8.3: A Method for Measuring Droplet Volume of Electrospray Deposition Based on AdaBoost Regression

Abstract

OLED (organic light‐emitting diode) displays have become the next generation of mainstream display technology due to their high luminous efficiency and flexibility, and the manufacturing technology of OLEDs has a critical impact on their longevity and display quality. ESD (Electrospray Deposition) is an innovative technique to achieve micron‐scale membrane structures to meet the requirements for effective manufacturing of organic TFE (thin film encapsulation) layers for use in organic light‐emitting diode displays. Measuring array droplet deposition volume produced by Electrostatic Spray Deposition plays a vital role in the consistency control of film thickness.This paper presents a method for measuring the deposition volume of array droplets. The volume of the deposited droplets is estimated by establishing the mapping relationship between a large number of deposition variables (including the print parameters and the features of the deposited droplets) and the volume. This paper uses a data set containing 427 samples to build a machine learning (ML) model. The AdaBoost regressor is selected to ensure accuracy and avoid overfitting. Based on this measurement method, a deposition droplet measurement system (DDMS) is established, and the performance of the proposed method is verified. The results show that volume prediction performance (R2) reached 0.96, the regression volume error is about 0.51%, and the average time for each droplet measured is 0.5ms.is