US Patent 7285855 Packaged device and method of forming same

A method of packaging an integrated circuit die (12) includes the steps of loading an array of soft conductive balls into recesses formed in a platen and locating the platen in a first part of a mold cavity. A second part of the mold is pressed against the balls to flatten a surface of the balls. A first mold compound then is injected into the mold cavity such that the mold compound surrounds exposed portions of the balls. The balls are removed from the platen and a first side of an integrated circuit die is attached to the balls such that the die is surrounded by the balls. Die bonding pads on a second side of the die are electrically connected to respective ones of the balls surrounding the die, and then the die, the electrical connections, and a top portion of the conductive balls is encapsulated with a second mold compound. The result is an encapsulated IC having a bottom side with exposed balls.