What are HALT and HASS?
Highly Accelerated Life Testing (HALT) is an instrument that uses the stepped stress method by exposing your product to various accelerated stress levels to determine the physical limits of the product’s design and its reliability. Manufacturers are able to identify their products’ failure patterns and discover the cause of their failure.
The Highly Accelerated Screening (HASS) is a process of production quality inspection that can quickly and effectively detect any flaws that the product could have developed inadvertently during the manufacturing phase.
Both are “Test Analyze, Check and Fix” strategies – each with Root Cause Analysis along the method!
Why is it important to perform HALT testing?
Highly accelerated tests for life find defects and weaknesses during the design phase, testing up to failure. Similarly, high-speed stress screening (HASS) uncovers manufacturing flaws on the production part prior to assembly without affecting the life of the component. HALT also provides important data on reliability indicators at the level of components. The results of the test are beneficial to customers, safeguard the reputation of the manufacturer, and can prevent costly re-designs at the end of the product development process.
What’s unique in a test chamber?
In contrast to other chambers for environmental simulation, HALT and HASS chambers have a rapid rate of temperature ramp (up to 60C in a minute) and incorporate vibration, thermal, and shock simulation into one device. Like other types of Vibration and Shock Testing devices, the test equipment require mounting fixtures in order to replicate the orientation of the test and transmit energy from vibration without interference.
Up of up to Grms could be applied using 3 linear axes (X Z, Y, and Z) as well as three rotational Axes (pitch and roll, as well as yaw).
What is the best way to define the HALT/HASS test?
The profiles for HALT and HSS are comprised of various segments that are defined by the intended application environment:
Warm Step Stress as well as Cold Incrementally increasing or decreasing the temperature in order to find the limits of the product. Choose the start and ending dates based on the intended environment to ensure the reliability of the product and the limitations physical of the component.
Vibration Stress Step: gradually increasing the level of vibration, as you go up to check how your product reacts. Start at a predetermined Grms level, then stay for a set amount of time and then increase the amplitude to a greater amplitude, and repeat the process to trigger failures.
Rapid thermal transitions (or thermal shock) The process of exposing your product to specified minimum and maximum temperatures, and quickly cycling between them.
Mixed Environment: Simulating actual situations in which your product is exposed to a variety of different types of environments simultaneously.
Here are a few HALT/HASS acronyms commonly used to describe test profiles:
“Grms””Grms” Vibrational G’s inside the square of the root in which “G” is the acceleration caused by gravity.
“PSD””PSD” – Power Spectral Density – In the spectrum of random vibrations, it’s the measurement of frequency and amplitude.
“LOL” along with “LDL” in the step the stress stage, they are”Lower Operating Limit” and “Lower Destructive Limit” “Lower Operating Limit” and “Lower Destructive Limit”
“UOL” in addition to “UDL””UOL” and “UDL “Upper Operating Limit” and the “Upper Limit of Destruct Limit ” occur during the step stress at a high temperature stage.
