Overview

A diaphragm etching service forms thin metal sensing diaphragms by photochemical machining of stainless, nickel and titanium foils. Dry-film resist is laminated to both faces of the foil, the diaphragm geometry — membrane land, relief corrugations, port holes and sealing rim — is exposed and developed, and the unprotected metal dissolves in a matched etchant. Because the process removes metal evenly from both sides without mechanical force, the finished membrane reaches its target thickness within ±0.005 mm, and that thickness is what sets deflection, sensitivity and working pressure. Foils run from 0.02 mm to 0.3 mm, thin enough for fast response and strong enough to survive assembly.

Design teams turn to a diaphragm etching service when rolling and stamping cannot hold membrane behavior. Rolled foil carries residual stress that shows up as hysteresis and zero drift, and stamped diaphragms leave burrs and work-hardened rims where fatigue cracks start. Etched parts keep the foil in its annealed condition, with burr-free rims and half-etch corrugations formed in the same pass, so every diaphragm in a batch responds the same way on the test bench. Prototype sensors, regulator parts and instrument membranes therefore move from drawing to tested samples without die cost.

Parameter Window

• Available Materials: stainless steel 304/316L, nickel, titanium
• Material Thickness Range: 0.02–0.3 mm
• Tolerance: ±0.005 mm on diaphragm thickness, ±0.02 mm on outline, ±0.01 mm on relief depth
• Minimum Feature: 0.08 mm port holes and 0.02 mm relief steps on 0.05 mm foil
• Surface Options: electropolishing, stress-relief annealing, passivation, micro-deburring, protective lamination
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Response Review — Confirm target membrane thickness, working pressure, deflection range and sealing method before artwork is released.
2. Material Selection — Stainless 304/316L for general media, nickel for alkalis and welding, titanium for corrosive and lightweight duties.
3. Foil Handling & Lamination — Laminate thin foils on carriers and coat both faces so the membrane stays flat through exposure and etching.
4. Double-Sided Exposure — Register port holes and relief patterns on both faces to keep features concentric within ±0.02 mm.
5. Gentle Development — Wash out unexposed resist with low-pressure spray so webs as fine as 0.08 mm stay intact.
6. Controlled Etching — Etch both faces at matched rates and monitor time and temperature until membrane thickness hits ±0.005 mm.
7. Stripping & Annealing — Strip resist, neutralize, stress-relieve the foil, then electropolish, passivate or micro-deburr as specified.
8. Inspection & Packaging — Verify thickness, flatness and rim condition, then pack diaphragms between soft liners with a first-article report.

Core Advantages

1. Repeatable response: Membrane thickness drives sensitivity and working pressure, and etch control keeps that thickness within ±0.005 mm across the batch.
2. Stress-free foils: No rolling or stamping load enters the metal, so hysteresis, creep and zero drift stay low over service life.
3. Burr-free rims: Clean edges carry no microcracks or work-hardened zones, where fatigue failure typically starts.
4. Thin-gauge capability: Foils down to 0.02 mm are processed reliably for fast-response sensing elements.
5. Features in one part: Ports, corrugations, recessed lands and sealing rims are all formed in the same etch step.
6. No tooling cost: Sensor prototypes and small series skip stamped tooling entirely, and a diaphragm etching service revises parts with new artwork only.

Typical Applications

• Pressure sensor diaphragms: Gauge and absolute sensing elements for gases and liquids where deflection must match the calibrating curve.
• Regulator and valve diaphragms: Control elements that flex repeatedly in gas and fluid valves with long cycle life requirements.
• Acoustic and ultrasonic membranes: Thin vibrating membranes for transmitters and receivers needing uniform thickness.
• Vacuum and level sensing membranes: Deflection-based measurement elements for sealed chambers and tanks.
• Instrument and gauge diaphragms: Mechanical gauges and transmitters where repeatable response replaces adjustment.
• Dosing pump diaphragms: Chemically resistant membranes for metering pumps in analytical and process equipment.

Design Notes & Process Considerations

1. Thickness defines response: State target membrane thickness and tolerance explicitly; two-sided etching is what holds ±0.005 mm.
2. Relief depth: Corrugations and recessed lands need depth callouts — typically 20–40% of foil thickness — with a measurement datum.
3. Sealing land flatness: Leak rate follows the flatness of the clamped rim, so call out flatness on the sealing land itself.
4. Rim condition: Require burr-free edges and no microcracks at the rim, since fatigue cracks start at stress risers there.
5. Stress relief: Ask for annealing after etching when zero-point stability matters over temperature cycles.
6. Handling and packaging: Ship diaphragms between soft liners; thin foils dent easily and a dent changes local stiffness.