Metal chemical etching, also known as photochemical etching, is a subtractive manufacturing process that uses controlled chemical reagents to selectively remove unwanted metal material from thin metal sheets to produce highly precise custom components. Unlike mechanical cutting processes, this technology delivers burr-free and stress-free finished parts, making it ideal for complex, ultra-thin metal structures that are difficult to machine via traditional methods.

How Metal Chemical Etching Works

1. Material Preparation: Clean thin metal sheets (stainless steel, copper, nickel, nitinol, kovar, molybdenum etc.) to remove oil, oxide and surface contaminants.
2. Photoresist Lamination: Apply UV-sensitive photoresist film evenly onto both sides of the cleaned metal substrate.
3. Artwork Exposure: Align the precision film tooling with the metal sheet and expose under UV light to transfer the designed pattern.
4. Developing: Wash away unexposed photoresist to expose the metal areas that need to be etched.
5. Chemical Etching: Immerse the workpiece in etching solution. Exposed metal will be dissolved uniformly, while regions covered by cured photoresist remain intact.
6. Stripping: Remove the remaining photoresist protective layer after etching completes.
7. Inspection & Post-processing: Conduct dimensional inspection, cleaning, surface finishing and packaging.

Core Advantages of Metal Chemical Etching

• Burr-free edges: No mechanical contact during material removal, eliminating burrs and secondary deburring operations.
• Zero tooling cost: Digital artwork replaces hard metal dies. Low cost for prototype and small-batch custom orders.
• Stress-free parts: No mechanical force applied, so thin or delicate components will not deform or warp.
• High precision & tight tolerance: Capable of producing ultra-fine patterns, micro holes and complex geometries on thin foils down to 0.02mm thickness.
• Fast turnaround: Rapid design modification, short lead time for prototyping and mass production.
• Wide material compatibility: Works on stainless steel, copper, brass, nickel, titanium, nitinol, kovar, molybdenum and other metal alloys.

Typical Applications

• Semiconductor components: lead frames, packaging stencils, shielding parts
• Automotive industry: fuel cell bipolar plates, sensor components, filter meshes
• Medical devices: nitinol surgical components, micro filters, precision shims
• Electronics: EMI/RFI shielding cans, speaker grilles, etched encoder discs
• Industrial filtration: custom sieves, micro porous filter screens, metal mesh filters

Design Considerations

• Minimum feature width is generally equal to the thickness of the metal sheet.
• Wall thickness and hole size must follow etching design rules for consistent quality.
• Material selection and sheet thickness directly affect etching speed and dimensional tolerance.
• Complex multi-layer patterns can be realized without extra cost increase compared to simple shapes.