The Bin Mixing Design To Increase The Utilization Rate Of A Multichip LED Package Wafer

LED is a new type of solid-state lighting, it has been widely used in the field ofthe backlighting, road traffic, transportation, signage and display for its advantage ofsmall size, light weight, low cost, long life, environmental protection, etc. Especiallythe Multichip white LED package, it is has caused people more and more attentionand spread in the field of lighting for its low cost, high photosynthetic efficiency, lowthermal. Currently, LED is still in the early development stages, its service life, priceand colo7r consistency has always restricted the development of LED. In this paper,the spectrum is the research foundation of LED, studying the opto-electricparameters effect of LED to the performance of devices and the method of binmixing design to improve the LED chip utilization ratio of a wafer.This design is based on different Bin blue chips of a wafer, research therelationship between bin mixing and spectral, optical radiation flux, colorcoordinates, wavelength. The different wavelength chips are used by the bin mixingexperiment, the measurement has been conducted in a0.5m integrating sphere fromEVENFINE. The experiment also changed the different parameters of current andtemperature, the opto-electrical parameters of package with two blue chips indifferent bins was measured separately, then their spectrum was superposed, the newspectral opto-electrical parameters was calculated, and the opto-electrical parametersof package with two blue chips in different bins was measured. As the result, theopto-electrical parameters obtained from theoretical calculation and the experimentalmeasured were compare.The bin mixing equation of radiation flux and wavelength was established anddeduced, then the equation was verified the correctly by the experiment. Thisequation is also used as a standard for bin mixing multi-chip LED packaging,calculated the opto-electrical parameters of the chips needed to mix.The mode of COB package usually includes more than two LED dies. By theequation to calculate the opto-electrical parameters of the chips needed to mix. When choosing chips more chip conveniently to use the equation while can guarantee thecolor consistence of the package source, improving the chip utilization rate of waferchip and decreasing the cost of the LED.Under the condition of blue die and different color phosphors converses intowhite LED, the equation is also used to prospect the opto-electrical parameters of binmixing LED, the different blue dies can be packaged in same phosphors, improvingthe utilization efficiency of phosphors while reducing the cost of white LED.