Display Week 2026

"Hi, I'm Nakcho Choi from Samsung Display. Our poster shows a new way to predict where cracks will happen in laser-drilled glass — before they actually break. We use liquid crystal sensors to see invisible stress patterns around the holes. The key finding? The most dangerous moment is at about 75% drilling depth, not when you punch all the way through. This helps us catch defects early in manufacturing for Under Display Cameras and Glass Core Substrates."

"So here's the problem — when you laser-drill tiny holes in glass for smartphone cameras or chip packaging, sometimes cracks form and you don't know why. Traditional inspection only catches defects after the damage is done.

Our approach is different. We use something called stress-induced birefringence — basically, when glass is stressed, it bends light differently. We put a liquid crystal layer on the glass and measure how the light changes. That gives us a colorful stress map.

[Point to Figure 2] Here you can see — as we increase the laser energy, the stress rings get bigger and more intense.

[Point to Figures 3-4] This is the interesting part. We drilled at different depths — 300, 400, and 500 microns. The stress peaks at 400 microns, which is about 80% through. After the hole breaks through at 500, the stress actually drops. So the half-cut stage is the most dangerous.

[Point to Figures 5-6] And here's where it gets cool. We mapped the slow axis orientation — which shows you the direction the stress is pointing. The cracks follow exactly perpendicular to the slow axis vectors. So we can literally predict the crack path before it happens.

The bottom line — this gives manufacturers a non-destructive way to find problem holes before they crack, saving yield in both display and semiconductor fabrication."