In some implementations, a substrate for coupling to an integrated circuit includes multiple layers. Each of the multiple layers has, in a particular region of the substrate, a repeating pattern of regions corresponding to power and ground. The multiple layers include (i) a top layer having, in the particular region, power contacts and ground contacts for coupling to an integrated circuit and (ii) a bottom layer having, in the particular region, power contacts and ground contacts for coupling to another device. At least one layer of the multiple layers has a repeating pattern of signal traces that extend along and are located between the regions corresponding to ground in the at least one layer.