Patent ID: 9536849
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a semiconductor substrate; a pad electrode which is formed on the semiconductor substrate; a post electrode which is electrically connected to the pad electrode and is made of a copper film formed on the pad electrode; a solder ball electrode which is formed on the post electrode and is made of a ternary alloy containing tin; a terminal which is connected to the solder ball electrode and is formed on a front surface of a wiring board; and a sealing material which fills a gap between the semiconductor substrate and the wiring board, wherein the post electrode includes a stem portion having a cylindrical shape and an overhanging portion which protrudes to an outer side of the stem portion in an upper part of the stem portion, the solder ball electrode is connected to an upper surface of the post electrode over the stem portion and the overhanging portion, and a sidewall of the stem portion of the post electrode is in contact with an underfill over an entire circumference thereof.