ASLI OK-HAST Series High-Accelerated Stress Test (HAST) Chamber

Overview

The ASLI OK-HAST Series High-Accelerated Stress Test (HAST) Chamber is an engineered environmental stress screening system designed for reliability validation of hermetically sealed electronic components and packaging under elevated temperature, pressure, and 100 % relative humidity conditions. Unlike conventional temperature-humidity testing, HAST accelerates moisture ingress through dielectric layers and package interfaces via super-saturated steam under controlled overpressure—enabling failure mechanisms such as corrosion, wire bond degradation, and delamination to manifest in hours rather than weeks or months. The chamber operates on the principle of saturated steam pressurization, where water vapor is generated externally in an isolated steam generator chamber and introduced into the test chamber without direct thermal or mechanical impact on samples. This architecture ensures uniform environmental exposure while minimizing localized thermal shock or condensation-induced stress—a critical requirement for high-reliability qualification per JESD22-A118, JEDEC Standard No. 22-A110, and IEC 60749-26.

Key Features

• Dual-circuit high-temperature solenoid valve system enhances long-term operational reliability and reduces maintenance frequency.
• Independent steam generation chamber isolates heat source from test specimens, preventing direct steam impingement and ensuring sample integrity during extended cycles.
• Ergonomic lever-based door locking mechanism eliminates manual torque fatigue associated with traditional rotary latches—improving operator safety and repeatability across daily use.
• Integrated pre-test and in-test cold-air purge functionality removes residual ambient air from the chamber interior, stabilizing partial pressure of water vapor and improving test reproducibility across multiple runs.
• Continuous operation capability up to 400 hours supports ultra-long-duration qualification protocols required for automotive AEC-Q200 and aerospace DO-160 compliance verification.
• Redundant water-level sensing using submersible ultrasonic sensors triggers automatic shutdown if low-water condition is detected—preventing dry-heating damage to heating elements.
• Chamber body constructed from high-strength stainless steel with validated structural integrity at 2.65 kg/cm² (38.5 psi) at 140 °C; certified to withstand hydrostatic test pressure of 6 kg/cm² (87 psi).
• Two-tier pressure protection architecture combines programmable electronic pressure monitoring with a fail-safe mechanical pressure relief valve—meeting ISO 13850 and IEC 61508 functional safety requirements.
• Emergency dual-stage pressure release button enables rapid depressurization in abnormal operating conditions, supporting OSHA-compliant lab safety protocols.

Sample Compatibility & Compliance

The OK-HAST series accommodates a broad range of miniaturized electronic assemblies including bare dies, wire-bonded ICs, stacked-die packages, MEMS sensors, LCD modules, multilayer PCBs, and permanent magnets. Its cylindrical internal chamber design minimizes dead zones and promotes uniform steam distribution. All models comply with international standards governing accelerated life testing: JESD22-A118 (HAST methodology), JEDEC J-STD-020 (moisture sensitivity level classification), IPC-9701 (reliability qualification for printed boards), and MIL-STD-883 Method 1030 (humidity resistance). The system’s pressure and temperature control stability—±0.5 °C and ±0.1 kg/cm²—is traceable to NIST-calibrated reference instruments, enabling full audit readiness for ISO/IEC 17025-accredited laboratories.

Software & Data Management

Equipped with a 7-inch color touchscreen HMI running embedded Linux firmware, the chamber supports real-time logging of temperature, pressure, humidity, and cycle time at user-defined intervals (1–60 seconds). Data export is available via USB 2.0 or optional Ethernet interface in CSV format for integration into LIMS or statistical process control platforms. Optional software add-ons include GLP/GMP-compliant audit trail functionality (21 CFR Part 11 compliant), remote monitoring via Modbus TCP, and automated report generation aligned with ASTM E2927-13 reporting conventions. All firmware updates are digitally signed and verified to ensure system integrity.

Applications

Primary applications include qualification of moisture barrier performance in wafer-level chip-scale packages (WLCSP), evaluation of underfill adhesion strength in flip-chip assemblies, validation of conformal coating efficacy on flex-rigid PCBs, and accelerated corrosion testing of rare-earth magnets exposed to humid environments. The system is routinely deployed in semiconductor foundry process development labs, automotive Tier-1 supplier quality assurance departments, and third-party reliability test houses performing AEC-Q100/Q200 certification.

FAQ

What is the difference between HAST and standard THB (Temperature-Humidity-Bias) testing?

HAST uses saturated steam under pressure to achieve equivalent failure acceleration at lower temperatures and shorter durations—typically 96 hours of HAST correlates to 1,000 hours of 85 °C/85 % RH THB per JESD22-A118 Annex A.

Can the chamber operate without applied pressure?

Yes—the system supports standalone high-humidity soak mode at atmospheric pressure and 100 % RH, useful for preconditioning prior to burn-in or solderability assessment.

Is calibration documentation included with shipment?

Each unit ships with a factory calibration certificate covering temperature, pressure, and time accuracy, traceable to national metrology institutes per ISO/IEC 17025 requirements.

What maintenance intervals are recommended?

Steam generator descaling every 200 operational hours; solenoid valve inspection every 6 months; pressure relief valve functional verification annually per ASME BPVC Section VIII guidelines.

Does the system support custom test profiles?

Yes—up to 100 user-defined multi-step profiles can be stored, each supporting ramp/soak sequences, pressure modulation, and conditional logic based on real-time sensor feedback.