pcb manufacture and assembly, double sided components or not ?

[Simon]

I'm making a project and I'm wondering what is the most cost effective solution for pcb size and automated assembly.

The board is small and smaller means cheaper and a smaller cheaper box, so I could do double sided but does it cost more to place parts on both sides ? should i make the board slightly larger with everything on one side ?

[wemme]

Generally If you plan on making these in small to medium production then single is usually cheaper.
If you go double sided you end up paying for another solder mask, set-up, loading pass and lap through the reflow oven and pcb is not that expensive in comparison.

[8086]

By using both sides you are doubling the machine time except pick and place.

So yes it will be more expensive. How much is really anyone's guess. Get some quotes.

[fcb]

If you want to make things easy.

Stick with a single sided load.
Put THT on the same side as the SMT (makes for easier wave soldering).
Rectangular PCB, with space down each side for the conveyor in the printer/placer and possibly wave solder.
Put fiducials (1-2mm round pads, make sure they are blanked out on the stencil, and leave at least 0.5mm gap off resist - makes for better visioning) in the opposite corners, and at the corners of any fine-pitch parts.
Make sure your ident doesn't go over the pads...
Provide proper RS274-X Gerbers, check them with something like GC Prevue.
Let them panelise the PCB..
Check your BOM includes X/Y/Rotation coordinates, adjust so bottom-left of PCB is 0.00, 0.00
Get a list of their preferred common stock items.

Talk to them!