With all my new projects, I need a way to produce the PCBs (Printed Circuit Boards) for the electronics.
The classic homebrew approach involves the use of a etch resistant transfer to the board and the use of an etchant solution (here is an example which uses transfer from laser printer toner). The main problems with this approach is that it is of limited precision due to the etching process and I am not keen on playing around with these chemicals unless I need to (not like I have enough health problems anyways) 🙂
A second approach is to make use of a PCB prototyping company (such as ExpressPCB). The pros to such an approach is that the will provide boards with solder masks and even silk screen. The drawback, is the pricing (although reasonable), can still be quite high at $30/board. In addition although they have a quick turnaround, you still have to wait at least a few days to get your boards.
Another interesting approach that i’ve seen is the uses of a CNC mill to essentially route a PCB. Below is a clip from YouTube.com showing how a CNC mill can be used to create a PCB. Notice how the mill essentially takes out the coper around the traces, which is somewhat the reverse process which happens with regular processes. You could have the mill take out the excess copper elsewhere but it would take longer. And then in general, you can also use this copper as a ground plane.
The one interesting thing with the idea of a CNC mill, is that it can also be used to do woodwork and other projects (some of them would be cool for around the house). Unfortunately, a commercial CNC mill of a reasonable size is in the $5000+ range. Didn’t I mention that I was broke 🙂
So, now what? Well looking at those, their construction seems straightforward. So I smell another project coming on. Did some research and I should be able to construct one which meets my needs for under $1000. Surprisingly, you would think the most expensive part would be the motors and controllers. But the expensive parts appear to be the aluminum framing for the mill and the ball screws and slides (to convert the motor rotation into a linear motion). $200 for a 6ft screw? Ouch!!
Of course getting pricing on some components have been hard, most manufacturers don’t list their prices. I’ve only found a few places online where I can get some pricing info…