Solder foil, semiconductor device and electronic device
View Patent ↗A solder foil formed from a material comprising particles of Cu, etc. as metal particles and Sn particles as solder particles by rolling is suitable for solder bonding at a high temperature side in temperature-hierarchical bonding, and semiconductor devices and electronic devices produced by use of such solder bonding have distinguished reliability of mechanical characteristics, etc.
1. A semiconductor device comprising:
a semiconductor chip, a tab on which the semiconductor chip is to be disposed, a lead serving as an output connector terminal, and a wire which is configured to electrically bond an electrode on the semiconductor chip to the lead, wherein
the semiconductor chip and the tab are bonded to together by connection portions containing a solder foil formed from a solder material comprising Cu particles and Sn particles by rolling so as to subject the Sn particles to plastic flow-through between the Cu particles, whereby preventing generation of voids during or after the solder bonding process, wherein
the Cu particles are not melted at a soldering temperature of the soldering foil, but the plastically flowing Sn particles are melted to react with the Cu particles at the soldering temperature of the soldering foil, wherein
the connection portions further contain a CuSn compound containing Cu 6 Sn 5 which is not melted at the soldering temperature of the soldering foil, and the CuSn compound bonds the Cu particles together.
2. A semiconductor device according to claim 1 , wherein the solder material contains the Cu particles in a volume ratio between 50% and 60% and the Sn particles in a volume ratio between 40% and 50%.
3. A semiconductor device according to claim 1 , wherein the Cu particles and the Sn particles are balls.
4. A semiconductor device according to claims 1 , wherein the solder material contains at least one of the materials selected from the group consisting of: Ag, Bi, Cu, Zn, Ni, Pd, and Au, in addition to the Cu particles and the Sn particles.
5. A semiconductor device according to claim 1 , wherein the solder foil is plated with Sn or a plating material comprising Sn and at least one of the following materials: Bi, In, Ag, Au, Cu, Ni, and Pd.