Nitto-denko Corporation

Mitsuo Iimura

Toshimitsu Tachibana

Kenji Sato

In a method of resin-encapsulating a semiconductor chip using a polytetrafluoroethylene film as the mold-releasing film, a polytetrafluoroethylene film F wherein the thermal shrinkage percentages thereof in both the longitudinal direction and the width direction are 5% or lower, the difference of the thermal shrinkage percentages is within 3%, and the ratio of the elastic modulus of the longitudinal direction to the elastic modulus of the width direction is from 0.5 to 2.0 during resin encapsulating is used. By using the mold-releasing film, resin encapsulating can be carried out with an excellent yield while preventing the occurrence of resin covering of the terminals or the top surfaces of the post electrodes.

Method of resin-encapsulating semiconductor chip and mold-releasing film used for the method

The release member has a thermoplastic layer sandwiched between stripping films such that it flows toward the hole upon melting when it is heated under pressure and the stripping film in contact with the laminate has a breaking elongation of not less than 600% and a 100% elongation load of not more than 350 gf per unit width of 1 cm at the temperature to which the laminate is heated.

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Osaka, Japan

Mitsuo Iimura