Overview

Custom shim etching is a photochemical machining process that cuts shim profiles, holes, slots and tabs out of thin metal without dies, lasers or mechanical force. Sheets are laminated with dry film resist, exposed through artwork film, developed, and then sprayed with chemistry matched to the alloy, so the unprotected metal dissolves and the finished shim shape is left behind. Because metal is removed atom by atom, edges come out square and burr-free, thin foils stay flat, and no heat-affected zone is introduced. Common substrates are stainless steel 304/316L, copper, brass and nickel, supplied from 0.03 mm foil up to 1.5 mm sheet, with outline tolerance typically held to ±0.05 mm.

For buyers who manage dozens of shim part numbers, custom shim etching removes the two costs that make stamped shims expensive: a die for every revision, and the deburring that thin parts always need. A design change becomes a new film rather than a new tool, so prototypes and small batches stay economical, and the same artwork repeats identically from the first sample to the last production lot. Shims leave the line degreased, flat and ready for assembly, whether they are one-off adjustment packs for a machine build or scheduled releases for an equipment platform.

Parameter Window

• Available Materials: stainless steel 304/316L and 301 spring temper, copper C1100, brass H62/H68, nickel 200/201, titanium Grade 1, low-carbon steel
• Material Thickness Range: 0.03–1.5 mm, covering foil, strip and thin sheet
• Tolerance: ±0.05 mm on outline and hole positions; etched depth within ±10% of stock thickness
• Minimum Feature: 0.1 mm slot width and 0.3 mm hole diameter on 0.05 mm foil; webs at least 1× stock thickness
• Surface Options: degreased, passivated, tin or nickel plated, gold flash, protective PE film, PSA adhesive backing, stress-relieved flat
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Drawing Review — Import DXF/DWG or STEP data, check hole positions and outline against the tolerance stack, and flag any feature below the process limit.
2. Material & Temper Selection — Choose alloy and hardness for the job: spring-temper stainless for load-bearing shims, annealed copper for soft electrical spacers, brass for wear plates.
3. Cleaning & Lamination — Degrease both sides and hot-roll dry film resist onto foil so it stays flat, with no bubbles sitting under fine slots or small holes.
4. Double-Sided Exposure — Expose top and bottom artwork in register; double-sided imaging keeps sidewalls square when the stock is thicker than 0.5 mm.
5. Development — Wash out unexposed resist to open the profile line, holes and slots, then inspect for pinholes that could etch unwanted marks.
6. Etching — Spray both faces with alloy-matched chemistry; conveyor speed and bath temperature set the cut width and keep slot edges vertical.
7. Stripping & Finishing — Remove resist, neutralize, then plate, apply adhesive or stress-relieve as specified before parts are separated from the sheet.
8. Inspection & Packing — Verify thickness, hole gauges, outline and flatness against the drawing, then interleave shims with film or pack them in labeled sets.

Core Advantages

1. Burr-free edges as standard: Chemical removal leaves no roll-over or burr, so shims seat flat and never need a separate deburring operation.
2. No tooling cost: Every revision is just a new film, so prototype, pilot and mixed batches carry the same unit cost as repeat production.
3. Stress-free thin foil: No mechanical force or heat is applied, so 0.03 mm foil stays flat and does not work-harden or warp.
4. Tight tolerance at small size: Outline and hole positions hold ±0.05 mm, and fine slots stay open down to 0.1 mm width on thin stock.
5. Many part numbers per sheet: Mixed shim designs nest on one panel, so a full kit of adjustment shims moves through as one job.
6. Alloys on one line: Stainless, copper, brass and nickel run through the same process, and custom shim etching lets one order mix materials without extra tooling.

Typical Applications

• Motor and gearbox shims: Axial adjustment shims in 0.05–0.5 mm stainless for gear mesh setting and end-play correction.
• Bearing preload shims: Thin washers and crescents that set bearing preload in pumps, compressors and spindle housings.
• Valve and pump spacers: Corrosion-resistant shims in 316L or titanium for chemical and fluid-handling assemblies.
• Electrical contact washers: Copper and brass shims that carry current and close gaps in switchgear and battery modules.
• Optical and sensor alignment shims: Fine adjustment packs for lens mounts, encoders and measuring frames where flatness is critical.
• Semiconductor and vacuum hardware: Burr-free nickel and stainless shims for chamber fixtures and wafer handling modules.

Design Notes & Process Considerations

1. Hole-to-edge distance: Keep hole edges at least 1× stock thickness from the outer profile, or the web will etch through and the position will open up.
2. Slot width versus thickness: Through-cut slots should be at least as wide as the stock is thick; narrower slots are better half-etched to avoid taper.
3. Through-cut or half-etch: State which features are cut through and which are half-etched, and give an explicit depth callout for each.
4. Tolerance stack: Mark the dimensions that are truly critical; ±0.05 mm is standard, while tighter hole-to-hole spacing needs to be flagged early.
5. Edge condition for sealing: When the shim seals fluid or gas, require burr-free edges and flatness per 100 mm directly in the drawing notes.
6. Tab layout and packing: Micro-tabs hold parts in the sheet for delivery; specify tab positions and whether shims ship loose or in matched kits.