Electronic – Why has the auto-router put the PCB traces on two different layers


This is my first PCB design.

I want to design the PCB layout of the following switched mode regulator:

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This is the resulting PCB layout in which I've placed my components and the auto-router function of EasyEDA has created the traces:

enter image description here

  1. Can you tell me the reason why the auto-router has put the traces to J5 and J2 on a different layer (bottom layer)?
  2. Do you have any particular advice for components placement or routing? I'm quite hesitant since it's my first project.

Best Answer

Here's some advice - never use an auto-router until you have had several years experience in designing circuit boards. If I were to tell you what to do based on my own experience (many years) my advice would be simply: NEVER use an auto-router. I've never used one in decades of designing many printed circuit boards and so you, as a beginner on this (maybe) shouldn't be considering it as an option.

Do you have any particular advice for components placement or routing?

  • Spend more time on placement than routing. Time spent on placement saves you time on routing and delivers a better design.
  • Always use a double sided board as a minimum and make sure you have a ground plane that is minimally affected by connection tracks from the top having to enter the ground plane side in order to cross other tracks on the top layer.