Manufacturing method of graphite radiating fin

Abstract

A method for manufacturing a graphite heat sink according to the present invention comprises: a first step in which a graphite sheet (110) having a certain width is disposed between a pair of protective films (120), each of which has a thermally welded layer (121) on the inner side surface thereof, and both side surfaces of the graphite sheet (110) are sealed by thermally welding both side surfaces of the pair of protective films (120); a second step in which the inside of the graphite sheet (110), the two side surfaces of which are sealed, is evacuated, and then the openings of the pair of protective films (120) are thermally fused to seal the entire graphite sheet (110), and the surfaces of the pair of protective films (120) are heated to thermally fuse the surfaces of the graphite sheet (110); and a third step of cutting the edge portion of the graphite sheet (110).

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a graphite heat sink, and more particularly to a method for manufacturing a graphite heat sink in which a graphite sheet is wrapped with a film or bag having a heat-welding layer on the inner side thereof and the inside thereof is evacuated to remove gas and moisture inside the graphite sheet, and then the heat-welding layer is heated to simultaneously achieve a welding effect between the graphite sheet in a molten state and the surface of the film or bag and an extrusion effect based on a vacuum pressure difference, thereby manufacturing a graphite heat sink in which the film or bag and the graphite sheet are more firmly integrated. Background Art

[0002] In recent years, as electronic devices have rapidly developed towards high density and slimness, the performance of chips installed in the devices has become increasingly powerful, not only in the field of electrical / electronic equipment, but also in the fields of automobiles and medical equipment. As the chips used in electronic devices tend to be integrated at a high density, more heat is generated, and the generated heat can cause a variety of problems such as performance degradation of electronic devices, malfunction of peripheral components, and degradation of substrates.

[0003] In particular, electronic devices (such as televisions (TVs)) using light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs) require thinner heat dissipation components, and for this purpose, a metal printed circuit board (PCB) with excellent thermal conductivity is used to manufacture a substrate for mounting an integrated circuit (IC) chip, or a heat sink such as aluminum is used to control heat. In addition, in order to control heat in electronic devices, thermally conductive films such as natural graphite films, artificial graphite films, and copper plates based on carbon materials are mainly used.

[0004] In addition, a large number of research and development activities are being carried out on heat sinks using natural graphite and / or artificial graphite because they can be made into thin films, have excellent heat dissipation performance, and can be easily attached to heat-generating parts of electronic devices (such as televisions (TVs)).

[0005] The graphite heat sink as described above is generally manufactured into a sheet form by calendering the foamed graphite particles, but has the disadvantages of generating dust and weak brittleness. In order to compensate for the structural disadvantages as described above and adhere to the applicable object, as described in Korean registered patent No. 1509494, an adhesive layer and a release film for protecting the adhesive layer can be separately provided after lamination with a protective film. At this time, the protective film and the graphite sheet are bonded by inserting a hot melt adhesive and an acrylic adhesive between the two.

[0006] In addition, because the graphite sheet is made by calendering and has a layered structure, there are residual gases and moisture inside, which will cause bubbles to be generated after lamination. In addition, when there are foreign objects on the surface of the graphite sheet during the lamination process, bubbles may also be generated, and there is also a problem of peeling due to the decrease in the adhesion between the protective films at the edge. Summary of the invention

[0007] Technical issues

[0008] Therefore, the present invention aims to solve the problems existing in the prior art as described above, and its purpose is to provide a method for manufacturing a graphite heat sink in which a film or bag is wrapped with a graphite sheet and the interior is vacuum-exhausted to remove gas and moisture inside the graphite sheet, and then the heat-extrusion layer is heated to simultaneously achieve a welding effect between the molten graphite sheet and the surface of the film or bag and an extrusion effect based on the vacuum pressure difference to manufacture a graphite heat sink in which the film or bag and the graphite sheet are more firmly integrated.

[0009] Means for solving problems

[0010] In order to achieve the above-mentioned purpose, the manufacturing method of the graphite heat sink of the present invention is characterized by comprising: a first step of arranging a graphite sheet of a certain width between a pair of films each provided with a thermoplastic heat-sealing layer having a thermoplastic property that melts at a certain temperature on its inner side, and sealing both sides of the graphite sheet by heat-sealing both sides of the pair of films; a second step of sealing the entire graphite sheet by heat-sealing the openings of the pair of films after vacuum evacuating the interior of the graphite sheet with both sides sealed, and a second step of melting the heat-sealing layer by heating the surfaces of the pair of films to heat-seale the graphite sheet and the surfaces of the pair of protective films; and a third step of cutting the edge of the graphite sheet.

[0011] The first step may include: after continuously supplying the pair of films from a film supply assembly and inserting the graphite sheet between the pair of films, sealing the two sides of the graphite sheet by heat-melting the two sides of the pair of films; and cutting the pair of films into a length sufficient to cover the graphite sheet.

[0012] In the second step, the graphite sheet with sealed sides is placed in a vacuum chamber and subjected to vacuum decompression for a certain period of time, and then pressed by upper and lower heating components to complete the vacuum exhaust, thermal welding of the opening, and thermal welding of the surface at one time in the vacuum chamber.

[0013] In addition, the second step may include: the step of performing the vacuum exhaust and heat welding of the opening by placing the graphite sheet with sealed sides into a vacuum chamber and heating and pressing after vacuum decompression for a certain period of time; and the step of performing surface heat welding of the pair of films and the graphite sheet by placing the sheet into a high-temperature chamber and heating.

[0014] Furthermore, in order to achieve the above-mentioned purpose, the manufacturing method of the graphite heat sink of the present invention is characterized by comprising: a first step of inserting a graphite sheet of a certain width into a film-type bag which is open on one side and has a heat-welding layer with thermoplastic properties that melts at a certain temperature on the inner side thereof; a second step of sealing the entire graphite sheet by heat-welding the opening of the film-type bag after vacuuming the inside of the graphite sheet by applying a vacuum to the film-type bag which is open on one side, and heat-welding the graphite sheet and the surface of the film-type bag by heating the surface of the film-type bag; and a third step of cutting the edge of the graphite sheet.

[0015] In the second step, it is preferable to complete the vacuum exhaust, the heat welding of the opening and the surface heat welding at one time in the vacuum chamber by placing the film bag with the graphite sheet arranged therein into the vacuum chamber and performing vacuum decompression for a certain period of time and then pressing it using upper and lower heating components.

[0016] In addition, the second step may include: a step of performing the vacuum exhaust and heat-welding of the opening by placing the film bag having the graphite sheet disposed therein into a vacuum chamber and performing vacuum decompression for a certain period of time and then heating and pressing the film bag; and a step of performing surface heat-welding of the film bag and the graphite sheet by placing the film bag into a high-temperature chamber and heating the film bag.

[0017] Effects of the Invention

[0018] The present invention has the effect of removing gas and moisture inside the graphite sheet by wrapping a graphite sheet with a film or bag equipped with a heat-welding layer on the inner side and vacuum exhausting the inside, and then heating the heat-welding layer to simultaneously achieve the welding effect between the molten graphite sheet and the surface of the film or bag and the extrusion effect based on the vacuum pressure difference, thereby manufacturing a graphite heat sink in which the film or bag and the graphite sheet are more firmly integrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. 4 is a schematic diagram of a method for manufacturing a graphite heat sink according to an embodiment of the present invention.

[0020] Figure 2 Yes through Figure 1 A cross-sectional view illustrating the structural relationship of a graphite heat sink manufactured by the manufacturing method illustrated in FIG.

[0021] Figure 3 FIG. 4 is a schematic diagram of a method for manufacturing a graphite heat sink according to another embodiment of the present invention. DETAILED DESCRIPTION

[0022] Next, the preferred embodiment of the method for manufacturing the graphite heat sink according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the embodiments disclosed in the following content, but can be implemented in a variety of different forms. These embodiments are only for more complete disclosure of the present invention and more complete introduction of the scope of the present invention to people with general knowledge.

[0023] Figure 1 is a schematic diagram of a method for manufacturing a graphite heat sink according to one embodiment of the present invention, and Figure 2 Yes through Figure 1 A cross-sectional view illustrating the structural relationship of a graphite heat sink manufactured by the manufacturing method illustrated in FIG.

[0024] like Figure 1 as well as Figure 2As shown, the manufacturing method of the graphite heat sink of the present embodiment includes: a first step of arranging a graphite sheet 110 of a certain width between a pair of protective films 120 respectively provided with a heat-welding layer 121 on the inner side surfaces, and sealing the two side surfaces of the pair of protective films 120 by heat-welding the two side surfaces; a second step of sealing the entire graphite sheet 110 by heat-welding the openings of the pair of protective films 120 after vacuum exhausting the interior of the graphite sheet 110 sealed on both side surfaces, and heating the surfaces of the pair of protective films 120 to heat-weld the surfaces of the graphite sheet 110; and a third step of cutting the edge of the graphite sheet 110.

[0025] The first step may include: after a pair of protective films 120 are continuously supplied from a film supply roller 130 constituting a film supply assembly and a graphite sheet 110 is inserted between the pair of protective films 120, a step of sealing the two side surfaces of the pair of protective films 120 by heat-melting the two side surfaces of the pair of protective films 120; and a step of cutting the pair of protective films 120 into a length sufficient to cover the graphite sheet 110.

[0026] The graphite sheet 110 is formed into a certain width by extruding or rolling graphite powder according to a certain thickness and width, and natural graphite, artificial graphite or a mixture thereof can be used. For example, the graphite sheet 110 of this embodiment can be used by mixing 80-95% by weight of natural graphite and 5-20% by weight of artificial graphite. Among them, natural graphite and foamed graphite can be obtained by pulverizing and powdering natural graphite and then performing sulfuric acid impregnation, neutralization washing and high-temperature heating and foaming. The natural graphite of this embodiment can be natural graphite mixed with foamed graphite with diameters of 30-50μm and 200-250μm respectively according to a certain ratio, and artificial graphite can be artificial graphite with a diameter of 20-80μm.

[0027] That is, the graphite sheet 110 of the present embodiment can be formed by natural graphite and / or artificial graphite having the above-mentioned characteristics (diameter and composition ratio), but is not limited to the graphite having the above-mentioned characteristics. In addition, the graphite sheet 110 of the present embodiment can be extruded into a diameter of 0.8 to 1.65 g / cm 3 density, but is not limited thereto.

[0028] The graphite sheet 110 as described above has a porous structure and forms pores even when extruded or rolled to a certain density because the graphite itself contains a trace amount of gas. Moreover, the pores will inevitably contain gases such as sulfuric acid gas generated during the manufacturing process of the graphite sheet 110 and moisture in the atmosphere.

[0029] The protective film 120 is composed of a heat-melting layer 121 constituting the inner side and a protective layer 122 constituting the outer side. The heat-melting layer 121 can be composed of polyethylene (PE), cast polypropylene (CPP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE) with thermoplastic properties that melt at a certain temperature. In addition, in order to minimize the impact on thermal diffusion performance, the thickness of the heat-melting layer 121 is preferably less than 50μm. The protective layer 122 plays a role in protecting the graphite sheet 110 located inside it, and can be composed of polyethylene terephthalate (PET), nylon (Ny) and ethylene vinyl alcohol (EVOH). In order to minimize the impact on thermal diffusion performance, the thickness of the protective layer 122 is preferably less than 20μm.

[0030] In the process of performing the first step using the graphite sheet 110 and the pair of protective films 120 as described above, the pair of protective films 120 are continuously supplied by a pair of film supply rollers 130. The film supply assembly and the pair of film supply rollers 130 can be constructed according to the structural relationship commonly used in the industrial field, and the pair of protective films 120 can be continuously supplied in a general manner. At this time, the pair of film supply rollers 130 supply the pair of protective films 120 in a state of being arranged at a certain distance from top to bottom, thereby forming a space between the pair of protective films 120 into which the graphite sheet 110 can be placed.

[0031] Thus, the graphite sheet 110 is put into the space formed between the supplied pair of protective films 120 and arranged between the pair of protective films 120, and is in a state of being closely attached to the pair of protective films 120 by means of the pair of film supply rollers 130 and the pair of guide rollers 140 located at the rear end. The graphite sheet 110 as described above is sealed by heat-melting the side surfaces of the pair of protective films 120 between the pair of film supply rollers 130 and the pair of guide rollers 140. At this time, the heat-melting of the side surfaces of the pair of protective films 120 refers to the bonding of the pair of protective films 120 by heating the heat-melting layer 121 constituting the inner side surfaces of the pair of protective films 120, and a heating member (not shown) having a certain width can be used. Next, by using the cutting component 150 located at the rear end of a pair of guide rollers 140 to cut the pair of protective films 120 into a length sufficient to cover the graphite sheet 110, a graphite heat dissipation component 160 can be completed, which has two side surfaces sealed with the help of a pair of protective films 120 and has openings 161 at the front and back or upper and lower parts.

[0032] The second step is to seal the entire graphite sheet 110 and to perform heat-fusion bonding on the surfaces between the pair of protective films 120 and the graphite sheet 110. The graphite heat dissipation component 160 is placed in the vacuum chamber 170 and subjected to vacuum decompression for a certain period of time. The interior of the graphite heat dissipation component 160 is then vacuum-exhausted by pressing with the upper and lower heating components 180, and the opening 161 of the graphite heat dissipation component 160 is heat-fused and joined, thereby performing heat-fusion bonding on the surfaces between the pair of protective films 120 and the graphite sheet 110. All of the above processes can be performed at one time inside the vacuum chamber 170.

[0033] Among them, the vacuum chamber 170 is commonly used in the industrial field, and the inside of the graphite heat dissipation component 160 is vacuum-exhausted as long as it has a vacuum pressure that can vacuum exhaust and remove the gas and moisture remaining in the graphite sheet 110. In addition, the upper and lower heating components 180 are respectively composed of a hot stamping machine in the form of a mold that wraps the upper and lower surfaces and edges of the graphite heat dissipation component 160, so that the opening 161 of the graphite heat dissipation component 160 is heat-welded and joined, and the surface between the pair of protective films 120 and the graphite sheet 110 is heat-welded and integrated. As described above, in the second step, by heating the heat-welding layer 121 formed on the inner side of the protective film 120, the welding effect between the molten graphite sheet 110 and the surface of the pair of protective films 120 and the extrusion effect based on the vacuum pressure difference are simultaneously achieved, thereby integrating the pair of protective films 120 with the four membranes 110 more firmly.

[0034] In addition, the second step may firstly be a step of vacuum exhausting the inside of the graphite heat dissipation component 160 by heating and pressing after placing the graphite heat dissipation component 160 in the vacuum chamber 170 as described above and performing vacuum decompression for a certain period of time, and heat-melting and joining the opening 161 of the graphite heat dissipation component 160, and then a step of heat-melting the surface between the pair of protective films 120 and the graphite sheet 110 by heating after placing the graphite heat dissipation component 160 in a high-temperature chamber above 110°C. Among them, heat-melting the opening 161 of the graphite heat dissipation component 160 means heating the heat-melting layer 121 constituting the inner side surface of the pair of protective films 120 to join them to each other, and a heating component (not shown) with a certain width may be used.

[0035] The third step is to complete the graphite heat sink 100 by cutting the unnecessary part of the edge of the graphite heat sink 160 using the cutting assembly 190. The cutting assembly 90 can be constructed according to the structural relationship commonly used in the industrial field, and can cut and remove the unnecessary part of the edge of the graphite heat sink 160. At this time, it is preferable to cut the edge of the final graphite heat sink 100 in such a way that the edge has a minimum blade angle.

[0036] Figure 3 FIG. 1 is a schematic diagram of a method for manufacturing a graphite heat sink according to another embodiment of the present invention. Figure 3 As shown, the manufacturing method of the graphite heat sink of this embodiment includes: a first step of inserting a graphite sheet 310 of a certain width into a film-type bag (envelope) 320 with a heat-welding layer on the inner side and one side open; after vacuuming the inside of the graphite sheet 310 by applying vacuum to the film-type bag 320 with one side open, a second step of sealing the entire graphite sheet 310 by heat-welding the opening 321 of the film-type bag 320, and heat-welding the surface of the film-type bag 310 with the graphite sheet 310; and a third step of cutting the edge of the graphite sheet 310. It is preferable that the film-type bag 320 of this embodiment is heat-welded and sealed on three sides of the film.

[0037] The method for manufacturing the graphite heat sink of this embodiment uses a film-type bag (envelope) 320 with a heat-sealed layer on the inner side and an opening on one side, and performs the same Figure 1 The final graphite heat sink is completed by the first step, the second step and the third step which are the same or similar to the manufacturing method shown in the figure, so the description thereof will be omitted. Figure 3 In the figure, the reference numeral 360 represents a graphite heat sink, 370 represents a vacuum chamber, 380 represents an upper and lower heating component, and 390 represents a cutting assembly.

[0038] The method for manufacturing a graphite heat sink of the present invention can remove gas and moisture inside the graphite sheet by wrapping the graphite sheet with a protective film or bag provided with a heat-welding layer on the inner side and evacuating the interior, and then heating the heat-welding layer to simultaneously achieve a welding effect between the molten graphite sheet and the surface of the protective film or bag and an extrusion effect based on the vacuum pressure difference, thereby manufacturing a graphite heat sink in which the protective film or bag and the graphite sheet are more firmly integrated.

[0039] In the above content, the technical matters related to the method for manufacturing the graphite heat sink of the present invention are described with reference to the accompanying drawings, but this is only an exemplary description of the best embodiment of the present invention. Therefore, the present invention is not limited to the embodiments described in the above content, and a person with general knowledge in the technical field can make various modifications and variations without departing from the idea and scope of the present invention, and these variations or modifications are all included in the scope of the claims of the present invention.

[0040] Industry availability

[0041] The graphite heat sink of the present invention can be manufactured into a thin film, has excellent heat dissipation performance and can be conveniently pasted to the heat generating part of electronic equipment (such as a television (TV) etc.) for use.

Claims

1. A method for manufacturing a graphite heat sink, characterized in that: include: A first step of placing a graphite sheet of a certain width between a pair of films each having a thermoplastic heat-sealing layer on its inner side that melts at a certain temperature, and sealing both sides of the graphite sheet by heat-sealing both sides of the pair of films; A second step of sealing the entire graphite sheet by heat-sealing the openings of the pair of films after vacuum evacuating the interior of the graphite sheet sealed on both sides, and heating the surfaces of the pair of films to melt the heat-sealing layer and thereby heat-sealing the graphite sheet and the surfaces of the pair of protective films; as well as, The third step is to cut the edge of the graphite sheet.

2. The method for manufacturing a graphite heat sink according to claim 1, characterized in that: The first step includes: after continuously supplying the pair of films from a film supply assembly and inserting the graphite sheet between the pair of films, sealing the two sides of the graphite sheet by heat-melting the two sides of the pair of films; and cutting the pair of films into a length sufficient to cover the graphite sheet.

3. The method for manufacturing a graphite heat sink according to claim 1 or claim 2, characterized in that: In the second step, the graphite sheet with sealed sides is placed in a vacuum chamber and subjected to vacuum decompression for a certain period of time, and then pressed by upper and lower heating members to complete the vacuum exhaust, the heat welding of the opening, and the surface heat welding at one time in the vacuum chamber.

4. The method for manufacturing a graphite heat sink according to claim 1 or claim 2, characterized in that: The second step includes: a step of performing vacuum exhaust and heat welding of the opening by placing the graphite sheet with sealed sides into a vacuum chamber and heating and pressing after vacuum decompression for a certain period of time; and a step of performing surface heat welding of the pair of films and the graphite sheet by placing the sheet into a high-temperature chamber and heating.

5. A method for manufacturing a graphite heat sink, characterized in that: include: A first step of inserting a graphite sheet of a certain width into a film-type bag which is provided with a heat-welding layer having thermoplastic properties that melt at a certain temperature on the inner side and has an opening on one side; A second step of applying a vacuum to the film bag having an opening at one side to evacuate the inside of the graphite sheet, sealing the entire graphite sheet by heat-sealing the opening of the film bag, and heat-sealing the graphite sheet to the surface of the film bag by heating the surface of the film bag; as well as, The third step is to cut the edge of the graphite sheet.

6. The method for manufacturing a graphite heat sink according to claim 5, characterized in that: The second step is to place the film bag having the graphite sheet therein into a vacuum chamber and perform vacuum decompression for a certain period of time, and then press the film bag using upper and lower heating members to complete the vacuum exhaust, the heat welding of the opening, and the surface heat welding at one time in the vacuum chamber.

7. The method for manufacturing a graphite heat sink according to claim 5, characterized in that: The second step includes: a step of performing vacuum exhaust and heat welding of the opening by placing the film bag having the graphite sheet disposed therein into a vacuum chamber and performing vacuum decompression for a certain period of time and then heating and pressing the film bag; and a step of performing surface heat welding of the film bag and the graphite sheet by placing the film bag into a high-temperature chamber and heating the film bag.

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