4-Inch LED Wafer Scribing
Oct 2005IPG Photonics, Microsystems Div.Request Info
Uses ChromaDice Laser SystemHOLLIS, N.H., Oct. 6 -- JP Sercel Associates (JPSA) has developed a scribing process for four-inch LED wafers. This larger format was recently introduced by Tekcore Co. Ltd., a Taiwan manufacturer of high-brightness LED chips in 450 to 480-nm (blue), 495 to 510-nm (cyan), 510 to 530-nm (green) and ultraviolet LED 370 to 430-nm wavelengths.
JPSA developed the scribing process using its ChromaDice ultraviolet diode-pumped solid-state laser system, which delivers high-speed wafer scribing with typical yields greater than 99 percent at very low operating costs, the company said.
"ChromaDice cuts a well-defined chip, with consistently narrow cuts as small as 2.5 microns," JPSA said in a statement. "Narrower streets permit increased die population, adding value to each wafer. With its high throughput and minimal impact on device performance, the process is tolerant of wafer warp and bow and delivers very fast scribing speeds compared to other methods using an advanced 266-nm (or 355-nm) DPSS laser process."
ChromaDice has a footprint of 60 by 42 inches and features an air-cooled laser, motion control, beam delivery and video inspection. It has a true, unmapped position radius of 2 microns over a 100 by 100-mm-square area and a stage orthogonality of more than 2 arc seconds.
Scribing of four-inch wafers can be difficult due to handling and bowing issues. Bowing of unthinned wafers can potentially reach 1 centimeter, creating processing problems. JPSA's process involves scribing a wafer that is held precisely in a vacuum fixture that corrects wafer bowing consistently to within a few microns, ensuring precise scribing for optimum yields.
For more information, visit: www.jpsalaser.com; e-mail: firstname.lastname@example.org
JP Sercel Associates Inc.
17D Clinton Drive
Hollis, NH 03049
Phone: (603) 595-7048
Fax: (603) 598-3835