The trend in Integrated Circuit (IC) manufacturing is towards smaller and smaller components, often resulting in a much higher density and complexity. Just a minor variation in important variables can cause electronic components to malfunction in strange ways.
As all electronics manufacturers know, today’s complex electronic components miss-fire frequently and finding out what went wrong isn’t easy. Failure analysis using high-resolution x-ray techniques can help electrical engineers discover and understand where the electronic failure lies. In this article we see why x-rays are so useful for electronic failure analysis work.
Proper imaging is a critical component of the failure analysis process since it underpins every other step. In fact, if you submit your samples for analysis, it would greatly help if you were to provide detailed data on how often the failure takes place, and under what load. More data, better analysis.
Suitability of X-Rays
If possible, analysis techniques must not damage the piece which has the fault. This is important for say random sampling purposes and for the analysis of some expensive components. Techniques such as using electron microscopes for example necessitate careful preparation like smoothing out the surface thereby damaging it. Analyzing a sample without damaging it is called Non Destructive Testing (NDT).
X-Ray imaging is ideal for NDT techniques for several reasons. In the first place, X-rays have tiny wavelengths which are much smaller than those possessed by visible light. This allows very high-resolution x-ray images to be taken which becomes more and more important as the size of components decreases. The amount of energy carried by the X-rays which translates into greater or lesser wavelengths as dictated by Planck’s hypothesis can be varied depending on the requirements.
Second, the penetrating power of X-rays allows engineers to get an in-depth look at the internal structure of components just like doctors use them to peer inside the human body. 2D micro graphs present images in two dimensions with components overlapping each other. While this can be useful in many circumstances, we’re increasingly turning to a 3D x-ray image in order to get a clearer picture of the insides. In fact, 3D imaging will soon become the most important technique used due to the greater complexity of modern ICs.
Sophisticated X-Ray analysis techniques also rely on tools which allow analysis experts to mount the sample and use joystick like controls to rotate it, thus enabling them to gain a much better understanding of its structure. Failure analysis using high-resolution x-ray systems are therefore an indispensable component of the process of figuring out the weaknesses in an electronic system.
Thomas Paquette is the founder and president of Insight Analytical Labs, an electrical engineering firm offering electronic failure analysis to the semiconductor and printed circuit board (PCB) industries. Tom is an expert at assessing new integrated circuit (IC) technologies, implementing failure analysis solutions, improving board-level reliability and supporting IC development efforts.