Overview
IEC 60749-23:2025 - Semiconductor devices: High temperature operating life (HTOL) specifies an accelerated life test to determine the effects of bias conditions and elevated temperature on solid‑state devices over time. The standard is intended for device qualification and ongoing reliability monitoring, simulating operating conditions in an accelerated manner. It documents test apparatus, procedures, stress conditions and reporting requirements. A short‑duration form of this test, commonly called burn‑in, may be used to screen for infant‑mortality failures; however, detailed burn‑in application is outside the scope of this document.
Key topics and technical requirements
- Test scope and purpose: Defines HTOL objectives - accelerated evaluation of device lifetime under combined temperature and bias stress.
- Test apparatus: Requirements for environmental chambers (temperature control ±5 °C), calibrated power supplies and monitoring instrumentation.
- Circuit and mounting considerations: Guidance to avoid overstress, thermal runaway and excessive power transfer to neighboring devices. Test circuitry must limit power dissipation on failure.
- Stress conditions and duration: Stress is applied continuously (except for interim measurements). The standard references a common benchmark of junction temperature 125 °C for 1 000 h, while allowing higher junction temperatures for extended‑temperature designs (up to technology absolute maximums). Absolute stress definitions and resultant test durations were updated in this edition.
- Operating voltage and bias: Default stress voltage is the device’s maximum operating voltage unless otherwise specified; higher voltages for additional acceleration are permitted only up to the absolute maximum rated voltage and by agreement with the manufacturer.
- Bias configurations: Static or pulsed biasing and dynamic operating stress are covered; the standard describes High Temperature Forward Bias (HTFB) as a common configuration to stress power‑handling junctions.
- Procedure elements: Includes cool‑down, interim measurements, failure criteria, measurements and life‑testing reporting.
Applications
IEC 60749-23:2025 is used for:
- Device qualification during product development and technology transfers.
- Reliability monitoring for manufacturing lots and process changes.
- Accelerated life testing to estimate field lifetime and identify wearout modes.
- Screening for early failures (burn‑in) when applied appropriately, while noting burn‑in specifics are not covered in detail here.
Who should use this standard
- Semiconductor device manufacturers and test engineers
- Reliability engineers and qualification teams
- Test lab operators and equipment suppliers
- Automotive, aerospace and defense organizations requiring documented HTOL procedures for critical components
Related standards
- IEC 60749 series - Mechanical and climatic test methods for semiconductor devices
- IEC 60747 - Semiconductor devices (discrete and ICs)
- JEDEC JESD22‑A108G (informative basis for this edition)
Keywords: IEC 60749-23:2025, high temperature operating life, HTOL, HTFB, semiconductor reliability testing, burn‑in, accelerated life test, device qualification.