2
\$\begingroup\$

I have heard/read somewhere that one bigger PCB is cheaper than multiple smaller PCBs, is this correct?

If so, then rather than order seperate PCBs for different parts of a project e.g main board with "daughter boards", is it possible that the PCB file of different PCBs be combined together such as to create one single PCB which can then be cut into its individual pieces once manufactured.

I am not talking about combining the schematics. I am talking about the actual files that give the details of how to manufacture the PCB and combine them such that it becomes one board.

If this is good idea and possible, how can this be done in Eagle PCB?

\$\endgroup\$
  • \$\begingroup\$ How many pcbs do you want to fabricate? This tends to vary a bit (at least where I'm from) \$\endgroup\$ – Wesley Lee Apr 16 '16 at 19:09
  • 1
    \$\begingroup\$ Some prototype PCB makers charge extra for PCBs that appear to have more than one design in them, so it's not always significantly cheaper. I'll leave the Eagle-specific details to others, but it's not that hard to do in Altium. \$\endgroup\$ – Spehro Pefhany Apr 16 '16 at 19:15
  • 2
    \$\begingroup\$ The term you are looking for is "panelizing". Be aware that some manufacturers (most) charge extra for panelization, which can decrease the savings. Searching "eagle panelize" will get you lots of tutorials, here's one that looks decent. \$\endgroup\$ – uint128_t Apr 16 '16 at 19:23
  • 2
    \$\begingroup\$ The only way to know for sure is to ask your board manufacturer to quote for single circuit and combined boards. If you have a helpful board manufacturer they should be able to combine the gerber files for you in a way that results in the lowest cost. \$\endgroup\$ – Steve G Apr 16 '16 at 19:49
  • 2
    \$\begingroup\$ ...you seem to be jumping over the point that in many cases this won't actually save money; The answer to your very first question is "maybe", or "it depends." For some fab houses a square inch (or centimeter) has a fixed cost; for some, a larger board is cheaper, but a larger board which they can clearly see is 5 smaller boards will be charged as 5 smaller boards. No real point in checking on panelizing until you've checked with your board vendor(s) to see if there are ANY savings to be had, and if so, how that works, precisely. \$\endgroup\$ – Ecnerwal Apr 17 '16 at 3:31
3
\$\begingroup\$

I have done exactly what you describe, and it did lower the price.

I designed a robotics servo controller that required two stacked boards, a top one for logic and analog, and a bottom one for the power supplies and motor amp. I designed the PCB as a single board with a "breakaway" between them (it was originally a single "rigid-flex" board). I also ran small power traces across the breakaway, so that the "dual" board could run self-tests prior to separating them.

Per board, there was no price advantage, as the board house charged per square-inch. But where I saved was:

  • One setup charge, instead of two, for both fab and assembly.
  • The two boards could be auto-assembled as one.
  • A single bill-of-materials.
  • Initial testing as a single board, while all components were still accessible prior to separation (there's components on both sides of both boards).

Sorry, I can't help with Eagle, as I use PADS PowerPCB. But for me, it was as simple as treating the board as a single design.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.