delorie.com/archives/browse.cgi   search  
Mail Archives: geda-help/2022/01/28/03:34:05

X-Authentication-Warning: delorie.com: mail set sender to geda-help-bounces using -f
X-Recipient: geda-help AT delorie DOT com
X-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net;
s=badeba3b8450; t=1643358800;
bh=Tzhx9BRIAK4/5GyslXPVJObEOTHWtf5njaJDMnoY06o=;
h=X-UI-Sender-Class:Date:Subject:To:References:From:In-Reply-To;
b=D19DLeddnohiY2/NJrDdtVc1CQ87ygEmVf0bYYuU/hIEstq6urFOlXBzsQ3/vHCyE
MFWqAmQBmn7MWGprpH4004b1131+LVybOLh4I2WsYIRR4baA7qpkFiV25Xw/IXukPL
YhlusUPaAh6i/dtyW0PdoCFW1tzf5LmYqhYWK5yc=
X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c
Message-ID: <090135c7-163a-1cd3-aa73-eed87c3bf256@gmx.de>
Date: Fri, 28 Jan 2022 09:33:17 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
Thunderbird/91.3.0
Subject: Re: [geda-help] geda pcb: footprint with non rectangular pads
To: geda-help AT delorie DOT com
References: <495872f6-0679-512e-4699-bec292f8da70 AT gmx DOT de>
<CAHUm0tN41Ym=7O18A90YHPA-F=idx5OkHLB9Pm=ykZMJ=8_-5w AT mail DOT gmail DOT com>
From: "Klaus Rudolph (lts-rudolph AT gmx DOT de) [via geda-help AT delorie DOT com]" <geda-help AT delorie DOT com>
In-Reply-To: <CAHUm0tN41Ym=7O18A90YHPA-F=idx5OkHLB9Pm=ykZMJ=8_-5w@mail.gmail.com>
X-Provags-ID: V03:K1:t3BqfeWCdYO5bGpsV0K/opm1lXgc6ownyu9XayomJG+UDrL5S20
zIAS+dzuJ/091CeDnXCw/2XwLK4O0DPvtR6CsDVJ3qZHf6In8kD38V0frtmBpf/GgRUddlY
Y9Y1YcK5SxO9oo/sDKDZikVhgcT9aMbrVeu2h7Ktqp0dcmT0EGkPgcSajX/GrPdklwAhN9U
VhshqBZ/s8u83QkV/I18A==
X-Spam-Flag: NO
X-UI-Out-Filterresults: notjunk:1;V03:K0:erzJu7mfSI8=:fHZOTXZdgv5IgTBf47/om/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X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id 20S8XQj3006974
Reply-To: geda-help AT delorie DOT com
Errors-To: nobody AT delorie DOT com
X-Mailing-List: geda-help AT delorie DOT com
X-Unsubscribes-To: listserv AT delorie DOT com

Hi Erich,

thanks for pointing me to the land patters from Microchip. Most of them
are simply rectangle and I can simply draw them. That makes, in the
moment, any further research unnecessary.

Thank you very much!
  Klaus


Am 27.01.22 um 11:02 schrieb Erich Heinzle (a1039181 AT gmail DOT com) [via
geda-help AT delorie DOT com]:
> There appears to be a range of recommended land patterns for the VQFN
> 20 3.0x3.0.0.9 mm Microchip ICs.
>
> https://www.microchip.com/en-us/support/package-drawings
>
> Some of them have rectangular pads.
>
> If you want to have arbitrary polygons in footprints, you may wish to
> implement the footprint in pcb-rnd, as it allows a polygons to be
> drawn and used as the copper shape in a custom padstack. You will not
> be able to successfully export the footprint to gEDA PCB as there is
> no internal support in gEDA PCB for polygonal SMD pads.
>
> Similarly, pcb-rnd allows custom polygons to be specified for the
> various apertures, i.e. soldermask, stencil, etc, or they can be
> autogenerated in the padstack property editor.
>
> translate2geda has to skip non rectangular or circular polygonal pads
> when converting to gEDA PCB because there is no easy way to draw the
> polygonal pad shapes.
>
> It is worth mentioning the tutorial
>
> http://www.penguin.cz/~utx/pstoedit-pcb/
>
> which shows conversion of pdf or postscript land patterns to gEDA PCB
> footprints using the pstoedit utility.
>
> As of version 3.76, pstoedit also supports export to pcb-rnd's native
> footprint format, allowing to export paths as well as polygons.
>
> http://www.calvina.de/pstoedit/changelog.htm
>
> Regards,
>
> Erich.
>
> On Thu, Jan 27, 2022 at 6:20 PM Klaus Rudolph (lts-rudolph AT gmx DOT de)
> [via geda-help AT delorie DOT com] <geda-help AT delorie DOT com> wrote:
>>
>> I want to create a board with a VQFN 20 package which has non
>> rectangular pads.
>>
>> A detailed drawing can be seen here:
>> https://ww1.microchip.com/downloads/en/DeviceDoc/ATtiny806_1606_Data_Sheet_40002029A.pdf
>> Section 34.2 20-Pin VQFN
>>
>> As you can see, the pads at the corner have a non rectangular shape.
>>
>> I read http://pcb.geda-project.org/pcb-cvs/pcb.html#Library-Creation
>> and there was mentioned:
>>
>> 10.2.1 Creating Newlib Footprints
>> "Currently a rectangle or polygon may not be used as a pad."
>>
>> Is there any chance to create a footprint for PCB for VQFN-20 as given
>> in the above linked data sheet with non rectangular pads?
>>
>> Thanks
>> Klaus
>>

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019