UK-based Plessey has announced the realization of high-volume, large-die LED performance based on its gallium nitride on silicon MaGIC (Manufactured on GaN-on-Si I/C) high-brightness LED (HBLED) technology.
The large die benefits from three core features of Plessey’s process: the low thermal resistance of silicon; a single-surface emitter die design; and 6-inch wafer processing. To exploit these benefits, Plessey has produced a 20mm2 die design (i.e. 4.5mm x 4.5mm) that can generate up to 5W of blue light over a 400-480nm wavelength range. This die is produced as a technology demonstrator to enable meaningful engagement with customers to determine the optimum application fit.
Picture: Plessey’s 4.5mm x 4.5mm large-die GaN-on-Si LED.
Large-area LED die can help in many ways, particularly for chip-on-board (CoB) products in providing a much simpler, more uniform light emitter while reducing die attach and wire bond overheads. The low thermal resistance of the silicon substrate allows easier thermal management and enhanced reliability resulting from lower temperature operation. The die uses Plessey’s vertical design structure, which has a cathode top contact and anode bottom contact, making it suitable for scaling the effectiveness in applying large die. Plessey also says that 6-inch wafer processing, coupled with what is claimed to be best-in-class across-wafer uniformity, makes such large die a commercial proposition.
“The next wave of general lighting products will see LEDs applied in ways that truly exploit the benefits obtained through Plessey’s leading GaN-on-Si technology,” believes marketing director David Owen. “This announcement marks the start of a phase where we engage with our key partner customers in defining the commercial realization of lighting products based on Plessey's large GaN-on-Silicon LED die.”
Plessey’s range of products for lighting applications and fixtures is being showcased in stand D31 at LuxLive (the UK’s biggest lighting show) at ExCel London (19-20 November).
