Halt Hass Chamber For PCB Accelerated Aging Test

PCB are an integral part of a wide variety of electrical and electronic devices and are the backbone of the device's functionality. PCBS play such an important role that thorough testing and inspection at every stage of the manufacturing process, including design, circuitry, functionality, etc., is essential. Therefore, HALT&HASS method is very popular in the electronic and electrical industry, high accelerated life test (HALT) and high accelerated screening test (HASS) can enable users to quickly determine the reliability of electronic and electrical products, which is an effective practical quality control means, among which HALT is used in the design stage of electronic and electrical products. It can quickly expose design defects to allow design changes, eliminate defects, and thus reduce maintenance costs. HASS is used in the production stage of electronic and electrical products, it can quickly expose any process defects, in a very short time to help manufacturers eliminate defective products before leaving the factory.

What is HALT Testing & HASS Testing?

Halt test

HALT stands for Highly accelerated life test. HALT is a test method for accelerating the exposure of product defects and weaknesses by applying progressively increasing environmental stresses or working loads. Mainly used in the product development stage, it can promote the product design and process defects exposed in a short time, so as to provide a basis for us to make design improvements and improve product reliability.

Hass test

HASS stands for High Accelerated Stress Screening Test. HASS is the high accelerated stress screening done in the production stage after the product obtains the working limit or the damage limit value through HALT, and generally requires 100% of the product to participate in the screening.

The purpose of HASS is to reduce the potential defects of products and try to eliminate these defects before the product leaves the factory. HASS mainly uses accelerated stress to find defective products in a short time and shorten the product improvement cycle.

The importance of HALT and HASS for Telecom PCB components

Unlike other environmental simulation chambers, halt chambers and hass chambers offer fast warming rates (up to 60C per minute) and combine thermal, vibration and shock simulations in a single unit. Vibration levels of up to 50 g can be applied simultaneously on three linear axes (X, Y and Z) and three rotational axes (pitch, roll and yaw).

High and low temperature stress:In this case, telecommunications products with embedded PCB components are exposed to temperature changes, in which the temperature gradually increases from cold to hot, and then gradually decreases from hot to cold. Here you can learn about design flaws and component behavior.
Vibration stress：A product with a PCB is exposed to shock and vibration to check its resistance and if there is any effect on the design or function. Here the vibration level also gradually increases and then decreases over a certain period of time.
Thermal transition：During testing, the product is exposed to a faster thermal cycle at the highest and lowest temperatures.
Composite testing: Here you create a simulated environment that combines all of these factors to test all of the above aspects of the product.

Halt/hass Reliability test procedure

High and low temperature step stress

Firstly, the initial temperature is set at 20℃, and the temperature is lowered by 10℃ in each stage. After the stage temperature is stabilized, the function test is maintained for 10min. Then, the function is performed at least once at the stage stable temperature. And so on until a functional failure occurs to determine whether the operating limit has been reached or the failure limit has been reached. After the low temperature stress test is completed, the high temperature stress test can be carried out according to the same procedure, that is, the comprehensive environmental stress test machine starts at 20℃, the temperature is raised by 10℃ in each stage, and the temperature is maintained for 10 minutes after the temperature is stabilized, and then the functional test is carried out until the high temperature operating limit and high temperature damage limit are found.

Rapid thermal cycling test

In this stage of the experiment, the low temperature and high temperature control limits obtained in the stress test of the high and low temperature stage were used as the high and low temperature limits here, and the high and low temperature changes were carried out for 6 cycles within this interval at a rapid temperature change rate of 60℃ per minute. The maximum and minimum temperature of each cycle should be kept for 10min, and the temperature should be stabilized before the functional test is performed. Check whether the object to be tested has recoverable faults and find its operable limit. There is no need to look for breaking limits in this test.

Vibration stress stage
In order to apply stress through vibration parameters, vibrational step stress is very useful (room temperature) once the product is firmly fixed to the shaking table at a temperature set of 20 ° C using some kind of mechanical fixture (simulating the same situation as the actual installation/orientation/installation position/conditions). Start at the 5/10 Grms vibration level, increase it by 5/10 Grms according to the product specifications (stay for about 10 minutes to run the diagnosis), and continue the process until you get a UOL and UDL for the vibration. Then, reduce the pressure on the surrounding normal conditions in order to take corrective action.

Combined environmental testing (temperature and vibration)

The combined stress is the final step in the HALT test process, which combines high-speed temperature conduction and random vibration testing to accelerate aging. Here, the previous rapid temperature change cycle conditions and temperature change rate are used, and random vibration is increased by 5g with each cycle starting from 5g, and the maximum and minimum temperature of each cycle are maintained for 10min. After the temperature is stabilized, the functional test is performed, and the process is repeated until the operable limit and the damage limit are reached. Record any abnormal state of the tested object during the above four test runs, analyze whether these problems can be overcome by changing the design, and modify it before proceeding to the next test. By improving the operational limits and damage limits of electronic and electrical products, the purpose of improving reliability is achieved.
Each of the above tests is carried out with a specific goal in mind (i.e., checking for material degradation in cold and hot environments, finding mechanical problems and better understanding potential electrical and mechanical problems with the desired properties).
However, the power-on/power-off cycle may not be suitable for every product, and sometimes it is applied to each temperature or vibration step to cause additional electrical stress at the same time. This power cycle should proceed quickly, but with enough time to generate any artificial overloads and failure modes.

JOEO HALT HASS Chamber Meet the following test standard

ESS process: Mil Std 2164(EC)
JSS on Environmental test methods: JSS 55555
Test method standard and laboratory tests: Mil Std 810
FRequirements for EMI/EMC for subsystems and equipments: Mil std 461E
Military standard for Aircraft Electrical power considerations : Mil std 704E
General requirements and norms of quality of Electrical Energy: GOST 19705-89
COTs Components used in design of EW & avionics systems: Industrial grade
Lighting Induced Transient susceptibility: RTCA DO 160E (Chapter 22)
Components used in design of EW & avionics systems: Mil std 883E

JOEO engineering team has been established for over 15 years now. Extensive experience in embedded hardware, ranging from concept/feasibility, system architecture, PoC/MVP, final product certification to volume production transfer.
If you are an OEM in the telecommunications or data communications space, you may want to include these tests as part of your PCB functional testing. You can contact our engineers online to customize your solution.