Overview

A reel to reel etching line is a continuous photochemical machining system that images, develops and etches a moving metal strip in a single pass instead of handling separate sheets. Coil stock is unwound, laminated with dry-film resist on both faces, exposed through a registered photo-tool, sprayed with etchant, stripped, rinsed, inspected by inline vision and rewound — all without stopping the strip. Because etch time, bath temperature, spray pressure and conveyor speed are locked to line speed, feature width, pitch and half-etch depth stay uniform along hundreds of meters of material. Typical strip runs 0.05–0.5 mm thick and 50–350 mm wide, in stainless, copper alloys, phosphor bronze and nickel-iron alloys, and leaves the line as a handled reel ready for automated plating, forming or assembly.

For buyers producing lead frames, EMI shields, precision meshes, encoder discs and connector contacts at million-piece volumes, a continuous line addresses three limits of batch processing: sheet etching cannot match continuous throughput, stamping below about 0.15 mm introduces stress and die wear, and manual sheet handling drives per-part cost and variation. The line holds 0.1 mm lines and 0.2 mm pitch, controls the etch factor symmetrically on both faces, and delivers coil-form parts that feed directly into downstream equipment. Design changeover is a photo-tool swap rather than a progressive die, so high-mix programs stay economical on one line.

Parameter Window

• Available Materials: 304/316L stainless, C194/C7025 copper, phosphor bronze, nickel and nickel-iron Alloy 42, Kovar
• Material Thickness Range: 0.05–0.5 mm strip, 50–350 mm coil width
• Tolerance: ±0.02 mm on feature width, ±0.01 mm on half-etch depth, pitch held per reel
• Minimum Feature: 0.08 mm line, 0.10 mm gap, 0.20 mm pitch at 0.15 mm stock
• Surface Options: selective silver/nickel plating, anti-tarnish, reel & leader tape, 2D/3D half-etch, passivation
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Coil Prep & Splicing — Slit, level and splice incoming coil, verify temper, thickness and surface cleanliness.
2. Double-Sided Lamination — Apply dry-film resist to both faces under controlled heat and pressure as the strip advances.
3. Registered Continuous Exposure — Image the photo-tool on the moving strip with front-to-back alignment held by fiducials.
4. Inline Development — Wash out unexposed resist to open the feature areas and check line definition on the fly.
5. Controlled Spray Etching — Spray etchant matched to the alloy, balancing line speed, temperature and pressure for a stable etch factor.
6. Stripping & Rinsing — Remove resist, neutralize and rinse the strip in-line before it is dried.
7. Inline Vision Inspection — Measure feature width, pitch and defect count continuously and log results per reel position.
8. Rewind & Lot Packing — Rewind with interleaving, attach leader/trailer tape and pack with reel-linked inspection records.

Core Advantages

1. Continuous throughput: Coil-fed processing removes sheet loading and holds etch conditions stable across long runs.
2. Fine features without a die: Chemical removal forms 0.1 mm lines without the mechanical shock or cost of a stamping tool.
3. Symmetric double-sided etch: Two-sided spray keeps undercut balanced, so line width matches on both faces of the strip.
4. Direct downstream feed: Coil-form output mates with automatic plating, die-attach and placement equipment.
5. Fast changeover: A new pattern is a new photo-tool, not a progressive die, easing high-mix production.
6. Low cost at volume: A reel to reel etching line amortizes setup over thousands of meters, cutting per-part cost on long runs.

Typical Applications

• Lead frames & contact strips: Fine-pitch IC and connector frames fed reel-to-reel into plating lines.
• EMI shielding cans: Etched outlines later formed into shields on the same continuous strip.
• Precision filter meshes: Uniform-aperture screens for filtration, acoustics and sensors in coil form.
• Encoder discs & apertures: High-resolution code wheels and optical slits with consistent slot geometry.
• Battery current collectors: Perforated and half-etched foils for cells and fuel-cell flow fields.
• Flexible heaters & circuits: Etched resistive foils and lead patterns on thin continuous metal.

Design Notes & Process Considerations

1. Etch factor compensation: Size artwork for the expected undercut so finished line width lands on target.
2. Feature versus thickness: Keep line width at roughly 1.2 × stock thickness or greater for reliable long-run etching.
3. Tie-bar and carrier design: Hold parts rigid through etching and plating without leaving stubs that snag feeders.
4. Coil format definition: Specify width, pitch, core size, leader/trailer length and winding tension for downstream machines.
5. Half-etch depth control: Call out remaining thickness and tolerance where 3D or stepped features are needed.
6. Registration and splices: With a reel to reel etching line, define fiducial strategy and splice allowance so pitch does not drift across a reel.