Laser dicing, a technique that uses focused laser pulses to separate individual chips from a semiconductor wafer, is increasingly favored over mechanical blade cutting because it can process delicate, low-strength materials with minimal physical stress. However, achieving proper yield requires precise control over the process.

If pulses fall short, they leave a wafer only partially cut, while excessive pulses can damage the material or the tape used to hold it. While techniques for monitoring processing depth exist, most are too slow or fragile for use on production lines.

Now, a team of researchers led by Professor Hirofumi Hidai from the Graduate School of Engineering, Chiba University, Japan, focused on a different signal: recoil force. Recoil force is the minute reaction force generated on a material’s surface when it is rapidly heated and vaporized by a laser pulse.