Magnetron sputtering explained.

Technological advances are wondrous

I'm an admirer of all things technological, and especially super innovations that make the world a cleaner and safer place. Sometimes I scout around the web just to see what's new and I came across this odd video that to me looked like it was a very slow game of pong, which it wasn't. It turned out to be a video explaining in laymans terms what magnetron sputtering is.

Honestly, if you had asked me before what Magnetron sputtering was, I would have guessed that it's the sound your microwave makes if you forget to take the little twistie off your reheating food, you know, the kind that has just a little bit of metal in it so it makes you microwave all sparky and, if it goes unchecked quite broken as well? Well, it turns out that I would have been very wrong.

Playing Pong!

How magnetron sputtering differs from galvanization

Magnetron spluttering is a technique by which a tiny coating is created on a substrate. The process is used to make all kinds of usefull stuff, for instance in micro-technology, parts of batteries, electronics (coatings put over printplates to protect them) and a myriad of other applications ranging from childrens toys to motorcycle components.

There's a big difference between the technology I remember from physics class growing up and this sputtering. Back then you would use a big vat of fluids and loads of electricity and I believe some chemicals as well and you could galvanize things. That meant a “thin”layer of zinc would be deposited on your metal object. In Holland our traditional garbage cans were galvanized, which meant the were more durable than just plain iron ones because they wouldn't rust (or at least not while the zinc was in place. You could also galvanize with chromium (making things nice and shiny) and you could copper, silver or goldplate stuff in much the same way. Commercial galvanisation used large quantities of Chromium 6, and even cyanide which of course have a rather desastrous effect on the environment. So, thank goodness they've come up with an alternative!

Pong, the simple explanation

So how does it work? The pong video shows the process in a very simplified way. Something that is the base for the coating (the bottom piece in the pong game) is put inside a chamber. The chamber is then filled with Argon, which as I understand it is like a catalyst, it doesn't get used up in the process but it does help it along. The electrons play their little pong game and a thin layer of the agent (at the bottom) is deposited onto the target (at the top in the ponggame). It sticks there and a tiny film of the material from the bottom is now stuck to the material at the top. The smart part is that there is a magnet at the top that catches any stray electrons so that all those that are knocked free from the bottom actually make it to the top.

So that's the basic process, a really simple explanation of it anyway. But this Magnetron sputtering is at the heart of many of our modern instruments. It's in our batteries, our cars are coated with it, it's used in sporting goods and childrens toys, in cutting tools and TV screens. And of course it's still used to protect metal from corrosion and to decorate all things that look better when the shine!