Sumitomo Bakelite Company Limited

Keiichi Tsukurimichi

Hitoshi Kawaguchi

Yoshitaka Okugawa

There is provided a circuit board manufacturing method that makes it possible to manufacture a next-generation semiconductor device in a stable manner and improve the yield during secondary mounting processing. A circuit boardwith a thickness of 230 &#x3bc;m manufactured using a cyanate-based prepregcontaining a resin composition with which a glass cloth is impregnated is heated at a higher temperature than a glass transition temperature of the resin composition after it is cured before reflow processing.

Circuit board manufacturing method, semiconductor manufacturing apparatus, circuit board and semiconductor device

Disclosed is a granular resin composition for encapsulating a semiconductor used for a semiconductor device obtained by encapsulating a semiconductor element by compression molding, satisfying the following requirements (a) to (c) on condition that ion viscosity is measured with a dielectric analyzer under a measurement temperature of 175&#xb0; C. and a measurement frequency of 100 10 Hz: (a) the time from the initiation of the measurement until a decrease of the ion viscosity to the lowest ion viscosity is 20 seconds or shorter; (b) the lowest ion viscosity value is not more than 6.5; and (c) the time interval between the time from the initiation of the measurement until a decrease of the ion viscosity to the lowest ion viscosity and the time from the initiation of the measurement until the ion viscosity reaching 90% of an ion viscosity value measured at 300 seconds is 10 seconds or longer.

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Tokyo, Japan

Keiichi Tsukurimichi