Hai

I have a small doubt about PCB Layout

At turning point could we do route at 45 degree's , some one told in
PCB manufaturing the edge will cutout,we cannot see by eye's,we can
see that by microscope only.

suppose we do route at 90degree 's ,may be that path current will be
short

plse anybody tell

what is the correct one and reasons



Thank u

"sp" <swapnapriya2020 at (no spam) gmail.com> wrote in message
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Hai

I have a small doubt about PCB Layout

At turning point could we do route at 45 degree's , some one told in
PCB manufaturing the edge will cutout,we cannot see by eye's,we can
see that by microscope only.

suppose we do route at 90degree 's ,may be that path current will be
short

plse anybody tell

what is the correct one and reasons



Thank u



It is common practice not to turn a trace less than 90 degrees.
Tight turns make pockets in the wave soldering process.
Sharp edges may be a concern in super high frequency application also.
Tom

It is common practice not to turn a trace less than 90 degrees.
Tight turns make pockets in the wave soldering process.
Sharp edges may be a concern in super high frequency application also.

Tom Biasi wrote:

It is common practice not to turn a trace less than 90 degrees.
Tight turns make pockets in the wave soldering process.
Sharp edges may be a concern in super high frequency application also.

Surely you mean more than 90 degrees ? Unlesss I completely misunderstood
the
question.

Graham

I believe he was referring to acute angles.

"Eeyore" <rabbitsfriendsandrelations at (no spam) hotmail.com> wrote in message
news:4880D007.CB6C78EA at (no spam) hotmail.com...


Tom Biasi wrote:

It is common practice not to turn a trace less than 90 degrees.
Tight turns make pockets in the wave soldering process.
Sharp edges may be a concern in super high frequency application also.

Surely you mean more than 90 degrees ? Unlesss I completely misunderstood
the
question.

Graham

I believe he was referring to acute angles.
When I designed boards it was common practice not to turn at acute angles
for the reasons I mentioned.
But as John says, It really is not all that important.

Tom

The high voltage boys don't like sharp features.

John Larkin <jjlarkin at (no spam) highNOTlandTHIStechnologyPART.com> writes:
The high voltage boys don't like sharp features.

PCB uses round-end traces all the time, so even on 90 degree corners
the outside edge has a (width/2) radius bend in it. What do other EDA
packages do? Do any of them use sharp outside corners?
The radius is not necessary. It was used back in the tape and light table

The radius is not necessary. It was used back in the tape and light
table days but for CAD progs its just style.

"Tom Biasi" <tombiasi*** at (no spam) optonline.net> writes:
The radius is not necessary. It was used back in the tape and light
table days but for CAD progs its just style.

Actually, in PCB we use round ends because otherwise we have to
compute gerber apertures separately for each trace angle and end
junction.

Maybe you're confusing "round end caps" with "the trace bends" ? I
mean the former when I say "round ended traces".

John Larkin <jjlarkin at (no spam) highNOTlandTHIStechnologyPART.com> writes:
The high voltage boys don't like sharp features.

PCB uses round-end traces all the time, so even on 90 degree corners
the outside edge has a (width/2) radius bend in it. What do other EDA
packages do? Do any of them use sharp outside corners?

Probably an artifact/bonus of using round Gerber aperatures to draw
the traces.

"Tom Biasi" wrote:
"Eeyore" <rabbitsfriendsandrelations at (no spam) hotmail.com> wrote in message
Tom Biasi wrote:

It is common practice not to turn a trace less than 90 degrees.
Tight turns make pockets in the wave soldering process.
Sharp edges may be a concern in super high frequency application also.

Surely you mean more than 90 degrees ? Unlesss I completely misunderstood
the question.

I believe he was referring to acute angles.
When I designed boards it was common practice not to turn at acute angles
for the reasons I mentioned.
But as John says, It really is not all that important.

The prohibition on 90 degree corners is mostly esthetic/historical. It
does tend to produce inefficient packing in tight layouts.
Electrically, below 5 GHz or so, a 90 degree bend is pretty much
invisible.

The high voltage boys don't like sharp features.

John Larkin <jjlarkin at (no spam) highNOTlandTHIStechnologyPART.com> writes:
The high voltage boys don't like sharp features.

PCB uses round-end traces all the time, so even on 90 degree corners
the outside edge has a (width/2) radius bend in it. What do other EDA
packages do? Do any of them use sharp outside corners?

Reminds me. Which packages can do teardrops ? AFAICS only PADS
could, at least of the packages I reviewed.

I liked tape ups with curves.