MANUFACTURE OF MULTILAYERED PRINTED WIRING BOARD

摘要

PURPOSE: To reduce the occurrence of uneven etching even when copper foil for internal layer having roughed surfaces on both sides is thick so as to improve the accuracy of a wiring pattern by sticking the shinny roughed surface of the copper foil to the surface of a substrate. CONSTITUTION: An internal-layer circuit 1p is formed by sticking copper foil 1 having a thickness of >=70μm to the surface of the substrate 2 of an internal layer having an insulating property and etching the foil 1. The copper foil 1 has a shinny-side roughened surface is having surface roughness of 3-6μm on one side and mat-side roughened surface 1m having surface roughness larger than that of the surface is on the other side and the surface is side is stuck to the surface of the substrate 2. Therefore, the occurrence of uneven etching can be reduced when the copper foil 1 is etched and patterned, because the cutting of the surface 1s into the insulating substrate 2 becomes less and the etchant can easily etch the copper foil 1.