IEC 63522-16:2025

Overview

IEC 63522-16:2025 is part 16 of the international standard series IEC 63522, published by the International Electrotechnical Commission (IEC). This standard focuses on electrical relays, specifically outlining methods for tests and measurements related to soldering processes. It provides standardized procedures to assess the resistance to soldering heat and solderability of relay terminals, vital for ensuring relay performance under transportation, storage, and operational conditions.

The standard defines test conditions and methods that evaluate the durability of relay components during typical soldering processes used in industrial applications. Its purpose is to guarantee relays maintain functionality after exposure to soldering heat and to verify terminals wet easily with solder.

Key Topics

• Scope of Testing
  IEC 63522-16:2025 applies to tests designed to simulate real-world soldering conditions, assessing relay terminals’ ability to withstand heat stress and maintain solderability. Tests are aligned with expected operational environments including transportation, storage, and use.

• Standardized Test Methods

  • Soldering Iron Method: Evaluates relay terminal resistance by applying heat from a soldering iron calibrated to specific temperatures and durations.
  • Solder Bath Method: Simulates mass soldering by immersing terminals in molten solder under controlled conditions to verify heat resistance and solder wetting.

• Test Conditions
  The standard references IEC 60068-2-20 for detailed soldering heat and solderability test conditions:

  • Solder bath temperature at (260 ± 3) °C with immersion lasting (5 ± 0.5) seconds
  • Soldering iron at 350 °C applied for (10 ± 1) seconds
  • Use of thermal screens simulating printed circuit boards during immersion for accurate heat transfer representation

• Functional Assessment
  Functional tests in accordance with IEC 63522-7 must be performed both before and after soldering tests to ensure relay operational integrity is maintained throughout.

• Solderability Measurement
  Wetting balance (force measurement) methods, as defined by IEC 60068-2-69, are also referenced for precise quantification of solder wettability on relay terminals.

Applications

IEC 63522-16:2025 is essential for:

• Relay Manufacturers
  Ensuring product quality and reliability during the manufacturing process, particularly in surface mount technology (SMT) and through-hole soldering applications.

• Quality Control and Compliance Professionals
  Verifying that relays meet international standards for solder heat resistance and solderability prior to shipment and deployment.

• Design and Testing Engineers
  Selecting appropriate relay components capable of withstanding industrial soldering processes, minimizing defects caused by poor solder joints or heat damage.

• Certification Bodies and Test Labs
  Applying consistent, recognized test methods for evaluating relay durability and solder performance to provide compliance certification.

By following IEC 63522-16:2025, organizations can reduce field failures, improve product safety, and enhance manufacturing consistency in electrical relay applications.

Related Standards

• IEC 60068-2-20:2021 - Environmental testing methods including solderability and resistance to soldering heat of devices with leads.
• IEC 60068-2-69 - Specifies the wetting balance method for solderability testing of electronic components and printed circuit boards.
• IEC 63522 Series - Comprehensive tests and measurements for electrical relays, including:
  • Part 0: General and guidance (under preparation)
  • Part 1: Visual inspection and check of dimensions
  • Part 7: Functional tests
  • Part 11: Enclosure protection and degree of protection
• IEC 61760-1:2020 - Standard methods for specifying surface mounting components (SMDs), applicable to relay terminals requiring surface mounting.

Adhering to IEC 63522-16:2025 supports global alignment on soldering quality standards in electrical relay manufacturing and testing, helping ensure electrical systems reliability across industries. For further information and purchasing access, visit the official IEC Webstore and consult IEC Electropedia for terminology related to electrotechnology.