Patent ID: 7727805
Filing Date: 2010-06-01
Classification: H01L

Abstract:
1. A method comprising: depositing an alloy material on lead-free bumps coupled to a package substrate; placing a semiconductor die including conductive bumps on the package substrate so that the conductive bumps contact the alloy material; elevating a temperature of the attached semiconductor die and the package substrate to a first elevated temperature to reflow the alloy material; underfilling an epoxy material between the semiconductor die and the package substrate and allowing the epoxy material to gel at a temperature below the first elevated temperature; curing the epoxy material at a second elevated temperature, the second elevated temperature greater than the first elevated temperature; and elevating the semiconductor die and the package substrate to a third elevated temperature to reflow the alloy material and the lead-free bumps to form an alloy joint between the semiconductor die and the package substrate.