A leadframe design for a diode or other semiconductor device that reduces stress on the device and provides increased heat dissipation is provided. According to various embodiments, the leadframe has a contoured profile including a recessed area and a raised surface within the recessed area. The surface supports the device such that the edges of the device extend past the surface. Also provided are device assemblies including the novel leadframes. In certain embodiments, the assemblies include one or more leadframes attached via a solder joint to a device. According to various embodiments, the leadframes are attached to the front side of the device, back side of the device or both. In particular embodiments, the device is a bypass diode for one or more solar cells in a solar module.