OK Instruments OK-HAST-35 High-Accelerated Stress Test Chamber

Overview

The OK Instruments OK-HAST-35 High-Accelerated Stress Test (HAST) Chamber is an engineered environmental stress screening system designed for reliability validation of semiconductor devices, LED packages, photovoltaic modules, printed circuit boards (PCBs), magnetic components, and other moisture-sensitive electronic assemblies. Unlike traditional temperature-humidity storage testing (e.g., 85 °C/85 % RH), the OK-HAST-35 applies elevated temperature, high relative humidity, and controlled saturated or near-saturated steam pressure—typically 105–135 °C at 70–100 % RH and 0–200 kPa gauge pressure—to accelerate moisture diffusion into encapsulants and die attach interfaces. This enables detection of latent failure mechanisms—including wire bond corrosion, mold compound delamination, solder joint degradation, and electrochemical migration—in days rather than weeks or months. The chamber operates on a non-saturated steam principle: forced convection circulation ensures uniform thermal and hygric distribution while minimizing condensation artifacts that may compromise test fidelity.

Key Features

• Automated water replenishment system with real-time liquid-level monitoring and fail-safe cut-off to maintain consistent steam generation throughout extended test cycles.
• Digital LED temperature controller with ±0.5 °C accuracy and programmable ramp-soak profiles; integrated PID algorithm ensures stable thermal regulation under dynamic load conditions.
• Precision digital timer activated only after chamber reaches setpoint temperature—eliminating pre-heat bias and ensuring accurate exposure duration compliance per JEDEC JESD22-A118 and A110 standards.
• Calibrated analog pressure/temperature dual gauge with direct-read scale for instantaneous verification of internal process parameters during operation.
• Steam quality optimization via continuous low-flow purge of non-condensable gases, preserving vapor-phase purity and reducing risk of localized oxidation or hydrolysis anomalies.
• One-piece molded silicone door gasket with compression-set resistance >10,000 cycles—ensuring long-term sealing integrity and leak rate <1.0 × 10⁻⁵ mbar·L/s (helium leak tested).
• Electropolished 304 stainless-steel interior chamber surface (Ra ≤ 0.4 µm) resistant to chloride-induced pitting and compatible with ISO 14644-1 Class 7 cleanroom handling protocols.
• Interlocked safety architecture: motorized door latch prevents pressurization unless fully engaged; independent mechanical pressure relief valve activates at 210 kPa (±5 kPa); redundant thermal fuses interrupt power at 150 °C and 165 °C.
• ABS-insulated outer door panel compliant with IEC 61000-4-2 ESD protection requirements and surface temperature limits per UL 61010-1 Clause 7.4.2.

Sample Compatibility & Compliance

The OK-HAST-35 accommodates standard JEDEC trays (JEDEC MO-118), 24-pin DIP carriers, and custom fixtures up to Ø300 mm × 450 mm height. Its non-saturated steam environment avoids immersion artifacts associated with autoclave-based testing, making it suitable for evaluating conformal-coated PCBs, wafer-level chip-scale packages (WLCSP), and stacked-die configurations where liquid ingress must be excluded. The system supports full traceability for GMP/GLP-regulated environments: all operational events—including start/stop timestamps, temperature/pressure excursions, alarm triggers, and manual interventions—are logged with millisecond resolution and exportable in CSV format. Optional firmware upgrade enables 21 CFR Part 11-compliant electronic signatures, audit trails, and role-based user access control.

Software & Data Management

Standard configuration includes OK-LogView™ v3.2 data acquisition software running on Windows 10/11 platforms. It provides real-time graphical display of chamber temperature, relative humidity, and absolute pressure with configurable alarm thresholds and email/SMS notification via SMTP gateway. Historical datasets are stored in encrypted SQLite databases with SHA-256 hash verification. Export functions support ASTM E29–23-compliant rounding rules and include metadata fields for operator ID, test specification (e.g., JESD22-A118 Rev. F), sample lot number, and calibration certificate reference. Raw binary logs retain native 100 Hz sampling for post-test root-cause analysis of transient thermal gradients.

Applications

• Qualification of IC packaging materials (epoxy molding compounds, underfill resins) per IPC-9701 and IPC-SM-785.
• Reliability screening of GaN-on-Si and SiC power modules subjected to high-voltage bias during HAST exposure.
• Process validation of plasma-enhanced atomic layer deposition (PEALD) barrier layers on MEMS sensors.
• Failure mode identification in automotive-grade LED headlamp assemblies exposed to combined thermal cycling and HAST stress.
• Accelerated life modeling of polymer electrolytic capacitors using Arrhenius–Peck humidity acceleration factors.

FAQ

What standards does the OK-HAST-35 comply with?
It is configured to meet the procedural requirements of JEDEC JESD22-A110 (HAST) and JESD22-A118 (uHAST), as well as IEC 60068-2-66 for damp heat testing. Calibration certificates are traceable to NIM (China National Institute of Metrology) standards.

Can the chamber operate at 143 °C?
Yes—143 °C operation requires optional high-temp heater elements, reinforced gasket material (VMQ-FKM hybrid), and upgraded pressure transducer rated to 300 kPa. Contact OK Instruments technical support for configuration review prior to order.

Is remote monitoring supported?
Standard Ethernet (RJ45) and optional RS-485 Modbus RTU interfaces enable integration into factory SCADA systems. Web-based status dashboard available via optional OK-CloudLink™ subscription service.

How often does the water reservoir require maintenance?
With deionized water input and typical 96-hour test cycles, refills are needed every 5–7 days. Automatic drainage cycle initiates after each test sequence to prevent mineral buildup in the boiler assembly.

Does OK Instruments provide IQ/OQ documentation?
Yes—Factory Acceptance Test (FAT) reports, Installation Qualification (IQ), and Operational Qualification (OQ) templates aligned with ISO 9001:2015 and ISO/IEC 17025:2017 are included with purchase. On-site qualification support available upon request.