A Printed Circuit Board (PCB) is the base on which electronic components are placed. It provides a way for the various packages to connect with each other. Once a PCB has been outfitted with a set of components, it’s known as a Printed Circuit Assembly or a PCA. In this article, we look at PCB failure analysis and examine the various things which can go wrong with a PCB as well as the techniques used to detect these flaws.
PCB Failure Analysis
PCBs have become more and more complex over the years, and failure analysis services have increased in step with this trend. For example, PCBs typically have various “layers” inside them made of conducting material. These days, we can have as many as 14 layers in a single wafer. Because of this complexity, many things can go wrong with a PCB and careful testing is required to find out what the problem is.
We’ve already seen the issues which can occur in a semiconductor such as impurities in the material as well as other mechanical flaws such as cracks and stresses. On a PCB specifically, we have the same problems as well as some additional ones such as those arising from improper assembly. Sometimes, the layers within the board aren’t placed correctly and this leads to a malfunction. In addition, we also have components called “vias” which act as conductors between the conducting plates. They can be “buried”, or “through hole” - meaning they connect the top, bottom and every layer in between. Errors in the fabrication of vias will make the PCBs faulty.
There are many testing services which can be used to determine the cause of the problem. Impurities of course can be testing using optical emission techniques like Auger spectroscopy which are extremely sensitive to even small quantities of trace metals. For testing mechanical problems, we turn to acoustic microscopy which can highlight small cracks and delaminations.
Of course, all PCB failure analysis techniques are put to use only after a thorough analysis of the PCB has been made. The circumstances surrounding the error are examined and we first try and find out which kind of test to apply. This isn’t a simple matter and it requires years of expertise to figure out what could be the problem. These are just a few examples of PCB failure analysis techniques. Find out more on our website about the various testing services we offer.
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