Optical metrology for mass production of microLED displays & wafers

Metrology for microLED mass production requires high speed and accuracy, especially as the number of microLEDs on a 6-inch wafer approaches billions. Traditional methods, like electrically contacting each LED and spectroscopically characterizing emitted light, are becoming impractical. Instead, LEDs can be optically excited using light. A wafer scanning system with an imaging light measuring device (ILMD) and photoluminescence microscope can capture images of up to millions of LEDs in one shot. The ILMD, connected to a spectrometer, provides spectral reference data. This autocalibrating setup ensures accurate color measurements, close to those obtained with a spectrometer, for millions of LEDs in minutes.