kicad-developers team mailing list archive

[Wayne Stambaugh <stambaughw@xxxxxxxxxxx>]

On 11/26/2014 3:14 PM, LordBlick wrote:
> In response to a message written on 26.11.2014 18:03, from jp charras:
>> Currently, this is by design.
>>
>> Adding thermal relief to a trapezoidal shape creates discontinuity, and
>> the shape is no more a trapezoid.
>> In fact, using a trapezoidal shape for a pad in a copper zone has no
>> interest.
>>
>> For these reasons, I did not spent time to code thermal reliefs for
>> trapezoidal shapes.
>>
>> Of course, trapezoidal shapes can have now applications outside the
>> microwave applications, but I don't know these applications.
>>
> Trapezoid pads can be useful for control distribution of melting solder
> paste. For each pad, you can set its connection to the copper zone to
> "None" and still it will be microwave compatible.
> 

This is sort of what I was using the trapezoidal pads for.  Someone
created them in the Resistors_Universal library.  It appears they were
designed to handle multiple SMD resistor sizes.  I only use them when
prototyping since most of my in house passive components are 0805 and
1206 sizes so it's handy to have these footprints rather than using an
oversized rectangular pad which can make soldering more difficult.  I
was trying to save etching away large amounts of copper by using a
ground plane instead of traces.  This is the first time I tried this so
I was caught off guard by the fact the the zone did not connect to the
pads.  I checked the zone documentation in Pcbnew and I didn't see
anything about trapezoidal pads not connecting.  It's not a big deal but
we should document the fact that trapezoidal pads are not connected to
zone fills.  Although, it would be useful to allow trapezoidal pads to
connect to zones as long as the can be excluded for microwave purposes.
 Thanks JP for the information.