting films with the medium layers to form a block structure;
and cutting the block structure to obtain the heat conduction structure.
44. The method for manufacturing a heat conducting structure according to claim 43, wherein the step of cutting the block structure to obtain the heat conducting structure comprises:
cutting the blocky structure along a cutting direction, wherein an included angle is formed between the direction perpendicular to the heat-conducting film and the cutting direction, and the included angle is greater than or equal to 0 degree and less than or equal to 45 degrees.
45. The method of manufacturing a heat conductive structure according to claim 43 or 44, wherein the forming a dielectric layer on the first surface and the second surface of each of the heat conductive films includes:
providing vinyl silicone oil, hydrogen-terminated silicone oil, hydrogen-containing silicone oil and a catalyst, and mixing to obtain the first organic material;
providing butanetriol and octyltriethoxysilane, and mixing said butanetriol and octyltriethoxysilane to produce said second organic material;
mixing the first organic material and the second organic material to form the organic slurry;
coating the organic slurry on the first surface and the second surface of each of the heat conducting films to form the medium layer;
alternatively, the first and second electrodes may be,
providing a first organic material comprising 4-hydroxybutyl acrylate and divinyl adipate;
providing a second organic material comprising 2-ethylhexyl acrylate;
providing an initiator, wherein the initiator comprises a photopolymerization initiator and a thermal initiator;
mixing the 4-hydroxybutyl acrylate, the divinyl adipate, the 2-ethylhexyl acrylate, the photopolymerization initiator and the thermal initiator to prepare the organic slurry;
coating the organic slurry on the first surface and the second surface of each of the heat conductive films to form the dielectric layer.
CN202010625164.9A 2020-07-01 2020-07-01 Heat conduction structure, manufacturing method thereof, heat conduction system, chip packaging structure and electronic equipment Pending CN113889440A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115709988A (en) * 2022-11-30 2023-02-24 广东墨睿科技有限公司 Graphene superconducting film and preparation method thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115709988A (en) * 2022-11-30 2023-02-24 广东墨睿科技有限公司 Graphene superconducting film and preparation method thereof
CN115709988B (en) * 2022-11-30 2024-01-26 广东墨睿科技有限公司 Graphene superconducting film and preparation method thereof

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