IEC 60068-2-20:2021 PDF

Overview

IEC 60068-2-20:2021 is an international environmental test standard that defines Test Ta and Test Tb procedures for assessing the solderability and resistance to soldering heat of components with leads. It covers devices with through‑leads and lead terminations used with eutectic or near‑eutectic tin‑lead (Pb) or lead‑free solder alloys and specifies two principal test methods: the solder bath method and the soldering‑iron method. This edition clarifies pre‑conditioning (accelerated ageing) and how it relates to natural aging.

Key topics and requirements

• Test scope
  • Test Ta - verification of solderability of wire, tag terminations and leads.
  • Test Tb - determination of component resistance to the thermal load of soldering processes.
• Test methods
  • Solder bath method: immersion-based wetting and heat exposure procedure.
  • Soldering‑iron method: localized heating using a controlled iron tip.
• Performance criteria
  • Acceptance is based on achieving adequate wetting and avoiding unacceptable damage to the component body or lead terminations.
  • Includes consideration of de‑wetting, contact angle/wetting behavior, and recovery after thermal exposure.
• Pre‑conditioning (accelerated ageing)
  • Procedures and clarification on how accelerated pre‑conditioning is used prior to solderability testing to simulate natural aging.
• Supporting materials
  • Guidance on flux types (colophony‑based compositions are referenced) and specimen preparation.
  • Cross‑references to wetting balance methods (see IEC 60068‑2‑54 and IEC 60068‑2‑69) for quantitative wetting time/force data.

Applications and users

• Who uses IEC 60068-2-20:
  • Component manufacturers (through‑hole components, leaded devices)
  • PCB assemblers and process engineers verifying solder processes
  • Quality assurance and reliability teams validating component compatibility with tin‑lead and lead‑free soldering
  • Test labs performing environmental and solderability qualification
• Practical uses:
  • Qualifying components to meet solder joint requirements in IEC 61191‑3 and IEC 61191‑4.
  • Establishing process windows and acceptance criteria for wave soldering, hand soldering and other leaded‑component assembly operations.
  • Assessing the impact of soldering heat on component integrity and termination wetting behavior.

Related standards

• IEC 60068‑1 (general environmental testing guidance)
• IEC 60068‑2‑58 (soldering tests for SMDs)
• IEC 60068‑2‑54, IEC 60068‑2‑69 (wetting balance / quantitative wetting methods)
• IEC 61191‑3, IEC 61191‑4 (requirements for soldered assemblies)
• IEC 60194 (PCB terms and definitions)

Keywords: IEC 60068-2-20, solderability test, resistance to soldering heat, solder bath method, soldering iron method, leaded components, lead‑free solder, pre‑conditioning, PCB assembly, wetting.