IEC 61747-40-3:2015

Overview

IEC 61747-40-3:2015 defines a mechanical performance test for display cover glass used in mobile electronic devices, measuring surface impact resistance by a ball drop method that induces biaxial flexure. The procedure is statistical: a series of specimens from a sample are impacted by a dropping ball and the biaxial flexural energy to failure (breaking energy) is recorded and analyzed to characterize strength and reliability.

Key topics

• Scope and intent
  • Mechanical testing of cover glass for electronic flat panel displays in mobile devices.
  • Focus on measuring energy required to cause fracture under a centrally applied ball drop (biaxial flexure).
• Apparatus components
  • Height adjustment beam (marked in 5 cm increments; max drop ≥ 180 cm).
  • Specimen holder (rigid polymer frame with a 4–6 mm ledge and containment barrier).
  • Armature, ball release mechanism, ball release controller, and base.
  • Test ball - example: 128 g ball is cited as adequate for 50 mm × 50 mm specimens (0.55–2.0 mm thick).
• Procedure fundamentals
  • Sample vs specimen: statistical sample of specimens sharing common pedigree.
  • Start at a minimum drop height and increase in fixed increments until breakage.
  • Pre-conditioning and environment per IEC 61747-40-1; specimens stored in test environment for at least four hours.
  • Safety considerations: broken glass hazards and compression risk from moving ball.
• Measurements and analysis
  • Breaking energy calculated from ball mass and drop height (with allowed height correction for specimen thickness).
  • Statistical treatment of results (including Weibull analysis per IEC 61649) to report characteristic strengths and reliability metrics.
  • Reporting requirements include per-test data and sample statistics.

Applications

• Who uses it
  • Display manufacturers, cover-glass suppliers, mobile device OEMs, independent test labs, R&D and quality assurance teams.
• Practical uses
  • Compare surface impact resistance across glass formulations, strengthening processes (e.g., ion exchange), or manufacturing lots.
  • Validate cover-glass performance targets for drop-impact durability specifications.
  • Provide data for material selection, design trade-offs (thickness vs weight vs strength), and reliability claims.

Related Standards (if applicable)

• IEC 61747-40-1 - Guidelines for mechanical testing of display cover glass (environment and general test guidance).
• IEC 61649:2008 - Weibull analysis (statistical analysis of failure data referenced for reporting).

Keywords: IEC 61747-40-3, ball drop, biaxial flexural energy to failure, cover glass testing, mobile display impact resistance, specimen holder, Weibull analysis.