Anablog

The always-great Jon Titus has a nice article in ECN magazine about circuit board mills. I mentioned these machines in my recent cover story about prototyping, but I did not go into the detail Jon does and I also did not know about some of the vendors Jon mentions. As I said in my article, many of the engineers I know are just sending out to get real boards back in a few days. Heck, several of the board shops can do single day turn on 2-layer boards. Do be aware of what my buddy Paul Grohe ran into at National Semiconductor. They wanted to get the chemical plating addition to the circuit board mill so they could have real vias instead of having to solder little jumper wires in the all the via holes. The facilities department told them it would take about a million dollars to comply with all the Sunnyvale’s regulations, double revetment containment, fume hoods and the like. Still if you need a pretty good board make in a matter of hours, you can’t beat the milling machines. RF guys love them because they can tweak the trace widths constantly and get close to the right impedance, which does change a little when you have a real production board with soldermask.