As you move through the product development lifecycle of a printed circuit board assembly (PCBA), different stages of functional testing serve essential roles in ensuring quality assurance for your product. As you progress further through the product lifecycle, each failure identified in your PCBA results in an ever-increasing cost to correct. The earlier you can identify failure(s) and failure modes, the less costly it will be to address them. Progressing through the product development lifecycle, you should begin by verifying the design meets the functional intent, followed by a validation cycle where you validate the long-term durability and conformance of the product to the design intent as it was built in a manufacturing environment that approximates your eventual final production process. Finally, in full-scale production, each part should be functionally verified to ensure that each device shipped will satisfy customer requirements for quality and functionality. electronics functional testing in its different forms helps this evaluation and through the product development lifecycle. You’ll see how each provide different functions and data for the test engineer to evaluate. Let’s look at the distinct aspects of each:
Engineer validation and testing (EVT)
During the EVT stage, the functional testing of PCBA ensures it has been designed correctly and meets its functional intent. This helps prevent product that does not comply with requirements from being assembled in subsequent phases of the product development lifecycle, or worse-yet, into the final product and shipped to the end customer. If the initial product design is unable to produce the metrics and results expected, changes will be made to the hardware. In this stage, your PCBA may be tested for logic functions, power, thermal and Electromagnetic interface (EMI) conformance.
Design validation and testing (DVT)
After you’ve validated the performance of the PCBA design, it’s time to validate the design of the product through environmental stresses. This can take multiple forms, Environmental Stress Screening (ESS), Highly Accelerated Life Testing (HALT), Highly Accelerated Stress Screening (HASS), and Highly Accelerated Stress Audit (HASA). Environmental stresses and different conditions are applied to the DUT to see how it reacts. The DVT testing regimen simulates the actual DUT physical environment and sometimes is applied to several DUTs simultaneously. The goal is to determine how long your product can hold up to the limit conditions of its specification profile. Is it ready for production? This stage helps determine the answer.
Through these operating modes and environmental conditions, DVT helps collect key parametric data for the device over a long period of time. Systems used in the DVT stage generally require more interaction from an operator to configure, start, and monitor the test. Once it has started, the system will run until the test cycle has complete or the DUT has failed.
Production Validation and Testing (PVT)
Ideally you should select a test partner with experience at each stage and which can create solutions for high-volume production. Ball Systems can deliver open-architecture solutions that meet your critical test design requirements while meeting your needs for repeatable, high-precision data collection, and long-term test equipment reliability. If you're considering whether to buy your PCBA functional system or build it in-house, check our guide for determining the best path.