A robotic device can provide power management and other functionality for various electronic devices. An embodiment includes forming a plurality of contact pads on a substrate, each contact pad having sidewalls, forming a first photoresist over the substrate, and removing the first photoresist from the substrate thereby forming sidewall spacers along the sidewalls of the plurality of the contact pads. The present invention enables the center part of the fan blade to enwrap the insert part of the shaft, and firmly engage with the shaft. In a preferred embodiment, the sintered layer consists of silver powder. The valve includes a control piston that is movable at least to actuate a connection between the coolant circuit and the pump circuit. Consequently, the solder bump 15 is not interposed between opposed surfaces of the first connection terminal 13 and the second connection terminal 14, thereby allowing electrical connection by the solder bump 15 between the first connection terminal 13 and the second connection terminal 14 to be confirmed from the appearance by visual observation.