Embedded Capacitance Material in Sheet Form
Figure 1. The Leyden jar, typically credited as being the first capacitor (Image source: howstuffworks.com)
I have many great memories of college. However, I do have to admit the last day is probably one of the most memorable. Not because it was the last day of my college career, but because it was finally our “free for all” in class. Our instructor, weeks prior to graduation, said we could pop capacitors and have a heyday on some boards on our last day. So here you have twenty-two geeky, electronic technical college students chomping at the bit, and waiting for the opportunity to create some structural havoc. The loud pops, nasty smells, and thick pluming smoke has made it a day I will never forget.
Long before we could pop capacitors in class, the capacitor had to be invented. The invention of the capacitor varies somewhat depending on who you ask. There are records that indicate a German scientist named Ewald Georg von Kleist invented the capacitor in November 1745. Several months later Pieter van Musschenbroek, a Dutch professor at the University of Leyden came up with a very similar device in the form of the Leyden jar (Figure 1), which is typically credited as the first capacitor. Since Kleist didn't have detailed records and notes, nor the notoriety of his Dutch counterpart, he's often overlooked as a contributor to the capacitor's evolution. Over the years, both have been given equal credit as it was established that their research was independent of each other and merely a scientific coincidence.1
As new technology is developed, and increased speed is a must, this can create potential issues with PI-Power integrity, SI-Signal integrity, and EMC-Electro Magnetic compatibility. To help combat these issues, 3M has developed an ultra-thin Embedded Capacitance Material (ECM). The planar sandwich structure of the ECM provides a higher decoupling bandwidth than today’s discrete MLCC capacitors. The ECM can be embedded into PCBs and chip packages as either a power ground plane or a discrete capacitor. Upfront costs are on the higher side, but the end results provide a simplified board layout, more cost savings, and an appealing look. In Figure 2, you can see, depending on what you are trying to build, that the ECM can replace many discrete capacitors on your board.
Figure 2. 3M’s ECM can replace many discrete capacitors (PCB image source: 3M)
In conclusion, there are clearly both pros and cons of adolescent technology, especially when you are comparing it to the tried-and-true capacitor that has been around for 270+ years. However, this new technology is something I’m looking forward to seeing how it advances in the years to come.
1 – How Stuff Works “http://electronics.howstuffworks.com/capacitor3.htm”