When you’re inside either of these libraries, you’ll be able to modify the footprints and schematic symbols if needed. Sometimes this is necessary, such as if you discover a footprint has an error and needs to be changed. In other cases, you may want to add in a new footprint or symbol to a library.
Now that you’ve created your PCB library for the project, go to the File → Save As… command from the top menu, and save the new library as MiniPC.PcbLib. If there is an existing library in the project folder, you can overwrite that file. You’ll use this new library in the next lesson to learn more about creating components.
Let’s review what we’ve done here by creating these libraries. When the project was originally created, it likely had component data brought in from multiple component libraries in the Components panel, from the Manufacturer Part Search panel, or from Altium 365. By creating these libraries, we’ve taken all of that data and placed it in one location.
Why do we need to do all of this? If you’re working as a professional designer, you will need to keep this data in one location for your customers or employer. When you send the schematics and PCB layout file to someone on your design team or to a customer, you want to make sure they can access and use all the project data. This means, whenever you deliver project files to someone, you should also deliver libraries for the project so that all the required component data can be accessed.
In other cases, you might request that another designer make modifications to an existing layout with new components. If you have libraries with the new component data, the designer can quickly add the new components into the design and make the modifications. The designer won’t need to manually create symbols and footprints, they can quickly use the existing data to place components in the design.
Mixing and Matching Symbols and Footprints
Suppose someone emails you a schematic sheet or a PCB file. You will always be able to open that file in your ECAD software and view any information for components in the file. However, you need the library that contains the component for:
Reusing one of the components in a different project
- Using the symbol or footprint to create a different component
Remember that a component will generally have a single symbol, but it could have different footprints. As an example, let’s look at the ADS1118 component from Texas Instruments. Go to Octopart and search for “ADS1118”. As you scroll through the list of results, you should see two entries for what appear to be different components: