A manufacturing method of a package-on-package structure includes at least the following steps. A plurality of conductive bumps of a first package is attached to a tape carrier. A second package is coupled to the first package opposite to the plurality of conductive bumps. When coupling the second package, the plurality of conductive bumps are deformed to form a plurality of deformed conductive bumps, and a contact area between the tape carrier and the respective deformed conductive bump increases.