US 8,558,252 B2 · White LEDs with emission wavelength correction

Abstract

Methods for fabricating semiconductor devices such as LED chips with emission wavelength correction and devices fabricated using these methods. Different embodiments include sequential coating methods that provide two or more coatings or layers of conversion material over LEDs, which can be done at the wafer level. The methods are particularly applicable to fabricating LED chips that emit a warm white light, which typically requires covering LEDs with one or more wavelength conversion materials such as phosphors. In one embodiment, a base wavelength conversion material is applied to the semiconductor devices. A portion of the base conversion material is removed. At least two different tuning wavelength conversion materials are also applied to the semiconductor devices, either before or after the application of the base conversion material.

Claims37

Dependent claims

A method for fabricating light emitting devices, comprising:

coating a plurality of semiconductor devices with a base wavelength conversion material, said semiconductor devices emitting over a range of wavelengths;
removing a portion of said base wavelength conversion material;
and
disposing a tuning wavelength conversion material on said plurality of semiconductor devices, said tuning wavelength material comprising at least two tuning phosphors each having a different emission spectrum, such that said emission spectrums are also different from an emission spectrum of said base wavelength conversion material;
wherein the volume of said tuning wavelength conversion material is calculated based on the output lighting characteristics of said semiconductor devices and said base wavelength conversion material.

2 more elements

Dependencies are inferred from the claim text.

White LEDs with emission wavelength correction

Life of this patent

White LEDs with emission wavelength correction

Life of this patent

Abstract

Claims37