Overview
IEC 61086-2:2004 is an important international standard published by the International Electrotechnical Commission (IEC) that defines the methods of test for coatings applied to loaded printed wire boards (PWBs), commonly known as conformal coatings. These coatings serve as electrical insulating materials designed to protect loaded PWBs from environmental and mechanical damage, ensuring reliable performance and longevity in electrical and electronic equipment.
This standard specifies test procedures for both uncured conformal coating materials and coatings after their application to printed wire boards. An updated second edition released in 2004 introduced new specimen types, cleaning and test procedures, and a modernized document layout. It also incorporates corrections made in a 2005 corrigendum.
Key Topics
IEC 61086-2:2004 covers a broad range of testing methodologies to assess the performance characteristics of conformal coatings. Key topics include:
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Test Specimens
Four different types of test specimens (A, B, C, D) are defined to evaluate coatings under various conditions. Specimen A is a new addition improving the relevance of testing.
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Environmental Exposure Tests
To simulate real-world conditions, coated specimens undergo various environmental stress tests such as:
- Thermal cycling and thermal shock
- Thermal aging
- Humidity resistance (damp heat)
- Salt mist exposure
- Low temperature, low atmospheric pressure, and warm humid environments (specific for class 3 coatings)
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Electrical Property Tests
These include measurements of:
- Breakdown voltage to assess electrical insulation integrity
- High-frequency dielectric properties to evaluate performance at resonance frequencies
- Insulation resistance testing to check material’s electrical insulation capability
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Non-Electrical Property Tests
Critical evaluations such as:
- Visual examination for coating integrity
- Measurement of coating thickness to ensure uniformity
- Fluorescence testing for inspection under UV light
- Tackiness tests to determine the degree of cure
- Flexibility assessments to evaluate mechanical resistance
- Flammability testing for fire safety compliance
- Mold growth resistance under humid conditions
- Resistance to organic solvents to confirm chemical stability
- Procedures for coating removal when necessary
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Shelf Life Testing
Ensures that uncured coating materials remain stable and usable over their indicated periods.
Applications
The IEC 61086-2:2004 standard is essential for manufacturers and quality assurance professionals working with loaded printed wire boards where conformal coatings are used. Typical applications include:
- Protection of printed circuit boards (PCBs) in industrial electronics, aerospace, automotive, and consumer electronic devices
- Ensuring long-term reliability of electronic assemblies subjected to harsh environments such as moisture, temperature fluctuations, and chemical exposure
- Establishing uniform quality control processes for electrical insulating coatings to meet international benchmarks
- Testing new conformal coating formulations and materials during product development
- Compliance with regulatory requirements and customer specifications for electronic equipment protection
Implementing IEC 61086-2 methods facilitates improved durability, electrical safety, and functional integrity of PWBs throughout their operational lifespan.
Related Standards
IEC 61086-2:2004 complements other standards that oversee conformal coatings and printed wire board materials, including:
- IEC 61086-1: Coatings for loaded PWBs – Part 1: General requirements and tests for coatings
- IEC 60068 series: Environmental testing methods for electronic equipment
- IPC standards: Such as IPC-CC-830, which also guide qualification and performance of conformal coatings
- ASTM standards related to polymeric coatings and electrical insulation materials
Together, these standards ensure consistent testing, high-quality materials, and protection measures for electronic components used globally.
By adhering to IEC 61086-2:2004 test methods, electronics manufacturers can guarantee that conformal coatings provide optimal protection against environmental hazards, thereby enhancing product reliability and customer satisfaction in demanding applications. This standard remains a critical reference for conformal coating test procedures in the electronics industry.
Open preview (PDF)Coatings for loaded printed wire boards (conformal coatings) - Part 2: Methods of test
