Preparation method of circuit board with heat-conducting coating

Abstract

The invention discloses a preparation method of a circuit board with a heat-conducting coating, which comprises the following steps: dissolving polyimide in an organic solvent, adding expanded beads, stirring to obtain a first mixed solution, then adding copper powder and graphite powder in the organic solvent to obtain a heat-conducting material, and then adding a second mixed solution in the heat-conducting material to obtain the circuit board with the heat-conducting coating. The method comprises the following steps: sequentially mixing and stirring organic silicon resin, a first mixed solution and a heat conduction material to obtain a second mixed solution, coating a substrate of the circuit board with the second mixed solution, and finally, carrying out heat treatment on the circuit board to obtain the circuit board with the heat conduction coating. The heat conduction coating has excellent heat conduction performance and capability of reducing the dielectric constant, and can greatly improve the heat conduction capability and performance of the circuit board, so that the circuit board can still work stably in a high-temperature environment, and the service life of the circuit board is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of circuit boards, and in particular to a method for preparing a circuit board with a thermal conductive coating. Background Art

[0002] With the continuous development of human science and technology, electronic products have become an indispensable tool in modern life. As an important part of electronic products, the excellent performance of circuit boards has attracted more and more attention. However, with the increasing density of electronic equipment, the heat generated by circuit boards during operation is also increasing, causing the temperature of the circuit boards to rise, affecting the stability and life of the circuit boards. Therefore, how to improve the heat dissipation capacity of circuit boards is particularly critical to improving their operating stability and life. Summary of the invention

[0003] In view of the deficiencies in the prior art, an embodiment of the present invention provides a method for preparing a circuit board with a thermal conductive coating, comprising:

[0004] Adding polyimide into an organic solvent to dissolve it, adding expanded microbeads, and stirring to obtain a first mixed solution;

[0005] Adding copper powder and graphite powder into an organic solvent to obtain a thermal conductive material;

[0006] Mixing the silicone resin, the first mixed liquid, and the thermally conductive material in sequence to obtain a second mixed liquid;

[0007] Applying the second mixed solution on a substrate of a circuit board;

[0008] The circuit board is heat treated to obtain a circuit board with a thermal conductive coating.

[0009] As a preferred embodiment, the preparation steps of the silicone resin include:

[0010] One of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder are mixed, heated and stirred to obtain an organic silicone resin.

[0011] As a preferred embodiment, the silicone resin is obtained by mixing one of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder, and heating and stirring. Specifically, the silicone resin includes:

[0012] Take 100 parts by weight of phenylene siloxane or methyl siloxane, 10 parts by weight of aluminum oxide powder and 1 part by weight of silicone oil or silane compound, mix them in proportion and heat and stir at 100-120 degrees Celsius to obtain an organic silicone resin.

[0013] As a preferred embodiment, the heating and stirring time for one of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder is 10 hours.

[0014] As a preferred embodiment, the polyimide is added into an organic solvent for dissolution, and expanded microspheres are added, and the first mixed solution is obtained by stirring, which specifically includes:

[0015] 10 g of polyimide was added to an organic solvent for dissolution, and 5 parts by weight of expanded microbeads were added thereto, followed by stirring to obtain a first mixed solution.

[0016] As a preferred embodiment, the step of adding copper powder and graphite powder into an organic solvent to obtain a thermally conductive material specifically comprises:

[0017] 5 g of copper powder and 10 g of graphite powder were added to an organic solvent to obtain a thermal conductive material.

[0018] As a preferred solution, the heat treatment temperature during the heat treatment of the circuit board is 120 to 150 degrees Celsius.

[0019] The method for preparing the circuit board with the thermal conductive coating further comprises:

[0020] A punching device is provided; the punching device comprises a fixing plate and a plurality of punching needles, wherein the plurality of punching needles are connected to the fixing plate;

[0021] During the heat treatment of the circuit board, when the second mixed liquid is in a gel stage, inserting a punching needle of the punching device into the second mixed liquid in the gel stage;

[0022] When the second mixed liquid is in the final solidification stage, the punching needle of the punching device is taken out.

[0023] As a preferred solution, the distance between each two adjacent punching needles is equal.

[0024] As a preferred solution, after heat treating the circuit board to obtain the circuit board with the thermal conductive coating, the method further includes:

[0025] The thermal conductive coating is subjected to a punching process.

[0026] Compared with the prior art, the beneficial effect of the embodiments of the present invention is that: the embodiments of the present invention provide a method for preparing a circuit board with a thermally conductive coating, by adding polyimide into an organic solvent for dissolution, adding expanded microspheres, and stirring to obtain a first mixed liquid, then adding copper powder and graphite powder into the organic solvent to obtain a thermally conductive material, then mixing and stirring the silicone resin, the first mixed liquid, and the thermally conductive material in sequence to obtain a second mixed liquid, and coating the second mixed liquid on the substrate of the circuit board, and finally, heat-treating the circuit board to obtain a circuit board with a thermally conductive coating. In this way, by arranging a thermally conductive coating on the circuit board, the thermally conductive coating is prepared by specific ingredients and processing technology, has excellent thermal conductivity and the ability to reduce the dielectric constant, can greatly improve the thermal conductivity and performance of the circuit board, so that the circuit board can still work stably in a high temperature environment, and prolongs the service life of the circuit board. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic flow chart of a method for preparing a circuit board with a thermal conductive coating in an embodiment of the present invention;

[0028] Figure 2 It is a schematic diagram of the principle of forming holes in the thermal conductive coating by a punching device in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] See also Figure 1 As shown, the method for preparing a circuit board with a thermal conductive coating according to an embodiment of the present invention comprises:

[0031] Step S101, adding polyimide into an organic solvent to dissolve it, adding expanded microbeads, and stirring to obtain a first mixed solution;

[0032] Step S102, adding copper powder and graphite powder into an organic solvent to obtain a thermally conductive material;

[0033] Step S103, mixing and stirring the silicone resin, the first mixed liquid, and the thermal conductive material in sequence to obtain a second mixed liquid;

[0034] Step S104, coating the second mixed liquid on a substrate of a circuit board;

[0035] Step S105, heat-treating the circuit board to obtain a circuit board with a thermal conductive coating.

[0036] In an embodiment of the present invention, polyimide is added to an organic solvent for dissolution, and expanded microspheres are added, and a first mixed liquid is obtained by stirring. Then, copper powder and graphite powder are added to the organic solvent to obtain a thermally conductive material. Next, the silicone resin, the first mixed liquid, and the thermally conductive material are sequentially mixed and stirred to obtain a second mixed liquid, and the second mixed liquid is coated on a substrate of a circuit board. Finally, the circuit board is heat-treated to obtain a circuit board with a thermally conductive coating. In this way, by arranging a thermally conductive coating on the circuit board, the thermally conductive coating is prepared by specific ingredients and processing technology, has excellent thermal conductivity and the ability to reduce the dielectric constant, can greatly improve the thermal conductivity and performance of the circuit board, so that the circuit board can still work stably in a high temperature environment, and extend the service life of the circuit board.

[0037] In an optional embodiment, the preparation step of the silicone resin comprises:

[0038] One of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound and aluminum oxide powder are mixed, heated and stirred to obtain silicone resin. Of course, in the specific implementation, other methods can be used to prepare silicone resin according to actual use requirements, which will not be described in detail here.

[0039] In an optional embodiment, the step of mixing one of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder, and heating and stirring to obtain an organic silicone resin specifically includes:

[0040] 100 parts by weight of phenylene siloxane or methyl siloxane, 10 parts by weight of alumina powder and 1 part by weight of silicone oil or silane compound are mixed in proportion and heated and stirred at 100 to 120 degrees Celsius to obtain an organic silicone resin. The temperature of heating and stirring can be, for example, 100 degrees Celsius, 101 degrees Celsius, 102 degrees Celsius, 103 degrees Celsius, 104 degrees Celsius, 105 degrees Celsius, 106 degrees Celsius, 107 degrees Celsius, 108 degrees Celsius, 109 degrees Celsius, 110 degrees Celsius, 111 degrees Celsius, 112 degrees Celsius, 113 degrees Celsius, 114 degrees Celsius, 115 degrees Celsius, 116 degrees Celsius, 117 degrees Celsius, 118 degrees Celsius, 119 degrees Celsius, 120 degrees Celsius, etc. Of course, the temperature of heating and stirring can also be set to other values ​​according to actual use requirements, which will not be described in detail here.

[0041] The organic silicon resin prepared in this embodiment has extremely high temperature resistance and chemical stability, and can work safely for a long time in a high temperature environment.

[0042] In an optional embodiment, the heating and stirring time for one of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder is 10 hours, so that each component can fully react and be evenly mixed.

[0043] In an optional embodiment, the step S102 of "adding polyimide to an organic solvent for dissolution, adding expanded microspheres, and stirring to obtain a first mixed solution" specifically includes:

[0044] 10 g of polyimide is dissolved in an organic solvent, and 5 parts by weight of expanded microspheres are added, and a first mixed solution is obtained by stirring. For example, the organic solvent may be N-methylpyrrolidone (NMP), etc. Of course, other organic solvents may be used according to actual use requirements, and no further details are given here.

[0045] In a specific implementation, the expanded microspheres and polyimide have excellent filling properties and the ability to reduce the dielectric constant. The polyimide and expanded microspheres with the above ratio can be used to reduce the size of the circuit board and improve the performance of the circuit board.

[0046] In an optional implementation manner, the step S103 “adding copper powder and graphite powder to an organic solvent to obtain a thermally conductive material” specifically includes:

[0047] 5 g of copper powder and 10 g of graphite powder are added to an organic solvent to obtain a thermal conductive material. For example, the organic solvent may be N-methylpyrrolidone (NMP), etc. Of course, other organic solvents may also be used according to actual use requirements, which will not be described in detail here.

[0048] The thermally conductive material prepared in this embodiment can significantly improve the thermal conductivity of the thermally conductive coating, thereby greatly improving the heat dissipation capacity and thermal conduction capacity of the circuit board.

[0049] In an optional embodiment, the heat treatment temperature during the heat treatment of the circuit board is 120 to 150 degrees Celsius, for example, it can be 120 degrees Celsius, 123 degrees Celsius, 125 degrees Celsius, 128 degrees Celsius, 130 degrees Celsius, 133 degrees Celsius, 135 degrees Celsius, 138 degrees Celsius, 140 degrees Celsius, 143 degrees Celsius, 145 degrees Celsius, 148 degrees Celsius, 150 degrees Celsius, etc. Of course, the heat treatment temperature during the heat treatment of the circuit board can also be set to other values ​​according to actual use requirements, which will not be described in detail here. In this embodiment, the heat treatment temperature during the heat treatment of the circuit board is set to 120 to 150 degrees Celsius to solidify the second mixed liquid, thereby obtaining a thermally conductive coating without damaging the circuit board.

[0050] The embodiment of the present invention prepares a circuit board by the above preparation method, wherein the circuit board includes a circuit board substrate and a thermal conductive coating, and the thermal conductive coating is arranged on the circuit board substrate. The thermal conductive coating is composed of an organic silicon material, including an organic silicon resin, polyimide, expanded microspheres and a thermal conductive material. During the preparation process, these important components are added in different proportions and obtained through a certain regular processing process.

[0051] In an optional embodiment, the method for preparing the circuit board with the thermal conductive coating further comprises:

[0052] A punching device is provided; the punching device comprises a fixing plate and a plurality of punching needles, wherein the plurality of punching needles are connected to the fixing plate;

[0053] During the heat treatment of the circuit board, when the second mixed liquid is in a gel stage, inserting a punching needle of the punching device into the second mixed liquid in the gel stage;

[0054] When the second mixed liquid is in the final solidification stage, the punching needle of the punching device is taken out.

[0055] In this embodiment, the gel stage refers to the state in which the second mixed liquid is between the fluid state and the final solidified state. In this stage, the second mixed liquid will become a soft gel similar to hard rubber, which can be pressed by fingers and will leave pits on the surface. Figure 2The punching device in this embodiment includes a fixed plate 10 and a plurality of punching needles 20 connected to the fixed plate 10. The connection end of the punching needle 20 is connected to the fixed plate 10. The tip of the punching needle 20 penetrates into the second mixed liquid in the gel stage. At this time, the second mixed liquid is in the gel stage, that is, it is basically formed and will not be fully attached to the punching needle 20. Therefore, when the punching needle 20 is taken out in the state where the second mixed liquid is in the final curing stage and solidified into the thermal conductive coating 30, the punching needle 20 will not bring out too much colloid and will not cause too much impact on the heat dissipation effect of the circuit board 40. If the punching needle 20 is inserted when the second mixed liquid is in a liquid state, the second mixed liquid is easy to be fully attached to the punching needle during its curing process. In this way, when the punching needle 20 is subsequently taken out, the punching needle 20 is easy to bring out more colloid, which is not conducive to the heat dissipation of the circuit board 40. In this embodiment, the punching device is used to perform holes, so that the thermal conductive coating 30 has multiple holes, which increases the heat dissipation area of ​​the thermal conductive coating 30, and is therefore conducive to the discharge of heat from the thermal conductive coating 30. In addition, the inventors found in the process of implementing the present invention that if the thermal conductive coating 30 is not provided with holes, when the thermal conductive coating 30 is heated, it is easy to expand and deform, causing partial separation or even overall detachment from the circuit board 40, thereby affecting the heat dissipation effect of the thermal conductive coating 30 on the circuit board 40. In this embodiment, the multiple holes of the thermal conductive coating 30 provide deformation space for the thermal conductive coating 30, avoiding the phenomenon that the thermal conductive coating 30 is easily partially separated from the circuit board 40 or even overall detachment due to expansion and deformation, thereby ensuring the heat dissipation effect of the thermal conductive coating 30 on the circuit board 40. In the specific implementation, the multiple holes of the thermal conductive coating 30 are through holes, that is, the holes penetrate the upper and lower surfaces of the thermal conductive coating 30, so as to better dissipate heat and provide sufficient deformation space for the thermal conductive coating 30. Of course, in actual applications, the multiple holes of the thermal conductive coating 30 can also be set as blind holes according to actual use requirements, which will not be described in detail here.

[0056] Furthermore, the distance between each two adjacent punching needles 20 is equal, so that the obtained thermal conductive coating 30 has evenly distributed holes, which is beneficial to the uniform heat dissipation of the circuit board 40 and ensures the normal operation of the circuit board 40. Of course, the distribution of the punching needles 20 on the fixed plate 10 can also be set according to actual use requirements, which will not be elaborated here.

[0057] In an optional embodiment, after the circuit board is heat-treated to obtain a circuit board with a thermal conductive coating, the method further includes:

[0058] The thermal conductive coating is subjected to a punching process.

[0059] In the specific implementation, the fully cured thermal conductive coating can also be punched, so that there are multiple holes on the thermal conductive coating, which increases the heat dissipation area of ​​the thermal conductive coating, thus facilitating the discharge of heat from the thermal conductive coating. In addition, the embodiment provides deformation space for the thermal conductive coating through the multiple holes of the thermal conductive coating, avoiding the phenomenon that the thermal conductive coating is easily separated from the circuit board or even falls off as a whole due to expansion and deformation, thereby ensuring the heat dissipation effect of the thermal conductive coating on the circuit board.

[0060] Compared with the prior art, the beneficial effect of the embodiment of the present invention is that: the embodiment of the present invention provides a method for preparing a circuit board with a thermal conductive coating, by adding polyimide into an organic solvent for dissolution, adding expanded microspheres, and stirring to obtain a first mixed liquid, then adding copper powder and graphite powder into the organic solvent to obtain a thermal conductive material, then, the silicone resin, the first mixed liquid, and the thermal conductive material are sequentially mixed and stirred to obtain a second mixed liquid, and the second mixed liquid is coated on the substrate of the circuit board, and finally, the circuit board is heat-treated to obtain a circuit board with a thermal conductive coating. In this way, by arranging a thermal conductive coating on the circuit board, the thermal conductive coating is prepared by specific components and processing technology, has excellent thermal conductivity and the ability to reduce the dielectric constant, can greatly improve the thermal conductivity and performance of the circuit board, so that the circuit board can still work stably in a high temperature environment, and prolongs the service life of the circuit board.

[0061] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a circuit board with a thermal conductive coating, characterized in that: include: Adding polyimide into an organic solvent to dissolve it, adding expanded microbeads, and stirring to obtain a first mixed solution; Adding copper powder and graphite powder into an organic solvent to obtain a thermal conductive material; Mixing the silicone resin, the first mixed liquid, and the thermally conductive material in sequence to obtain a second mixed liquid; Applying the second mixed solution on a substrate of a circuit board; The circuit board is heat treated to obtain a circuit board with a thermal conductive coating.

2. The method for preparing a circuit board with a thermal conductive coating according to claim 1, characterized in that: The preparation steps of the organosilicon resin include: One of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder are mixed, heated and stirred to obtain an organic silicone resin.

3. The method for preparing a circuit board with a thermal conductive coating according to claim 2, characterized in that: The method comprises mixing one of phenylene siloxane and methyl siloxane, one of silicone oil and silane compound, and aluminum oxide powder, and heating and stirring to obtain an organic silicone resin, which specifically comprises: Take 100 parts by weight of phenylene siloxane or methyl siloxane, 10 parts by weight of aluminum oxide powder and 1 part by weight of silicone oil or silane compound, mix them in proportion and heat and stir at 100-120 degrees Celsius to obtain an organic silicone resin.

4. The method for preparing a circuit board with a thermal conductive coating according to claim 3, characterized in that: The heating and stirring time for one of phenylenesiloxane and methylsiloxane, one of silicone oil and silane compound, and aluminum oxide powder was 10 hours.

5. The method for preparing a circuit board with a thermal conductive coating according to claim 1, characterized in that: The step of adding polyimide to an organic solvent for dissolution, adding expanded microspheres, and stirring to obtain a first mixed solution specifically comprises: 10 g of polyimide was added to an organic solvent for dissolution, and 5 parts by weight of expanded microbeads were added thereto, followed by stirring to obtain a first mixed solution.

6. The method for preparing a circuit board with a thermal conductive coating according to claim 1, characterized in that: The step of adding copper powder and graphite powder into an organic solvent to obtain a thermally conductive material specifically comprises: 5 g of copper powder and 10 g of graphite powder were added to an organic solvent to obtain a thermal conductive material.

7. The method for preparing a circuit board with a thermal conductive coating according to claim 1, characterized in that: The heat treatment temperature during the heat treatment of the circuit board is 120 to 150 degrees Celsius.

8. The method for preparing a circuit board with a thermal conductive coating according to any one of claims 1 to 7, characterized in that: The method for preparing the circuit board with the thermal conductive coating further comprises: A punching device is provided; the punching device comprises a fixing plate and a plurality of punching needles, wherein the plurality of punching needles are connected to the fixing plate; During the heat treatment of the circuit board, when the second mixed liquid is in a gel stage, inserting the punching needle of the punching device into the second mixed liquid in the gel stage; When the second mixed liquid is in the final solidification stage, the punching needle of the punching device is taken out.

9. The method for preparing a circuit board with a thermal conductive coating according to claim 8, characterized in that: The distance between each two adjacent punching needles is equal.

10. The method for preparing a circuit board with a thermal conductive coating according to any one of claims 1 to 7, characterized in that: After the circuit board is heat-treated to obtain a circuit board with a thermal conductive coating, the method further includes: The thermal conductive coating is subjected to a punching process.

Images