Chemical etching is an ideal manufacturing method for custom precision shims. Unlike stamping or laser cutting, photochemical etching shapes thin metal sheets without mechanical impact. It eliminates burrs, deformation and residual stress, delivering ultra-flat shims with highly consistent thickness and precise outer profiles.

Process Flow

1. Material selection: Choose thin metal foils including stainless steel, copper, brass, nickel, Invar and Kovar.
2. Surface cleaning: Remove oil, oxide and surface contaminants to ensure photoresist adhesion.
3. Dry film lamination: Apply photoresist film on both sides of the metal sheet.
4. UV exposure & development: Transfer custom shim outlines via UV exposure, wash away unexposed resist to expose the metal area for etching.
5. Chemical etching: Selective etching removes unwanted metal to form the final shim geometry.
6. Photoresist stripping: Remove the protective photoresist layer after etching.
7. Post-processing: Cleaning, passivation and flatness correction if required.
8. Quality inspection: Check dimensional tolerance, flatness, edge quality and surface finish.

Core Advantages

• Burr-free edges, no secondary deburring required.
• Stress-free parts, no warping or distortion after processing.
• Wide thickness range: from ultra-thin 0.02 mm up to 2 mm.
• Highly flexible custom shapes: slots, holes, notches and complex contours can be easily integrated.
• No hard tooling, low cost for prototyping and small-batch orders.
• Consistent dimensional accuracy and repeatability for mass production.
• Excellent flatness, critical for gap adjustment and alignment applications.

Application Fields

• Precision machinery gap adjustment and spacing
• Aerospace and aviation assembly shimming
• Automotive transmission and engine assembly
• Instrumentation, sensors and optical equipment
• Electronics, motors and pump component alignment

Design Notes

• Maintain sufficient wall width to avoid thin fragile features.
• Specify material grade, thickness, overall dimensions and hole tolerances clearly on drawings.
• Multiple shim profiles can be nested on one sheet to save material cost.
• For high temperature or low expansion scenarios, select Invar or Kovar alloy.
• Tolerance capability depends on material thickness; consult for tight tolerance requirements.