INDUSTRY COMPONENT

Glass Substrate

High-precision glass substrate for optical encoder grating discs, providing dimensional stability and optical clarity for accurate position sensing.

Component Specifications

Definition
A specialized glass substrate used as the foundational element in precision optical encoder grating discs. This ultra-flat, optically transparent component serves as the carrier for microscopic diffraction gratings that enable high-resolution position and motion detection in industrial automation, robotics, and precision measurement systems. The substrate's thermal stability, surface quality, and dimensional accuracy are critical for maintaining grating pattern integrity and measurement precision.
Working Principle
The glass substrate provides a stable, optically transparent platform for precision-etched diffraction gratings. When light passes through the grating pattern on the substrate, it creates interference patterns that are detected by photodiodes. The substrate's dimensional stability ensures consistent grating spacing, while its optical clarity minimizes light scattering and distortion, enabling accurate position calculation through phase comparison of the interference patterns.
Materials
Borosilicate glass (e.g., Corning 7740/Pyrex) or fused silica/quartz for high-temperature applications. Typical specifications: Coefficient of Thermal Expansion (CTE): 3.25×10⁻⁶/°C (borosilicate), <1×10⁻⁶/°C (fused silica); Surface roughness: Ra < 1 nm; Flatness: λ/10 to λ/20 (at 632.8 nm); Thickness tolerance: ±0.01 mm.
Technical Parameters
ParameterTypical rangeNotes & selection driver
Diameter25-300 mm
Thickness0.5-3.0 mm
Parallelism< 5 arcseconds
Transmission> 92% (400-700 nm)
Surface Quality60-40 scratch-dig
Thermal StabilityOperating range: -40°C to +150°C
Wavefront Distortion< λ/4

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Standards
ISO 10110, ISO 14997, DIN 3140, DIN 58750

Parent Products

This component is used in the following industrial products

Engineering Analysis

Risks & Mitigation
  • Surface contamination affecting optical transmission
  • Thermal expansion causing grating pattern distortion
  • Mechanical stress leading to substrate warpage
  • Chemical degradation from cleaning solvents
  • Adhesive failure in mounting applications
FMEA Triads
Trigger: Improper handling during installation
Failure: Surface scratches or micro-cracks
Mitigation: Implement cleanroom handling procedures, use vacuum pick-up tools, provide operator training on glass component handling
Trigger: Thermal cycling beyond design limits
Failure: Grating pattern distortion or delamination
Mitigation: Specify appropriate glass type for operating environment, implement thermal management in encoder design, add temperature sensors for monitoring
Trigger: Incompatible mounting adhesives
Failure: Stress-induced birefringence or substrate fracture
Mitigation: Validate adhesive compatibility through testing, use low-stress mounting techniques, specify adhesive application parameters

Industrial Ecosystem

Compatible With

Typical Suppliers & Equivalents

Compliance & Inspection

Tolerance
Diameter: ±0.02 mm, Thickness: ±0.01 mm, Flatness: λ/10 at 632.8 nm, Parallelism: < 5 arcseconds
Test Method
Interferometric flatness testing (Fizeau interferometer), surface profilometry (white light interferometer), spectrophotometric transmission measurement, thermal cycling testing per MIL-STD-883

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation
Request current drawings, revision history, and a signed specification sheet.
Manufacturing capability
Verify equipment lists, process limits, capacity, and representative production evidence.
Inspection readiness
Confirm test methods, calibrated equipment, sampling plans, and traceable reports.
Supplier transparency
Check the legal entity, factory address, ownership, certifications, and direct contacts.

CNFX does not score or rank suppliers. Buyers must verify all claims and documents with the legal manufacturer before ordering.

Manufacturers of Glass Substrate

Manufacturer profiles associated with Glass Substrate.

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Manufacturer listings support early research and capability understanding. They are not certification, ranking, or transaction guarantees.

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Frequently Asked Questions

What is the difference between borosilicate and fused silica glass substrates for encoder applications?

Borosilicate glass offers excellent thermal stability (CTE ~3.25×10⁻⁶/°C) and cost-effectiveness for most industrial applications. Fused silica provides superior thermal stability (CTE <1×10⁻⁶/°C) and higher temperature resistance for extreme environments, but at higher cost. The choice depends on operating temperature range and precision requirements.

How does substrate flatness affect encoder accuracy?

Substrate flatness directly impacts grating pattern consistency and optical path length. Deviations from perfect flatness cause phase errors in the interference pattern, leading to position measurement inaccuracies. For high-resolution encoders (nanometer scale), λ/20 flatness or better is typically required to maintain sub-micron measurement precision.

What cleaning methods are recommended for glass encoder substrates?

Use particle-free wipes with high-purity isopropyl alcohol (IPA) in cleanroom conditions. Avoid abrasive materials and ultrasonic cleaning unless specifically validated, as they can damage delicate grating patterns. Nitrogen blow-off is recommended for removing loose particles before contact cleaning.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records. See the editorial policy.

Preliminary Technical Classification
This page supports structured research, RFQ preparation, and supplier evaluation. It does not replace buyer-led supplier qualification, standards review, or technical approval.

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