kicad-developers team mailing list archive

[David Godfrey <info@xxxxxxxxxxx>]

On 03/02/16 01:19, Jean-Paul Louis wrote:
> Checking for overlapping courtyard areas should be the first task of DRC,
> as there is no point checking for any other type of error if parts overlap
> (non manufacturable).
> But that feature will also need a switch to turn it off on very specific
> instances.
I agree here, there are cases where overlapping components may make a
lot of sense.
Consider a mechanical object like a heatsink or mounting bracket that
"needs" to be a footprint on the pcb as it is part of an electrical
connection.
The component that the heatsink cools could well overlap the heatsink.

Another case would be perhaps placing a thermistor inside a toroid
mounted on the pcb.
I am sure that there are a large number of similar uses for overlapping
courtyards.

Another thing to consider would be handling  the case where you want
overlapping footprints to allow 2 different versions of a component to
be fitted.
To use a very simple example the use of 3 holes for both 0.1" and 0.2"
radial capacitors. You would only ever fit one, but due to supply issues
you may need to be able to fit either.

Another good example would be narrow and wide IC packages that have the
same pitch, common in both DIP and SOIC packages

Of course you could create special footprints for these cases, but if
it's just one component on your board, and you only need to do it
occasionally it's simpler to just overlap the footprints.
Regards
David G
> Just my $0.02,
> Jean-Paul
> N1JPL
>
>
>> On Feb 2, 2016, at 5:05 AM, jp charras <jp.charras@xxxxxxxxxx> wrote:
>>
>> Le 02/02/2016 10:31, Tomasz Wlostowski a écrit :
>>> On 02.02.2016 10:29, Maciej Sumiński wrote:
>>>> Pads on the same net overlapping are *not* a DRC error.
>>>>> (Only overlapping holes could be a DRC error, although I am not
>>>>> sure)
>>> Hi Jean-Pierre,
>>>
>>> I would refine that:
>>> - overlapping pads within the same component are not an error
>>> - overlapping pads between different components is an error
>>>
>>> Cheers,
>>> Tom
>>>
>> Yes I agree.
>>
>> However, testing overlapping pads could be made only after
>> moving/placing a footprint (or changing a clearance value).
>> Checking the courtyard layers (feature to do ...) could be a good
>> complement.
>>
>> -- 
>> Jean-Pierre CHARRAS
>>
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