Overview
IEC 60068-2-67:1995 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies a test method for evaluating the durability of small electrotechnical components-primarily non-hermetically sealed-to damp heat. This accelerated, steady-state damp heat test (Test Cy) is designed to assess the resistance of components to the deteriorative effects caused by prolonged exposure to high temperature and humidity environments. The standard defines procedures for testing under controlled temperature and humidity conditions, providing valuable insights into component reliability in humid climates and demanding applications.
This test is crucial for manufacturers, designers, and quality assurance engineers who want to ensure the long-term performance of electrical and electronic components exposed to moist and warm conditions without focusing on external corrosion or physical deformation.
Key Topics
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Test Purpose: To evaluate the resistance of electronic components, especially small, non-hermetically sealed products, against damp heat deterioration under accelerated testing.
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Test Conditions:
- Temperature: 85°C (±2°C)
- Relative Humidity: 85% (±5%)
- Duration options: 168, 504, 1000, or 2000 hours depending on severity level
- Electrical biasing of the specimen is usually applied during the test.
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Test Environment Setup:
- Use of a specialized test chamber capable of maintaining steady temperature and humidity with tight tolerances.
- Prevention of condensation on specimens to avoid unintended test outcomes.
- Use of distilled or deionized water with specified resistivity and pH for humidification to avoid contamination or damage.
- Continuous drainage of water to maintain test integrity.
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Test Procedure:
- Preconditioning and initial measurements, including visual, dimensional, and functional checks.
- Controlled ramp-up to specified temperature and humidity.
- Maintaining steady state damp heat conditions for the defined duration.
- Intermediate and final measurements to assess changes.
- Recovery period and evaluation of component performance post-exposure.
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Limitations: The test focuses on internal degradation mechanisms such as moisture absorption by plastics and moisture ingress along terminals, and it does not cover external corrosion or physical deformation effects.
Applications
IEC 60068-2-67:1995 is widely used in industries requiring high reliability of electrotechnical components under harsh environmental conditions, including:
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Electronics Manufacturing: Ensuring component robustness in consumer electronics, industrial controls, and instrumentation exposed to humid environments.
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Automotive Industry: Validating components that operate in high humidity and elevated temperature conditions within vehicles.
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Telecommunications: Testing of sensitive components in base stations and communication devices expected to endure climatic stress.
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Aerospace and Defense: Assessing the stability of electronic fittings in environments prone to heat and moisture exposure.
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Medical Devices: Verifying the endurance of non-hermetic components in medical equipment subject to sterilization and humidification cycles.
This standardized test aids product design improvements, quality control processes, and compliance with environmental durability requirements, supporting reliable product performance and customer satisfaction.
Related Standards
For a comprehensive environmental testing approach, the following related IEC standards complement IEC 60068-2-67:
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IEC 60068-1: General and guidance for environmental testing - offers foundational principles and procedures applicable to all environmental tests.
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IEC 60068-2-30: Tests - Test Db: Damp heat, cyclic (12 + 12-hour cycle) - focuses on cyclic damp heat rather than steady state.
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IEC 60068-2-78: Tests - Test Cab: Damp heat, steady state - longer duration steady-state damp heat testing often intended for larger products.
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ISO 16750-4: Road vehicles - Environmental conditions and testing for electrical and electronic equipment - Part 4: Climatic loads, which includes damp heat tests applicable to automotive components.
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IEC 60068-3: Background information on environmental testing that supports method selection and interpretation of results.
Aligning IEC 60068-2-67:1995 with these and other standards enables organizations to develop robust environmental test programs that address diverse stress factors impacting electrical and electronic components.
Keywords: IEC 60068-2-67, damp heat test, environmental testing, electrotechnical components, accelerated testing, steady-state damp heat, humidity resistance, temperature and humidity testing, IEC environmental standards, component durability, electronic component testing, test chamber, electrotechnical product reliability.