Overview

A mass production surgical shim for aerospace components is a photochemically etched, burr-free spacer used to set a precise gap, preload or alignment in an assembly where a few microns change fit and function. Unlike ground or stamped shims, the profile is dissolved out of a flat sheet with no mechanical force, so the part leaves the line flat, stress-free and free of rolled edges — essential when shims are stacked, bonded or slid into a tight tolerance chain.

What makes a mass production surgical shim for aerospace components economical at volume is that thickness is set by the starting stock and the outline by film artwork: thousands of identical shims are etched on one panel, and a new part number is only a new film. 301/304/316L stainless and titanium cover the strength and corrosion needs, with tight thickness tolerance held across the whole lot. Because prototype and production share the same process, a validated shim moves to volume without a tooling requalification step.

Parameter Window

• Available Materials: stainless steel 301/304/316L, titanium, beryllium copper
• Material Thickness Range: 0.02–1.0 mm, held to ±0.005 mm on thickness
• Tolerance: ±0.01 mm on profile, ±0.005 mm on thickness
• Minimum Feature: 0.10 mm slot, 0.15 mm web
• Surface Options: passivation, electropolish, deburr-free edges, adhesive backing
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Artwork & DFM Review — Convert the shim outline into vector artwork and check slot width, web and bend relief against the chosen stock.
2. Material Selection — Certify 301/304/316L or titanium stock to the required thickness tolerance before lamination.
3. Cleaning & Lamination — Degrease and laminate dry-film photoresist on both faces under controlled heat and pressure.
4. UV Exposure — Expose the shim profile through high-resolution film registered to the sheet datum for panel-level accuracy.
5. Development — Wash out unexposed resist to open the outline and slots, checking the narrowest webs.
6. Controlled Etching — Spray chemistry matched to the alloy, holding profile and thickness through time, temperature and conveyor speed.
7. Stripping & Finishing — Remove resist, neutralize, then passivate or electropolish and verify the thickness stack.
8. Inspection & Packaging — Measure profile, thickness and flatness against the first article, then pack by lot in trays.

Core Advantages

1. Burr-free edges: Chemical removal leaves no rolled edge, so shims stack and seat flush.
2. Tight thickness control: Stock is certified to ±0.005 mm and held across the full lot.
3. Stress-free flatness: No mechanical force keeps thin shims dimensionally stable.
4. Volume economy: Thousands of identical parts are etched on one panel at low unit cost.
5. No hard tooling: A new part number is a new film, so variant stacks stay economical.
6. Repeatable fit: Lot-to-lot consistency removes selective shimming at assembly.

Typical Applications

• Gap spacers: Shims that set rotor or actuator clearances.
• Preload shims: Thin spacers controlling bearing preload.
• Alignment shims: Profile shims for optical or sensor mounts.
• Bonded stacks: Laminated shim sets for adjustable height.
• Masking spacers: Burr-free shims in bonding fixtures.
• Thickness gauges: Calibrated shim stock for inspection.

Design Notes & Process Considerations

1. Slot versus thickness: Keep the minimum web at or above 1.2 × material thickness so narrow ribs do not lift.
2. Thickness callout: State ±0.005 mm on stock separately from profile tolerance.
3. Burr and edge: Require burr-free edges where shims mate to a housing or stack.
4. Flatness: Call out flatness per 100 mm for bonded or stacked shim sets.
5. Surface spec: Name the finish, since plating adds to the final thickness stack.
6. Lot traceability: Group parts with shared registration marks and keep lot records for repeat volumes.