LAND STRUCTURE, ITS PRODUCTION METHOD, AND ELECTRONIC COMPONENT MOUNTING STRUCTURE USING LAND STRUCTURE

摘要

PROBLEM TO BE SOLVED: To solve the problem that a part where a land touches a solder bump is susceptible to cracking along the circumferential face part of the land and bonding reliability is lowered at the bonding part. SOLUTION: In a land structure provided on the mounting face 5A of a printed wiring board 5 and connected with the large number of electrodes 3 of a CSP 1 through solder bumps 4, a part F for bonding the solder bump 4 to the land 8 by causing the solder of the solder bump 4 bite at least on the circumferential face part 8A of the land 8 comprising a conductor pattern formed on the mounting face 5A. The solder biting part F makes the end face part 8b side of the land 8 wider than the bottom face part 8a thereof so that the circumferential face part 8A of the land 8 spreads reverse conically.