Building a sub-micron inspection strategy

One of the most challenging inspection goals I worked toward was pushing resolution into the sub-micron range. At that scale, everything matters.

A fine repeating grid used to expose aberrations — At high resolution, a fine repeating target exposes distortion and aberration long before the camera is the limit.

The problems

Vibration
Temperature drift
Optical aberrations
Focus repeatability
Contamination
Illumination stability

The major realization

The camera was not the bottleneck. Real improvement came from:

Better optics
Better illumination
Better motion control
Better calibration targets

The camera is often the least interesting component.

This completely changed how I evaluate high-resolution systems today: I start with the optical path, the mechanics, and the calibration strategy, and only then worry about the sensor.