Patent ID: 8227273

Claim:
A method for producing a white LED of predetermined color temperature, comprising: in a plurality of LEDs that includes uncoated blue LEDs or uncoated UV LEDs, or both, the uncoated blue LEDs or uncoated UV LEDs each having a respective wavelength, the wavelengths of the uncoated blue LEDs or uncoated UV LEDs not all being equal, measuring a wavelength of each respective uncoated blue LED or uncoated UV LED of the plurality of LEDs; determining a single time a respective quantity of a conversion layer to be applied over each respective uncoated blue LED or uncoated UV LED of the plurality of LEDs based on at least the measured wavelength of each respective uncoated blue LED or uncoated UV LED of the plurality of LEDs, wherein the conversion layer includes a color conversion agent, said conversion layer configured to absorb at least one of blue light and UV light, and emit light of longer wavelength; determining a single time a respective concentration of the conversion layer to be applied over each respective uncoated blue LED or uncoated UV LED of the plurality of LEDs based on at least the measured wavelength of each respective uncoated blue LED or uncoated UV LED of the plurality of LEDs, wherein the conversion layer includes a color conversion agent, said conversion layer configured to absorb at least one of blue light and UV light, and emit light of longer wavelength; and coating each respective uncoated blue or UV LED individually, with the conversion layer having the respective quantity and concentration determined that single time in said step of determining the quantity and concentration, wherein the coated LED has the predetermined color temperature, wherein the quantity and concentration of the conversion layer to be applied over each uncoated blue LED or uncoated UV LED are measured such that a constant dispensing volume of the applied conversion layer is present on each of the plurality of LEDs.