A system includes: a heat sink module with a plurality of first through-holes linking its top and bottom surfaces and a plurality of grooves on the bottom surface, wherein each groove passes through a respective sequence of the first through-holes; and a driving circuit module with a plurality of conductive connectors and electrical driving surfaces that are disposed substantially perpendicular to the top and bottom surfaces of the heat sink module, wherein each conductive connector lies partially within a respective groove in the bottom surface of the heat sink module, the conductive connectors include internal connectors that each links at least two of the first through-holes in a respective sequence of first through-holes, and external connectors that each links at least one of the first through-holes in a respective sequence of first through-holes to an electrical driving surfaces of the driving circuit module.