This month’s material is part of one of the most popular smartphones, specifically the central processor – the ‘brain’ of the phone. Here we have images obtained by Optical Microscopy (OM) at various magnifications. On the home page we show a precision-lapped cross-section through the processor unit, which is a multi-device assembly that includes IC chips, circuit boards, solder balls, ceramic chip capacitors, and more.

 

At higher magnifications we find that some voids are clearly visible in the solder balls, which are typically found in BGA (ball grid array) packaging for surface mount applications. At higher magnification, so are intermetallics extending into the balls from the device contact pads.

Of particular note is the precision lapping of this device package that was required to produce the Homepage image (a composite image of multiple fields of view) showing features on the order of 0.010 inches (25 µm) in the same plane over the entire length of the chip – distance of approximately 1 inch (25,400 µm). That amounts to a 1,000:1 aspect ratio.

In our November 2019 webinar, we explored some aspects this device and other semiconductor related applications and how an analytical “Double Take” can help you better understand those materials, contaminants, problems, failures and more.