In the 1966 movie Fantastic Voyage, a submarine along with its crew was shrunk to microscopic size to be injected into a human body and perform delicate surgery. Not surprisingly, everything they encountered—body parts, organisms, and antibodies—was huge. In a way, we’re facing a similar situation today in our electronics. Gadgets of all kinds, led by implantable medical devices, are getting smaller. At the same time, those devices are becoming more sophisticated, so their components—transformers for example—must get smaller as well. The same goes for the ultra-fine wire that goes into those magnetic components.
Wire gets finer, and the techniques for winding it change as well. But one thing that doesn’t change size is the particles of dust in the air that surround us wherever we go. In most cases, dust particles, small as they are, can be safely ignored. But like the tiny surgical team in the movie, smaller component are suddenly faced with boulder-size dust motes that can’t be ignored. The only viable option is to filter them out of the air; hence the cleanroom.