90 degrees bends are bad as the trace will act as a mini antenna. You might
think you won't have a problem since you not doing radio or high frequency
stuff, but you will.
The trace will both radiate & receive RF. It may sound odd, but low-speed
switch can contain high-speed noise, leading to glitches.
10, 20, 40 MHz speeds are becoming common in hobby apps.
You won't get bitten often, but you will get 'odd' problems, such as 'my
board fails when I breathe on it!' (capacitance problem) and 'fails outside
my house' (local transmitter interference).
Whatever happened to the groovy curved traces from years back (old
calculators, etc). Well, apart from no hand layout!
Tony
Date: Sat, 31 Jan 2004 16:45:21 +0100
From: Stefan Trethan <
stefan_trethan@...>
Subject: Re: Sunny making his first PCB
On Sat, 31 Jan 2004 14:39:40 +0000 (GMT), jagjot singh
<
mundasocute2000@...> wrote:
> Hi friends ,
> I am looking for some very basic information about pcb
> designing sunny
>
ALWAYS CHANGE THE SUBJECT LINE OR NOBODY WILL ANSWER!
I have no url or book for you (sorry) because i learned that in school but
i want to add the following:
These "rules" like 90/45 degree bend etc. sometimes come from only very
special methods of
manufacturing the pcb (like "acid traps" occur only with tin plating as a
resist).
Or they are only true for certain applications (like very high frequency).
Always think yourself why you should do things a certain way, and if
someone says "do it that
way" always ask him why. This also greatly increases the chance that you
remember it.
...
I use only 45degree bends, because it looks better, but on a pcb are so
many 90degree edges
(like when 3 tracks join or at each solder pad) that there is not really a
good reason
for not using 90 degree bends.
...