Hello, I am new to SMT layout. Where I work we are taking everything to SMT
in the future. I have experience with PTH, and I am sure some of that will
carry over, but I need to learn more about SMT layout so that I am prepared
if and when the time comes to go to SMT.
I am doing some SMT layouts in eagle just to get the hang of things. Simple
low frequency analog circuits that do not need more then 2 layers.
My intuition was to have the bottom be a GND pour, and to route most of the
board on the top layer. Run power on the bottom, via up to the power pins.
By PTH habit I have my ICs in line with each other so that power maybe run
to them in straight lines. Decoupling caps near power pins, via down to the
Again, by habit, I have all resistors aligned the same direction. This made
much difference in PTH layout, as it allowed a "tunnel" to run traces
through. With SMT, it does not seem so necessary...
Using smaller traces too, as the pads are smaller. I see that some people
run traces between the pins of a SOIC (typical SMT opa) chip! This seems
hazardous. I guess I need to trust the fabrication process more?
I hope this post is not too much of a ramble. Is there a good resource for
SMT layout guidelines? That might answer some of my questions.