# Designators in Altium PCB Libraries

I've noticed that some Altium PCB Libraries contain a designator in a Text field using the .Designator parameter. I've duplicated this in my own libraries, however if I attempt to place a component on the PCB, I have two designators displayed (the default, and the one I added to the library). Is there something I'm missing?

The reason why I ask is I've been working on using some smaller components lately, and the default designator is too large. At the very least this would save me some time in the Inspector.

Any ideas?

• Not at work to try this, but maybe check "hide designator" in the properties dialog for the component (in the library), then add your own ".Designator" where you want it. – The Photon Feb 25 '17 at 18:46

As far as I know you can't do anything about this in the library, but in the PCB layout, you can open the properties for the component and select the 'Hide' option under the Designator section. That is the default designator properties. Any additional string you add in the PCB library with .Designator as the text will appear as and where you place it in the PCB footprint, even multiples.

• Thanks! Out of curiosity, how common is embedding designators in the PCB library? I'm fairly new to AD, so this seems a bit strange compared to other CAD packages like OrCad or EAGLE. – Steven Stallion Feb 26 '17 at 2:02
• Can't speak for everyone, but I don't use it and none of the other engineers I've worked with do either. I use the defaults and when the all the parts are on the PCB, I select all the designators in the PCB List, and change them all there. This usually means just changing the text height and line width to something appropriate for the density of the board (sometimes making the connector designators larger than the other components), but I have also changed the font from Stroke to TrueType to make them look nicer. Caution - that slows Altium down a bit if you have a lot of components. – AngeloQ Feb 26 '17 at 3:26
• I could see this might be useful if you really wanted your designator for a certain part to be positioned or look a certain way, I just have never had the need for that. Typically you have to move those around anyway after the placement is done. – AngeloQ Feb 26 '17 at 3:29
• Not common, it will add one for you. – Joel Wigton Feb 27 '17 at 4:43

There is a use for two designators - one for silkscreen and one for assembly.

Have a read of PCB Design Perfection Starts in the CAD Library – Part 16.

It's a good description - as are a lot of the blogs by Tom.

• Link only answer? It's best to include the info from the link – Greenonline Apr 30 '19 at 4:17
• Fantastic link, thank you. – BenYL May 6 '19 at 17:22