Lead free solder
AssigneeKabushiki Kaisha Toshiba
InventorsToshihide Takahashi, Kazutaka Matsumoto, Izuru Komatsu, Masahiro Tadauchi, Yoshiyuki Fukuda
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Abstract
A lead-free solder comprises tin and zinc at a weight ratio between tin and zinc ranging from about 88:12 to about 80:20 on the basis of total weight of the lead-free solder.
Claims11
Lead-free solder comprising tin and zinc at a weight ratio between tin and zinc ranging from about 88:12 to about 80:20.
Lead-free solder comprising tin and silver at a weight ratio between tin and silver ranging from about 99.9:0.1 to about 98.0:2.0.
Lead-free solder comprising tin and silver at a weight ratio between tin and copper ranging from about 99.7:0.3 to about 99.0:1.0.
Lead-free solder comprising tin and copper at a weight ratio between tin and copper ranging from about 99.9:0.1 to about 99.5:0.5.
A semiconductor device comprising:
- a first body to be bonded to a lead-free solder;
- a second body to be bonded to a lead-free solder that has a different coefficient of thermal expansion than the first body;
- and
- a lead-free solder interposed between the first body and the second body;
- the solder comprises tin and zinc, the zinc content of a surface in contact with the first body being larger than the zinc content of a surface in contact with the second.
Dependencies are inferred from the claim text.