Printed circuit boards are an integral part of several electrical and electronic devices, and serve as a backbone for the functioning of that device. Having such an important role to play, it is crucial that PCBs are tested and inspected thoroughly at every stage of their manufacturing process, in terms of design, circuit, functionality, and so on. There are various types of tests carried out by PCB manufacturers. However, it also depends upon the domain for which the circuit boards are being manufactured. Telecommunication is a crucial domain, wherein PCBs have a large application. So specific tests such as HALT and HASS are performed on PCBs for the telecom sector. This post discusses the details and importance of HALD and HASS test methodologies for telecom PCB assemblies.
What Are HALT and HASS Test Methodologies?
Testing is usually carried out in a standard environment or a lab environment, which may not test the PCBs enough in terms of withstanding harsh environments of the industry. HALT and HASS are used by manufacturers nowadays to check the PCB resistance under stress or at certain temperatures, depending upon the application requirement. Most importantly, these tests are done at an accelerated speed or really fast so that bugs if any can be fixed well in time. HALT stands for Highly Accelerated Life Tests, while HASS stands for Highly Accelerated Stress Screens. Both these testing methodologies are categorized under the Accelerated Stress Testing (AST) segment. Both these tests add the reliability when it comes to the accurate performance of the PCB and the product.
- HALT Testing: This focuses on finding errors related to manufacturing such as bugs, component issues, and design. The stress or harsh conditions applied here may be in the form of temperature variations and vibrations or both. The test determines if and why there are any operational level limitations in the PCB design. The resistance of the boards to these parameters can be checked as if in a live environment. This is a sure way of identifying failure mechanisms of the board and the test methodology also analyzes and fixes the bugs.
- HASS Testing: This test identifies the bugs in the manufacturing of the telecom product at any given stage. This test methodology also identifies, analyzes, and fixes the bugs. The stress or pressure is applied and increased gradually.
Know the Significance of HALT and HASS for Telecom PCB Assemblies
These tests offer reality checks and hence they are significant. Also, this can be done fast, which helps save time and costs which may be otherwise wasted if the bugs are identified at later stages. As for telecom, the manufacturer must have a chamber or an area which can simulate the telecom environment and the harshest parameters can be applied. Most importantly, all other types of testing and the related documentation must be ready before doing these tests. Also, it is crucial to document all the findings and analysis of HALT and HASS. In a typical telecom simulation setup, here are some ways in which the tests are performed:
- Cold Step and Hot Step Stress: In this case, the telecom product with an embedded PCB assembly is exposed to temperature variations, wherein the temperature is increased from cold to hot and later decreased from hot to cold gradually. In this you get to know the design flaws as well as component behavior.
- Vibration Stress: The product with PCBs is exposed to shocks and vibrations to check its resistance and if there is any impact on the design or functioning. Here also the vibration levels gradually increased and then decreased for a certain duration.
- Thermal Transitions: Here, the product is exposed to more rapid thermal cycles within the maximum and minimum temperatures.
- Combined Tests: Here, a simulating environment combining all these factors is created to test the product in terms of all the above aspects.
If you are an OEM in the telecom or data communication sectors, you may require these tests as part of the PCB functional testing. Ensure you partner with the right PCB manufacturer and assembly services provider who understands and caters to your requirements. Also, it is essential that they must have enough experience in PCB manufacturing and assembling as well as prototyping. Accelerated Assemblies offers end-to-end PCB manufacturing and assembling solutions in these and other sectors. The company is focused on quality and hence emphasizes on thorough testing and inspection of PCBs.
