What importing a component means in Altium

Importing a component in Altium Designer means bringing a part definition into your project so you can place it on a schematic or PCB layout. The component includes the symbol (what you draw on the schematic), the footprint (the physical shape on the circuit board), and the connection rules between them. Altium stores these as separate objects — you import the symbol and footprint independently, then link them together.

Most of the time you will not import a single component one at a time. Instead, you will either add components from Altium's built-in libraries, read a library file from a manufacturer or online source, or create your own component and save it to a library you can reuse. Understanding the difference between these routes saves you time and prevents the frustration of a component that looks right on the schematic but has no footprint for the board.

Key Takeaways

  • Components in Altium are made of two separate pieces — a schematic symbol and a PCB footprint — and both must be present before you can use the part.
  • The fastest way to get a component is to search Altium's built-in libraries or read a manufacturer library file rather than importing manually.
  • If you read a component library from a manufacturer or third-party source, you add it to Altium's library search path so the software can find it when you place parts.
  • Creating your own component and saving it to a custom library is the right choice if you use the same part repeatedly across multiple projects.

Adding components from Altium's built-in libraries

The easiest path is to use the libraries that come with Altium. Open the Libraries panel on the right side of the screen (or go to View > Panels > Libraries). Search for the part by name or part number — for example, typing "1N4148" will show you diode options. When you find the component you want, drag it onto your schematic. Altium automatically links the symbol to its footprint, so the component is ready to use.

This works well for common parts like resistors, capacitors, diodes, and standard ICs. For specialized or newer parts, the built-in libraries may not have what you need. That is when you move to downloading a library from the manufacturer or a third-party source.

Downloading and installing a manufacturer library

Many manufacturers — Texas Instruments, STMicroelectronics, NXP, and others — publish component libraries for Altium. Visit the manufacturer's website, find the part you need, and look for a read link labeled "Altium Library", "Component Library", or "Design Files". The file will usually be a .zip archive containing symbol files (.SchLib), footprint files (.PcbLib), and sometimes a 3D model file (.Step).

Extract the .zip file to a folder on your computer. Then tell Altium where to find it: go to Tools > Preferences > Data Management > Installed Libraries. Click "Install" and navigate to the folder where you extracted the files. Altium will scan the folder and add the libraries to your search path. Now when you open the Libraries panel and search for that part, it will appear in the results.

If the library file is a single .SchLib or .PcbLib file rather than a folder, you can open it directly in Altium by going to File > Open and selecting the file. This does not add it to your permanent library path, but it lets you browse the components and copy them into your project library if you want to keep them.

Creating and saving your own component library

If you use the same custom part across multiple projects — a connector with a specific pinout, a module you designed, or a part that does not exist in any public library — create a component once and save it to a library you control. In Altium, go to File > New > Library > Schematic Library to create a symbol file, and File > New > Library > PCB Library to create a footprint file. Draw the symbol or footprint, save each file with a clear name (for example, "MyConnectors.SchLib" and "MyConnectors.PcbLib"), and store them in a dedicated folder.

Add that folder to your Installed Libraries the same way you would a manufacturer library: Tools > Preferences > Data Management > Installed Libraries, then click Install and point to your folder. Now your custom components appear in the Libraries panel alongside the built-in ones. When you update the component — fix a pin label, adjust the footprint dimensions — the change is available in all your projects that use that library.

Linking a symbol to a footprint

A component is not complete until the symbol and footprint are linked. If you read a component from a manufacturer, this link is usually already set. If you create your own component or combine a symbol and footprint from different sources, you have to make the connection yourself.

In the schematic, right-click the component and select "Edit Component". In the dialog that opens, go to the "Models" tab. Under "PCB Models", click "Add" and select the footprint file and the specific footprint name from that file. Save the component. Now when you place this component on the schematic and run the PCB layout, Altium knows which footprint to use.

Troubleshooting components that do not appear

If you read a library and the components do not show up in the Libraries panel, the most common cause is that Altium is not looking in the right folder. Go to Tools > Preferences > Data Management > Installed Libraries and check that the path points to the correct location. If the path is wrong or the folder is missing, remove it and add the correct one.

Another common issue is that the library file itself is corrupted or in a format Altium does not recognize. If you downloaded a .zip file, make sure you extracted it completely — sometimes Windows shows the contents of a .zip without actually extracting it. If the library still does not work, try downloading it again from the manufacturer or source.

If a component appears in the Libraries panel but has no footprint, you will see an error when you try to place it on the PCB. Go back to the symbol, edit it, and add the footprint link as described in the section above.

When to import versus when to create

Import (or read) a component library when you need a part that already exists — a standard IC, a common connector, a resistor network. This is faster and more reliable than creating it yourself, because the manufacturer has already tested the symbol and footprint against the actual part.

Create your own component when you have a custom part, a part that does not exist in any public library, or a part you use so often that maintaining your own version saves time. The upfront work of drawing the symbol and footprint pays off after the second or third project.

Frequently Asked Questions

Can I use a symbol without a footprint?

You can place a symbol on the schematic without a footprint, but you cannot complete the PCB layout without one. Altium will flag the component as missing a footprint when you try to generate the layout. Add the footprint link before you move to the board design.

What if the manufacturer library is in a different format, like Eagle or KiCad?

Altium does not directly read Eagle or KiCad libraries. You have two options: search for an Altium version of the library from the manufacturer or a third-party source, or recreate the component in Altium yourself. Some manufacturers publish libraries in multiple formats; check their design resources page.

Do I need to install a library if I only use it once?

No. You can open a library file directly (File > Open) and copy the components you need into a project library. This is slower than installing the library, but it works if you only need a few parts from that source.

Can I edit a component after I import it?

Yes. Right-click the component in the Libraries panel and select "Edit Component". Any changes you make are saved to the library file and will appear in all future projects that use that library. Be careful not to break existing projects by changing a component they already use.

What happens if I delete a library after I have used it in a project?

The components you placed are still on the schematic and board, but Altium can no longer find the library definition. If you need to edit the component later, you will have to reinstall the library or recreate the component. It is safer to keep libraries you use in a permanent location.