An improved solid image-pickup device is so formed that its semiconductor device has on its surface an image-pickup area having a plurality of light sensors arranged thereon. A plurality of bonding pads are formed on the surface of the semiconductor device and arranged around the image-pickup area. A plurality of through holes are formed through the semiconductor substrate, extending from the lower surfaces of the bonding pads to the back surface of the semiconductor substrate and each of the through holes is filled with an electrically conductive material, thereby effecting an electric connection between the bonding pads and the copper wire of the flexible circuit substrate bonded to the back surface of the semiconductor substrate.