Indium Corporation of America

Benlih Huang

Ning-Cheng Lee

Hong-Sik Hwang

Ning C Lee

A technique for technique for increasing the compliance of lead-free solders containing silver is disclosed. In one particular exemplary embodiment, the technique may be realized as a Sn&#x2014;Ag&#x2014;Al alloy composition comprising (0.01-20)% Ag, (0.01-2)% Al, balanced with Sn. In another particular exemplary embodiment, the technique may be realized as a Sn&#x2014;Ag&#x2014;Cu&#x2014;Al alloy composition comprising (0.01-20)% Ag, (0.01-1)% Cu, (0.01-2)% Al, balanced with Sn. In still another particular exemplary embodiment, the technique may be realized as a Sn&#x2014;Ag&#x2014;Al&#x2014;Ni composition comprising (0.01-20)% Ag, (0.01-2)% Al, (0.01-4)% Ni, balanced with Sn. In yet another particular exemplary embodiment, the technique may be realized as a Sn&#x2014;Ag&#x2014;Cu&#x2014;Al&#x2014;Ni alloy composition comprising (0.01-20)% Ag, (0.01-1)% Cu, (0.01-2)% Al, (0.01-4)% Ni, balanced with Sn.

Technique for increasing the compliance of lead-free solders containing silver

A technique for increasing the compliance of tin-indium solders is disclosed. In one particular exemplary embodiment, the technique may be realized as a lead free solder alloy comprising from about 58.0% to about 99.998% by weight tin, from about 0.001% to about 40.0% by weight indium, and from about 0.001% to about 2.0% by weight at least one rare earth element.

Technique for increasing the compliance of tin-indium solders

The object of this invention is to employ a solder alloy comprising tin/lead/silver in order to provide a wider solidification range and achieve balance between the surface tensions of both side of a small leadless component. The expanded solidification range slows the melting and wetting time so as to balance the surface tension of the molten solder, and in turn reduces the tombstoning frequency. The preferred Ag concentration is 0.2-0.5% in weight, the more preferred Ag concentration is 0.3-0.4% in weight. For reflow soldering of small leadless components, the pastes made with the alloy compositions of Sn62.6Pb37Ag0.4 and Sn63Pb36.6Ag0.4 results in improvements in tombstoning.

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New Hartford, NY, United States of America

Benlih Huang