H01L2224/13263

Lead free solder columns and methods for making same
10937752 · 2021-03-02 · ·

Disclosed herein are embodiments of lead-free (Pb-free) or lead-bearing solder column devices that can include an inner core, an outer sleeve surrounding a portion of the inner core, at least one space along a length of the outer sleeve, and a second layer including a solder material coupled with a portion of the inner core within the at least one space. The inner core can be configured to support the solder column so as to prevent a collapse of the solder column at temperatures above a liquidus temperature of the outer sleeve's solder material and the second layer's solder material. The column serves as a heat-sink to conduct excessive heat away from a heat generating semiconductor chip. Moreover, the compliant solder column absorbs strain and mechanical stress caused by a difference in the coefficient of thermal expansion (CTE) connecting the semiconductor chip to a printed circuit board (PCB).