Patent ID: 7614787

Claim:
A marking apparatus used in a process for producing multi-layered printed circuit board having a core board and a plurality of vertically separated isolation layers and a plurality of vertically separated conductive layers at both front and rear sides of the core board, the apparatus comprising; at least one standard mark formed on a front side of the core board and at least one standard mark formed on a rear side of the core board, wherein said at least one standard mark on the front side of the core board is different from said at least one standard mark formed on the rear side of the core board in at least one of size and shape and each of the at least one standard marks is disposed in a certain area, a position detecting device that simultaneously detects the positions in a plane direction of the standard marks by simultaneously photographing the standard marks in the certain area using X-rays irradiating toward thickness direction of the multilayered printed circuit board, a marking device for making a first new mark on a surface of the multi-layered printed circuit board based on the detected position of said at least one standard mark disposed on the front side of the core board, and a marking device for making a second new mark on a surface of the multi-layered printed circuit board based on the detected position of said at least one standard mark disposed on the rear side of the core board.