Some
notes on the use of the LPKF S63 PCB mill
To make a PCB will you need to
have four files:
- Gerber file top copper layer
(file extension usually .gtl)
- Gerber file bottom copper
layer (file extension usually .gbl)
- Gerber file board outline
(file extension usually .gbo)
- Excellon format drill file
(file extension usually .txt)
A few caveats for producing a
layout for the LPKF S63 machine:
- Although the board can be
double sided, we don't have a means of plating through holes (vias).
To make a via you'll need to solder a short wire link through the
board. It can be done but it's fiddly. We do have a plated through
hole rivet kit but it takes almost as long and soldering wires though.
- If using a through-hole
component connected to top and bottom copper, be sure you will be able
to solder both sides. Sometimes this is tricky e.g., 0.1” pitch
headers or through-hole electrolytic capacitors. Usually you work
around this with careful routing of tracks.
- The smallest gap we can make
between tracks is 0.2mm. This is the absolute minimum, larger is
better if your design can cope with it
- Make your tracks quite wide
0.2mm (8 thou) is an absolute minimum. Again larger is better e.g.,
10, 16, 32 thou (of an inch).
- Don't use really small
drills unless you have to - we can do 0.5mm but the smallest drill I
would suggest is 0.7mm. For most through-hole stuff 1.0mm is probably
OK. If in doubt measure the component leg with a vernier calliper
before you mill the board
- We only have metric drill
sizes in 0.1mm increments below 1.0mm. However, if you want a
hole/slot bigger than 1mm the machine will mill it
- The PCB substrate is 1.55mm
thick FR4. The copper on the boards is 1/2oz copper (approx. 18um
thick). This can be important for some applications e.g., RF or high
current work say >1A.
Final tips:
- Print out your finished
board layout actual size on paper and see if the components fit. This
is especially important if you’d have to create your own PCB component
footprints.
- The PCB world uses wacky
units and mixes imperial and metric measures all over the place so you
need to be a bit careful.
RJW 14/3/2013