摘要 |
A device with a solder joint made of a copper contact pad ( 210 ) of certain area ( 202 ) and an alloy layer ( 301 ) metallurgically attached to the copper pad across the pad area. The alloy layer contains copper/tin alloys, which include Cu<SUB>6</SUB>Sn<SUB>5 </SUB>intermetallic compound, and nickel/copper/tin alloys, which include (Ni,Cu)<SUB>6</SUB>Sn<SUB>5 </SUB>intermetallic compound. A solder element ( 308 ) including tin is metallurgically attached to the alloy layer across the pad area. No fraction of the original thin nickel layer is left after the reflow process. Copper/tin alloys help to improve the drop test performance, nickel/copper/tin alloys help to improve the life test performance.
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