In some implementations, the sensor board 1108 includes a connector 1108A that is coupled to another connector of the main board 1110 directly. Alternatively, a flexible cable is optionally connected to the connector 1108A for electrically coupling the main board 1110 to the sensor board 1108. In some implementations, two ends of a flexible printed circuit FPC 1126 are electrically coupled to a respective connector at the main board 1110 and the secondary board to couple them to each other. The sensor board 1108 optionally sits on a rear interior surface of the device housing 702. An image sensor array 1114 may be disposed on top of an end of the sensor board 1108, and the lens assembly 704 may be further disposed on top of the image sensor array 1114, such that light passing through the lens assembly 704 arrives at the image sensor array 1114 to form an image captured by the image sensor array 1114. In some implementations, the sensor board 1108 includes an image processor. The image processor of the sensor board 1108 is optionally located directly below the image sensor array 1114 to facilitate further processing of the image captured by the image sensor array 1114. In some implementations, the sensor board 1108 also includes a connector for communicatively coupling the sensor board 1108 to the image sensor array 1114. In some implementations, the image sensor array 1114 and/or the image processor of the sensor board 1108 is thermally coupled to a heat spreader 1138 that is disposed under the image sensor array 1114 and configured for dissipating heat generated while images are being captured and processed. The sensor board 1108 may include one or more of a power supply connector 11082, an AC DC converter 11084, a voltage regulator 11086 and a power unit 11088. The power supply connector 11082 is electrically coupled to the plurality of wire terminals 720, and configured to receive an external power supply.