Nearly all of the electronic devices we use today have an internal component called a printed circuit board (PCB) that houses and supports the complex electrical components within the machine. Smartphones, computers, and intricate industrial technologies are just a few examples of devices that use a PCB to keep the electronic components operating properly. What happens when the component fails, however? If a malfunction occurs within the PCB, an analyst must rely on tools and techniques to discover the root cause. Here are three of the methods most often used by an analyst to determine why a printed circuit board might stop working the way it should.

1) Optical Microscopy

This is one of the more common methods employed by analysts to troubleshoot PCB failure because it is quite accurate and faster than other approaches. A special tool called a scanning electron microscope (SEM) with an extremely high magnification is used to see if there any problems with the construction of the PCB. Even a small issue with the internal structure can create weaknesses at stress points and lead to an overall failure. This method will also provide the analyst with reliable proof of a breakdown in the integrity or quality of the PCB structure. The SEM gives the technician a very detailed, three-dimensional image of the inner workings of the PCB so that a repair action plan can be created. Optical microscopy is a fairly non-invasive way to get clarity of the problem and perform a quick examination.

2) X-Ray Inspection

X-rays are another popular approach to detecting the issue without using visible light. The technician can choose from a variety of X-ray systems to find the cause of the failure. A simple X-ray film will show if there are any internal parts that can't be seen by the naked eye, especially components that are hidden beneath other elements of the PCB. A three-dimensional X-ray can uncover finer details such as an insufficient solder or a deformity in the internal wiring. With the data from the X-ray, the analyst can conduct a thorough inspection of the parts that are revealed and look for defects in those areas. This is a non-destructive method that preserves the PCB sample.

3) Micro-sectioning

Also known as cross-sectioning, this approach requires the analyst to slice away a piece (or cross-section) of the PCB to visually inspect the inside of the board. The components of the removed sample are then compared to other components that are still functioning properly. The analyst is able to see exactly where the malfunction is occurring and isolate the problem for repair. This is a good technique for finding anomalies in the internal conductors, base materials, and connections between multilayer boards. While micro-sectioning is a destructive testing method, it can ultimately help the technician perform an analysis on a more stable surface and indicate if the failure is due to a change in the internal structure of the PCB.

An effective investigation into the root cause of the failure in a printed circuit board using one of the analysis methods described above can ensure that the technician makes the proper repairs and troubleshooting decisions to avoid a similar issue in the future. 

If you need printed circuit board analysis equipment to test your equipment, talk to a supplier near you.