Author Topic: PCB-RND  (Read 13772 times)

0 Members and 1 Guest are viewing this topic.

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #50 on: November 27, 2017, 04:15:11 pm »
From gEDA's mailing list. Think of this as a coming soon post.



Hi all,

a long standing user request is to have thermals on SMD pads, mentioned e.g. in these 13 and 9 years old threads:

http://archives.seul.org/geda/user/Aug-2004/msg00118.html

http://archives.seul.org/geda/user/Jul-2008/msg00411.html

In pcb-rnd we make things happen. This week's minute video demonstrates how to do this with pcb-rnd, using padstacks and a subcircuit:

https://archive.org/details/pcb-rnd-pad-thermal

It starts with 3 pad stacks and 2 silk lines converted into a subcircuit, terminal names ("pin numbers") assigned to the SMD pads. These steps are similar to how we used to build elements.

Then from 00:30 the thermal tool is used to toggle thermals on each padstack.

The generic polygon shaped padstack is in the video to demonstrate that we are free from special casing and hacks: the rectangular pad is really a rectangular polygon, not a square cap line, and everything (including the thermal tool) works on every object type.

Regards,

Igor2
 

Offline saike

  • Contributor
  • Posts: 41
  • Country: gb
Re: PCB-RND
« Reply #51 on: November 27, 2017, 08:45:55 pm »
I used GEDA PCB for a lot of  years before switching to Kicad because of the faster pace of development and I still have many designs archived that I need to open with PCB-RND now and then.
What is the plan for schematic capture for pcb-rnd?  without that in place the whole system is going to fall many years of development time behind Kicad.
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #52 on: November 28, 2017, 03:27:58 am »
saike at the moment we support gschem, kicad's eeschema, ltspice, tinycad and mentor (Mentor Graphics Design Capture). We intend to support more and we are aware to grow more we need newer infrastructure than gEDA... a plan is in the works.
« Last Edit: November 28, 2017, 04:02:31 am by ScribblesOnNapkins »
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #53 on: December 02, 2017, 03:21:10 am »
This isn't a coming soon. This is a HERE NOW. Also from the email list...

Hi,

Over the last year I started working on a library to directly export our geometry from pcb-rnd into OpenEMS. In the course of doing that Koen (one of the contributors to OpenEMS) decided to join our project and he added hyperlinx format support.

The following video shows my recreation of one of his demos of OpenEMS simulating a hair pin (distributed element) filter using pcb-rnd instead of eagle which is what he was using.



So yea, we already have one way to simulate RF on boards and we are working on another.

Have fun,
Evan Foss
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #54 on: December 15, 2017, 05:12:40 am »
@saike - It's official pcb-rnd is splitting off from gEDA. gEDA is in our rear view mirror.
 

Offline saike

  • Contributor
  • Posts: 41
  • Country: gb
Re: PCB-RND
« Reply #55 on: December 15, 2017, 06:00:08 am »
Good, I haven't checked in on PCB-RND for a while. I hope a few more developers come on board now.
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #56 on: December 16, 2017, 11:17:07 am »
Yes more people are coming on board. Some from the various factions of gEDA, others from KiCAD, and yet more from parts previously unknown.
 

Offline Fusion916

  • Contributor
  • Posts: 41
  • Country: us
Re: PCB-RND
« Reply #57 on: January 10, 2018, 08:53:25 am »
Is it possible in PCB to remove soldermask from specific traces for copper plating to be reflowed to increase current capability?

Like this:

https://i.ytimg.com/vi/Gy1K3ayPfOk/maxresdefault.jpg
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #58 on: January 11, 2018, 05:31:41 am »
Fusion916 Yes that is possible in fact it was one of the reasons I joined the project.

In pcb-rnd we have very good layer system at this point. It's one of the largest advancements we made over the mainline of pcb. It took a lot of work but at this point you can both add and subtract from the solder mask layer. There are several ways to do it.
1. The simple way: Turn visibilty on for the solder mask layers and use the polygon, line, arc, or text tools to draw and the features they create will be subtracted from the solder mask.
2. The subcircuit way: This is for people who want to have things like footprints that use pads as heatsinks (where you want exposed copper but solder paste is optional) or for people who are doing microwave design like hairpin filters.
http://repo.hu/cgi-bin/pool.cgi?cmd=show&node=subc1

On a related note we now have a more functional thermal tool. http://repo.hu/cgi-bin/pool.cgi?cmd=show&node=thermals


In the mainline (2014 release of pcb) it was done by making elements that fit over the traces but this was painful, time consuming and very unpleasant to edit.
 

Offline ScribblesOnNapkins

  • Regular Contributor
  • *
  • Posts: 99
Re: PCB-RND
« Reply #59 on: January 14, 2018, 06:56:27 pm »
From Igor2 (the lead developer of PCB-RND)

The short answer is: geda/pcb can not do it, pcb-rnd can do it.

The long answer is: the solder mask of pcb-rnd is a layer you can draw on, so you can make arbitrary shaped openings on it. So it is possible to make various shaped openings over traces.

For example I've seen real life examples of traces thickened only in a single narrow line in the middle of the trace or other examples on multiple parallel thin lines on the trace.

Random examples (not drawn with pcb-rnd, but could be reproduced with pcb-rnd):

http://www.eevblog.com/forum/blog/eevblog-317-pcb-tinning-myth-busting/

http://www.eevblog.com/forum/projects/pcb-soldermask-question/?action=dlattach;attach=84686;image

http://www.eevblog.com/forum/projects/show-me-your-interesting-pcb-layout-solutions/?action=dlattach;attach=168817

https://i.stack.imgur.com/lZgOc.jpg


(this last one is the grid thing; I guess they are using this to avoid uneven solder distribution, like a huge ball in the middle of a largish polygon)


Regards,

Igor2

 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf