0
\$\begingroup\$

Designing a 4-layer board (signal+pwr, gnd, signal+pwr, gnd), and I have some newbie doubts about the best option to connect different connector's pin or IC's pad to power lines, or sometimes to different signals. Board has different parts: Power, MCU & RF.

The main issues I have:

  1. Power at connectors. Which is the design guideline to right connect these pads? Will this type connection create EMI which affect to RF module? VBAT plane at connectors
  2. Power planes instead of traces. Which is the design guideline for routing at this situations? I think plane, instead of traces, will be better to reduce EMI and impedance, but I'd like to have a second option due to I'm worried about how it would affect to RF. VREG traces to connect different components
  3. Best layer for planes. I would have to create several planes to connect different voltages on top layer, is this suitable? On the internal signal layer, there's only a power plane and trace.
\$\endgroup\$
  • \$\begingroup\$ The manufacturer of the RF Module should have some design guidelines as to where to and where not to have traces and ground planes. It'll be in a ludicrously scary large looking document I am sure. \$\endgroup\$ – MrPhooky Apr 14 '15 at 8:12
1
\$\begingroup\$

At connectors narrow traces are used to connect terminals to the planes to allow wave or hand soldering to heat the joint sufficiently, if oven reflow soldering is used instead these thermal releifs are not needed. as the thermal releifs are symmetrical they do not have a dipole moment and thus do not radiate significantly.

There's nothing that two ground planes can do that one ground plane and one correctly bypassed power plane cannot do better.

if you need to split the power plane into regions for different voltages that can work well too.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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