AUSSENSCHICHTMATERIAL VON EINER GEDRUCKTEN MEHRSCHICHTLEITERPLATTE UND VERFAHREN ZU DEREN HERSTELLUNG

Two aluminum-copper foils are joined with their aluminum surfaces in contact for use as an outer layer material (20) of a multilayer printed wiring board. In producing this board, an outer layer material, a prepreg (2), an inner layer material (1), a prepreg (3) and an outer layer material (21) are built up in this order. Therefore, the aluminum portion of the outer layer material (20) works as a conventional mirror plate and a dummy plate. Further, the aluminum surfaces can be easily released from each other and work as conventional mold releasing films. The outer layer material (20) has aluminum surfaces tightly adhered to each other and does not permit resin scums or foreign matter to adhere thereto unlike that of the prior art, this structure further prevents scars or damage caused by impact from developing. Moreover, since no mirror plate is used, the operation steps can be simplified and the built-up operation can be easily and automatically carried out. It is also possible to use plastic metal foils of aluminum alloy, copper, brass, soft steel, lead alloy and the like instead of the aluminum foil.