IEC 62739-1:2013

Overview

IEC 62739-1:2013 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies a test method to evaluate the erosion resistance of metallic materials used in lead-free wave soldering equipment. This standard focuses on metal materials without surface processing that come into direct contact with molten lead-free solder alloys. It provides a reliable procedure to simulate and measure the degree of erosion caused by molten solder on components such as solder baths and mechanical parts within the wave soldering system.

The erosion phenomenon addressed by this standard refers to the gradual dissolution and thinning of base metal materials due to their contact with molten solder. With the industry’s shift towards lead-free soldering alloys such as Sn96.5Ag3Cu0.5, understanding and mitigating erosion is critical to improving equipment longevity and maintaining consistent soldering quality.

Key Topics

• Test Methodology: The standard describes a controlled test setup where specimens of the base material are mounted on a motor-driven rotation block and immersed in molten lead-free solder. The rotation simulates the dynamic solder flow environment encountered in wave soldering equipment.
• Test Equipment: Comprises a heater unit to melt solder, a pot holding the molten solder, a rotation block motor to simulate material movement, and a control unit to maintain precise temperature and rotation conditions. Additional features include ventilation to remove dross (oxide buildup) generated during testing.
• Specimen Requirements: Specimens are metallic material samples matching those used in solder baths and related components, with specific dimensions and laser-engraved material identification. Both the marked face and backside, particularly 50 mm from the lower edge, are exposed to testing.
• Test Conditions: The solder alloy specified is Sn96.5Ag3Cu0.5, a common lead-free alloy, maintained at 350°C ± 3°C. Rosin flux with low halide content is used to replicate typical soldering environments.
• Measurement Process: After the test duration, erosion depth is determined using an optical microscope and focal depth measurement technique. This allows accurate depth profiling of the eroded areas.
• Data and Reporting: The standard outlines the required data points to be included in test reports, facilitating consistent analysis and comparison.

Applications

IEC 62739-1:2013 is essential for manufacturers and designers of wave soldering equipment, specifically those transitioning to lead-free soldering technologies. Practical applications include:

• Material Selection: Evaluating and comparing erosion resistance of different metallic materials before adoption in manufacturing equipment.
• Quality Assurance: Conducting erosion tests to ensure solder bath and wave soldering component durability meets performance criteria.
• Equipment Development: Informing design improvements to increase the lifetime and reliability of soldering equipment facing aggressive lead-free solder environments.
• Process Optimization: Understanding how solder temperature, flux composition, and mechanical motion affect material degradation for process refinement.

By following this standard, companies engaged in electronics assembly can reduce unexpected maintenance needs, avoid contamination from eroded parts, and enhance their overall soldering process reliability.

Related Standards

• IEC 61190-1-3: Specifies requirements for electronic-grade lead-free solder alloys used in the test method.
• IEC 60068-2-20:2008: Details environmental test methods related to solderability and resistance to soldering heat for components.
• IEC 62739 series: Additional parts of this series address erosion testing for materials with various surface treatments and further test methods for wave soldering equipment.

By integrating IEC 62739-1 with these complementary standards, stakeholders benefit from a comprehensive framework for managing material erosion in wave soldering systems using lead-free alloys.

This standard is a critical tool for advancing wave soldering equipment technology in the era of lead-free electronics manufacturing, helping to ensure equipment robustness, product quality, and environmental compliance.