Stainless Steel Encoder Disc Etching Manufacturer, Zhuolida

As a core sensing component of optical rotary encoders, stainlesssteel encoder discs convert mechanical rotational motion into readable electrical pulse signals for measuring rotational speed, angular position and rotation direction. The performance of servo motors, industrial robots, automated inspection equipment and motioncontrol systems heavily relies on grating edge sharpness, linewidth uniformity and dimensional stability of encoder discs. Traditional manufacturing approaches such as mechanical stamping, microCNC machining and laser cutting struggle to satisfy highresolution encoder requirements. Stamping creates burrs, residual stress and thinsheet warping; laser processing brings thermalaffected zones, microcracks and inconsistent grating edges, which will trigger signal jitter and measurement deviation during realworld operation. As a leading stainless steel encoder disc etching manufacturer, Zhuolida delivers highprecision photochemical etching solutions for custom metal code discs, producing burrfree, stressfree, highuniformity grating patterns without hard mould investment

Material Selection & Core Technical Specifications

The most popular substrate for etched encoder discs is SUS304 stainless steel. It maintains stable mechanical strength, good flatness after etching and general corrosionresistance, widely adopted for incremental encoder discs, tachometer code discs and lowtomediumresolution absolute encoder components. SUS316L stainless steel is selected for devices operating in humid, coastal or chemicalvapour environments to enhance saltspray resistance. For ultralightweight highspeed rotating scenarios, special springgrade stainless steel foils are available.

Zhuolida handles material thickness ranging from 0.03 mm to 1.0 mm for encoder disc production卓力达. Minimum achievable grating line width reaches 0.02 mm, dimensional tolerance can be controlled to ±0.005 mm under optimized production parameters, holeposition and gratingpitch accuracy up to ±0.0075 mm. Both incremental encoder discs with dense periodic grating tracks and absolute encoder discs with complex multibit coded patterns can be realised by photochemical etching. Zeroposition Zphase mark slots, mounting holes, positioning notches can be integrated in onestep forming. Ultrathin foil encoder discs keep excellent flatness, no deformation after processing, avoiding signal distortion induced by disc warping. Strict incoming rawmaterial inspection is enforced: surface scratches, oxide inclusions and uneven rolling texture must be eliminated, as tiny surface defects will evolve into grating breakage or edge distortion after chemical etching.

StepbyStep Photochemical Etching Workflow for StainlessSteel Encoder Discs

Encoder disc etching adopts doublesided synchronous photochemical etching process, every procedure is strictly optimised for gratingedge quality, dimensional repeatability and batch consistency.

Sheet Cutting and MultiStage UltraClean PreTreatment

Stainlesssteel foils are cut into processing panel dimensions. Continuous pretreatment production line completes alkaline degreasing, solvent rinsing and mild microetch activation to fully remove rolling oil, fingerprints and passive oxide layers. Incomplete surface cleaning results in poor dryfilm adhesion, causing grating peeling, broken lines and local pattern distortion. Uniform surface activity across the whole panel lays the foundation for stable grating pitch in massvolume production.

DualSided BubbleFree DryFilm Lamination

Photosensitive dryfilm photoresist is hotlaminated on both sides of cleaned stainlesssteel substrate. Lamination temperature, pressure and conveying speed are precisely tuned according to foil thickness. Trapped microbubbles between photoresist and metal surface will produce defective grating notches. Doublesided lamination supports simultaneous bilateral etching and improves gratingsidewall verticality, critical for stable optical signal reception from transmitterreceiver sensors.

HighPrecision UV Exposure and Controlled Developing

Highaccuracy photomask transfers complete graphic information including multitrack grating arrays, Zphase zeroposition marks, mounting holes and outer disc contours. Under collimated ultraviolet light exposure, photoresist covering grating ribs polymerises and forms stable protective mask layers. Unexposed photoresist above slot regions dissolves in alkaline developer solution, exposing bare stainlesssteel areas for chemical dissolution. Mask artwork includes accurate undercut compensation calculation. Since chemical etching is isotropic, uncontrolled lateral undercut will enlarge grating slot width and break pitch tolerance, especially for highPPR highresolution encoder discs.

ClosedLoop TemperatureStabilised Spray Etching

Panels covered with patterned photoresist pass through automatic constanttemperature spray etching chamber. Ferricchloridebased etchant is sprayed evenly from top and bottom nozzles. Exposed metal dissolves selectively until grating slots are fully penetrated. Etching liquid specific gravity, working temperature, nozzle pressure and conveyor speed are managed by closedloop automatic control system. Homogeneous sprayliquid distribution over fullpanel area prevents pitch deviation between central zone and outerdiameter zone of largesize encoder discs. Technicians balance vertical etching removal rate and lateral undercut magnitude to guarantee every grating slot stays within drawing tolerance requirements.

Photoresist Stripping and MultiCycle HighPurity Rinsing

Once all grating slots are fully throughetched, alkaline stripping solution removes all polymerised photoresist. Multistage highpressure circulating rinsing combined with ultrasonic cleaning washes residual corrosive etchant out of narrow grating gaps. Residual chemical residues trapped inside grating slots will lead to spot rusting in later application and shorten encoder service life.

EncoderDiscOriented PostTreatment Process

Posttreatment workflow includes passivation for enhanced corrosion resistance, precision flatness correction, ultrasonic deep cleaning for grating gaps and visual preliminary sorting. Unlike lasercut or mechanicallyprocessed code discs, photochemicallyetched encoder discs feature naturally sharp, burrfree grating edges, no secondary deburring operation is required. Optional electropolishing treatment can further optimise surface texture to reduce light scattering and improve optical signaltonoise ratio.

MultiDimensional Strict Quality Inspection

Critical inspection items cover gratingslotwidth consistency, gratingpitch accuracy, Zphase mark position tolerance, overall flatness and outerdimension verification. Automated optical inspection (AOI) with highmagnification microscopy scans every grating track to detect broken lines, notch defects and edge irregularities. Sampling validation includes saltspray corrosion test, vibration simulation test and actual optical signaloutput testing to verify real encoder performance. Qualified panels go to final precision diecutting and dustproof packaging before shipmentzldetch.co....

Core Advantages of Zhuolida Etched StainlessSteel Encoder Discs

First, burrfree, zerostress highquality grating edges. Photochemical etching is noncontact cold subtractive manufacturing. No mechanical force or thermal impact applies to stainlesssteel substrate. Ultrathin foils maintain good flatness after processing. Sharp grating edges minimise light scattering, delivering stable pulsesignal output and lowering measurement jitter risk.

Second, excellent batchtobatch repeatability. Graphic patterns are reproduced via photomask. Thousands of encoderdisc units can be processed synchronously within one production panel. Dimensional deviation is wellcontrolled in massproduction, meeting strict quality standards for industrialgrade motioncontrol components.

Third, great design flexibility without expensive hard moulds. Incremental discs, multitrack absolute encoder discs, special custom coded patterns can be realised simply by updating photomask files. Prototyping leadtime is short, supporting fast design iteration from sample verification to largevolume OEM supply.

Fourth, outstanding adaptability for ultrathin stainlesssteel foils. Mechanical punching and microdrilling are hardly feasible for foils under 0.1 mm thickness. Photochemical etching manufactures intact highdensity grating structures on ultrathin sheets, reducing rotary inertia for highspeed rotating motor systems.

Typical Application Scenarios

Custometched stainlesssteel encoder discs manufactured by Zhuolida serve multiple highend industries: servomotor feedback encoders, jointposition sensors for humanoid robots, industrial automated equipment, optical inspection instruments, medical motioncontrol devices, newenergy vehicle motor speedmeasuring units and officeautomation precision sensorszldetch.co....

Main Process Challenges & Control Points

Undercut effect is the primary technical challenge for encoderdisc etching. Precise mask compensation together with highlystable etchingsolution parameters are essential to keep grating pitch accuracy. For multitrack absolute encoder discs with mixed wide and narrow slots, uneven etching load on differentwidth features may bring dimension drift, requiring graphic optimisation and homogenised sprayflowfield design. Grating gaps are narrow; etching byproducts or fine particles may cause partial slot blockage, demanding multiround ultrasonic cleaning and strict fullworkshop cleanliness management. Incomingmaterial quality must be tightly controlled, tiny surface flaws will generate grating defects after etching.

Conclusion

Photochemical etching has become a mainstream manufacturing technology for highperformance stainlesssteel encoder discs. Compared with stamping, micromachining and laser cutting, this coldprocessing technology produces burrfree, stressfree, highprecision metal grating discs. As a professional stainlesssteel encoder disc etching manufacturer, Zhuolida integrates strict incomingmaterial screening, accurate undercut compensation, closedloop etchingparameter stabilisation and complete multidimensional qualityverification workflow. Custom etched encoder discs satisfy demanding requirements for position feedback and speeddetection in robotics, servo drive and industrial automation. As motioncontrol systems keep pursuing higher resolution and reliability, custom photochemicaletched stainlesssteel encoder discs will gain broader adoption across advancedmanufacturing sectors.