Abstract: A method for manufacturing a build-up multi-layer printed circuit board is disclosed in which a YAG laser is used upon the formation of a via hole in the multi-layer printed circuit board, such that it can have the following advantages: the manufacturing process would become simple; the component packaging density and freedom for the design of the board would be improved; and a high speed of signal process would be ensured.

Abstract: A method for manufacturing a build-up multi-layer printed circuit board for use in computers, VTR, or portable telephones is disclosed, in which the method of forming a hole in a circuit layer and the method of forming a hole in an insulating layer are made different from each other by applying a combined formation method, thereby improving the formation precision and efficiency in forming the holes. Specifically, a resin-clad copper foil (RCC) is stacked on a CCL (copper-clad laminate) after forming a printed circuit layer, and this structure is heated and pressed. Then, beams of an Nd-YAG laser are irradiated to remove the copper-clad layer, and then beams of CO.sub.2 laser are irradiated to remove the residual resin insulator, thereby forming a via hole. Then, circuit patterns are formed on the board on which the via hole has been formed.