Circuit substrate and process for preparing the same

Patent metadata

Field	Value
Publication number	US-2016007452-A1
Application number	US-201414647412-A
Country	US
Kind code	A1
Filing date	Feb 19, 2014
Priority date	Jan 14, 2014
Publication date	Jan 7, 2016
Grant date	—

Abstract

The present invention relates to a process for preparing a bonding sheet for composing circuit substrate, comprising pre-treating glass fabrics with a pre-treating varnish having a same or close dielectric constant (DK) to glass fabrics being used. The present invention further relates to bonding sheets prepared by the process, as well as circuit substrate. The process for preparing circuit substrate of the invention, which has a lower cost, does not need to upgrade or adjust the equipment. The circuit substrates prepared thereby have less warp-wise and weft-wise difference in dielectric constant, and thus can effectively solve the problem of signal time delay.

First claim

1 . A process for preparing a bonding sheet for composing circuit substrate, comprising the steps of
(1) preparing a pre-treating varnish having a same or close dielectric constant (DK) to reinforcing material being used; (2) pre-glue-dipping the reinforcing material in the pre-treating varnish, and oven-drying solvent to obtain a pre-treated reinforcing material; and (3) main-glue-dipping the pre-treated reinforcing material, and oven-drying solvent to obtain a bonding sheet.

2 . The process according to claim 1 , characterized in that the pre-treating varnish is obtained by dissolving a resin composition in an organic solvent.

3 . The process according to claim 2 , characterized in that the resin composition comprises a resin and a hardener, wherein the resin is one or a mixture of at least two selected from the group consisting of epoxy resin, cyanate resin, polyphenyl ether resin, polybutadiene resin, copolymer resin of polybutadiene and styrene, polytetrafluoroethylene resin, polybenzoxazine resin, polyimide, silicon-containing resin, bismaleimide resin, liquid crystal polymer, bismaleimide triazine resin and thermoplastic resin.

4 . The process according to claim 3 , characterized in that the hardener is one or more selected from the group consisting of phenolic hardener, amine hardener, polymeric acid anhydride hardener, active ester and free radical initiator.

5 . The process according to claim 2 , characterized in that the organic solvent is one or a mixture of at least two selected from the group consisting of alcohol such as methanol, ethanol, butanol and the like, ether such as ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, diethylene glycol ether, diethylene glycol butyl ether and the like, ketone such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and the like, aromatic hydrocarbon such as toluene, xylene, sym-trimethylbenzene and the like, ester such as ethoxyethyl acetate, ethyl acetate and the like, and nitrogen-containing solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone and the like.

6 . The process according to claim 3 , characterized in that the pre-treating varnish further comprises a filler selected from the group consisting of silica, alumina, titanium dioxide, barium titanate, strontium titanate, magnesium titanate, calcium titanate, barium strontium titanate, lead titanate and glass dust, wherein said silica comprises molten amorphous silica and crystalline silica; said titanium dioxide comprises rutile-type titanium dioxide and anatase type titanium dioxide.

7 . The process according to claim 1 , characterized in that the reinforcing material is selected from electronic-grade glass fabric, glass fiber nonwoven fabric, aramid and other organic fiber woven fabric.

8 . The process according to claim 7 , characterized in that the reinforcing material is electronic-grade glass fabrics.

9 . The process according to claim 20 , characterized in that the pre-treated glass fabric has a resin content of from 20 wt. % to 50 wt. %.

10 . The process according to claim 9 , characterized in that the pre-treated glass fabric has a resin content of from 25 wt. % to 50 wt. % when the pre-treated glass fabric has a mass per unit area of less than 30 g/m 2 .

11 . The process according to claim 9 , characterized in that the pre-treated glass fabric has a resin content of from 20 wt. % to 45 wt. % when the pre-treated glass fabric has a mass per unit area of from 30 g/m 2 to 100 g/m 2 .

12 . The process according to claim 9 , characterized in that the pre-treated glass fabric has a resin content of from 20 wt. % to 40 wt. % when the pre-treated glass fabric has a mass per unit area of from 100 g/m 2 to 175 g/m 2 .

13 . The process according to claim 20 , characterized in that the glass fabric is an E-type one, and the corresponding treating varnish has a Dk of from 6.2 to 6.6.

14 . The process according to claim 20 , characterized in that the glass fabric is an NE-type one, and the corresponding treating varnish has a Dk of from 4.4 to 4.6.

15 . The process according to claim 20 , characterized in that the pre-treating varnish has a Dk within the range of Dk±10% of glass fabric.

16 . The process according to claim 15 , characterized in that the pre-treating varnish has a Dk within the range of Dk±5% of glass fabric.

17 . A bonding sheet prepared according to the process of claim 1 .

18 . A circuit substrate prepared from the bonding sheet according to claim 17 .

19 . (canceled)

20 . The process according to claim 1 , characterized in that the pre-treated reinforcing material is a pre-treated glass fabric.

Assignees

• Shengyi Technology Co Ltd

Inventors

• Yan Shanyin
• Zeng Xianping
• Xu Yongjing
• Yang Zhongqiang
• Su Xiaosheng
• Luo Li

Classifications

• C03C25/16

  Dipping · CPC title

• H05K1/0393

  Flexible materials (H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups) · CPC title

• C03C25/326

  Polyureas; Polyurethanes · CPC title

• H05K1/0306 Primary

  Inorganic insulating substrates, e.g. ceramic, glass · CPC title

• C03C25/30

  Polyolefins · CPC title