Reduction of phosphor particle segregation effects on the CIE & spatial CIE distribution of LED packages

For lighting applications, it is common to dispense multi-phosphor materials mixing with silicone on blue LED chips to obtain high color rendering index and superior white light quality. One of the technical challenges related to dispensing phosphor materials in LED packages is the settling of the phosphor particles with time due to density & size difference. The phosphor distribution directly affects the radiation pattern (viewing angle) and also the CIE distribution of LED packages. In current study, experiments have been conducted using lead frame 3528 packages to investigate the settling effect of phosphor particles on the spatial distribution of CIEx for i) a single phosphor package (as a control); ii) a dual phosphor package.