A day late and...

I finished routing and cleaning up the "final" four-layer replacement PCB for the Canon P170-DH calculator late last night. I didn't trust myself to submit the job properly at 2am. With the 13 hour time difference to Hong Kong it was already late Monday afternoon there, so I went to bed.

This morning I finished off the few things I'd thought about overnight. To double check I ran an ERC on the schematics, then a DRC on the board layout. I generated Gerbers, made a half-hearted effort to review them, then zipped them up and submitted them for fabrication. I also ordered a solder stencil for the top of the board (the bottom has no surface-mount components).

I'm running a day later than I'd hoped, but I should still get the boards before my xmas break. Production of these boards is quoted at 4-5 days, and the stencil at 4 days. If I assume 5 days starting Tuesday the 10th, then everything should ship Monday the 16th or Tuesday the 17th. With any luck I'll receive it by Saturday the 21st.

Now I need to make a list of what parts still need to be ordered and get that submitted this week.

One of the ideas I'm considering is building up only the power supply circuits on one board for a smoke-test. I've already tested the design of these circuits individually on test boards, but it's possible that I've botched the translation from the test boards to the final PCB. While it would be painful if I have to respin the PCB, it would be worse if I've also spent hours soldering components that get blown: the FPGA alone was $17. The minimum order from JLCPCB is five boards so I have three I'll never use otherwise, and the extra parts shouldn't cost more than about $10.

A small hint on saving money on stencil orders from JLCPCB: the default stencil size is huge compared to the boards most hobbyists will be making. If you order a smaller "custom" sized stencil the cost is the same. However, the smaller stencil will fit in a smaller box, and that may cut your shipping costs significantly. I think the DHL shipping for my order was initially estimated as $25 with the default stencil size, but with the stencil reduced to 182mm x 180mm (10mm larger than the board) the quoted DHL shipping dropped to $16. That's a big difference on an order that only cost $75 exclusive of shipping.