While it is technologically no problem, 90° trace corners just look
unprofessional and lazy.
A machinist will always chamfer or at least de-burr edges, otherwise
the part is not finished.
So I use 45° rules almost exclusively, with all corners mitered. Also
gives shorter connections.
Pulsonix has a "pull tight" command that, with the routing rules set
correctly, makes it look nice using the shortest length while
maintaining clearances.
In contrast I never teardrop pads unless requested specifically.
I just haven't seen the benefits to bother for my own designs.
Even in thermal cycling on single sided boards the solder broke before
the pads lifted.
I also don't fillet or miter the inside edges of T connections.
What I do is use rounded corner pads instead of square corner for SMT.
I would like to make an "old school" rounded trace design once.
So far I haven't had the chance to put one into production.
ST
On Mon, Jul 28, 2014 at 3:45 AM, Mitch Davis
mjd@...[Homebrew_PCBs] <
Homebrew_PCBs@yahoogroups.com> wrote:
> Hi John,
>
> On Mon, Jul 28, 2014 at 10:01 AM, hudakjm@... [Homebrew_PCBs]
> <Homebrew_PCBs@yahoogroups.com> wrote:
>>
>> I was looking at some commercially produced patterns and they seem to frequently employ fillets. This is I presume to prevent cutting in of the pattern at 90 degree corners when the board is etched.
>
> I reckon use of fillets to prevent overetch in the corners is a
> historical thing. These days it's mostly done for aesthetics. I
> supply thousands of PCBs a month commercially, and filletless right
> angles are not a problem at all.
>
> It may still be relevant for home etching though, where timing and
> process chemicals are not controlled as strictly as in commercial
> production. I suggest making a test board that you can use to explore
> how well the home etch process works for you. All the best!
>
> Mitch
> http://www.hackvana.com/guide
>
>
> ------------------------------------
> Posted by: Mitch Davis <mjd@...>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> ------------------------------------
>
> Yahoo Groups Links
>
>
>