Product Code: ICAL08_M101

Dicing of Hb-Led Devices Embedded in Copper Substrates
Authors:
Marie Di Marco, Synova Sa; Ecublens Switzerland
Alexandre Pauchard, Synova Sa; Ecublens Switzerland
Akos Spiegel, Synova Sa; Ecublens Switzerland
Bernold Richerzhagen, Synova Sa; Ecublens Switzerland
Notker U. Kling, Synova Usa; Fremont USA
Presented at ICALEO 2008

High-brightness light emitting diodes are often embedded into a heat sink layer, providing an efficient and inexpensive method of expending the surface area necessary to dissipate heat generated during operation. Copper, copper tungsten and Molybdenum layers offer high-performance thermal management due to high thermal conductivity and a low thermal resistance. Classical dicing techniques, such as laser or diamond blade cutting, face a number of constraints and challenges when used to cut Cu and CuW embedded LED chips, such as fast wear of the blades, low speed and heat damages. The Laser-Microjet® technology, combining a hair-thin water jet with a high-power laser beam, offers wear-free, fast and damage-free cutting of LED devices. The singulation of copper embedded LED devices has been successfully performed using the Laser Microjet technique. Q-switched solid-state lasers operating at a wavelength of 532nm and a repetition rate of 30kHz were combined with 40um diameter water jet. Copper substrate thicknesses of up to 600mm were processed with good cut quality, despite large film thickness non-uniformities. Secondly, 50um thick copper layers deposited on sapphire wafers were also diced successfully with 14 passes at 200mm/s. Thirdly, CuW wafers with a thickness of 250um have been diced with an excellent quality.