A substrate for a solid state lighting module has a plurality of serrated finger sections extending from an interconnecting base. The substrate may be formed from a single rectangular sheet by cutting away material between adjacent finger sections of a symmetrical second substrate to form the finger sections of the substrate. Parallel linear rows of solid state light sources may be disposed along the length of each finger section. For example, the solid state light sources may be disposed proximate to points of sawteeth at the edges of the finger sections.