Abstract: Embodiments of the present disclosure relate to the field of printed circuit boards and particularly to a multi-layer printed circuit board. The multi-layer printed circuit board includes at least two inner-layer circuit boards, each of which has a non-circuit pattern area including a welding area. Each welding area has at least one welding hole. Further, at least one prepreg is used to fill between two adjacent inner-layer circuit boards and is melted to fill into the welding hole in a welding process. In the multi-layer printed circuit board according to the embodiments of the disclosure, a welding area is arranged in a non-circuit pattern area, and one or more welding holes are arranged in the welding area so that a prepreg between two inner-layer circuit boards can be melted filling into the welding hole(s) in a welding process, thus enhancing effectively an adhesive force binding the inner-layer circuit boards.

Abstract: Disclosed are a purple solder proof ink composition for printing circuit board, a process for preparing a purple printed circuit board, and a purple printed circuit board.