Nondestructive in situ detection of microbubble defects in the screen by optical coherence tomography

Touching screens as a key component of smart devices play a vital role in exerting normal function and user experience. Usually, defective products containing deep tiny cracks, impurities, or microbubbles generated in the manufacturing process are difficult to be detected by the present methods. The existence of such tiny defects potentially damages the integrated function of smart devices, even jeopardizes the health of users. The precise identification of microscopic defects buried in deep touching screens is great in demand. In this work, we built a spectral-domain optical coherence tomography (SD-OCT) system with suitable imaging depth and spatial resolution and carried out nondestructive imaging of endogenic micro-bubbles generated in the bonding process of the screen. Using SD-OCT, we obtained in situ 2D, 3D imaging of microbubbles to show quantitative information of the defects including exact size, shape, and spatial location, which help to analyze the occurring stage of bubble defects in the manufacturing process with improving accuracy. This provides a useful tool for the quality monitoring of the screen in industrial manufacture, which cannot be attainable by the common approaches.

Automated summary

The research team successfully achieved precise localization of deep micro-defects in touch screens of smart devices using spectral-domain optical coherence tomography, providing important insights for defect analysis and improvement in the manufacturing process.