Issue link: https://iconnect007.uberflip.com/i/1436094
46 DESIGN007 MAGAZINE I DECEMBER 2021 d. Electrical test e. Cycle testing that simulates the environment the system will operate in (thermal, electrical, etc.) Reliance solely on functional testing might be due to reluctance on the customer's part to let the fabricator in on every aspect of the final system or due to security issues. In any case, it is highly recommended to conduct the most appropriate testing mix, even before the functional one, even though the process might take a bit longer. In the long run, it saves time since one can detect failures at a much earlier stage and can attend to them instantly. Even if these tests might result in design adjustments, they increase the process reliability and, hence, the final system. Optimal, end-to-end test and inspection process saves the execution of unnecessary tests. For example, many of our production reports prove that conducting ICT before functional tests improved production failure rate—from 5–7% scrap to 0.1%. Avoiding ICT might increase the risk of the entire production process and result in a high level of failures, which the functional test failed to trace. If, for instance, during the functional test, we find that one of the system's functions is not active, we won't be able to determine which capacitor or resistor has caused the problem without dismantling the entire sys- tem to check each one of its PCBs. Managing an effective test process prevents the need to replace components, alter design aer production has begun, and invest large amounts of time and money, not to mention avoiding the embarrassment of delivering a mal- functioning device to the end-user. Using the right test mixture in the early stages of the design is vital for delivering quality systems. Here are three examples of problem-solving in the works: In advance, you can make sure that test points are located in the right spot on the PCB surface and are adequately spaced from each other to allow for their effec- tive conduct. Allocating the suitable space for the test points (not too close to one another or too far away) on the PCB contributes to the successful production process. ere are times when a component under inspection interrupts the testing of the one adjacent to it due to the release of electronic signals. Planning for additional test points in the early stages of the design enables setting the interrupting component as "disabled" dur- ing testing and activating it again once testing is concluded. A PCB with a combination of misplaced resistors, which has gone through functional testing only (without adding an ICT to the test mixture), might result in no conclusion since the resistor's small size doesn't enable its mark- ing or traceability. DESIGN007 Ofer Manovitz with vice president of quality assurance and safety at PCB Technologies. Isaak Golod is manager of the ICT Test Development Group at PCB Technologies.