Research Of OLED-on-silicon Defect Inspection Equipment Based On Machine Vision

With the rapid development of microdisplay technology,more and more manufacturers begin to develop OLED-on-silicon.However,the domestic OLED-onsilicon industry is still immature,so in order to improve the yield of products,optimize the production process and reduce production costs,the defect inspection technology is introduced in the product production process.Traditional inspection technology relies on human eyes,due to the influence of human subjective consciousness,the inspection standard cannot be guaranteed to be consistent,and which has the disadvantages of low efficiency and low inspection accuracy.In recent years,an emerging technology,namely machine vision technology,can replace manual inspections,which has the advantages of high inspection accuracy and high efficiency,and make great contributions to the intelligentization of the manufacturing industry.In order to change the current situation that there is no OLED-on-silicon defect inspection equipment in China,this paper designed a OLED-on-silicon defect inspection equipment.The main tasks are as follows:1)The structure,light-emitting principle and production process of OLED-onsilicon was understood,and several common defects of OLED-on-silicon was analyzed.2)For the display defects of OLED-on-silicon,the selection of cameras,lenses and light sources was completed,and the visual inspection system was built.The inspection accuracy of the system can reach 2.2?m.Due to insufficient depth of field of the high-magnification lens,the product pixels and dust cannot be focused at the same time.Therefore,the visual inspection system was optimized.3)Through image processing technology,various types of algorithm inspection processes was designed.The images collected by the vision system was processed to detect defects in the product.Defect information such as defect type,defect location and defect size can be obtained,and the defect information was fed back to the process section to guide the improvement of the product production process.4)A human-computer interaction software was designed,which can control the inspection process of the product and show the inspection results.Finally,the visual inspection system,inspection algorithm and inspection software were integrated into one device,and the equipment was put into the production of OLED-on-silicon to verify the inspection capabilities of the equipment.The test results show that the missed inspection rate of this equipment for point,line and Mura defects was controlled within 2%,and the missed inspection rate of color defects was less than 6%,which was higher than the standard level of display defect inspection equipment in the market.The defect inspection equipment designed in this paper meets the requirements of OLED-on-silicon manufacturers.