Tested per JEDEC JESD51, natural convection. The definitions of high-k and low-k are per JESD 51-7 and JESD 51-3. Modified low-k (2 signal - no plane, 3 in. by 3 in. board, 0.062 in. thick, 1 oz. copper) test board with the pad soldered, and an additional 0.12 in.2 of top-side copper added to the pad. Modified high-k is a (2 signal – 2 plane) test board with the pad soldered. The best case thermal resistance is obtained using the recommendations per SLMA002 (2 signal - 2 plane with the pad connected to the plane).