PROBLEM TO BE SOLVED: To provide a wiring board having a via-on-via structure which is excellent in size, process, and continuity. ;SOLUTION: In a via-on-via structure, an inner layer via 15 is filled up with silver paste 17 and, at the same time, an upper-layer via 18 is provided across the inside of the via 15 and a land 19. Consequently, the in-plane size of the via-on-via structure is suppressed to a small value. Even when no plated lid is formed on the via 15, continuity is ensured, because a wiring pattern 14 is in direct contact with the land 19 (wiring pattern 11) of the inner layer via 15. Since the packing material of the via 15 is the silver paste 17, in addition, the damage given to the inside of the via 15 when laser beam machining is performed for forming the upper-layer via 18 can be minimized.;COPYRIGHT: (C)2001,JPO
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