Study of surface characterization techniques applied to gold coated contacts in printed circuit boards (PCBs).

Abstract

This study aims at providing insight in the world of surface characterization techniques with particular reference to gold coatings. These techniques have become indispensable to understand the causes of failure in many mechanical and electrical problems, particularly electrical contact pads in printed circuit boards in this work. This thesis is divided in two parts: theoretical background of the surface characterization techniques, with a comparison between them, and experimentation conducted on two samples aiming to define and compare two different gold coatings: immersion gold in ENIG and electrodeposited gold. The first part deals with many of the most used surface characterization techniques, approaching them in a comprehensible way, to ultimately make a comparison to help to choose between them depending on the information to be obtained. The experimental part is an example of application of this comparison to a particular problem, and consists on the design of experiments and following interpretation of results. This study shows that the subject of materials characterization has a very vast literature and further ... The comparison of techniques performed is useful in understanding which information can be obtained, rather than how much of it, and which techniques will probably be better to achieve this goal. The experimental results encountered multiple difficulties which have been tried to explain.