VILLACH, Austria--The SEZ Group here today announced shipment of an enhanced wafer-thinning system capable of reducing substrate thickness to less than 70 microns. Until now, wafer-thinning processes in volume production have been able to reach 100 microns, according to SEZ managers.
STMicroelectronics has taken delivery of the first two enhanced SEZ spin-processor platforms, which will be used on 8-inch wafers in flash IC and smart-card chip production. SEZ did not release the value of the order.
Over the past couple of decades, wafer thinning has played a bigger role in Europe because of the region's strong smart-card market. Chip thickness is a key factor in making smart cards thin enough to fit comfortably in wallets.
"As smart cards grow globally, and chip-scale packaging and flip-chip technology expand, enhanced wafer thinning will increase worldwide," said Michael West, business and strategic technology director for SEZ America in Phoenix.
SEZ enhanced the wafer-thinning capability of its tool by changing the handling system, the chuck, and other major components inside the platform. The spin-processor system continues to use SEZ's wet-chemical process to thin the wafers. "The platform does not look different, but the methodology by which wafers are transferred and handled was greatly enhanced," West said.
The new spin-processor platform uses an innovative Bernoulli contactless handling system. SEZ said the system has been designed to removes edge stress risers and microcracks from the backside of the thinned wafers.
After a traditional grinding process, SEZ's chemical-based spin-processing completes the job of wafer thinning. SEZ believes its chemical-based process has several advantages over new dry-etch wafer-thinning techniques, including lower temperatures, improved control of edge profiles and control over backside roughness.
"The non-contact, non-pressure induced thinning is capable of handling wafers that are bumped with contacts on the die," West said. "Seventy microns is becoming mainstream over the next year and 50 microns is the next target. We're now being asked to demonstrate 50 microns by customers."--J. Robert Lineback reporting from the U.S.