In recent years, the technology for use of Light-emitting diodes (LEDs) have progressed tremendously. Reliability requirements for LED optical inspection have
become more critical. Due to cost and design requirements, the manufacturers use mass-produced spectrometers which accuracy of measurement is poor than the high specification ones. Because manufacturers improve the accuracy with complex calibration method which is no physical basis, the method is prone to failure due to product factors.

     The main problem in optical inspection is stray light. The method to carry out this study was using the spectral stray light correction matrix which calibrates the spectrum. Various LED wafers are calibrated by different correction matrix. Compare the test machine’s dominant wavelength (WLD) and power with the standard machine’s ones. The results suggested that the energy is accurate, WLD is convergent. In addition, the calibration procedure is greatly simplified.

Keyword：LED Inspection、Spectrometer、Stray Light、The Spectral Stray Light Correction Matrix