Custom Photo Etched Optical Encoder Disc Slit Pattern Stainless Steel Etching Service

Xinhaisen has been etching thin metal since 2012, and encoder windows are one of our regular production jobs. The difference is in how the pattern is made: it comes from a phototool, and the etchant is sprayed on both faces of the foil at the same time. The slit is formed chemically rather than by a die or a cutter, and the foil is not heated during the process. What the encoder sensor reads is therefore defined by your artwork and by process control, not by tool wear.

Why Customers Place This Work With Us

• Photo chemical etching is the main process we run. Founded in 2012, with 120+ staff and eight automated etching lines in a 7,000 m2 plant plus a 1,000 m2 cleanroom in Dongguan.
• Design changes do not need a new die. When your encoder resolution or slit layout moves, we rebuild the phototool instead of a stamping die.
• Double sided spray etching. Etchant reaches both faces at once, which keeps the slit wall straighter through the foil thickness than a single side etch.
• Fine features on very thin foil. 0.01 mm line width and foil down to 0.02 mm, handled without the buckle and roll-over a press tends to put into thin sheet.
• The foil is not work hardened or heat affected. Because the process is chemical, there is no recast layer and no heat affected zone, so the magnetic and mechanical behaviour of the foil stays much closer to the supplied state than after stamping or laser cutting.
• Quality system built around export OEM requirements. Certified to ISO 9001, ISO 14001 and IATF 16949, with 80-90% of output shipping to overseas OEMs in automotive, aerospace, medical, electronics and energy equipment.

Etching Versus Stamping And Laser Cutting

How We Control The Process

1. Drawing review before tooling. Slit width, gap and foil thickness are checked against the etching window.
2. Phototool from your file. The exposure film is generated from DXF or STEP, so the pattern you approve is the pattern that is etched.
3. Resist lamination. Cleaned foil is laminated with photosensitive resist on both faces, in the cleanroom.
4. Exposure and development. The code pattern is transferred and the unexposed resist is washed away, leaving bare metal only where the windows will be.
5. Double sided spray etching. Etchant is sprayed on both faces, with line parameters set per material and thickness.
6. Strip, flatten, measure, pack. Resist is removed, parts are measured against the approved drawing and packed.

What We Etch For Encoders

• Incremental windows, single track and quadrature A / B / Z layouts
• Absolute binary and gray code tracks
• Aperture and slit masks used together with the disc
• Index marks, orientation notches, hub cut-outs and bores
• Linear code strips and arc segments on the same drawing set

Process Window

304 is the usual balance of corrosion resistance and cost, 316 is chosen for humid, chemical or wash-down equipment, and nickel is used where the pattern needs very fine slits in a very thin section. Grade and thickness availability is confirmed against your drawing before film work starts.

Inspection And Records

Parts are measured against the approved drawing, and slit integrity is checked on samples drawn from each batch. A first article inspection record can be issued with the shipment when the purchase order asks for it.

What To Put In The Enquiry

• DXF, STEP or dimensioned PDF of the disc, aperture mask or code strip
• Foil grade and thickness
• Slit count or PPR, and the tolerance that decides whether the part works
• Quantity for the first order, plus the annual volume you expect
• Any flatness, surface finish or marking requirement

Commercial Notes

These are custom etched parts, so price, minimum quantity and shipment schedule are settled per project once the drawing, the foil grade and the quantity are agreed. Prototype quantities can be discussed together with the production order. No fixed price band and no fixed lead time are published here, because two discs with the same outer diameter can need very different etching work.

Send the encoder disc drawing and the quantity you need, and our engineering team will confirm the etching route and the quotation for your review.