Patent ID: 8318516

Claim:
A method of wafer level purifying light color of a LED wafer, comprising the steps of: providing a LED wafer having LED chips thereon and an uppermost film of said LED chips having a index of refraction n s for forming multi-filtering layers; choosing silicon oxide as a first material “A” having a index of refraction n A ; choosing a metal oxide as a second material “B” having a index of refraction n B , said n B >n A ; setting a predetermined central wavelength according to a type of said LED wafer; setting a deposition order by A 1 B 1 A 2 B 2 . . . A T B T wherein sub-indexes represents a depositing sequence; listing mathematical algebra equations with a series of characteristic matrixes product of the layer to layer; calculating thicknesses of all transparent films by solving said algebra equations; and depositing said transparent films with said first material and said second material alternatively according to the calculated thicknesses.