Patent ID: 7626274

Claim:
A structure comprising: a first contact pad with a copper surface; a second contact pad with a copper surface, the second contact pad positioned opposite the first contact pad; a body of solder in contact with the first and second pads, the solder being an alloy including: tin in the amount of a first weight percent; silver in the amount of a second weight percent; and at least one metal from the transition groups IIIA, IVA, VA, VIA, VIIA, and VIIIA of the Periodic Table of the Elements in the average amount of about 0.01 to about 0.5 weight percent, wherein the solder body near the first and the second contact pad has a third weight percent greater than zero percent and near the center of the solder body has a fourth weight percent higher than the third weight percent; and a first layer of intermetallic compounds between the first pad and the solder body, and a second layer of intermetallic compounds between the second pad and the solder body; the compounds including grains of copper and tin compounds and copper, silver, and tin compounds; and the compounds contain transition metals.