kicad-developers team mailing list archive
Mailing list archive
Re: Polygon work
Rok Markovic <rok@...>
Sat, 24 Jan 2009 10:37:03 +0100
Thunderbird 22.214.171.124 (X11/20090105)
HI to all!
Yes, Jean-Piere I agree with you - it is not the code problem, it is
program problem. We have to tell users what each parameter means, but I
have no idea how. I am familiar with code, but I still ned some thinking
how to set parameters. Does anyone knows, how can we suggest to user how
to set parameters (maybe some sort of image) ???
I would like to see per_footprint/per_pad zone setings. I like proposal
from Vesa for Zones_Inside_Zone too. But this is not first thing in the
list. I agree with Dick that thermals are not neccessary for SMT pads,
but try to unsolder through hole component in 4 or more layer board.
I do *not* like my idea about adding stubs after removal anymore. Too
I would like too see stable release in february. TODO list is rather
short of short term items to be done (for release).
Dick Hollenbeck pravi:
> jean-pierre.charras@... wrote:
>> Removal all pads in zone is NOT the problem.
>> The problem is you have set parameters that cannot allow stubs.
>> You cannot want a minimun thickness copper zone bigger than max stubs
>> width and expect to have subs.
>> You cannot want an antipad size bigger than pads gap and have copper
>> between pads.
>> You cannot solve this by code modification, because this is not really a
>> code problem.
>> One can want to specify specific thermal parameters for a givn footprint
>> ( or a given pad).
>> A possible approach is to allow to define parameters (when are not set
>> to default) on a footprint and/or pad basis.
>> But obviously, minimun thickness copper zone must be bigger than max
>> stubs width.
>> Advantage: handle very small pads ans special cases.
>> Drawback: more and more complex way to handle zones parameters, and in
>> many cases not very easy to understand.
>> But this can be a solution in some cases and must be considered.
>> Many kicad users could be unable to set/choose good parameters.
>> the answer to your question is:
>> this can be done.
>> But this will creates some ugly code and problems:
>> - stubs must are tracks, not zone fill segments, because they will be
>> outside filled areas, and must be considered in connection and DRC
>> As a consequence, they are obstacle to create new tracks. Existing
>> zones are never obstacles, because copper in areas is removed when
>> calculating new filled ares in zones.
>> - stubs *must* be removed when a zone (or its filled areas) is removed.
>> So i am not well-disposed to this approach because this problem is only
>> the result of an other problem, mainly a bad parameters choice.
> On my boards most all components are SMT with a handful of through hole
> components. I asked my board manufacturer if they thought I needed
> thermal reliefs and they said no. I guess thermal reliefs are only for
> hand soldered components? If so, aren't hand soldered components
> typically fairly large pads with fairly large pad to pad distances?
> A wave machine or an SMT reflow process does not need thermal reliefs
> according to my board manufacturer. Does this information help,
> contradict, or confuse?