White-emitting led chips and method for making same

Abstract

Methods and devices for light emitting diode (LED) chips are provided. In one embodiment of a method, a pre-formed capping wafer is provided, with the capping wafer comprising a conversion material. A wire-bond free LED wafer is fabricated comprising a plurality of LEDs. The capping wafer is bonded to the LED wafer using an adhesive. The LED chips are later singulated upon completion of all final fabrication steps. The capping wafer provides a robust mechanical support for the LED chips during fabrication, which improves the strength of the chips during fabrication. Additionally, the capping wafer may comprise an integrated conversion material, which simplifies the fabrication process. In one possible embodiment for an LED chip wafer, a submount wafer is provided, along with a plurality of LEDs flip-chip mounted on the submount wafer. Additionally, a capping wafer is bonded to the LEDs using an adhesive, and the capping wafer comprises a conversion material. At least some of the light emitted from the LEDs passes through the capping wafer where at least some of the light is converted by the conversion material.