IEC 60749-42:2014

Overview

IEC 60749-42:2014 is an international standard published by the International Electrotechnical Commission (IEC) that specifies mechanical and climatic test methods for semiconductor devices, focusing on temperature and humidity storage. This standard is essential for assessing the durability and reliability of semiconductor components exposed to high temperature and high humidity environments. It provides a systematic test procedure to evaluate the resistance of semiconductor devices, particularly the corrosion endurance of metallic interconnections and the acceleration of moisture-induced leakage phenomena.

The test method described in IEC 60749-42:2014 is widely used for plastic moulded and other package types of semiconductor devices and serves as a crucial preconditioning process for subsequent testing.

Key Topics

• Test Purpose: Evaluates semiconductor device endurance against corrosion and moisture penetration under harsh climatic conditions.
• Test Equipment Requirements: Specifies that the thermostatic/humidi-static chamber must maintain stable temperature and humidity, use corrosion-resistant materials, and prevent water condensation from contacting test specimens.
• Water Quality: Recommends distilled or deionised water with a resistivity ≥ 500 Ωm at 23 °C to ensure consistent test conditions.
• Preconditioning: For plastic moulded surface-mounted devices (SMDs), the IEC 60749-20 moisture soaking and soldering heat stress treatment must be conducted before this test.
• Test Conditions: Six defined test profiles with varying temperature (40 °C to 130 °C), humidity (85% to 90%), and duration (hours to days) based on accelerated stress scenarios, including unsaturated pressurized vapour tests.
• Test Procedure:
  • Insertion and removal of test specimens avoiding any contact with condensed moisture.
  • Continuous maintenance of temperature and humidity during the test.
  • Post-test storage of the specimens at room temperature for stabilization before final electrical measurements.
• Failure Criteria: Defines the conditions under which a semiconductor device is considered to have failed the test, typically related to corrosion-induced defects or moisture leakage.

Applications

IEC 60749-42:2014 is critical for manufacturers, quality assurance teams, and R&D specialists involved in semiconductor device design, assembly, and testing. Its primary applications include:

• Reliability Testing: Ensuring semiconductor devices can withstand prolonged exposure to elevated temperature and humidity without degradation.
• Corrosion Resistance Evaluation: Assessing the robustness of metallic interconnections within chip packages, preventing failure in end-use electronic products.
• Preconditioning for Further Tests: Serving as a preparatory step for other mechanical and climatic tests by inducing potential moisture-related stresses.
• Quality Control in Semiconductor Manufacturing: Integrating endurance assessments to meet industry and customer specifications, reducing field failures.
• Accelerated Aging Studies: Facilitating rapid identification of vulnerabilities under accelerated environmental stresses, supporting product development cycles.

Related Standards

IEC 60749-42:2014 should be used in conjunction with other standards from the IEC 60749 series, which cover various mechanical and climatic test methods for semiconductor devices. Key related documents include:

• IEC 60749-20: Semiconductor devices – Mechanical and climatic test methods – Part 20: Resistance of plastic encapsulated SMDs to moisture and soldering heat. This standard is referenced for preconditioning plastic moulded SMDs before humidity storage tests.
• Other parts of IEC 60749 series dealing with vibration, shock, and thermal cycling tests provide a comprehensive framework for semiconductor reliability evaluation.
• International standards on environmental testing from ISO and JEITA, which inform related procedures and best practices in semiconductor testing.

Keywords: IEC 60749-42, semiconductor device testing, temperature and humidity storage, humidity endurance test, corrosion resistance, semiconductor reliability, plastic moulded package, environmental stress testing, accelerated aging, metallic interconnection corrosion.