Light micrograph of tracks, power plane and pins in a multilayer printed circuit for the CPU socket, on the back side of a motherboard. There is a through-hole technology for vertical interconnected access. The tracks are orange colored. The socket tin contacts are very visible; they present the tip of the pins soldered onto the socket, and some are also connected with tracks from the printed circuit. The broad orange area is for the power plane earth connected. Field of view size: 4.3 x 6.4 mm (0.17 x 0.25 in)