PROBLEM TO BE SOLVED: To provide the manufacturing method of a multilayered circuit board excellent in resistance to a repeated thermal load.;SOLUTION: In the manufacturing method of the multilayered circuit board by a build-up process, if a via hole and a through hole are formed on a laminated glass fiber reinforced resin substrate on a lower layer circuit board, the manufacturing method of the multilayered circuit board including the processes sequentially performing a process for forming a large window 15 by the process technology of a circuit formation; a process for boring a via hole 16 by a laser radiation; a process for removing a resin residue 13B left inside the via hole 16; a process for removing the etchant of a glass fiber 13A which protrudes from the wall surface 16a of the via hole 16 and a process for boring the through hole is provided.;COPYRIGHT: (C)2005,JPO&NCIPI
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