A semiconductor chip assembly includes a semiconductor device, a heat spreader, a substrate and an adhesive. The semiconductor device is electrically connected to the substrate and thermally connected to the heat spreader. The heat spreader includes a post and a base. The post extends upwardly through an opening in the adhesive into an aperture in the substrate, and the base extends laterally from the post. The adhesive extends between the post and the substrate and between the base and the substrate. The substrate includes first and second conductive layers and a dielectric layer therebetween and provides horizontal signal routing between a pad and a terminal at the first conductive layer.