Tape based CSP package supports fine pitch wirebonding

Abstract

Utilizing the existing wire bonding infrastructure, it is now possible to extend wire bonding, substrate, and molding technologies to produce extremely low cost, fine pitch CSP package solutions. These packages exploit available 35/spl mu/m die pad pitch capability and 20/20/spl mu/m line/space tape substrate technology to produce low-cost, miniature, light-weight devices at a maximum mounted thickness of 0.8mm (to comply with JEDEC outline for wfBGA). These types of CSP solutions are required in portable handheld devices with increased functionality, such as cell phones, pagers, personal digital assistants (PDAs), digital cameras, and gaming devices. 3M, Sumitomo Bakelite, and Kulicke & Soffa have collaborated in the design, manufacture, and validation of a 10mm /spl times/ 10mm flex circuit based BGA device at 0.5mm ball pitch and 276 I/Os. The key to this package is the use of an on-die in-line bond pad pitch of 35/spl mu/m and an on-substrate staggered bond pad design with an effective pitch of 50/spl mu/m. This substrate technology enables the ultimate in low cost packaging due to the small die size and resulting package size.