| 摘要 |
PURPOSE:To enable high-density wiring by divided via-holes by applying insulating permanent mask layers at the desired positions of the surface and rear of a multilayer substrate, to an outermost layer of which two insulating substrates containing catalysts are arranged and on the insides of the insulating substrates of which a substrate containing no catalyst and a prepreg, into which a resin containing the catalyst is buried, are interposed and molded, and boring a through-hole. CONSTITUTION:Insulating substrates 2, on the surfaces and the rears of which conductor circuit patterns 1, 1' are formed and which contain catalysts, are disposed to outermost layers, prepregs 3, into bored holes of which resins 4 including catalysts are buried and which contain not catalyst, and an insulating substrate 6, to which an inner-layer circuit pattern 5 is shaped and which includes no catalyst, are interposed and set on the insides of the insulating substrates 2, and a multilayer substrate 7 is acquired through heating and pressure. A permanent mask 9 having insulating properties and chemical resistance is applied and formed at a desired position on the surface of the multilayer substrate 7. Through-holes 8, 8' are bored at desired locations by an N/C borer. When electroless plating is executed on the whole surface, conductor layers 10 are shaped on the conductor circuit patterns 1 exposed and the inwalls of the through-holes 8, 8'. Accordingly, divided via holes 11' are formed, thus acquiring a multilayer printed wiring board 12. |
