-3
\$\begingroup\$

My team and i are working on a MIPS implementation using Xilinx spartan-6 LX9. We have a short deadline and we want to know what are some useful tips in terms of PCB design that would reduce the risk of error after printing, the pcb is 4 layers, and will contain:the fpga, spi flash, regulators, headers, oscillator, resistors, caps, etc.

So basically, with or without code, is there a book that contains good information for designing a PCB with the confidence of not having error?

\$\endgroup\$

closed as too broad by Rev1.0, winny, DoxyLover, Scott Seidman, StainlessSteelRat Feb 18 at 16:46

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 2
    \$\begingroup\$ Check, check and then check again. Preferably by different persons. There are so many errors you can make. A "good" designer is often one who has, at some time, made them all. Oh! there is also a big difference between hand soldering and production. The latter really requires an experienced PCB layout engineer. \$\endgroup\$ – Oldfart Feb 18 at 10:33
  • \$\begingroup\$ maybe i wasn't too accurate, though i meant, are there any "preferred" techniques, for placing, routing, and connecting components? \$\endgroup\$ – rex1 Feb 18 at 10:44
  • \$\begingroup\$ Use a ground plane under the MCU. With no slits or cuts under the MCU; only via-holes allowed in the Ground Plane under the MCU. If you have more than 20% visibility thru the Ground Plane under the MCU, with the total summed VIA_HOLES areas, please move some of the Vias to keep more integrity in the GROUND PLANE under the MCU. \$\endgroup\$ – analogsystemsrf Feb 18 at 14:35
  • 1
    \$\begingroup\$ Not to be snarky, but the most useful tip is to not do this sort of stuff under a short deadline. Allow time for a prototype, debug time, trace cutting and repairing, maybe even a second prototype. If this isn't in the cards, perhaps a consultant is a viable option, depending on how important this is, and how disastrous not having this work would be. \$\endgroup\$ – Scott Seidman Feb 18 at 14:49
  • 1
    \$\begingroup\$ Oldfart and Scott make excellent points. Be sure to incorporate manufacturers recommendations. There are lots of sites for beginners. The key is take your time. \$\endgroup\$ – StainlessSteelRat Feb 18 at 16:45
1
\$\begingroup\$

The problem is that there are many, many techniques/rules. And the answer when to use then is (as usual) "it depends".

Rules for decoupling, rules for high drive nets, rules for high speed nets. Rules for impedance matched lines. Rules to prevent 'tombstoning', the list is endless.
(You will find several post on EE about decoupling.) Your question is likely to be close as being "too broad".

There is one basic rule I follow: check the footprints on a 1:1 printout before ordering the board. This requires you to purchase the components before ordering the PCB. This may delay the project but not as much as having a wrong PCB come back. Below you find a mistake I spotted:

enter image description here Left wrong footprint, right correct footprint.

\$\endgroup\$
-1
\$\begingroup\$

Consider this idea in your Ground Plane under the MCU

schematic

simulate this circuit – Schematic created using CircuitLab

Why is "good" good? Because there are no long groups of vias that create SLITS under the MCU.

\$\endgroup\$

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