| abstract |
When a through-hole electrode and a rear-surface wire are formed on a rear surface of a chip, a convex portion is formed on the rear surface of the chip due to a rear-surface wiring pad which is a part of the through-hole electrode and the rear-surface wire. This causes the air leakage when the chip is sucked, and therefore, the reduction of the sucking force of the chip occurs. A concave portion is formed in advance in a region where a rear-surface wiring pad and a rear-surface wire are formed. The rear-surface wiring pad and the rear-surface wire are provided inside the concave portion. Thus, a flatness of the rear surface of the chip is ensured by a convex portion caused by thicknesses of the rear-surface wiring pad and the rear-surface wire, so that the reduction of the sucking force does not occur when the chip is handled. |