Please look this over carefully and  if you
see any mistakes please let me know.

Paul Lamar



Paul,
I'm new.
What layout software are you using, ExpressPCB?

You are running traces at odd angles.  I prefer to keep the angles on  my
boards evenly divisible by 45.  It's easier to keep track of the  signals.

You have pads for parts in the middle of traces; for example  your larger
caps (I assume they are caps; you have no reference designators  or part
numbers showing).  Try to avoid this wherever possible; the  trace wicks the
heat away while you are trying to solder the leads, and you will  be much more
likely to "lift" the pad and destroy the board.  By "lift", I  mean breaking
the bond between the FR4 fiberglass and the copper.  Once the  bond has
been broken, the board is scrap.

I do not know why you are using such thin traces.  It costs no more to
have boards made that have nice fat traces.  Narrow traces will be more  easily
damaged, and much harder to repair.  Just make certain you have 8  mil
separation from things that are not supposed to be connected.  I run  the widest
traces that I can while maintaining 8 mil separation.

I do not know what ICs you are using, but I do not see sufficient bypass
capacitors.  The "rule of thumb" is a minimum of one 0.1uF (100nF) metal
poly or ceramic bypass capacitor per IC, as close to the power pins as you can
get them.  It is also advised to use bypass capacitors sprinkled liberally
between the power and ground buses aka "rails" around the board.  If  you
don't do this, you may regret the omission later.

You are far better off to include pads that you don't need, than try to
cobble up the board later.

Steve

Yes express PC.

Paul Lamar