One of my favorite methods of examining a solder bond is cross sectioning. This may not give you a view over the entire area of the bondline, or give you an actual value you can use to determine if the bond is mechanically strong enough, but it does let you study any possible metallurgical issues visually.
This is what you can expect to see when you look at a sectioned NanoBond® for a thermal interface application:
- Your parts on the top and bottom (In the picture, this would be the silicon die and a copper heatsink
- Reacted NanoFoil® throughout the middle of the NanoBond®
- Solder encapsulating the NanoFoil® between your parts (pure indium solder in this case)
Other applications will look fairly similar, generally containing solder, NanoFoil®, and whatever parts are bonded.
If you have any questions about a NanoBond® cross section, send a picture to our engineers to confirm what you are seeing.
*This post is part of the NanoBond® Process series.