IEC 61747-20-3:2016

Overview

IEC 61747-20-3:2016 - "Liquid crystal display devices - Part 20-3: Visual inspection - Active matrix colour liquid crystal display modules" is an IEC international standard that defines quality assessment procedures and visual inspection methods for the active area of transmissive active-matrix colour LCD modules. The document specifies how to inspect display image defects by the human eye, provides clear defect definitions, and sets out standard inspection conditions and record‑keeping practices. This edition replaces IEC 61747-5-2 (2011) and aligns numbering with the IEC 61747 series.

Key topics and requirements

• Scope: Applies to visual (subjective) inspection of the active area of transmissive type active-matrix colour LCD modules; mura is explicitly excluded.
• Inspection method: Standardized setup for inspection equipment, module mounting, inspector qualification, and use of a limit sample as a reference for acceptable defect levels.
• Standard conditions: Prescribed ambient conditions, visual inspection environment, and electrical driving conditions for consistent, repeatable inspections.
• Defect definitions and classification:
  • Subpixel defects: bright, dark, intermediate
  • Adjacent and cluster subpixel defects: minimum-distance considerations
  • Line defects: bright line and dark line
  • Surface and mechanical defects: scratches, dents
  • Contamination: foreign material and bubbles
  • Light leakage: e.g., between top case and outer black matrix
• Criteria and documentation: Criteria tables and figures guide defect evaluation (shape, distance, and pass/fail examples). Final acceptance limits (defect types, counts, sizes) are to be specified in customer/supplier quality contracts (incoming inspection or acceptance specifications).
• Traceability: Procedures include recording inspection results and maintaining reference limit samples.

Applications and who uses it

• LCD module manufacturers: implement consistent QC/inspection procedures during production and final inspection.
• Quality assurance and inspection engineers: adopt standard conditions and defect definitions to reduce disputes and ensure uniform acceptance criteria.
• Incoming inspection teams and contract manufacturers: verify supplier shipments against agreed defect limits.
• Test laboratories and certification bodies: use the standard to harmonize visual assessment protocols.
• Buyers and OEMs: reference the standard in procurement and acceptance specifications to ensure consistent visual quality.

Related standards

• IEC 61747 series (Liquid crystal display devices) - other parts cover electrical, mechanical and environmental test methods.
• IEC 61747-10-2:2014 - Environmental, endurance and mechanical test methods (normative reference cited in this part).

Keywords: IEC 61747-20-3, visual inspection, active matrix colour liquid crystal display modules, LCD inspection, subpixel defects, line defects, scratch, foreign material, light leakage, inspection criteria.