Is expiation for breaking a fast only needed when it is done because of intercourse?
Or is it necessary for any action that invalidates fast?

I also have a question about kaffarah for breaking an oath.
I think (not sure) I have falsely swore sometime in the past, But at that time I didn't know that it was haram or if there was even any expiation for it. Is it still obligatory for me to do the kaffarah for breaking an oath (fasting 3 consecutive days)?