Laminating Encapsulant Film Containing Phosphor Over LEDs

Abstract

A process is described for wavelength conversion of LED light using phosphors. LED dies are tested for correlated color temperature (CCT), and binned according to their color emission. The LEDs in a single bin are mounted on a single submount to form an array of LEDs. Various thin sheets of a flexible encapsulant (e.g., silicone) infused with one or more phosphors are preformed, where each sheet has different color conversion properties. An appropriate sheet is placed over an array of LED mounted on a submount, and the LEDs are energized. The resulting light is measured for CCT. If the CCT is acceptable, the phosphor sheet is permanently laminated onto the LEDs and submount. The lamination encapsulates each LED to protect the LEDs from contaminants and damage. The LEDs in the array of LEDs on the submount are separated. By selecting a different phosphor sheet for each bin of LEDs, the resulting CCT is very uniform across all bins.

Dependencies are inferred from the claim text.