Today, printed circuit boards or PCBs find their uses in various electrical and electromechanical devices. PCBs drive these devices; therefore, their structure and function play a crucial role in terms of product functionality and the final outcome. As the demand for high-speed, performance-driven, and miniature devices has risen, PCBs are becoming more complex, compact, and intricate. A PCB should be designed in such a way that it functions flawlessly in the required application environment. Hence, PCBs are subjected to rigorous testing and inspections at each manufacturing and assembly stage. There are different types of PCBs testing techniques that ensure the performance of these boards. Flying probe testing is a widely used PCB testing technique which was initially developed to test blank boards but is now extensively used to ensure circuit board functionality.
What is Flying Probe Testing?
It is one of the most popular and widely used forms of in-circuit PCBs testing (ICT). However, it is completely different from ICT. The flying probe technique uses movable pitches, which are small and lightweight, to make direct contact with SMD pins. Also, FPT uses a camera for visual inspections of wires, open circuits, component injection and their polarity, and much more. FPT is also referred to as fixtureless testing as it does not require any custom fixtures. Flying probe testing has gained immense traction owing to its relatively simple pricing structure and ease of programming. The flying probe is typically suited for prototypes and low volume production. However, in certain cases it can be used for high volume production too.
Why is Flying Probe Testing in Demand?
Many OEMs heavily rely on flying probe testing to ensure the performance of the circuit boards. This is owing to their beneficial features, such as accuracy, cost-effectiveness, and more. Unlike other conventional methods, this testing technique can access the board components. The following list describes the beneficial features of FPT.
- FPT is well-known for its flexibility. This is because board tests are programmed and controlled using the software. So, if required, a change in component positioning or wiring can be done with ease. FPT does not require any testing points, making it more flexible than ever. The needle moves seamlessly over the board as there are no fixtures, thus it is also called fixtureless testing.
- FPT has a simple mechanism to hold the circuit board in place. The needles like probes can be set accurately to connect with specific nodes. The landing position of the probe can be changed if required.
- The testing starts when the probes move over the circuit board assembly. The probes are pre-programmed and executed accordingly in a specified manner. It will return a failed output if it finds any fault or something that does not meet the design requirement.
- The flying probe offers more clarity to OEMs, making it a reliable testing method available today. Earlier, FPT was designed to check empty circuit boards. However, it is now being used to test complex assemblies.
- This method allows checking of field-programmable gate arrays or FPGA testing that is quite difficult to test implementing other PCB testing methods.
Standard Checks Accomplished with Flying Probe
Like other PCB testing methods, flying prove testing checks:
- Opens
- Shorts
- Resistance value
- Capacitance value
- Inductance
- Micro shorts detection
- High-voltage stress detection
- Passive component measurements
- Diode and transistor orientation
- Component placement and orientation
- Simultaneous double-sided board testing
- Test boards that use both SMT and TH components
PCB manufacturing and assembly must meet two essential requirements, namely accuracy and precision. Therefore, it is essential to check and validate the same at each stage of the PCB manufacturing and assembly process. Being one of the prominent industry players, Accelerated Assemblies offers PCB manufacturing, assembly, and testing services across industries. With highly experienced and skilled employees, the company provides an entire gamut of PCB testing services. This ensures circuit boards perform as expected and meet the requirements of several challenging applications.
