Enables Cu pillar flip chip attach with T7 lead-free solder paste

05. December 2019, 10:30AM – 11:15AM
Venue: Jasmine Foyer
Authors: B. Senthil Kumar; Bayaras Abito Danila; Chong Mei Hoe Joanne; Zhang Rui Fen; Santosh Kumar Rath; Chan Li-San; Wong Chin Yeung Jason
Mode: Poster Session

This paper reports the evaluation of printability along with attachment of Copper (Cu) Pillar Flip Chip (FC) and passive component, such as 008004, for the solder paste AP5112 T7. The solder paste can sustain continuous printing up to 8hrs using 70um stencil opening and 50um line spacing. The pot-life and shelf-life of the paste have been evaluated to be 72hrs and 4 months, respectively. The solder paste has been designed for use in Systems in Package (SIP) such as components including 008004 and Cu Pillar FC. The advantage of using this paste would be the single step stencil printing process for attachment of both passive(s) and Cu pillar FC, without involving flux dipping/printing. The results indicate the paste is suitable for Cu pillar FC attachment, with no voids, enable consistent stand-off heights, with stencil opening, down to 90%. Results using 008004 components show <2% voids, no solder beads and no tombstones.