Cleaning, Coating, and Drying in Chemical Etching

In chemical etching, proper material preparation is essential to ensure high precision and reliable results. Three critical steps in this stage are cleaning, coating, and drying.

Cleaning
Before applying any photoresist, metal sheets must be thoroughly cleaned to remove oil, grease, oxides, dust, and other surface contaminants. This is typically achieved through a combination of alkaline degreasing, acid pickling, and rinsing. A perfectly clean surface ensures strong adhesion of the photoresist and prevents defects such as pinholes or uneven etching.

Coating
Once the surface is clean, a photoresist layer is applied to both sides of the metal. This can be done through dry film lamination or liquid resist coating, depending on the required precision and material type. The resist acts as a protective barrier, allowing only the exposed areas to be etched away during the process. Uniform coating thickness is critical for achieving accurate dimensional control.

Drying
After coating, the material must be dried in a controlled environment to remove residual solvents or moisture. Proper drying ensures the resist layer is stable, durable, and resistant to chemical attack during the etching stage. Any improper drying may cause adhesion loss or distortion of fine features.

Together, these preparation steps create a stable foundation for precise and repeatable chemical etching, ensuring high-quality results in both prototypes and large-scale production.