Special needs of large flip chip being addressed

06/01/2002

SAN JOSE, CALIF. - ASE Test Limited and MTBSolutions (MTBS) announced that they are jointly developing packaging technology for large flip chip devices. The widely known issue of a mismatch in the thermal coefficient of expansion (TCE) between silicon (4 ppm) and an organic substrate (typically 16 ppm) becomes more significant as the die size increases. The new packaging technology will target chips 20 mm square and larger, where standard packaging faces reliability concerns. ASE plans to offer the new large silicon flip chip package in body sizes from 27 mm square to 52.5 mm square. The packages will use a high-speed substrate material from AMITEC.

According to Bob Hilton, MTBS CTO, "AMITEC is the only supplier capable of meeting the substrate specifications to ensure the reliable assembly of large silicon flip chip."

Hilton cites the high glass transition temperature (260°C) as a key technical factor. The substrate material can also accommodate lines and spaces of 10 µm, and a low dielectric constant (2.55) enables high-speed performance.

Under the agreement, ASE Electronics Malaysia, a wholly owned subsidiary of ASE Test Limited, will manufacture the flip chip packages. The process and design details are being jointly developed by MTBS and ASE.