| 摘要 |
PURPOSE:To enable excellent electric insulation, effective thermal dispersion and the prevention of noises due to electromagnetic wave disturbance by a method wherein a semiconductor element is placed on a supporting body through a polyimide film. CONSTITUTION:With a polyimide film, volume resistivity if 10<18>OMEGAcm (25 deg.C), dielectric pressure resistance 280kV/cm (25 deg.C), a coefficient of thermal expansion 20X10<-6>/ deg.C (normal temperature) and density 1.42g/cm<3>, and a thin-film with about 10mum thickness is easily formed. Thus, insulation between a semiconductor element and a supporting body can easily be realized, and thermal fatigue is difficult to be generated at adhering portions because the coefficient of thermal expansion of the film is close to those of Cu and Al. Its thermal conductivity is 4X10<-4> cal/cm sec deg.C, but a radiating property which practically has no trouble can be ensured because the film is formed in the thin-film. Thus, when a Si element 1 is integrally fitted onto the copper plate 4 through the polyimide film 3 on the copper plate 2, dielectric resistance is high and thermal resistance is low, the copper plate 2 can be grounded because the copper plate 2 is insulated from the element 1, and noises can be decreased. |
