A custom footprint is a footprint that you design - generally because it does not already exist in the footprint library. You can create your own custom footprints and add them to the library. For example, you might need a custom footprint for an exotic connector you plan to use.
You can create a custom footprint manually by creating pads, silk screen legends, etc.
You can create a new footprint based on an existing footprint.
You can create a footprint using a wizard for DIP, SIP, SO, BGA, QFP and Tabbed devices.
- Review the component manufacturer's drawing of the component, noting the relevant dimensions.
- On the left toolbar select the Footprint / Component tool. A dialog appears.
- Select the Composer tab.
- Choose an appropriate footprint type.
- Enter the footprint parameters and dimensions.
- Click "Place on board".
- To edit your footprint, follow "To create a custom footprint based on an existing footprint" above starting from the step 2.
- If your footprint is saved alone in a separate .pcb file, skip to step 10.
- Select your footprint and choose Edit | Copy.
- Choose File | New.... A dialog appears.
- Click OK.
- Choose Edit | Select | All.
- Choose Edit | Delete.
- Choose Edit | Paste.
- Choose File | Save and enter a meaningful name for your footprint file.
- Choose File | Close.
- In the left toolbar select the Footprint / Component tool. A dialog appears.
- Select the Footprints tab and Click Add...
- Select the file of your footprint.
- Enter a description for your footprint.
- Your footprint will appear under the My Footprints branch of the footprint tree.
You can edit a custom footprint you previously added to the library. For example, you might need to make a change after testing a first run of boards.
- Edit the original footprint file.
- In the left toolbar select the Footprint / Component tool.
- Click Update...
- Select the original file you edited.
- Enter a new description for your footprint and click OK.
You can propagate changes made to a footprint. For more information click here.