| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin four-layered printed wiring board which has little dispersion in thickness and a smooth surface and is suitable for high density mounting. SOLUTION: The four-layered printed wiring board 7 is formed by laminating photo/thermosetting undercoat layers 3 comprising the following elements (a) to (e), a thermosetting insulating adhesive layer 4 mainly composed of bisphenol epoxy resin of a weight average molecule weight 10000 or more and bisphenol epoxy resin of equivalent weight 500 or less and a copper foil 5 one by one in both sides of an epoxy resin impregnated glass cloth board with a circuit pattern: (a) epoxy resin of molecule weight 500 or more in normal temperature solid state, (b) epoxy resin setting agent, (c) glycidyl acrylate or glycidyl methacrylate, (d) hydroxy ethylacrylate or hydroxy ethyl methacrylate and (e) photochemical polymerization initiator. |
