If your PCB design has failed, a thorough investigation and reliability analysis are necessary to determine the cause. When a board does not meet its specifications, an investigation must be performed to pinpoint the specific point of failure. The process starts with functional testing, which identifies specific features and capabilities that failed. During this step, a microsection can be done to determine the exact mechanism of failure. Once this step is complete, you can move on to reliability analysis.
In-circuit testing
In-circuit PCB testing is a critical component of electronics manufacturing. The process helps OEMs and contract manufacturers meet their production parameters by identifying the most common causes of electronic device failures. Most problems are caused by faulty components, open circuits, or short circuits. In-circuit testing ensures that the PCB meets the specifications of its design. But what are the different types of in-circuit testing?
Burn-in testing
Whether you’re designing a new electronic device or repairing an old one, burn-in testing is an essential part of the production process. This type of test accelerates component life span by eliminating defective parts. When a component passes the burn-in process, it will likely provide reliable service for the entire life of the product. In addition, burn-in testing is cost-effective and allows you to test the board’s reliability.
Micro-sectioning analysis
The use of micro-sectioning is an effective tool for failure analysis and in-process verification. This three-fold inspection procedure examines the internal makeup of a PCB. Specific inspection criteria are outlined in product specifications. If you are unsure of the criteria used for your PCB, contact an electronics contract manufacturer. They will be able to advise you on which test methods are best suited to your PCB testing needs.
In-circuit testing with multiple spring-loaded pogo pins
In-circuit PCB testing is a process whereby a PCB is tested while it is still populated using an electric probe. The electrical probes are designed to detect defects and check the basic quality of a populated PCB. Traditionally, in-circuit PCB testing has been performed using a “bed of nails” fixture. But today, ICT is performed with a custom-made fixture that uses spring-loaded pogo pins. These pogo pins are loaded with small amounts of electricity and are designed to make contact with various test points on the PCBA. Each spring-loaded pin contacts one of the nodes on the PCBA.
In-circuit testing with fixed probes
In-circuit PCB testing uses probes with fixed locations to test connections and solder quality. The probes are installed into pre-designed access points on the PCB. This method is ideal, but practical reasons make it difficult to cover the entire board. Moreover, low-value components are difficult to test because they can be distorted by spurious capacitance in the test system. Nevertheless, the results from in-circuit testing are easily interpreted and can be used to identify faulty components or nodes.