MICHAEL J BROWN
Pharmacy at Highgate Dr, Valrico, FL

2003000, Jan 2, 2003

May 15, 2002

10/146267

James Nering - Summit NJ, US
Robert Karlicek - Santa Maria CA, US
Mark Gottfried - Hillsborough NJ, US
Ivan Eliashevich - South Orange NJ, US
Michael Brown - Valrico FL, US

H01L021/301

438/463000

A method for separating a semiconductor wafer into several thousand devices or die by laser ablation. Semiconductor wafers are initially pre-processed to create multiple devices, such as blue LEDs, on the wafers. The wafers are then mounted with tape coated with a generally high level adhesive. The mounted wafer is then placed on a vacuum chuck (which is itself positioned on a computer controlled positioning table) to hold it in place during the cutting process. The cutting surface is then covered with a protective layer to prevent contamination from the effluent resulting from the actual cutting process. A laser beam is generated and passed through optical elements and masks to create a pattern, such as a line or multiple lines. The patterned laser projection is directed at the wafer at a substantially normal angle and applied to the wafer until at least a partial cut is achieved through it. A mechanical separation process completes the separation when only a partial cut is achieved by the patterned laser projection. The die are then transferred to a grip ring for further processing.