Overview

Sensor plate etching produces flat sensing substrates whose conductive traces, electrodes, windows and alignment features are formed directly in thin metal by photochemical machining. A photoresist mask is exposed with the trace layout, developed, and the bare metal is dissolved, so the circuit pattern is cut into the material with clean, straight edges and no burr, heat damage or mechanical stress. Materials are typically stainless steel 304/316L, copper C1100, nickel 200 and aluminum, in thicknesses from 0.1 mm to 1.5 mm. Because the trace geometry is defined by film artwork, trace width, spacing and flatness repeat precisely from the first plate to the last.

The value of sensor plate etching lies in the combination of fine trace resolution and dead-flat substrate it delivers. Trace widths down to 0.1 mm and spacing held to ±0.03 mm allow dense electrode or heater patterns to be laid out reliably, while the chemical process keeps the plate flat and stress-free so a sensing element can be bonded, deposited or printed on top without distortion. This makes the method a strong fit for resistive, capacitive and thermal sensing plates where both the conductor geometry and the substrate planarity directly determine measurement accuracy.

Parameter Window

• Available Materials: stainless steel 304/316L, copper C1100, nickel 200, aluminum 5052
• Material Thickness Range: 0.1–1.5 mm
• Tolerance: trace width ±0.03 mm, trace spacing ±0.03 mm, flatness 0.05 mm per 100 mm
• Minimum Feature: 0.1 mm trace width at 0.15 mm stock
• Surface Options: passivation, electropolish, gold flash, nickel plating, black oxide
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Trace Layout Review — Convert the sensor drawing to vector artwork, check trace width, spacing and island geometry against material thickness.
2. Material Selection — Match alloy and temper to the sensing mode; copper for low resistance, stainless for strain or corrosion resistance.
3. Cleaning & Lamination — Degrease the sheet and laminate dry film resist so no bubbles sit under fine traces or pad areas.
4. UV Exposure — Expose through high-resolution film with the trace pattern registered to the sheet edge for panel-level accuracy.
5. Development — Wash out unexposed resist to open traces and windows, then inspect for under-developed or broken lines.
6. Etching — Spray-etch in chemistry matched to the alloy, controlling trace width and sidewall quality through time, temperature and speed.
7. Stripping & Finishing — Remove resist, neutralize, then passivate, electropolish or plate; level where flatness must be restored.
8. Inspection & Packaging — Verify trace width, spacing, resistance and flatness, then pack plates flat in trays or on liner.

Core Advantages

1. Fine, accurate traces: Trace widths down to 0.1 mm with ±0.03 mm tolerance allow dense electrode and heater patterns.
2. Dead-flat substrate: Chemical removal leaves the plate flat and stress-free, so bonded or printed sensing elements stay undistorted.
3. Clean conductor edges: Etched traces have straight, burr-free edges, avoiding the shorts and leakage paths of mechanical cutting.
4. No tooling cost: Each trace layout is a new film, so sensor revisions and short runs stay economical.
5. Repeatable electrical geometry: Trace width and spacing repeat across the batch, keeping resistance and capacitance consistent.
6. Material flexibility: Stainless, copper, nickel and aluminum run on one line, so sensor plate etching fits many sensing technologies.

Typical Applications

• Resistive sensing plates: Etched serpentine or grid traces for strain gauges and heater elements.
• Capacitive sensor electrodes: Interdigitated electrode patterns etched on a flat metal substrate.
• Thermal sensor plates: Heater and thermistor trace layouts for temperature sensing and compensation.
• Flow and level sensors: Electrode plates for conductivity and level detection in liquids.
• Touch and proximity plates: Sensing electrodes for capacitive touch panels and proximity switches.
• Medical sensor substrates: Flat electrode plates for biosensor and diagnostic test strips.

Design Notes & Process Considerations

1. Trace width versus thickness: Keep the narrowest trace at 0.1 mm or 0.7 × material thickness, whichever is larger, to avoid undercutting.
2. Spacing and clearance: Maintain trace spacing of at least 0.1 mm to prevent shorts, and add clearance around pads for bonding.
3. Flatness callout: State flatness per 100 mm, typically 0.05 mm, since a bowed plate distorts bonded or deposited layers.
4. Resistance specification: Specify trace resistance or sheet resistance target so material and trace cross-section can be matched.
5. Surface finish: Name passivation, electropolish or plating; gold flash is common where wire bonding is required.
6. Islands and thermal relief: Tie isolated features into the panel; sensor plate etching should always state trace width, spacing and flatness on the drawing.