Ultra thin package and fabrication method

A method includes forming a substrate layer, the substrate layer including a circuit pattern having terminals and bump pads. A stiffener is formed, the stiffener including via apertures having electrically conductive via aperture sidewalls and an electronic component opening. The stiffener is attached to the substrate layer. The electrically conductive via aperture sidewalls are electrically connected to the terminals. An electronic component is mounted to the bump pads and within the electronic component opening thus minimizing the height of the package. Further, the stiffener minimizing undesirable bending of the package and acts as an internal heat sink.