What about CAE decals in part libraries?

[jdupre]

First off, I want to say that I am overwhelmed with all the information you have at pcbstandards.com. I have been making simple two layer through hole boards for the last couple of years, but now have to start in on some multi-layer SMT boards, so I am looking for any information I can find.

I'd really like to use the parts libraries that you have there, but I am confused in how to use the part definitions without CAE decals. Obviously the prepared land-pattern/footprint decals are invaluable, but what good are the part definitions without the associated CAE decals and gate & pin information?

If I were to assign my own CAE decals to the standard library of part definitions, they would get wiped out when you update the library.

- Joe

[Lameris]

True, but many of the authors use Orcad (Tom H) and Viewdraw (me) so CAE decals aren't a factor.

Having Gate swapping is useful, but you need to assign that to an IC, and not just a surface mount nominal part/decal

What I do, is use the PCBstandard libraries as a resource and copy the part to my library and then add/modify the gates as required.

If you note a problem with the libraries, document the issue and send it to the authors. They are usually quite responsive although this week is vacation week!

The accuracy is high, though I have found a few issues, and PowerPCB itself has some issues, usually discussed in other areas of this forum, that are not fully defined making generic library design difficult. For example ProE outlines, courtyards, and part outlines in general.

[jdupre]

>> True, but many of the authors use Orcad (Tom H) and Viewdraw (me) so CAE decals aren't a factor.<<

How do you create/input the netlist? It seems like there would be a huge margin of error having to maintain two libraries (a schematic library and a physical library) that do not talk to each other directly, and keep layout and schematic in sync. PowerLogic and PCB share the same library and sync to each-other, so you know instantly if there are discrepancies...

>>What I do, is use the PCBstandard libraries as a resource and copy the part to my library and then add/modify the gates as required. <<

I'd like to use the decals only, but I notice that the PCBstandards library doesn't have any attributes assigned to the decals, only to the part, so it is impossible to keep track of changes. But I'll bring this up in another topic...

- Joe

[Lameris]

Well, I have never like the fact that we have "Parts" and "Decals"

We would be better off with just one entity.

How do we sync the PowerPCB and Viewdraw libraries?
I use DxDatabook and link the 2 libraries with an Access database. Company part number, Viewdraw symbols, attributes, part types and decals are all linked through this database.

[jdupre]

>>Well, I have never like the fact that we have "Parts" and "Decals" We would be better off with just one entity.<<

But what of all the thousands of different parts that use the same decal? There would be a ton of duplication...

[dagrizz]

If you are worried about duplication, there is really no worry there. To me that is the good thing about this. Say you have a series of all of the 0805 5% resistors. I think there are about 100 different values. You would need to create 100 part types. One for each different cvalue and company part number. But you only need to create on PCB decal.

The 100 individual part types would reference that one decal. That is the way that this library works.

If you want to add pin and gate swapping then you can do that in PADs Power PCB. You would go into library editor for that part and add that information there. You don'tr need to have the CAE symbol for this. This is only if you are using Power Logic. Then you can do all of that in the Schematic Library editor.

If you do not use Power Logi# then if you do gate and pin swapping then you need to "back annotate" the schematic through their ECO process to get them back in synch.

[Tom]

Joe,

I just got word today that we are going to ramp up a major OrCAD Schematic library with full documentation. And it will be totally linked to all the land patterns in the Wind River / pcbstandards PowerPCB library.

It will not be available fo a couple of months, but I just wanted to let you know that I just got approval and funding to support a "Standard OrCAD Symbol Library" for pcbstandards.

First, we are writing a schematic symbol specification that defines the attributes and properties of the base library. I will make that available to the public so we can start the process of accepting other peoples schematic symbols.

The schematic symbol search engine with be an Excel spread sheet that will be linked to the manufacturers PDF file. It will contain a full description of the part and the land pattern.

Gary Lameris is working on the Viewdraw Symbol library and the day that we start using Viewdraw we'll quickly switch over to his library also.

[jdupre]

Sounds great, but I'm using PowerLogic!

I still don't see how you link your non-PowerLogic schematics to PowerPCB's library, but that is because I have zero experience with Orcad or Viewdraw...

At this point I am creating my own CAE deacals and part definitions, but always use the PCB Standards footprints when possible. In this respect I wish that you had attributes at the footprint level to define the creation date or library version, rather than putting this info in the part definition.

I was thinking it would also be good to have the JEDEC equivalent also stored in the footprint, although some might argue that the JEDEC standard refers to the part and not the footprint...

- Joe

[dagrizz]

When you set up your libraries in Orcad, you would put a reference to the PADs Power PCB part type. Then when the netlist is output it will call out the correct footprint.

[Tom]

Joe,

Why don't you submit all your PowerLogic schematic symbols to Randy Chase (pcbstandards web master) and we'll put them on this website to share with the rest of the world. We need to start a PowerLogic library sometime and now's just as good a time as any. I think anyone using the pcbstandards land pattern libraries should automatically submit their schematic symbols to complete the library process.

[ARGold]

I have not been to this site in awhile and and just getting updated. I'm sorry to see that the CAE decal issue has not really moved along much.

I too use Powerlogic and don't see where having CAE decals on this site interferes in any way with the Orcad or Viewdraw users.

A while back I created some update libraries including CAE decals that I would be happy to share with you guys. I'm working on a new project so I'll be creating some new decals soon.

I'll send what I did a few months ago to Randy and see what comes back.

Cordially,
Allen Goldstein
A.D. Pro Design Consulting
adpro@attbi.com