| 摘要 |
PROBLEM TO BE SOLVED: To avoid bleeding of solder bumps into the through-hole on double- surface circuit substrate and to perform the effective utilization of the mutually connected region, by filling the solder material which has high melting point prior to bonding the solder bump into the plated through-hole. SOLUTION: When solder is melted in bonding process at the time the double- surface substrate is bonded to a substrate with solder in solder-bump bonding and the solder is melted in the bonding process, the problem of solder bleeding occurs, and the strain and the breakdown of the solder bump occur. Then, the through-hole is covered with a solder mask. As a result, the solder bump is heated, the solder is melted, the bonding is affected, the air sealed in the through-hole is expanded and the solder bump is blown out. Therefore, when the through-hole is completely filled with solder material, the bleeding of the solder bump into the through-hole can be avoided. |
