Stainless steel chemical etching (photochemical etching) is a precision subtractive machining process that fabricates intricate stainless steel parts by selectively dissolving unwanted metal using controlled chemical etchants. Stainless steel is widely used for its excellent corrosion resistance, high tensile strength and stable physical properties, yet it is difficult to process with traditional mechanical methods for ultra-thin sheets and micro features. Chemical etching provides an ideal solution to produce complex stainless steel components while preserving the material’s inherent corrosion-resistant performance.

Stainless Steel Chemical Etching Process

1. Surface Cleaning: Stainless steel sheets are degreased and descaled to remove oil, rust and oxide layers for reliable photoresist adhesion.
2. Photoresist Lamination: Dry film photoresist is laminated on both sides of the cleaned stainless steel substrate.
3. UV Exposure: Align the artwork film and expose under UV light to cure the photoresist in the required pattern areas.
4. Developing: Wash away unexposed photoresist to expose the stainless steel regions that will be etched.
5. Chemical Etching: Specialized stainless steel etchant dissolves exposed metal evenly from two sides to form micro holes, slots and custom outlines.
6. Resist Stripping: Remove the remaining cured photoresist after etching completion.
7. Inspection & Post-treatment: Dimensional inspection, passivation, cleaning and packaging.

Core Advantages of Stainless Steel Chemical Etching

• Burr-free and stress-free: No mechanical cutting force, so edges remain clean and thin stainless steel foils avoid deformation.
• No hard tooling cost: Pattern changes only require digital artwork updates, economical for prototyping and small to medium batches.
• High precision micro features: Manufacture fine slots, micro sieves and encoder discs on stainless steel foil down to 0.02mm thickness.
• Preserve stainless steel corrosion resistance: The etching process does not compromise the base material’s anti-corrosion performance.
• Consistent quality across batches: Uniform chemical reaction delivers repeatable dimensional accuracy for mass production.
• Supports multiple stainless grades: Compatible with 304, 316L, 430 and other stainless steel alloys.

Typical Applications

• Filtration industry: stainless steel filter meshes, test sieves, micro filter screens
• Semiconductor & electronics: EMI shielding parts, precision shims, lead frame components
• Automotive: sensor diaphragms, fuel filter elements, fuel cell auxiliary parts
• Medical devices: stainless steel surgical components, micro fluidic plates, precision gaskets
• Industrial equipment: encoder discs, speaker grilles, thin metal spacers

Design Considerations

• Minimum feature width generally equals the thickness of the stainless steel sheet.
• Stainless steel has slower etching speed compared to copper; material grade affects etching rate and tolerance.
• Sharp internal corners will have minor radius, which should be considered in early design phase.
• Passivation post-treatment can be added to further improve corrosion resistance of etched stainless steel parts.