US Patent 9269687 Packaging methods and packaged semiconductor devices

Packaging methods and packaged semiconductor devices are disclosed. In one embodiment, a packaging method includes providing a first die, partially packaging the first die, and forming a plurality of solder balls on a surface of the partially packaged first die. An epoxy flux is disposed over the plurality of solder balls. A second die is provided, and the second die is partially packaged. The plurality of solder balls is coupled to the partially packaged second die.