Flip-Chip Underfill Development. In this program the Consortium will focus on development of an underfill to be used with flip-chips mounted on substrates in plastic BGA packages. Underfill of flip-chip structures can significantly increase solder joint life. The improvement level depends on the substrates material since thermal mismatch dictates the stress level on the joints. Key development efforts aim at high Tg (> 160 deg C) resins with: * Improved wetting characteristics, * Narrower filler size distribution for small chip gaps, * Faster cure by at least 50%, * Better adhesion to polyamide or other substrates and substrate coatings, * Lower stress by at least 25%, * Longer pot life for ease of processing, * Higher thermal conductivity than current underfill resins by 50%, and AGREEMENT NUMBER: MDA972-95-3-0024 ATTACHMENT NO. 1, PAGE 7 * Reworkability capability.
Flip-Chip Underfill Development. In this program we will focus on development of an underfill to be used with flip-chips mounted on substrates in plastic GBA packages. Underfill of lip-chip structures can significantly increase solder joint life. The improvement level depends on the substrate material since thermal mismatch dictates the stress level on the joints. Key development efforts aim at high Tg ( 160 deg C) resins with: * Improved wetting characteristics * Narrower filler size distribution for small chip gaps * Faster cure by at least 50% * Better adhesion to polyamide or other substrates and substrate coatings * Lower stress by at least 25% * Longer potlife for ease of processing * Higher thermal conductivity than current underfill resins by 50% * Reworkability capability
