OK-HAST Series High-Pressure Accelerated Stress Test Chamber

Overview

The OK-HAST Series High-Pressure Accelerated Stress Test Chamber is an engineered environmental simulation system designed for highly accelerated stress testing (HAST) of electronic components and materials under elevated temperature, humidity, and saturated steam pressure conditions. Unlike conventional temperature-humidity chambers, the OK-HAST chamber operates on the principle of saturated steam pressurization—leveraging the thermodynamic relationship between vapor pressure and saturation temperature to significantly accelerate moisture diffusion into microelectronic packaging structures. This enables rapid identification of latent defects such as wire bond corrosion, die attach delamination, mold compound blistering, and intermetallic growth in ICs, LEDs, PCBs, photovoltaic cells, and permanent magnets—within hours instead of weeks or months. The chamber conforms to industry-standard HAST protocols including JEDEC JESD22-A110 (HAST – Unbiased), JESD22-A118 (HAST – Biased), and IEC 60068-2-66, supporting both unbiased and biased test configurations with precise control over thermodynamic boundary conditions.

Key Features

• Automated water replenishment system with real-time level monitoring and fail-safe interruption of test cycles upon low-water detection
• Digital LED temperature controller offering ±0.5 °C setpoint accuracy and 0.1 °C resolution across the full operating range (105–135 °C)
• Integrated analog pressure/temperature gauge calibrated to NIST-traceable standards for continuous in-chamber monitoring of absolute steam pressure and saturation temperature
• Forced-convection saturated steam circulation architecture ensures uniform thermal and hygric distribution throughout the test volume—validated per IEC 60068-3-5
• One-piece molded silicone door gasket providing >10,000-cycle sealing integrity and leak rate <1.0 × 10⁻⁶ mbar·L/s (He leak tested)
• Electropolished 316 stainless-steel interior chamber surface (Ra ≤ 0.4 µm) resistant to chloride-induced pitting and facilitating ISO 14644-1 Class 5 cleanroom-compatible operation
• Interlocked safety door mechanism: power remains disabled unless door latch engagement is verified by dual mechanical and magnetic sensors
• ASME-certified pressure relief valve (set point: 2.2 kg/cm²) with redundant rupture disc backup for overpressure events
• Dual independent overtemperature protection circuits—primary PID-controlled heating cutoff and secondary bimetallic thermal cutout (150 °C)—with audible alarm and event logging
• ABS polymer insulated door panel ensuring surface temperature remains <45 °C during operation, compliant with EN 61000-3-2 and UL 61010-1 touch-safety requirements

Sample Compatibility & Compliance

The OK-HAST chamber accommodates a broad range of sample geometries via configurable stainless-steel shelving (standard: two tiers; optional: up to four). It supports standard JEDEC trays (JEDEC MO-178), 24-pin DIP carriers, QFP/QFN packages, wafer-level test boards, and encapsulated PV modules up to 650 mm diameter. All models are certified to meet CE marking requirements under the EU Machinery Directive 2006/42/EC and Low Voltage Directive 2014/35/EU. Pressure vessel design complies with PED 2014/68/EU Category II classification. Calibration documentation includes traceable certificates for temperature, pressure, and humidity sensors issued by an ILAC-MRA accredited laboratory. The system is compatible with GLP and GMP environments when integrated with optional audit trail-enabled software (see Software & Data Management).

Software & Data Management

Optional OK-LogPro™ HAST Control Suite provides full remote operation, real-time parameter visualization, and automated report generation in PDF/CSV formats. The software supports 21 CFR Part 11-compliant user access control (role-based permissions), electronic signatures, and immutable audit trails—including timestamped records of all setpoint changes, alarm events, and manual interventions. Data export adheres to ASTM E2500-22 Annex A3 for analytical instrument qualification. Optional integration with LIMS platforms (via OPC UA or Modbus TCP) enables seamless data ingestion into enterprise quality management systems (QMS) such as TrackWise or MasterControl.

Applications

• Qualification of semiconductor packaging reliability under high-humidity stress (e.g., qualification of Cu-wire bonding vs. Au-wire alternatives)
• Failure mode analysis of LED phosphor layer degradation and encapsulant yellowing
• Accelerated life testing of solder joint integrity in automotive-grade PCBAs per AEC-Q200
• Moisture sensitivity level (MSL) determination per J-STD-020 for plastic-encapsulated microcircuits
• Evaluation of anti-corrosion coatings on NdFeB magnets exposed to humid, pressurized environments
• Validation of hermeticity and seal performance in MEMS sensor housings
• Pre-screening of photovoltaic module backsheet materials for hydrolytic stability (IEC 61215-2 MQT 15)

FAQ

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

HAST replaces ambient-pressure humidity with saturated steam at elevated pressure, raising the dew point temperature and dramatically increasing moisture vapor concentration—resulting in 5–10× acceleration factors versus 85 °C/85 % RH THB testing.

Can the chamber operate without electrical bias applied to samples?

Yes—OK-HAST supports both unbiased (JESD22-A110) and biased (JESD22-A118) configurations; external DC bias sources connect via feedthrough terminals rated to 1000 VDC and 10 A.

Is calibration verification required before each test run?

Per ISO/IEC 17025 and internal lab SOPs, daily verification using NIST-traceable reference sensors is recommended; full calibration is performed annually or after maintenance.

How is condensate managed during depressurization?

An integrated condensate evacuation circuit activates during cooldown, routing condensed steam through a cooled trap and stainless-steel drain line to prevent re-condensation inside the chamber.

Does the system support custom test profiles with ramp/soak segments?

Yes—the OK-LogPro™ software allows definition of multi-step profiles with programmable pressure ramp rates (0.1–1.0 kg/cm²/min), temperature ramps (1–5 °C/min), and dwell times from 1 minute to 999 hours.