Preparation method of carbon fiber anti-bending anti-electromagnetic interference copper-clad plate

Abstract

The invention relates to the technical field of copper-clad plates, in particular to a preparation method of a carbon fiber anti-bending anti-electromagnetic interference copper-clad plate, which comprises the following steps: pickling short carbon fibers, removing surface grease, washing with water, drying, ball-milling into powder, screening, putting the carbon fiber powder into an epoxy resin emulsion, and uniformly stirring for later use; a polyimide film with a certain size is flatly laid on a polyfluortetraethylene plate, the two ends of a carbon fiber pre-oxidized filament bundle are fixed so that the filament bundle can be evenly flatly laid on the polyimide film, a curing agent is added into the obtained epoxy resin emulsion, after even stirring, uniform-speed spraying and hot roller rolling are conducted, after curing forming is conducted, the carbon fiber pre-oxidized filament bundle is taken down, the edge is cut off, and a composite film is prepared; and performing hot pressing on one side of the composite film polyimide and a copper foil to obtain the composite film.

Description

Technical Field

[0001] The invention relates to the technical field of copper clad laminates, and in particular to a method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper clad laminate. Background Art

[0002] Copper clad laminate is the basic material of the electronics industry. It is mainly used for processing and manufacturing printed circuit boards. It is widely used in electronic products such as televisions, radios, computers, computers, mobile communications, etc. With the development of science and technology, printed circuit boards must have various high-quality and high-tech characteristics, which makes the manufacturing technology of printed circuit boards directly involve a variety of contemporary high-tech technologies. Therefore, the requirements for the comprehensive performance of copper clad laminates are getting higher and higher. Under the development trend of lightweight and miniaturization of equipment, the compactness of various electronic devices inside the equipment is getting higher and higher, and the interference between different devices is becoming more and more obvious. As a core component, copper clad laminates have anti-electromagnetic interference as one of their important characteristics.

[0003] As a special fiber, carbon fiber occupies a relatively high proportion in the field of preparing high-performance composite materials. Carbon fiber has a carbon content of more than 90%, has good electromagnetic shielding ability and extremely high bending resistance. The copper clad laminate has a low thickness and is located inside the electronic device. Its excellent bending resistance and electromagnetic shielding ability are the key to its high-end application. Chinese patent CN 114714711 A discloses a highly wear-resistant and corrosion-resistant epoxy resin copper clad laminate and its preparation method. Modified carbon fiber is added to the transition layer between the insulating layer and the copper foil. The surface roughness of the modified carbon fiber is increased, which can improve the bonding force between the carbon fiber and other components and give the copper clad laminate impact resistance. The distribution of carbon fiber in this patent is uniform and disordered, which contributes less to increasing the impact resistance of the copper clad laminate but less to its bending resistance. Chinese patent CN 10314437 A discloses a composite material using unidirectional carbon fiber prepreg fabric and a copper-clad laminate using the composite material, wherein the prepreg fabric is prepared by using unidirectional carbon fiber, and then the fabric is used as a functional layer to prepare the copper-clad laminate, and the unidirectional carbon fiber prepreg fabric has high bending resistance, thereby increasing the bending resistance of the copper-clad laminate. However, the above two patents only use the high strength and high modulus of carbon fiber to increase the bending resistance and impact resistance of the copper-clad laminate, and neither involves the anti-electromagnetic interference performance of the copper-clad laminate. Summary of the invention

[0004] The existing carbon fiber copper clad laminate only uses the high strength and high modulus of carbon fiber to increase the bending resistance and impact resistance of the copper clad laminate, and cannot give full play to the role of carbon fiber in the copper clad laminate. To solve this problem, the present invention provides a method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper clad laminate, comprising the following steps: 1) Preparation of carbon fiber-epoxy resin emulsion The carbon fiber staple fibers are acid-washed to remove surface grease, washed and dried, and then ball-milled into powder. After sieving, the carbon fiber powder is placed in the epoxy resin emulsion and stirred evenly for later use; 2) Preparation of carbon fiber-pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate, and both ends of a carbon fiber preoxidized filament bundle are fixed so that the filament bundle is evenly laid flat on the polyimide film. A curing agent is added to the epoxy resin emulsion obtained in step 1), and the mixture is evenly stirred and loaded into a sprayer, and the mixture is sprayed uniformly on the carbon fiber preoxidized filament bundle, and then rolled back and forth with a hot roller. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber-preoxidized carbon fiber composite film; 3) Preparation of copper clad laminate The one side of the composite film polyimide obtained in step 2) is hot-pressed with the copper foil to produce a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0005] Furthermore, in step 1), the screening fineness is 300-500 mesh; the weight parts of epoxy resin emulsion are 60-100 parts, the weight parts of carbon fiber powder are 5-20 parts, and the following substances are also contained in weight parts: 2-5 parts of coupling agent, 1-2 parts of dispersant, and 0.5-1 part of defoaming agent.

[0006] Furthermore, in step 2), the specification of the carbon fiber pre-oxidized yarn is 10-25D, and the laying thickness is 5-15 fiber diameters; the curing agent is ethylenediamine or polyamide curing agent.

[0007] Furthermore, in step 3), the hot pressing temperature is 280-320° C., and the hot pressing pressure is 5-15 MPa.

[0008] The carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate of the present invention uses carbon fiber pre-oxidized wire as a fiber skeleton. The carbon fiber pre-oxidized wire has no electrical conductivity, and while improving the anti-bending performance of the copper-clad laminate, it will not make the copper-clad laminate conductive and lose its function. The carbon fiber powder filled in the gaps of the carbon fiber pre-oxidized wire provides an electromagnetic shielding function, and the copper foil and the carbon fiber powder are isolated by a polyimide film, so that the copper-clad laminate of the present invention has excellent anti-bending and anti-electromagnetic interference performance. In addition, the preparation process of the carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate of the present invention only involves hot pressing of the composite film and the copper foil, and the preparation process is simple and easy, and is suitable for large-scale production. DETAILED DESCRIPTION

[0009] The present invention is described below in conjunction with examples, which are only used to explain the present invention and are not used to limit the scope of the present invention.

[0010] Example 1 A method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate comprises the following steps: 1) Preparation of carbon fiber-epoxy resin emulsion Stir the carbon fiber staple fibers in 40°C dilute hydrochloric acid for 30 minutes to remove the grease on the surface of the carbon fiber, wash and dry it, then ball-mill it into powder, sieve out 500-mesh powder, weigh 20 parts of carbon fiber powder, 100 parts of epoxy resin emulsion, 3 parts of KH550 coupling agent, 1.5 parts of RD-9001 dispersant and 1 part of Dow 103 polyether defoamer by weight, mix them and stir them evenly for later use; 2) Preparation of carbon fiber-pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate by electrostatic adsorption, and both ends of a carbon fiber preoxidized yarn bundle are fixed so that the bundle is evenly laid on the polyimide film. The specification of the carbon fiber preoxidized yarn is 10D, and the laying thickness is 15 fiber diameters. Ethylenediamine curing agent is added to the epoxy resin emulsion obtained in step 1), and after stirring evenly, it is loaded into a sprayer and sprayed on the carbon fiber preoxidized yarn bundle at a uniform speed. Then, a 50°C hot roller is used to roll back and forth 3 times. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber-preoxidized carbon fiber composite film; 3) Preparation of copper clad laminate One side of the composite film polyimide obtained in step 2) is hot-pressed with copper foil at a temperature of 310° C. and a pressure of 10 MPa to obtain a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0011] Example 2 A method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate comprises the following steps: 1) Preparation of carbon fiber-epoxy resin emulsion Stir the carbon fiber staple fibers in 50°C dilute hydrochloric acid for 20 minutes to remove grease from the surface of the carbon fiber, wash and dry it, then ball-mill it into powder, sieve out 400-mesh powder, weigh 15 parts of carbon fiber powder, 80 parts of epoxy resin emulsion, 2 parts of KH560 coupling agent, 1 part of magnesium stearate dispersant and 1 part of white oil by weight, mix them and stir them evenly for later use; 2) Preparation of carbon fiber-pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate by water film adsorption, and the two ends of the carbon fiber preoxidized yarn bundle are fixed so that the bundle is evenly laid on the polyimide film. The specification of the carbon fiber preoxidized yarn is 25D, and the laying thickness is 5 fiber diameters. A polyamide curing agent 651 curing agent is added to the epoxy resin emulsion obtained in step 1), and the mixture is evenly stirred and loaded into a sprayer. The mixture is uniformly sprayed on the carbon fiber preoxidized yarn bundle, and then rolled back and forth with a 40° C. hot roller for 5 times. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber-preoxidized carbon fiber composite film; 3) Preparation of copper clad laminate One side of the composite film polyimide obtained in step 2) is hot-pressed with copper foil at a temperature of 280° C. and a pressure of 15 MPa to obtain a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0012] Example 3 A method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate comprises the following steps: 1) Preparation of carbon fiber-epoxy resin emulsion Stir the carbon fiber staple fibers in 40°C dilute hydrochloric acid for 60 minutes to remove grease from the surface of the carbon fiber, wash and dry it, then ball-mill it into powder, sieve out 300-mesh powder, weigh 5 parts of carbon fiber powder, 60 parts of epoxy resin emulsion, 5 parts of KH560 coupling agent, 2 parts of RD-9001 dispersant and 0.5 parts of Dow 103 polyether defoamer by weight, mix them and stir them evenly for later use; 2) Preparation of carbon fiber-pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate by water film adsorption, and the two ends of the carbon fiber preoxidized yarn bundle are fixed so that the bundle is evenly laid on the polyimide film. The specification of the carbon fiber preoxidized yarn is 20D, and the laying thickness is 10 fiber diameters. Ethylenediamine curing agent is added to the epoxy resin emulsion obtained in step 1), and after stirring evenly, it is loaded into a sprayer and sprayed on the carbon fiber preoxidized yarn bundle at a uniform speed, and then rolled back and forth with a 50°C hot roller for 4 times. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber-preoxidized carbon fiber composite film; 3) Preparation of copper clad laminate One side of the composite film polyimide obtained in step 2) is hot-pressed with copper foil at a temperature of 320° C. and a pressure of 5 MPa to obtain a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0013] Comparative Example 1 A method for preparing a pre-oxidized carbon fiber anti-bending copper-clad laminate comprises the following steps: 1) Preparation of epoxy resin emulsion Weigh 100 parts of epoxy resin emulsion, 3 parts of KH550 coupling agent, 1.5 parts of RD-9001 dispersant and 1 part of Dow 103 polyether defoamer by weight, mix and stir evenly for later use; 2) Preparation of pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate by electrostatic adsorption, and both ends of a carbon fiber preoxidized yarn bundle are fixed so that the bundle is evenly laid on the polyimide film. The specification of the carbon fiber preoxidized yarn is 10D, and the laying thickness is 15 fiber diameters. Ethylenediamine curing agent is added to the epoxy resin emulsion obtained in step 1), and after stirring evenly, it is loaded into a sprayer and sprayed on the carbon fiber preoxidized yarn bundle at a uniform speed. Then, a 50°C hot roller is used to roll back and forth 3 times. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a preoxidized carbon fiber composite film. 3) Preparation of copper clad laminate One side of the composite film polyimide obtained in step 2) is hot-pressed with copper foil at a temperature of 310° C. and a pressure of 10 MPa to obtain a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0014] Comparative Example 2 A method for preparing a carbon fiber anti-electromagnetic interference copper-clad laminate comprises the following steps: 1) Preparation of carbon fiber-epoxy resin emulsion Stir the carbon fiber staple fibers in 50°C dilute hydrochloric acid for 20 minutes to remove grease from the surface of the carbon fiber, wash and dry it, then ball-mill it into powder, sieve out 400-mesh powder, weigh 15 parts of carbon fiber powder, 80 parts of epoxy resin emulsion, 2 parts of KH560 coupling agent, 1 part of magnesium stearate dispersant and 1 part of white oil by weight, mix them and stir them evenly for later use; 2) Preparation of carbon fiber epoxy resin-polyimide thin composite film A polyimide film of a certain size is spread flat on a polytetrafluoroethylene plate by water film adsorption, a polyamide curing agent 651 curing agent is added to the epoxy resin emulsion obtained in step 1), the mixture is stirred evenly and then loaded into a sprayer, and the film is sprayed uniformly on the polyimide film, followed by rolling back and forth with a 40° C. hot roller for 5 times, and after curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber epoxy resin-polyimide thin composite film; 3) Preparation of copper clad laminate One side of the composite film polyimide obtained in step 2) is hot-pressed with copper foil at a temperature of 280° C. and a pressure of 15 MPa to obtain a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

[0015] Table 1 is the performance test of the copper clad laminates obtained in Examples 1 to 3 and Comparative Examples 1 to 2. It can be seen from the data in the table that the copper clad laminates obtained in Examples 1 to 3 have excellent anti-bending and anti-electromagnetic interference properties. The copper clad laminate of Comparative Example 1 does not contain carbon fiber powder, and its anti-electromagnetic interference performance is poor, but its mechanical properties are optimal. The copper clad laminate of Comparative Example 2 does not contain carbon fiber pre-oxidized filaments, and its physical indicators of anti-bending and impact resistance are poor, but its anti-electromagnetic interference performance is good.

[0016] Table 1. Performance test of copper clad laminates obtained in Examples 1 to 3 and Comparative Examples 1 to 2 Note: The bending strength test standard is GB T 9341-2000; the dielectric constant Dk test standard is GB / T 43801-2024; the impact strength test standard is ASTM / D256-99.

[0017] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate, characterized in that: The following steps are involved: 1) Preparation of carbon fiber-epoxy resin emulsion The carbon fiber staple fibers are acid-washed to remove surface grease, washed and dried, and then ball-milled into powder. After sieving, the carbon fiber powder is placed in the epoxy resin emulsion and stirred evenly for later use; 2) Preparation of carbon fiber-pre-oxidized carbon fiber composite film A polyimide film of a certain size is laid flat on a polytetrafluoroethylene plate, and both ends of a carbon fiber preoxidized filament bundle are fixed so that the filament bundle is evenly laid flat on the polyimide film. A curing agent is added to the epoxy resin emulsion obtained in step 1), and the mixture is evenly stirred and loaded into a sprayer, and the mixture is sprayed uniformly on the carbon fiber preoxidized filament bundle, and then rolled back and forth with a hot roller. After curing and forming, the polyimide film is removed from the polytetrafluoroethylene plate, and the edges are cut off to obtain a carbon fiber-preoxidized carbon fiber composite film; 3) Preparation of copper clad laminate The one side of the composite film polyimide obtained in step 2) is hot-pressed with the copper foil to produce a carbon fiber anti-bending and anti-electromagnetic interference copper-clad laminate.

2. The preparation method according to claim 1, characterized in that: In step 1), the screening fineness is 300~500 mesh.

3. The preparation method according to claim 1, characterized in that: In step 1), the weight parts of epoxy resin emulsion are 60-100 parts, the weight parts of carbon fiber powder are 5-20 parts, and the following substances are also contained in weight parts: 2-5 parts of coupling agent, 1-2 parts of dispersant, and 0.5-1 parts of defoaming agent.

4. The preparation method according to claim 1, characterized in that: In step 2), the specification of the carbon fiber pre-oxidized yarn is 10~25D, and the laying thickness is 5~15 fiber diameters.

5. The preparation method according to claim 1, characterized in that: In step 2), the curing agent is ethylenediamine or polyamide curing agent.

6. The preparation method according to claim 1, characterized in that: In step 3), the hot pressing temperature is 280-320° C., and the hot pressing pressure is 5-15 MPa.

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