Sumitomo Electric Industries, Limited

Sumitomo Electric Printed Circuits, Inc.

Takayuki Yonezawa

Koji Nitta

Yoshio Oka

Hideki Matsuoka

Jun Sugawara

Yoshifumi Uchita

Eiko Imazaki

Shingo Kaimori

Shigeaki Uemura

Ippei Tanaka

Shogo Asai

Masaya Kakimoto

A method of making a printed circuit board includes a step of providing a double-sided plate that is an insulating substrate having conductive layers on respective surfaces thereof, a first coating step of coating a first surface of the double-sided plate with a first photosensitive resin film, a second coating step of coating a second surface of the double-sided plate with a second photosensitive resin film, a first exposure step of exposing the photosensitive resin film coating the first surface after the first and second coating steps, and a second exposure step of exposing the photosensitive resin film coating the second surface after the first exposure step, wherein a maximum depth of a depression in an outermost surface of the second photosensitive resin film used in the second exposure step is less than 1.0 &#x3bc;m.

Method of making printed circuit board and laminated structure

An object of the present invention is to provide an adhesive composition for a printed wiring board, the adhesive composition having a good heat resistance. Another object of the present invention is to provide a coverlay for a printed wiring board, a copper-clad laminate, and a printed wiring board, all of which use the adhesive composition for a printed wiring board. The present invention provides an adhesive composition for a printed wiring board, the adhesive composition containing a siloxane-modified polyimide that includes structural units represented by formulae (1) and (2) below, an epoxy resin, and an inorganic filler. The siloxane-modified polyimide has a weight-average molecular weight (Mw) of 25,000 or more and 150,000 or less. A content of the inorganic filler is 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the siloxane-modified polyimide. In formulae (1) and (2), Ar represents a tetravalent aromatic tetracarboxylic acid residue, m is 0.35 or more and 0.75 or less, and n is 0.25 or more and 0.65 or less. Rin formula (1) represents a divalent diamine siloxane residue, and Rin formula (2) represents a divalent aromatic diamine residue. 

Adhesive composition for printed wiring boards, bonding film, coverlay, copper-clad laminate and printed wiring board

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Osaka, Japan

Takayuki Yonezawa