SILICON STORAGE TECHNOLOGY has come up with what may be the thinnest and—in most densities—the smallest footprint form-factor memory parts for demanding next-generation Bluetooth applications, which typically restrict device heights to 2 mm. Its ball-grid-array (BGA) and land-grid-array (LGA) Micro-Packages use proprietary packaging materials and careful wafer back grinding. As a result, the height of the XFLGA part with bump pads stands at just 0.52 mm in a 48-contact, 4- by 6-mm footprint. The WFBGA version has the same features, save a 0.73-mm height and ball pads. Both are rated for operation from −40°C to 85°C.
SST credits its NOR-type SuperFlash with split-gate cell architecture for this development. "With our technology, we can achieve smaller sectors without significantly increasing die size," says Ben Cheung, product marketing manager for the Standard Memory Product Group. "This is important for a fabless company like SST because SuperFlash's thicker oxide is more compatible with a standard logic process. This in turn means lower costs and higher reliability, especially for data retention."
Samples of both 3.3-V parts are available in 4- and 8-Mbit x16 densities. Their 0.5-mm contact pitch suits them for pinouts up to 32 Mbits. The XFLGA's thin height isn't that much thicker than a bare die, yet it costs less. SST expects the 4-Mbit version to cost about $1.50 to $1.60 in lots under 10,000 units.
Silicon Storage Technology Inc.
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