This disclosure provides devices and methods for 3-D device packaging with backside interconnections. One or more device elements can be hermetically sealed from an ambient environment, such as by vacuum lamination and bonding. One or more via connections provide electrical interconnection from a device element to a back side of a device substrate, and provide electrical interconnection from the device substrate to external circuitry on the back side of the device. The external circuitry can include a printed circuit board or flex circuit. In some implementations, an electrically conductive pad is provided on the back side, which is electrically connected to at least one of the via connections. In some implementations, the one or more via connections are electrically connected to one or more electrical components or interconnections, such as a TFT or a routing line.