HALT & HASS Testing Services

Scope

HALT and HASS apply combined thermal and vibration stress – in a dedicated chamber capable of rapid temperature change and 6-DoF vibration – to find design weaknesses (HALT) and screen production for latent defects (HASS).

Key aspects of the scope include:

• HALT stresses – cold step stress, hot step stress, rapid thermal transitions, vibration step stress, and combined thermal plus vibration stress, stepped progressively to find operating and destruct limits
• HASS stresses – a defined thermal cycling and vibration profile derived from HALT results, applied as a production screen at stress levels shown not to damage conforming product
• 6-DoF vibration – the HALT/HASS chamber applies broadband vibration in all six degrees of freedom simultaneously (three translational, three rotational), which is far more stimulating than single-axis vibration
• Rapid thermal transitions – temperature change rates far exceeding those of conventional temperature-cycling chambers (typically 60°C/min or more), which dramatically amplifies thermal stress
• Operating limit – the highest stress level at which the product still functions (with recovery)
• Destruct limit – the stress level at which the product sustains permanent failure
• HASS profile development and validation – the HASS stress profile must be proven not to consume product life or damage conforming units before it is applied in production
• Functional monitoring – the product is powered and exercised throughout both HALT and HASS so that failures are detected in real time

Applications

• Electronics design validation – finding the weakest points in a circuit board, module, or assembly design during development, before design freeze
• New product introduction – using HALT at the prototype stage to discover and fix vulnerabilities before tooling, with the widest opportunity to implement design changes
• Production defect screening – applying HASS to every production unit or batch to catch latent defects (solder bridges, cold joints, out-of-tolerance components, connector seating issues) before shipment
• Automotive electronics – HALT and HASS for automotive control modules and electronic components that must survive harsh vehicle environments
• Aerospace and defense equipment – reliability stress testing of avionics and defense electronics, where field failure consequences are severe
• Medical devices – finding latent weaknesses in implantable and capital medical electronics during development and production
• Consumer and industrial electronics – improving product reliability for competitive markets where warranty cost and reputation are at stake
• Component and subassembly screening – applying HASS at the subassembly level to detect defects before integration into a larger system

Benefits

• Finds failures in days, not months – by applying stress far beyond normal use levels, HALT exposes weaknesses in a short test that would take months or years of field use to surface
• Requires very few samples – HALT can deliver meaningful results from two to five units, far fewer than conventional reliability tests, making it practical at the prototype stage
• Fixes problems when it is cheapest – a design change in HALT during development costs far less than a field recall or warranty repair after launch
• 6-DoF vibration is highly stimulating – simultaneous multi-axis vibration excites more modes and finds more weaknesses than single-axis testing, especially for connectors, solder joints, and mechanical attachments
• HASS screens out latent defects before shipment – catching defects in production before they reach customers reduces warranty claims, returns, and the reputation damage of early-life failures
• Establishes design robustness margins – knowing the operating and destruct limits tells the engineering team how much design margin the product has against its rated specification, and where the risk lies