| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer insulating film for fully ensuring surface planarity of a resin sheet that is less likely to generate voids within a circuit board in the case of laminating resin on the circuit board including holes, such as, a through hole and a via hole and uneven areas, such as circuit patterns. SOLUTION: The multilayer insulating film includes an insulating layer formed of a resin compound, containing a base material, a thermosetting resin, a hardening agent, a polymer material and an inorganic filling agent. The insulating layer is constituted, by laminating a first layer including resin of 5 to 60 wt.% in 5,000 or higher weight-average molecular weight as a polymer material, provided in contact with a base material and a second layer provided on the first layer and contains a total amount of inorganic filling material in a range of 30 to 90 wt.%. COPYRIGHT: (C)2009,JPO&INPIT |
