| 摘要 |
PROBLEM TO BE SOLVED: To provide adequate strength and radiation resistance by a method in which the reflection films of adjacent metal layers which are set on a film of thermoplastic polyimide resin having a specified glass transition temperature, water absorption, and a dielectric constant are laminated through a net-shaped spacer to prevent the contact between the reflection films. SOLUTION: A laminated insulating material 10 is constituted by a process in which a reflection film 12 which is made by forming a metal layer of aluminum, etc., on one side, both sides, or in the inside of a plastic film and a net- shaped spacer 14 of plastic yarn are laminated alternately to prevent the direct contact between the reflection films 12 adjacent to each other through the spacer 14. The plastic film is made from a thermoplastic polyimide resin containing thermal fusion-bonding copolymer having a glass transition temperature of 150-250 deg.C, water absorption of 1% or less, and a dielectric constant of 3% or less as a main component. The reflection film 12 is obtained by a process in which aluminum foil is placed on one side or both sides of the polyimide resin film and press-bonded at a temperature near the glass transition temperature. |
