MULTILAYER PRINTED CIRCUIT BOARD FOR PHOTO JOINT

摘要

PURPOSE:To stabilize junction conditions and prevent an inner-layer printed circuit board from being burnt when performing photo joint of IC parts in a multilayer printed circuit board. CONSTITUTION:In a lower-side region 10 of a joint 7 of IC parts where laser beam and light beam are illuminated, joint conditions are stabilized for preventing an inner-layer printed circuit board 3 from being burnt without performing blackening treatment 9 to the inner-layer copper foil pattern 6 and by preventing reflection and dispersion even is laser beam and light beam are transmitted through a base 4 of the printed circuit board 2 and 3 and then reach the inner-layer copper foil pattern 6, and the conversion into absorbed heat.