IEC 60747-5-13:2021

Overview

IEC 60747-5-13:2021 defines an accelerated hydrogen sulphide (H2S) corrosion test for LED packages, focusing on the tarnishing of silver and silver alloys used in package metallization. The standard specifies a mixed-gas accelerated method intended to reproduce real failure modes and in‑situ kinetics so manufacturers and test labs can assess the impact of sulphide corrosion on luminous/radiant flux maintenance and on basic electrical performance (e.g., forward voltage/current). It is targeted at LED packages used in lighting applications when referenced by IEC SC 34A documents.

Key topics and requirements

• Scope and objective: Measure the influence of atmospheres containing hydrogen sulphide on parts made of silver, silver alloys, silver‑plated surfaces or metals covered with silver.
• Performance criteria: Main acceptance metrics are changes in luminous flux (lumen maintenance) and relevant electrical characteristics after exposure.
• Test apparatus: Requires a climatic system, sealed test enclosure, gas delivery and monitoring equipment consistent with flowing mixed‑gas corrosion practice; design follows principles in IEC 60068‑2‑60.
• Test method structure: Includes preconditioning (hygroscopic treatment where applicable), initial measurements, controlled exposure under mixed-gas conditions, and final measurements to quantify flux and electrical changes.
• Specimen considerations: Applies to silver and silver alloy elements and layered constructions; it does not aim to assess degradation of copper, silicone, or other non‑silver failure modes.
• Limitations: Not intended as a universal corrosion test-may not predict behaviour in all industrial atmospheres. Annex A provides guidance to relate test results to indoor corrosivity categories and potential field degradation.
• Informative annexes: Procedures for silver test pieces, mass‑increase monitoring, gas concentration setup, and examples to extrapolate laboratory results to specific environments.

Applications and users

IEC 60747-5-13 is practical for:

• LED package and component manufacturers performing reliability qualification and design validation.
• Supplier quality teams and incoming inspection to evaluate metallization choices (silver vs. protected finishes).
• Independent test laboratories conducting accelerated corrosion testing for lumen stability and electrical integrity.
• R&D and failure‑analysis teams investigating lumen degradation linked to silver tarnishing.
• Specifiers and product managers developing environmental robustness requirements for lighting products.

Using this standard helps reduce field failures from sulphide-induced lumen loss and provides a repeatable method to compare metallization options and mitigation strategies.

Related standards

• IEC 60068-2-60 (Flowing mixed gas corrosion test)
• IEC 60747-5-6 (LED device general requirements)
• CIE 127 (Measurement of LEDs)
• ISO 11844-1 (Indoor corrosivity categories)