TWI549907B - Graphite film and manufacturing method thereof - Google Patents

Description

Graphite film and method for producing graphite film

The present invention relates to a graphite film and a method of manufacturing the same, and more particularly to a flat, non-destructive graphite film and a method of manufacturing the same.

The graphite film is a polymer material having high thermal conductivity and is commonly used in electronic circuit devices as an important material for semiconductor elements and heat generating elements. For example, the industry uses graphite films as materials in the manufacture of printed circuit boards to help conduct and eliminate the heat generated by the boards during use. Since printed circuit boards are an important component in various electronic products, graphite films have become an indispensable material in the manufacture of various electronic products.

However, in the preparation of a graphite film, the film is extremely susceptible to volume shrinkage due to heating. In this way, the surface of the finished graphite film is distributed with wrinkles of different sizes. The graphite film having an uneven surface has a problem that it cannot be sufficiently adhered to the surface of the electronic circuit component, which causes a poor heat dissipation effect.

Therefore, how to develop a graphite film to solve the problem of wrinkles in the surface of the graphite film in the prior art in the prior art has become a problem that researchers need to solve.

In view of the above problems, the present invention relates to a graphite film and its preparation The method is to solve the problem of surface damage and unevenness of the graphite film in the prior art.

The invention discloses a method for manufacturing a graphite film. First, a polyimide film having a carbon material mixed is formed. Next, the polyimine film which is carbonized and mixed with the carbon material is heated at a carbonization temperature to form a carbonized polyimide film. Finally, the graphitized carbonized polyimide film is heated at a graphitization temperature higher than the carbonization temperature to form a graphite film.

The invention discloses a graphite film comprising a graphite film. The graphite film is a carbonized and graphitized polyimide film. The polyimide film comprises a polyimine and a carbon material.

According to the graphite film disclosed in the above invention and the method for producing the same, since the polyimide film contains a carbon material, the volume shrinkage of the polyimide film which occurs during heating can be reduced. In this way, the graphite film obtained by heating carbonization and graphitization by the polyimide film can be kept flat, and solves the problem that the wrinkles of the graphite film in the prior art are used.

The above description of the present invention and the following description of the embodiments of the present invention are intended to illustrate and explain the principles of the invention.

10‧‧‧Graphite film

11‧‧‧ graphite film

12‧‧‧ Polyimine film

Fig. 1A is a schematic view showing a graphite film according to an embodiment of the present invention.

1B is a schematic view of an uncarbonized and ungraphitized polyimide film according to an embodiment of the present invention.

2 is a flow chart of a method for fabricating a graphite film according to an embodiment of the present invention.

Figure 3 is a graphite film product of the first embodiment of the present invention.

Figure 4 is a graphite film product of the second embodiment of the present invention.

Fig. 5 is a view showing a graphite film of Comparative Example 1 of the present invention.

Figure 6 is a graph of the graphite film of Comparative Example 2 of the present invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Hereinafter, the structure of the graphite film of the present invention will be described first. Please refer to FIGS. 1A and 1B. Fig. 1A is a schematic view showing a graphite film according to an embodiment of the present invention. 1B is a schematic view of an uncarbonized and ungraphitized polyimide film according to an embodiment of the present invention.

The graphite film 10 contains a graphite film 11. The graphite film 11 is obtained by carbonizing and graphitizing the polyimide film 12 . The polyimide film 12 comprises a polyimide and a carbon material. The carbon material is uniformly distributed in the polyimide, and the weight ratio of the carbon material to the polyimide is 1:99 to 40:60, preferably 6:94 to 20:80. The polyimine is obtained by reacting a diamine with a dianhydride to form a poly-proline, and then performing a methanation reaction of the polyamic acid by heating. The carbon material contains carbon black, carbon ash, graphite, carbon spheres, carbon tubes or graphene, but is not limited thereto. In other embodiments of the invention, the carbon material may be other materials having a high carbon content. Polyimine film 12 In the process of carbonization and graphitization, since the carbonization temperature is as high as 800 ° C to 1500 ° C, the graphitization temperature is as high as 2600 ° C to 2900 ° C, and some of the carbon, hydrogen, oxygen and nitrogen in the polyimide film 12 are volatilized by heat, and finally only remain. Under carbon. Therefore, the thickness of the graphite film 11 formed by carbonization and graphitization of the polyimide film 12 is smaller than the thickness of the polyimide film 12 before carbonization and graphitization.

Next, a method of producing the graphite film of the present invention will be described, see Fig. 2. 2 is a flow chart of a method for fabricating a graphite film according to an embodiment of the present invention.

First, the carbon material is added to a polar solvent and mixed uniformly (S101).

In detail, the carbon material is added to the polar solvent. The weight ratio of carbon material to polyimine is from 1:99 to 40:60, preferably from 6:94 to 20:80. The polar solvent may be N, N-Dimethyl formamide (DMF), Dimethylacetamide (DMAc), Dimethyl sulfoxide (DMSO), N-methylpyrrolidone. (N-methyl-2-pyrrolidone, NMP), gamma-butyrolactone (GBL) and combinations thereof, but not limited thereto. The carbon material contains carbon black, carbon ash, graphite, carbon spheres, carbon tubes or graphene, but is not limited thereto. In other embodiments of the invention, the carbon material may be other materials having a high carbon content.

In order to mix the carbon material with the solvent uniformly and reduce the mixing time required, the solvent can be rapidly stirred at a frequency of 20 Hz (Hertz, Hz) to 100 Hz to accelerate the dispersion of the carbon material in the solvent. Further, the carbon material may be accelerated in the solvent by grinding.

Next, the diamine is dissolved in a polar solvent mixed with a carbon material to form A diamine solution of a carbon material is mixed (S102).

In detail, the diamine is added to a polar solvent mixed with a carbon material, and the diamine is dissolved in a polar solvent to form a diamine solution by a stirring or grinding process, and the carbon material is uniformly dispersed in the diamine solution. The diamine is selected from the group consisting of 1,4-diamino benzene, 1,3-diamino benzene, and 4,4'-diaminodiphenyl ether (4,4'-oxydianiline). , 3,4'-oxydianiline, 4,4'-methylene dianiline, di-p-phenylenediamine (N, N-Diphenylethylenediamine), diaminobenzophenone, diaminodiphenyl sulfone, 1,5-naphthalene diamine, diaminodiphenyl sulfide (4,4 '-diaminodiphenyl sulfide), 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoloxy)benzene (1,4-Bis(4-aminophenoxy)benzene), 1,3-bis(4-aminophenoxy)benzene, 2,2'-di[ 4-(4-Aminophenoxy)phenyl]propane), 4,4'-bis(4-aminophenoloxy) 4,4'-bis-(4-aminophenoxy)biphenyl, 4,4'-bis-(3-aminophenoxy)biphenyl 1,3-Bis(3-aminopropyl)-1,1',3,3'-tetramethyldisiloxane 1,3-dipropene 1,1-B'(3-aminopropyl)-1,1',3,3'-tetraphenyldisiloxane, 1,3-dipropylamine Base-1,1'-dimethyl-3,3'-diphenyldioxane (1,3-Bis(aminopropyl)-dimethyldiphenyldisiloxane) and the group formed thereof.

Next, the dianhydride is added to the diamine solution in which the carbon material is mixed to form a polyamine acid solution (103) mixed with the carbon material.

In detail, the dianhydride is added to the diamine solution mixed with the carbon material, and the dianhydride is reacted with the diamine in the diamine solution to form a poly-proline solution, and the carbon material is uniformly dispersed in the poly-proline solution. . The ratio of the molar amount of the dianhydride to the diamine solution to the diamine molar in the diamine solution is from 0.98:1 to 1.05:1. The dianhydride is selected from the group consisting of 1,2,4,5-Benzenetetracarboxylic dianhydride and biphenyltetracarboxylic dianhydride (3,3',4,4'-Biphenyltetracarboxylic). Dianhydride), 4,4'-Oxydiphthalic anhydride, Benzophenone tetracarboxylicdianhydride, diphenylphosphonium tetracarboxylic dianhydride (3,3',4,4 '-diphenyl sulfonetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, bis-(3,4-phthalic anhydride) dimethyl decane (bis(3,4-dicarboxypheny1)dimethylsilane dianhydride), 1,3-bis(3,4-dicarboxyphenyl)-1,1',3,3'-tetramethyldioxane dianhydride (1 , 3-bis (4'-phthalic anhydride)-tetramethyldisiloxane) and the group formed thereof. At this time, the polyamine liquid solution mixed with the carbon material has a viscosity of 100 poise (psise) to 1000 poise (that is, 10,000 cps to 100,000 cps).

It is worth noting that in this embodiment, a polyfluorene mixed with a carbon material is formed. The step of the amine acid film is to sequentially add carbon materials, diamines and dianhydrides in a polar solution to form a polyamic acid solution mixed with carbon materials, but not limited thereto. In other embodiments of the invention, the order in which the carbon material, diamine, and dianhydride are added to the polar solution is adjustable. In some embodiments of the invention, the carbon material is added to the diamine solution after the diamine is dissolved in the polar solvent to form the diamine solution. In some embodiments of the invention, the carbon material is added to the polar solvent along with the diamine to form a diamine solution. In some embodiments of the present invention, the carbon material is added to the polyamine solution after the dianhydride is added to the diamine solution, and then added to the polyaminic acid solution. In some embodiments of the invention, the carbon material is added to the diamine solution along with the dianhydride to form a polyaminic acid solution. In some embodiments of the present invention, the carbon material is added to the dianhydride solution after the dianhydride is dissolved in the polar solvent to form the dianhydride solution. In some embodiments of the invention, the carbon material is added to the polar solvent along with the dianhydride to form a dianhydride solution. In some embodiments of the present invention, the carbon material is added to the polyamine solution after the diamine is added to the dianhydride solution, and then added to the polyaminic acid solution. In some embodiments of the invention, the carbon material is added to the dianhydride solution together with the diamine to form a polyaminic acid solution.

Next, the polyamic acid solution in which the carbon material is mixed is heated and dried to form a polyamic acid film in which the carbon material is mixed (S104).

Specifically, a polyamine acid solution mixed with a carbon material is coated on a carrier, and then a carrier material coated with a polyamic acid solution mixed with a carbon material is placed in a high temperature environment of 120 ° C to 200 ° C. Heat drying in the middle. As a result, the solvent in the polyamic acid solution mixed with the carbon material is heated and vaporized to leave the polyamic acid solution mixed with the carbon material, and the polyamic acid solution mixed with the carbon material is not vaporized. Polylysine forms a polylysine film, while unvaporized carbon material is evenly distributed in polylysine In the film. After the solvent in the polyamic acid solution to be mixed with the carbon material is heated and vaporized, the polyamic acid film in which the carbon material is mixed is peeled off from the carrier material to obtain a polyamic acid film in which the carbon material is mixed. The temperature of the heat drying can be matched to the boiling point of the solvent. In some embodiments of the present invention, the drying temperature is from 120 ° C to 200 ° C, but is not limited thereto.

Next, the polyamic acid film in which the carbon material is mixed is subjected to a mercaptochemical reaction to form a polyimine film in which a carbon material is mixed (S105).

In detail, the imidization reaction may heat the polyglycolic acid film mixed with the carbon material at a temperature higher than the heat drying temperature (250 ° C - 450 ° C) to polymerize the polyamide film. The valine acid is dehydrated and closed to form a polyimide film. The methylene amination reaction may also be carried out by adding a dehydrating agent (for example, an acid anhydride) or a catalyst (polymer clamped catalyst) to the polyphthalic acid to dehydrate and close the polyglycolic acid in the polyaminic acid mold (chemical cyclization). Method) to form a polyimide film. After the berylation is completed, the carbon material is uniformly distributed in the polyimide film. Among them, the higher the heating temperature, the shorter the time required for the polyaminic acid film to undergo a imidization reaction to form a polyimide film. However, if the temperature of the reaction is too high, the bond between the atoms in the polyimine molecule may be destroyed, so that the polyimine is degraded due to high temperature. In some embodiments of the present invention, the temperature at which the polyamithanic acid film is subjected to the methylene amination reaction by heating is 270 ° C to 450 ° C, but is not limited thereto.

Next, a polyimide film having a carbon material mixed with a carbon material is heated at a carbonization temperature to form a carbonized polyimide film (S106).

In detail, the polyimine film mixed with carbon material is placed in a low pressure environment, a nitrogen atmosphere or an inert gas atmosphere, and the carbon is 800 ° C to 1500 ° C. The temperature is subjected to heat treatment to start carbonization of the polyimine on the surface of the polyimide film to obtain a carbonized polyimide film. For example, a polyimine film mixed with a carbon material may be placed in a heating chamber having an internal pressure lower than one atmosphere for carbonization, or a polyimide film mixed with a carbon material may be filled with a carbon material. Heating and carbonization is carried out in a heating chamber of nitrogen.

Finally, the graphitized carbonized polyimide film is heated at a graphitization temperature higher than the carbonization temperature to form a graphite film (S107).

In detail, the carbonized polyimide film is placed in a low pressure environment or an inert gas atmosphere, and heat treated at a graphitization temperature of 2600 ° C to 2900 ° C to carbonize the surface of the carbonized polyimide film. The imide starts to be graphitized to obtain a graphite film, and the preparation of the graphite film is completed. For example, the carbonized polyimide film can be placed in a heating chamber filled with argon or helium to be heated and graphitized to obtain a graphite film.

Since the polyimine film contains carbon material, the volume shrinkage of the polyimide film decreases during the process of heating carbonization and heating graphitization, and the polyimine film is reduced during heating. A condition caused by excessive shrinkage of the volume. In this way, the graphite film obtained by heating carbonization and graphitization by a polyimine film containing a carbon material can be kept flat.

In addition, the carbonization of the polyimide film and the graphitization of the carbonized polyimide film in one embodiment of the present invention may be performed in different heating chambers, but not limited thereto. In other embodiments of the present invention, the carbonization of the polyimide film and the graphitization of the carbonized polyimide film may also be performed on the polyimide film at the carbonization temperature in the same heating chamber. After carbonization, the heating temperature is raised to the graphitization temperature to graphitize the carbonized polyimide film.

The graphite film disclosed in the present proposal and a method for producing the same are described below by several examples and comparative examples, and experimental tests are conducted to compare the difference in properties.

Embodiment 1

First, 9.6 g of carbon black was added to 850 g of dimethylacetamide (DMAc) and stirred for 1 hour to uniformly mix the carbon black with DMAc.

Next, 71.8 g of 4,4'-diaminodiphenyl ether (ODA) was added to the DMAc mixed with carbon black and stirred for 1 hour to dissolve the ODA in the DMAc mixed with carbon black to form a mixture of carbon black. Amine solution.

Next, 78.2 g of 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA) was slowly added to the diamine liquid mixed with carbon black and stirred at room temperature for 6 hours to react PMDA with ODA to form a mixture. A polyamic acid solution of carbon material.

Next, the polyamine acid solution mixed with the carbon material was applied onto the carrier plate, and the polyamine solution mixed with the carbon material was dried by heating at 120 ° C for 10 minutes to form a polymer mixed with the carbon material on the carrier plate. A proline membrane, and the polyamic acid membrane mixed with the carbon material is peeled off from the carrier sheet.

Next, the polyamic acid film in which the carbon material was mixed was heated at 400 ° C for 10 minutes, and the polyamine membrane mixed with the carbon material was subjected to a mercaptochemical reaction to form a polyimide film in which a carbon material was mixed.

Next, the carbonized polyimide film was heated and heated at a carbonization temperature of 1000 ° C in a heating chamber filled with a nitrogen atmosphere for 60 minutes to form a carbonized polycondensation. 醯 imine film.

Finally, the graphitized carbonized polyimide film was heated in a heating chamber filled with an argon atmosphere at a graphitization temperature of 2900 ° C for 30 minutes to form a graphite film.

Embodiment 2

First, 37.5 g of carbon black was added to 850 g of dimethylacetamide (DMAc) and stirred for 1 hour to uniformly mix the carbon black with DMAc.

Next, 71.8 g of ODA was added to DMAc mixed with carbon black and stirred for 1 hour, and ODA was dissolved in DMAc mixed with carbon black to form a diamine solution in which carbon black was mixed.

Next, 78.2 g of 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA) was slowly added to the diamine solution mixed with carbon black and stirred at room temperature for 6 hours to react PMDA with ODA to form a mixture. A polyamic acid solution of carbon material.

The subsequent dry film formation, imidization, heat carbonization, and heat graphitization are similar to those of the first embodiment, and will not be described herein.

Comparative example one

First, 71.8 g of ODA was added to 850 g of DMAc and stirred for 1 hour to dissolve the ODA in DMAc to form a diamine solution.

Next, 78.2 g of PMDA was slowly added to the diamine solution and stirred at room temperature for 6 hours to react PMDA with ODA to form a polyaminic acid solution.

The subsequent dry film formation, imidization, heat carbonization, and heat graphitization are similar to those of the first embodiment, and will not be described herein.

Comparative example two

First, 36.5 g of ODA and 19.8 g of PPDA were added to 850 g of DMAc and stirred for 1 hour to dissolve the ODA and PPDA in DMAc to form a diamine solution.

Next, 39.8 g of PMDA and 53.8 g of BPDA were slowly added to the diamine solution and stirred at room temperature for 6 hours to react PMDA and BPDA with ODA and PPDA to form a polyaminic acid solution.

The subsequent dry film formation, imidization, heat carbonization, and heat graphitization are similar to those of the first embodiment, and will not be described herein.

Please refer to Table 1. Table 1 shows the composition of the graphite film and the related measurement results of the second embodiment and the second comparative example. 3 is a graphite film product of the first embodiment of the present invention, FIG. 4 is a graphite film product of the second embodiment of the present invention, and FIG. 5 is a graphite film product of the first comparative example of the present invention. FIG. The graphite film of Comparative Example 2 was finished.

The graphite film prepared according to the composition ratio of the first embodiment and the second embodiment has a flat surface and a wrinkle-free surface type, so that it can be sufficiently adhered to the surface of the electronic circuit component in use, thereby providing a better heat dissipation effect.

In the graphite film of Comparative Example 1 and Comparative Example 2, since the carbon material was not added to the polyimide film, the surface of the graphite film exhibited an uneven and wrinkled surface type, and cracks appeared even on the surface of the graphite film. . Therefore, it is not possible to sufficiently adhere to the surface of the electronic circuit component in use, resulting in a problem that the electronic circuit component has a poor heat dissipation effect.

According to the graphite film disclosed in the above invention and the method for producing the same, the polyimine film to which the carbon material is added can maintain a flat and wrinkle-free surface state during carbonization and graphitization, and thus can be sufficiently applied in use. It is integrated with the surface of the electronic circuit component to provide better heat dissipation. As a result, in the prior art, the graphite film cannot be sufficiently adhered to the surface of the electronic circuit component, and the problem that the heat dissipation effect of the electronic circuit component is poor is solved.

Although the present invention has been disclosed above in the preferred embodiment of the foregoing, It is not intended to limit the invention, and any skilled person in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The definition is final.

Claims (10)

A method for producing a graphite film, comprising: forming a polyimine film mixed with a carbon material; heating and carbonizing the polyimine film mixed with the carbon material to form a carbonized polyimide film at a carbonization temperature; Heating and graphitizing the carbonized polyimide film at a graphitization temperature higher than the carbonization temperature to form a graphite film; wherein the carbon material and the polyfluorene are contained in the polyimide film mixed with the carbon material The imine, the weight ratio of the carbon material to the polyimine is from 1:99 to 40:60. The method for producing a graphite film according to claim 1, wherein the polyimine film in which the carbon material is mixed is formed, comprising: adding the carbon material to a polar solvent and mixing uniformly; dissolving the monoamine in the mixture Forming a diamine solution mixed with the carbon material in the polar solvent of the carbon material; adding a dianhydride to the diamine solution mixed with the carbon material to form a poly-proline solution mixed with the carbon material; heating Drying the polyaminic acid solution mixed with the carbon material to form a poly-proline film mixed with the carbon material; and subjecting the polyamic acid film mixed with the carbon material to a methylene amination reaction to form a mixture The polyimine film having the carbon material. The method for producing a graphite film according to claim 2, wherein the diamine is selected from the group consisting of 1,4-diamino benzene, 1,3-diamino benzene, 4, 4'- Diamine diphenyl ether (4,4'-oxydianiline), 3,4'-diamino diphenyl ether (3,4'-oxydianiline), 4,4'-diaminodiphenyl (4,4 '-methylene dianiline), N,N-Diphenylethylenediamine, diaminobenzophenone, diamino diphenyl sulfone, dinaphthyldiamine (1,5- Naphthalene diamine), 4,4'-diamino diphenyl sulfide, 1,3-Bis(3-aminophenoxy)benzene 1,4-Bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoloxy)benzene (1,3- Bis(4-aminophenoxy)benzene), 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (2,2'-Bis[4-(4-amino phenoxy)phenyl]propane , 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoloxy) Biphenyl (4,4'-bis-(3-aminophenoxy)biphenyl), 1,3-dipropylamino-1,1',3,3'-tetramethyldioxane (1,3-Bis ( 3-aminopropyl)-1,1',3,3'-tetramethyldisiloxane), 1,3-dipropylamino-1,1',3,3'-tetraphenyldioxane (1,3-Bis ( 3-aminopropyl)-1,1',3,3'-tetraphenyldisiloxa Ne), 1,3-Bis(aminopropyl)-dimethyldiphenyldisiloxane (1,3-Bis(aminopropyl)-dimethyldiphenyldisiloxane) and its group group. The method for producing a graphite film according to claim 2, wherein the dianhydride is selected from the group consisting of 1,2,4,5-Benzene tetracarboxylic dianhydride, Bismuth tetracarboxylic dianhydride (3,3',4,4'-Biphenyl tetracarboxylic dianhydride), 4,4'-Oxydiphthalic anhydride, benzophenone tetracarboxylic dianhydride ), 3,3',4,4'-diphenyl sulfonetetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, naphthalic anhydride (Naphthalenetetracarboxylic Dianhydride), bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)- 1,1',3,3'-tetramethyldisiloxane (1,3-bis(4'-phthalic anhydride)-tetramethyldisiloxane) and a group thereof. The method for producing a graphite film according to claim 1, wherein the carbon material and the polyimine are contained in the polyimide film in which the carbon material is mixed, and the weight ratio of the carbon material to the polyimide is 6:94 to 20:80. A method of producing a graphite film according to claim 1, wherein the carbon material comprises carbon black, carbon ash, graphite, carbon spheres, carbon tubes or graphene. The method for producing a graphite film according to claim 1, wherein the carbonization temperature is 900 to 1500 ° C, and the graphitization temperature is 2600 to 2900 ° C. A graphite film comprising: a graphite film, which is a carbonized and graphitized polyimide film; wherein the polyimide film comprises a polyimine and a carbon material, the carbon material The weight ratio to the polyimine is from 1:99 to 40:60. The graphite film of claim 8, wherein the weight ratio of the carbon material to the polyimine in the polyimide film is from 6:94 to 20:80. The graphite film of claim 8, wherein the carbon material comprises carbon black, carbon ash, graphite, carbon spheres, carbon tubes or graphene.