Jsr Corporation

Shinichiro Iwanaga

Hiroyuki Ishii

Kiyoshi Murata

Katsumi Inomata

Takayoshi Tanabe

Akira Tsuji

Haruo Iwasawa

Masaru Ohta

Noboru Yamahara

Akihiko Sakurai

A process for forming bumps on electrode pads for a wiring board including a substrate and a plurality of electrode pads. The process (a) forms a laminated two-layer film on the wiring board and forms a pattern of apertures at positions corresponding to the electrode pads, the laminated two-layer film including a lower layer containing an alkali-soluble radiation-nonsensitive resin composition and an upper layer containing a negative radiation-sensitive resin composition; (b) fills a low-melting metal in the aperture pattern; (c) reflows the low-melting metal by pressing or heating to form bumps; and (d) peels and removes the laminated two-layer film from the board. The laminated film including two layers with different properties permits high resolution and easy peeling.

Method for forming bump on electrode pad with use of double-layered film

The present invention provides a radiation sensitive resin composition which comprises (A) a resin represented by a copolymer comprising recurring units represented by the general formulae (1) or (2) as shown below, and (B) a radiation sensitive acid-generator. The radiation sensitive resin composition has an excellent storage stability and the resist produced from the composition is a chemically amplifiable type sensitive to radiations represented by fartificial ultraviolet rays. The resist has a high transparency to radiations and it is excellent in basic physical properties for resist such as durability to dry etching, sensitivity, resolution, and pattern configuration: 

Radiation sensitive resin composition

A radiation sensitive composition comprising (A) a copolymer comprising recurring units of a p-hydroxystyrene unit and a styrene unit having an acetal group or a ketal group at the p-position, (B) a copolymer comprising recurring units of a t-butyl (meth)acrylate unit and a p-hydroxystyrene unit, and (C) a radiation sensitive acid-generating agent.

Radiation sensitive composition

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Tokyo, Japan

Shinichiro Iwanaga