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Home » CadSoft Support Forums » eagle.suggest.eng » Need devices with multiple packages
Need devices with multiple packages [message #148709] Thu, 20 December 2012 04:18 Go to next message
Joel Whitehouse
Messages: 1
Registered: December 2012
Junior Member
My company has designed boards in EAGLE for years, and it's worked well for us.  However, this year, we had a problem with EAGLE and a composite part that caused a run of boards to be populated incorrectly.  Cadsoft support suggested we post a feature request here to resolve this issue and help us avoid rework costs in the future.

ISSUE:
We noticed the issue when a board we designed came back from the manufacturer with all parts populated except for two 50-pin header sockets.  Looking further, we noticed that while these parts had a footprint in the layout, they were not listed in the BOM, which we had taken directly from EAGLE.  Their absence from EAGLEs BOM had to do with a mechanical constraint that we needed to place on them.

EXPLANATION:
Now these two 50-pin header sockets, J1 and J2, needed to be precisely spaced in order to seat a daughterboard with mating connectors.  Our board designer, a Mechanical Engineer, noticed after precisely placing J1 and J2 that one of them could be moved anywhere in the layout, destroying their mechanical compatibility with the daughter board.  In order to constrain them to the proper spacing and ensure that they'd always move as a pair, he created a custom device in our library with both of their footprints properly aligned and spaced.  Now the daughterboard's mechanical interface cannot be broken by an inadvertent drag-and-drop or by the autorouter.

The only trouble with this custom part, however, is that EAGLE does not support composite devices (a device that is placed like one package on the layout, but is really two devices on the BOM) and therefore our custom part could not correctly update the BOM.  However, EAGLE could resolve this by supporting one of both of the following features:

RESOLUTION:
Support for composite devices in libraries.  This would be comprised of any two or more library devices on the schematic -- and their packages on the layout -- with the packages being physically constrained to a fixed spacing.

Another solution would be if we could group individual packages on the layout so that when any package in the group was moved (via drag-and-drop or the auto-router) the other packages would move with it.  The important part here is that the packages don't need to be locked to the board--they just need to be locked in relative position to the other packages in a group.

Both of these solutions would keep EAGLEs BOM accurate without permitting a violation of any mechanical specifications.

Thanks for your time!  We look forward to seeing future improvements to EAGLE!
Re: Need devices with multiple packages [message #148713 is a reply to message #148709] Thu, 20 December 2012 12:10 Go to previous messageGo to next message
Olin
Messages: 903
Registered: December 2009
Location: Massachusetts
Senior Member
Another solution would be to have a single device be able to cause multiple BOM entries. This is something you can do completely on your own with attributes. My BOM system doesn't allow for this either right now because this hasn't come up so far, but that's probably how I'd approach it.

I would make a device for the daughter board. That would contain all the pads for all the connectors it uses, and might even contain footprint and other information. This device would contain attributes that would cause the BOM system to include both connectors, or however many parts have to be separately bought and installed.
Re: Need devices with multiple packages [message #165796 is a reply to message #148709] Wed, 25 May 2016 11:46 Go to previous messageGo to next message
Marius Aabel
Messages: 3
Registered: May 2016
Junior Member
I also need this functionality. I am placing a DART SoC module which
connects to the main board via two headers. I would like to treat the
module as one component in the schematics, and place it, move it, etc in
layout as one component, but build it of two devices in the library.

I think a good solution would to have packages work the same way a
symbol in the device editor: you can add multiple symbols to a device
and draw on the "composite symbol" in an editor looking like the
schematics editor. It should be possible to edit the package the same
way, where you could add multiple packages and edit it in an editor
looking like the layout editor.

Using daughter board modules is a very common ting, so I recon this
feature will be helpful for many users.

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Re: Need devices with multiple packages [message #165797 is a reply to message #165796] Wed, 25 May 2016 12:23 Go to previous messageGo to next message
Morten Leikvoll
Messages: 1343
Registered: November 2007
Senior Member
On 25.05.2016 13:46, Marius Aabel wrote:
> I also need this functionality. I am placing a DART SoC module which
> connects to the main board via two headers. I would like to treat the
> module as one component in the schematics, and place it, move it, etc in
> layout as one component, but build it of two devices in the library.
>
> I think a good solution would to have packages work the same way a
> symbol in the device editor: you can add multiple symbols to a device
> and draw on the "composite symbol" in an editor looking like the
> schematics editor. It should be possible to edit the package the same
> way, where you could add multiple packages and edit it in an editor
> looking like the layout editor.
>
> Using daughter board modules is a very common ting, so I recon this
> feature will be helpful for many users.

I think you are trying to solve a common problem the hard way. Try this:
-Copy the single plug package, paste it twice on a new package.
-Named the new package it after the soc board, not the plug!
-Draw placement drawings of the full board outline at tPlace.
-Add mounting holes too with correct relative placement.
-If there are space limitations between the soc and your pcb, put that
very visible on the package too.
-Make sure the valuable relative placement is correct. It may be lost
the way you describe.
-Give the two instances different logical pin names that match what the
soc is using, like U1-1,U1-2,....U2-1,U2-2.. for example. Remember the
pin number doesnt have to be a numeric. Strings will do.

Ive done this with success on comExpress modules and I can't understand
why you want to do it a different way. Its after all the SOC you are
describing, and not the single plug. This is not hard to do.
Re: Need devices with multiple packages [message #165798 is a reply to message #165797] Wed, 25 May 2016 12:32 Go to previous messageGo to next message
Marius Aabel
Messages: 3
Registered: May 2016
Junior Member
> CadSoft Guest wrote:
>
> Ive done this with success on comExpress modules and I can't
> understand
> why you want to do it a different way. Its after all the SOC you are
>
> describing, and not the single plug. This is not hard to do.
>

When the board is sent to manufacturing, the pick and place is not going
to mount one single component, but two header plugs. For the PCB
manufacturer, this is not one component, it is two. The BOM would have
to be manually edited instead of using automatic integrations to Eagle.

So, what I am probably going to do, is make the module into two
components, each with one header. It is more important for me to keep
the PCB correct, than the schematic.

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Re: Need devices with multiple packages [message #165799 is a reply to message #165798] Wed, 25 May 2016 12:57 Go to previous messageGo to next message
Tilmann Reh
Messages: 2068
Registered: October 2004
Senior Member
Marius Aabel schrieb:

> When the board is sent to manufacturing, the pick and place is not going
> to mount one single component, but two header plugs. For the PCB
> manufacturer, this is not one component, it is two. The BOM would have
> to be manually edited instead of using automatic integrations to Eagle.
>
> So, what I am probably going to do, is make the module into two
> components, each with one header. It is more important for me to keep
> the PCB correct, than the schematic.

However, take care that with your method you get the maximum chance to
make your board completely invalid, by putting the two connectors (and
eventually additional mechanical things like centering or mounting
holes) in the wrong relation to each other.

For me, it is also most important to keep the PCB correct, and that's
exactly why I use a single package in such cases.

Manually editing the BOM for P&P appears as the much better way to go...

Tilmann
Re: Need devices with multiple packages [message #165800 is a reply to message #165799] Wed, 25 May 2016 13:08 Go to previous messageGo to next message
Marius Aabel
Messages: 3
Registered: May 2016
Junior Member
> Manually editing the BOM for P&P appears as the much better way to
> go...
>
> Tilmann
>
Thanks! Valuable tips!

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Re: Need devices with multiple packages [message #165801 is a reply to message #165799] Wed, 25 May 2016 13:17 Go to previous messageGo to next message
Morten Leikvoll
Messages: 1343
Registered: November 2007
Senior Member
On 25.05.2016 14:57, Tilmann Reh wrote:
> Marius Aabel schrieb:
>
>> When the board is sent to manufacturing, the pick and place is not going
>> to mount one single component, but two header plugs. For the PCB
>> manufacturer, this is not one component, it is two. The BOM would have
>> to be manually edited instead of using automatic integrations to Eagle.
>>
>> So, what I am probably going to do, is make the module into two
>> components, each with one header. It is more important for me to keep
>> the PCB correct, than the schematic.
>
> However, take care that with your method you get the maximum chance to
> make your board completely invalid, by putting the two connectors (and
> eventually additional mechanical things like centering or mounting
> holes) in the wrong relation to each other.
>
> For me, it is also most important to keep the PCB correct, and that's
> exactly why I use a single package in such cases.
>
> Manually editing the BOM for P&P appears as the much better way to go...

We could also ask the rhetoric question:

Whats best for your project between:

1-The manufacturers finds an issue with pick and place files that doesnt
seem to match the board, and contacts you about this.

vs

2-You find that your soc doesnt fit after the board is manufactured.
Re: Need devices with multiple packages [message #165803 is a reply to message #165801] Wed, 25 May 2016 13:47 Go to previous messageGo to next message
Tilmann Reh
Messages: 2068
Registered: October 2004
Senior Member
Morten Leikvoll schrieb:

> We could also ask the rhetoric question:
>
> Whats best for your project between:
>
> 1-The manufacturers finds an issue with pick and place files that doesnt
> seem to match the board, and contacts you about this.
>
> vs
>
> 2-You find that your soc doesnt fit after the board is manufactured.

That's exactly the point here.

Tilmann
Re: Need devices with multiple packages [message #165807 is a reply to message #165803] Thu, 26 May 2016 09:49 Go to previous messageGo to next message
rachaelp
Messages: 551
Registered: March 2015
Location: UK
Senior Member
I have to ask, why did the boards actually come back without the parts fitted? Any good CM would have contacted you with a query which you would have answered and your board would have been correctly populated. I suggest you should think long and hard about if your current CM is giving you an adequate service....

On my BOM's I list ALL part and have them marked as fitted or not fitted so there is no doubt as to my intentions. Then any pads on the board that don't have a corresponding line in the BOM, whether fitted or not are an issue that needs to be addressed.

For me, all my parts have a unique in house part number which then maps to either a manufacturers part number or a sub-BOM so if there was a case where I needed to create a composite component it would have a unique part number which would call up it's own sub-BOM with all the parts it contained. My system, once finished will roll these parts into the main BOM automatically.

Best Regards,

Rachael
Re: Need devices with multiple packages [message #165808 is a reply to message #148709] Thu, 26 May 2016 09:54 Go to previous messageGo to next message
rachaelp
Messages: 551
Registered: March 2015
Location: UK
Senior Member
Also, I meant to say, the suggestion for being able to create a permanent "locked together" group and move components in that group relative to each other in layout should be an actual thing whether it's done for this particular use case or not. It would be useful for many things so I support that as a suggestion.

Best Regards,

Rachael
Re: Need devices with multiple packages [message #170326 is a reply to message #148709] Tue, 25 April 2017 19:19 Go to previous messageGo to next message
Stefan Richter
Messages: 1
Registered: April 2017
Junior Member
Hello,

I know this thread is old but it's very relevant to the issue I'm having.

I'm pretty new to Eagle and I'm wondering how to even create a custom device with multiple existing packages contained within it. I'd like to create a device containing pads for two different Samtec headers in order to connect to a daughter board. Much like you, I need them to maintain the appropriate spacing as I move the sub-board around my main board.

I've seen many tutorials about manually creating and positioning the pads, but I'm curious if it's possible to combine the existing packages for the Samtecs I need into one device? So far I have copied the two Samtec devices into a new library and attempted to edit the packages but found no options for adding other existing packages to a device.

When you guys created this device with the two 50 pin headers, did you do so from existing packages or did you have to manually place the pads? Or were you able to just copy and paste the same footprint within the same device since it was an exact duplicate?

Thanks,
Stefan

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Re: Need devices with multiple packages [message #170331 is a reply to message #170326] Wed, 26 April 2017 10:35 Go to previous messageGo to next message
c4m4ch0
Messages: 3
Registered: February 2017
Junior Member
Hi,

If you already have the package in your library and you want to add a new footprint (for example, one with larger pads) you just need to go to "Device" and add a "New" package.

Then you need to connect each pin from the symbol with the correspondent pad.

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Re: Need devices with multiple packages [message #170332 is a reply to message #170326] Wed, 26 April 2017 11:07 Go to previous message
Lorenz
Messages: 643
Registered: December 2006
Senior Member
Stefan Richter wrote:
>
> I'm pretty new to Eagle and I'm wondering how to even create a custom
> device with multiple existing packages contained within it. I'd like
> to create a device containing pads for two different Samtec headers in
> order to connect to a daughter board. Much like you, I need them to
> maintain the appropriate spacing as I move the sub-board around my
> main board.
>
> I've seen many tutorials about manually creating and positioning the
> pads, but I'm curious if it's possible to combine the existing
> packages for the Samtecs I need into one device? So far I have copied
> the two Samtec devices into a new library and attempted to edit the
> packages but found no options for adding other existing packages to a
> device.
> [...]

You need to create your own package for your daugter board.

But if you have have the packages for the Samtec connectors, you can
create it by copying the packages together.

open the Samtec package, display all layers, group all and copy.
Then open the package of your daughter board and paste to the
appropriate location (you can run two instances of eagle in parallel,
no need to switching between libraries).
--

Lorenz
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