Patent attributes
An object of the present invention is to provide a multi-layered printed wiring board which does not require roughening such as black oxide treatment and the like on inner layer circuits. For the purpose of achieving this object, there is adopted a multi-layered printed wiring board characterized by comprising a primer resin layer P comprising exclusively a resin between each inner layer circuit Ci formed without roughening and an insulating resin layer 5 of the multi-layered printed wiring board. The multi-layered printed wiring board is manufactured by taking the steps such as (a) a steps for producing a primer resin sheet with a carrier film including a 2 micron m to 12 micron m thick primer resin layer; (b) a steps for placing the primer resin sheet on the inner-layer circuit board in which the primer resin layer of the primer resin sheet with a carrier film is placed on the inner layer circuit board and then the carrier film is removed; (c) a steps for pressing in which a pre-preg and a metal foil for forming a conductive layer are superposed on the primer resin sheet, and pressed to form the multi-layered metal clad laminate; and (d) a steps for forming an outer layer circuit wherein the outer layer circuit is formed by etching the outer layer metal foil of the multi-layered metal clad laminate to make the multi-layered printed wiring board.
