Electronic – Is one big PCB cheaper than multiple smaller ones, if so how to do this in Eagle PCB

eaglepcbpcb-fabrication

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?

Best Answer

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.