Electronic Circuit Boards Tested For Reliability and Functionality
electronic circuit boards (PCBs) are exposed to a wide range of stressors, from varying temperatures and humidity to chemicals and mechanical vibration. The more stress a board undergoes, the greater its risk of failure. Fortunately, testing methods can help detect issues and ensure that a product will operate reliably in its intended environment.
The first step in reliability testing is functional testing, which verifies that the PCB works as designed. This can include a variety of tests, including:
Resistors: These devices transmit electrical current, and you can test them by connecting the multimeter probes to each lead on the board and checking their readings. Sensors: These devices can sense alterations in the board’s environment, and respond with an electrical signal. Tests can be done using a multimeter or other instrument. Capacitors: These components store electric charge and release it when needed. They are tested with a digital multimeter.
Connectors: Connectors provide an interface between components and the outside world. These can be tested with a digital multimeter or other instrument. ICs: These are the key logic and memory chips that power a PCB. You can test them with a digital multimeter, or by emulating the IC in a simulation tool.
IC testing can also identify thermal stress, which can be caused by variations in component temperature or changes in the copper’s expansion. This can weaken solder joints, cause a short circuit or even damage the components. ICT can spot these issues and allow engineers to make adjustments to improve the design.
How Are Electronic Circuit Boards Tested For Reliability and Functionality?
Another important test is burn-in testing, which subjects a board to constant stress over long periods of time. This helps to identify early failures, establish load capacity and increase the lifespan of a board. This is especially critical for industries that must meet strict standards like aerospace, medical or automotive electronics.
Other testing methods, such as automated optical inspection (AOI), X-ray for BGAs and in-circuit testing, can catch defects during the manufacturing process. This can save costs by reducing the need for repairs and replacements, while improving functionality and reliability.
Ultimately, the best way to evaluate a PCB’s reliability is through accelerated stress testing with a high number of cycles and duration. This enables engineers to test for the most common issues, and it provides the necessary confidence that the product will perform as expected in its intended environment. The precise number of simulated stress cycles and duration will depend on the end-use environment, so careful analysis is required to balance risk reduction with design margin. For example, safety-critical products should undergo extensive qualification testing, whereas low-volume consumer devices can be qualified with less effort to reduce development cost. Performing more testing than necessary can also increase the likelihood of finding errors and faults, so a careful risk/benefit analysis is essential.
Beyond the industrial sector, the tech and aerospace industries rely on sophisticated PCBs to power the next generation of gadgets. For example, 5G infrastructure is powered by advanced PCBs that feature high layer counts and unique materials to handle the speed of data transfer. The military, too, depends on these devices for reliable communication systems in remote locations.
