阅读说明：本技术 一种高相对漏电起痕指数高耐热fr4覆铜板及其制备方法 (FR4 copper-clad plate with high relative tracking index and high heat resistance and preparation method thereof ) 是由 付军亮 陈长浩 郑宝林 杨永亮 秦伟峰 刘俊秀 于 2020-05-20 设计创作，主要内容包括：本发明公开了一种高相对漏电起痕指数高耐热FR4覆铜板,两侧均覆有铜箔,最外两个半固化片为表料半固化片,两个表料半固化片之间设有3-6层里料半固化片,二者基材均为为电子级玻璃布,含胶量42-54wt％,流动度18-20％,里料半固化片的浸胶液包括以下重量份的组分：溴化环氧树脂30-80份、高耐热树脂10-30份、多官能团环氧树脂5-20份、固化剂1-5份、促进剂0.2-5份、填料10-40份和溶剂10-35份,表料半固化片的浸胶液为在里料半固化片浸胶液的基础上增加20-40重量份的高CTI树脂。本发明浸胶液采用固化剂与酚醛树脂共同固化环氧树脂,同时加入高CTI树脂,使覆铜板的CTI值达到了600V,降低了溴含量,较低的溴含量有利于CTI值的提高,通过调节多种树脂的含量,提高了覆铜板的耐热性。(The invention discloses an FR4 copper-clad plate with high relative tracking index and high heat resistance, wherein copper foils are covered on two sides, two prepregs at the outermost are surface prepreg layers, 3-6 lining prepreg layers are arranged between the two surface prepreg layers, the two substrates are electronic-grade glass cloth, the glue content is 42-54 wt%, the fluidity is 18-20%, and the dipping solution of the lining prepreg layers comprises the following components in parts by weight: 30-80 parts of brominated epoxy resin, 10-30 parts of high heat-resistant resin, 5-20 parts of polyfunctional epoxy resin, 1-5 parts of curing agent, 0.2-5 parts of accelerator, 10-40 parts of filler and 10-35 parts of solvent, wherein the dip solution of the surface prepreg is high CTI resin added with 20-40 parts by weight on the basis of the dip solution of the lining prepreg. The gum dipping solution adopts the curing agent and the phenolic resin to cure the epoxy resin together, and simultaneously adds the high CTI resin, so that the CTI value of the copper-clad plate reaches 600V, the bromine content is reduced, the lower bromine content is beneficial to improving the CTI value, and the heat resistance of the copper-clad plate is improved by adjusting the content of various resins.)

1. A high-relative-tracking-index high-heat-resistance FR4 copper-clad plate is characterized in that copper foils are covered on two sides of the FR4 copper-clad plate, the two outermost prepregs covered with the copper foils are surface prepreg layers, 3-6 lining prepreg layers are arranged between the surface prepreg layers,

the surface material prepreg base material is electronic-grade glass cloth, the gel content is 42-54 wt%, and the fluidity is 18-20%, the lining material prepreg base material is electronic-grade glass cloth, the gel content is 42-54 wt%, and the fluidity is 18-20%;

the gum dipping solution of the lining prepreg comprises the following components in parts by weight: 30-80 parts of brominated epoxy resin, 10-30 parts of high heat-resistant resin, 5-20 parts of polyfunctional epoxy resin, 1-5 parts of curing agent, 0.2-5 parts of accelerator, 10-40 parts of filler and 10-35 parts of solvent;

the dip solution of the surface prepreg is prepared by adding 20-40 parts by weight of high CTI resin on the basis of the dip solution of the lining prepreg.

2. The FR4 copper-clad plate with high relative tracking index and high heat resistance as claimed in claim 1, wherein the brominated epoxy resin is one of a low bromine epoxy resin with a bromine content of 18-21% or a high bromine epoxy resin with a bromine content of 50-60%.

3. The FR4 copper-clad plate with high relative leakage tracking index and high heat resistance as claimed in claim 1, wherein the high heat-resistant resin is one or more of naphthol type bisphenol A resin, MDI modified phenolic resin, bismaleimide resin, polyphenylene oxide resin, polyimide resin or aminophenol type epoxy resin.

4. The FR4 CCL with high relative leakage tracking index and high heat resistance as claimed in claim 1, wherein the multifunctional epoxy resin is one of tetraphenylglycidylethane or triphenylglycidylethylmethane.

5. The FR4 copper-clad plate with high relative leakage tracking index and high heat resistance according to claim 1, wherein the curing agent is one or more of dicyandiamide, phenol-type phenolic resin, o-cresol-type phenolic resin, BPA-type phenolic resin or bisphenol A novolac resin.

6. The FR4 copper clad laminate with high relative leakage tracking index and high heat resistance as claimed in claim 1, wherein the accelerator is one or more of 2-methylimidazole, 2-phenylimidazole, undecylimidazole or 2-ethyl-4-methylimidazole.

7. The FR4 copper-clad plate with high relative leakage tracking index and high heat resistance as claimed in claim 1, wherein the filler is one or more of superfine aluminum hydroxide, aluminum hydroxide oxide, nano-silica, high-purity magnesium oxide, talcum powder or barium sulfate with D50 < 3 μm.

8. The FR4 copper-clad plate with high relative leakage tracking index and high heat resistance according to claim 1, wherein the solvent is one or more of acetone, butanone, cyclohexanone and dimethylformamide.

9. The FR4 copper-clad plate with high relative leakage tracking index and high heat resistance according to claim 1, wherein the high CTI resin is one or a combination of hydrogenated bisphenol A epoxy resin and polyphenylene ether resin.

10. The preparation method of the FR4 copper-clad plate with high relative tracking index and high heat resistance as defined in any one of claims 1-9, wherein the steps are as follows: weighing each component of a dipping solution of a lining prepreg and a dipping solution of a surface prepreg according to the weight parts, respectively mixing and stirring uniformly to prepare two glue solutions, respectively coating the two glue solutions on a plurality of pieces of electronic-grade glass cloth according to the glue content, and drying for 2-15min at the temperature of 150-; and (3) superposing the inner prepreg with the required number of layers, placing the inner prepreg between two surface prepregs, paving a copper foil on the outermost side, and pressing for 120-180min at the temperature of 60-220 ℃ under the pressure of 1.6-8MPa to obtain the composite prepreg.

Technical Field

The invention relates to a copper-clad plate, in particular to an FR4 copper-clad plate with high relative tracking index and high heat resistance and a preparation method thereof.

Background

In order to improve the safety and reliability of electronic products, particularly electronic products used in a humid environment, such as air conditioners, washing machines and the like, the electronic industry is currently actively developing and producing electronic products with high tracking index of electric leakage resistance. With the development of Printed Circuit Boards (PCBs) toward fine lines, high density and high multi-layer, higher requirements are placed on heat resistance, flatness and related electrical properties of the board. At present, most of copper clad plates with higher Comparative Tracking Index (CTI) use a dicyandiamide cured epoxy resin system, but the CTI value is only 175-220V, and the heat resistance is low, so that the requirement of high-temperature use cannot be met.

Disclosure of Invention

Aiming at the problems of the existing copper-clad plate of a dicyandiamide curing epoxy resin system, the invention provides an FR4 copper-clad plate with high relative tracking index and high heat resistance, wherein copper foils are covered on both sides of the FR4 copper-clad plate, the two outermost prepregs covered with the copper foils are surface prepreg layers, 3-6 layers of lining prepreg layers are arranged between the surface prepreg layers, the surface prepreg layer is electronic-grade glass cloth, the glue content is 42-54 wt%, the fluidity is 18-20%, the lining prepreg layer is electronic-grade glass cloth, the glue content is 42-54 wt%, and the fluidity is 18-20%; the gum dipping solution of the lining prepreg comprises the following components in parts by weight: 30-80 parts of brominated epoxy resin, 10-30 parts of high heat-resistant resin, 5-20 parts of polyfunctional epoxy resin, 1-5 parts of curing agent, 0.2-5 parts of accelerator, 10-40 parts of filler and 10-35 parts of solvent; the dip solution of the surface prepreg is a high CTI resin added by 20-40 parts by weight on the basis of the dip solution of the lining prepreg.

Wherein the brominated epoxy resin is one of low-bromine epoxy resin with bromine content of 18-21% or high-bromine epoxy resin with bromine content of 50-60%; the high heat-resistant resin is one or a combination of more of naphthol type bisphenol A resin, MDI modified phenolic resin, bismaleimide resin, polyphenyl ether resin, polyimide resin or aminophenol type epoxy resin; the polyfunctional epoxy resin is one of tetraphenyl glycidyl ether ethane or triphenyl glycidyl ether methane; the curing agent is one or the combination of more of dicyandiamide, phenol-type phenolic resin, o-cresol-type phenolic resin, BPA-type phenolic resin or linear bisphenol A phenolic resin; the accelerant is one or more of 2-methylimidazole, 2-phenylimidazole, undecylimidazole or 2-ethyl-4-methylimidazole; the filler is one or the combination of more of superfine aluminum hydroxide, hydroxyl alumina, nano silicon dioxide, high-purity magnesium oxide, talcum powder or barium sulfate with the D50 less than 3 mu m; the solvent is one or more of acetone, butanone, cyclohexanone or dimethylformamide; the high CTI resin is hydrogenated bisphenol A type epoxy resin or polyphenyl ether resin or the combination of the hydrogenated bisphenol A type epoxy resin and the polyphenyl ether resin.

The preparation method of the FR4 copper-clad plate with high relative tracking index and high heat resistance comprises the following steps: weighing each component of a dipping solution of a lining prepreg and a dipping solution of a surface prepreg according to the weight parts, respectively mixing and stirring uniformly to prepare two glue solutions, respectively coating the two glue solutions on a plurality of pieces of electronic-grade glass cloth according to the glue content, and drying for 2-15min at the temperature of 150-; and (3) superposing the inner prepreg with the required number of layers, placing the inner prepreg between two surface prepregs, paving a copper foil on the outermost side, and pressing for 120-180min at the temperature of 60-220 ℃ under the pressure of 1.6-8MPa to obtain the composite prepreg.

The invention has the beneficial effects that: the gum dipping solution adopts a curing agent and phenolic resin to jointly cure epoxy resin, and simultaneously adds high CTI resin, so that the CTI value of the copper-clad plate reaches 600V, and compared with the low bromine resin dosage in a dicyandiamide curing epoxy resin system, the bromine content of the copper-clad plate is reduced to 11-13% on the premise of ensuring that the flame retardance of the plate is V0 grade, and the lower bromine content is favorable for improving the CTI value; the gum dipping solution used in the invention improves the heat resistance of the copper-clad plate by adjusting the content of various resins, and has high dimensional stability at high temperature.

Detailed Description

The present invention is described below with reference to examples, which are provided for illustration only and are not intended to limit the scope of the present invention.