Exposure and Development in Chemical Etching

After cleaning, coating, and drying, the next critical steps in material preparation for chemical etching are exposure and development. These stages define the precise pattern that will later be etched into the metal.

Exposure
The coated metal sheet is placed under a phototool (a high-resolution film containing the desired design). Using UV light, the photoresist is selectively exposed through the transparent areas of the phototool. This process transfers the pattern directly onto the resist layer with extremely high accuracy. The quality of exposure—light intensity, alignment, and exposure time—directly determines the sharpness and resolution of the final features.

Development
After exposure, the sheet undergoes development, where the unexposed (or exposed, depending on positive or negative resist) areas of the photoresist are dissolved and removed. This reveals the bare metal areas that will later be etched, while the remaining resist continues to protect the areas that must stay intact. Proper development ensures clean edges, accurate line widths, and defect-free patterns.

Together, exposure and development form the “blueprint” for chemical etching. Precision in these stages ensures that even the most complex geometries, fine meshes, or micro-scale features can be reproduced with consistency and repeatability.