| ??? 05/06/12 21:50 Read: times |
#187294 - Much work Responding to: ???'s previous message |
Hi Mahmood,
I wonder how professional PCB manufacturers do so much work for so little money. I guess it is pretty much automated and they rely on mass production. They panelize everything, and process the panels with wet processes. In the time it takes me to mill a single small board they will have etched dozens or hundreds. It's called commoditization. If you make a dollar a thousand times in an hour, you make a thousand dollars an hour. I will never do other than single or double sided prototype on my machine because it consumes so much time and effort and chemicals equipment etc.... Don't be so sure. If you do anything beyond the absolutely simplest things possible with a ยต-controller, you will quickly learn that you must maintain controlled impedances of your traces. And you aren't going to do that with a QFP to DIP adapter, nor will you do that without at least a ground plane. About using your CNC as a pick and place machine, it's certainly possible to do if your machine has sufficient precision and repeatability, but you're going to need quite a vision system and the software to utilize it. I used to have a QUAD IVc pick and place machine (3,600 parts per hour, dual intelligent vision systems, laser alignment head, etc.), and I can tell you that for prototype assembly, you'll be much better off mounting a vacuum pickup tube (with a knob to move it up and down) under a microscope and just aligning the board to the parts manually. I found that for the smallest parts (0805s, the CP2102) scaling the tube down to a needle diameter is necessary to accommodate viewing the alignment. Good luck, Joe |
