Electronic – First time PCB layout recommendations


I have been assigned the task of laying out an A4-sized 10-layer PCB board using Allegro. Someone else is doing the schematics, which I will receive soon (all I know now is that the board contains an FPGA and an ARM, and that there are less than 1000 components). I have never laid out a PCB before.

My boss has given me a couple days to learn the basics of Allegro and PCB layout. Internally, we have a "PCB Design Guidelines and Checklist" I'm going to read, and a book by Kraig Mitzner

Complete PCB Design Using OrCAD Caputre and PCB Editor

What recommendations do you have for PCB layout beginners? What are major time savers you wished you knew when you started PCB layout? Are there must-read PCB layout resources online or elsewhere?

Best Answer

A couple of hints :

(1) Get a feel by stealing a simple schematic - maybe an Arduino - and spending a few days laying that out. You'll get a feel for the tools, what is easy and what is harder.

(2) Location, location, location ... What are the important design considerations when laying out a PCB?

You'll see this if you try to lay out an Arduino in an Arduino-sized space! Especially with the full board, try several placements and save them all.

(3) I suggest trying it as an 8-layer board with 2 planes (power, ground) leaving 4 inner layers for routing. Use these in pairs : 1 layer for vertical tracks (with small deviations) and 1 for horizontal tracks. You have plenty of room for vias so use them freely for changing layers, and don't bother with blind or buried vias.

Clump vias together in clumps of 4 to 8 rather than cutting the ground plane into pieces with them...

The advantage of disciplining yourself to 8 layers is that if you do get utterly stuck you have 2 clean layers to rescue yourself with. And if you don't, you save a little on the board cost.

4) Make sure the boss understand that this is probably 2 months solid work, and very likely both more cost effective and faster to use a specialist.

EDIT : I forgot one... 5) To get a feel for the placement problem, play this game If you can get to level 20 quickly enough, you'll do OK...