CAD libraries of schematic symbols and layout footprints

( in Protel and other CAD formats )

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libraries of schematic symbols and layout footprints

see Making your own symbols #symbols , and making your own footprints #footprint .

(where to get symbols for your schematic)

(where to get footprints for your layout)

Brian Guralnick has generously donated a library with both "schematic components" and "PCB footprints" ("land patterns") at ftp://ftp.point-lab.com/quartus/Public/ProtelUsers/BHGlibs.zip [FIXME: has moved elsewhere ?] and ftp://ftp.point-lab.com/quartus/Public/ProtelUsers/SuperCompact.zip "all schematic discrete components are optimized for the schematic capture display. They are super compact. The pcb foot prints are also space optimized." ``Except for double diodes, discrete component pinouts are B,S,E, G,S,D, A,K instead of pin numbers for matching footprints within your own footprint libraries.''

Protel keeps putting updated parts libraries on its web site: Protel Libraries http://www.protel.com/resources/libraries/ /* was http://www.protel.com/library/ */ and http://www.protel.com.au/resources/libraries/ /* was http://www.protel.com.au/library/index.html */ and http://www.protel.com/news.htm /* was http://www.protel.com/library/qa/whats_new.html */ .

a free library of footprints and symbols (which they call ``decals''): http://www.cadprosystems.com/ (is this compatible with Protel ?)

Q: What's the quickest way to print a page that lists *all* the footprints of a pcb library ? Looking at a page full of footprints at once is much faster than scrolling through the library looking at one at a time. (Especially with several pcb libraries full of parts).

A: "Geoff Harland" on 2001-05-24 08:39:28 PM writes: (lightly edited by the FAQ maintainer):

  1. Create a new blank Pcb file.
  2. Open the pcb footprint library file (``.lib'') you're interested in, and look at one of the footprints.
  3. With the Design Manager panel on, select the "Browse PCBLib" Tab while you have the Pcb Library file concerned currently selected.
  4. Using the left mouse button, click on the *first* footprint listed in the Design Manager panel.
  5. While holding a Shift key down, (left mouse button) click on the *last* footprint listed in the Design Manager panel. *All* of the footprints listed in the Design Manager panel should now be in a highlighted state.
  6. While the cusor is located over the area listing these footprints, right-mouse click, then select "Copy" from the resulting popup menu.
  7. Switch to the (blank) Pcb file, then do ``Edit | Paste'' and click in the PCB area. One copy of each of the footprints will then be pasted into the Pcb file. Now all the components are in a pile where you clicked.
  8. Select the components (perhaps with "Select | All").
  9. From the Component Placement toolbar, select the ``Arrange selected components within defined area'' icon. (If you let the mouse pointer rest on any icon for a couple of seconds, a short line of text pops up explaining that icon.) Click in the PCB area 2 or more times to space out the components.
  10. [optional] Add a string to the Drill Drawing layer, with a caption of .LEGEND (this is a Special String), and preferably place this in the lower left hand corner of the Pcb file.
  11. [optional] Run a process to set the Comment field of each component within a Pcb file equal to its Footprint (string). Geoff Harland wrote a PcbAddon Server to do this.

There's several different things you can do at this point.

Q: Which footprint should I use ?

A: Unlike through-hole components, there is no One True Footprint for a SMT part.

My understanding is that IPC footprints are (were ?) optimized for (c) wave soldering, so many people use smaller footprints that work fine for their process (a) or (b).

There is a (free) online land pad calculator from IPC, http://www.ipc.org/html/fsresources.htm .

Bugs in the Protel footprint library (Have these been fixed already ?)

David A Cary of Motorguide Pinpoint Says: " points to a couple of CAD libraries "

Protel users FAQ

end http://massmind.org/techref/app/PWB_libraries.htm