Nitto-denko Corporation

Miyoko Ikishima

Masahiko Ando

Takahiro Nonaka

Masahiro Oura

Masahiro Ooura

Noritsugu Daigaku

The present invention relates to a double-sided pressure-sensitive adhesive tape or sheet for wiring circuit board, which comprises a pressure-sensitive adhesive layer formed by a pressure-sensitive adhesive composition containing an acrylic polymer and a chain transfer substance, in which the pressure-sensitive adhesive layer has characteristics that a gel fraction in the initial stage is from 40 to 70% by weight, and a difference between a gel fraction (% by weight) of the pressure-sensitive adhesive layer after the following solder reflow step and the gel fraction (% by weight) of the pressure-sensitive adhesive layer in the initial stage is 10 or less. The solder reflow step satisfies the following heat treatment conditions. Surface temperature of the double-sided pressure-sensitive adhesive tape or sheet reaches 175&#xb1;10&#xb0; C. within 130 to 180 seconds, the surface temperature reaches 230&#xb1;10&#xb0; C. within 200 to 250 seconds, the surface temperature reaches 255&#xb1;15&#xb0; C. within 260 to 300 seconds and the solder reflow step finishes within 370 seconds after start of the solder reflow step for the double-sided pressure-sensitive adhesive tape or sheet.

Double-sided pressure-sensitive adhesive tape or sheet for wiring circuit board and wiring circuit board

A wiring circuit board at least contains an electric insulator layer and an electric conductor formed on the electric insulator layer so as to form a predetermined circuit pattern, which further comprises an adhesive layer formed by thermal hardening of the thermosetting adhesive and pressure-sensitive adhesive composition as described in the specification.

Growing community of inventors

Osaka, Japan

Miyoko Ikishima