Abstract: When an operation knob 10 formed of silicone rubber is pushed laterally, a stem 7 tilts with a contact portion (i) as a fulcrum, a push button portion 6b is pushed, and a contact point in a switch mechanism portion 6a operates to turn on a switch circuit. Even if, by a large operating force F3 being applied, the operation knob 10 is extended and the inner surface portion 15, which is a ceiling surface of an internal space 13 of the operation knob 10, rides on an upper end portion 7c, a reinforcing surface 19 provided on the inner surface portion 15 slides on the upper end portion 7c, and the operation knob 10 returns to the initial shape.

Abstract: Provided is a cooler having high cooling efficiency and low pressure loss of fluid. A cooler includes: a flow-channel part at least including a plate-like fin (top plate) and a plate-like fin (bottom plate); and a continuous groove-like flow channel defined between the top plate and the bottom plate to flow fluid, the cooler being configured to cool semiconductor elements. When the flow-channel part is viewed from the direction parallel to the top plate and intersecting the flow channel, the flow channel has a corrugated shape so that a face of the flow channel closer to the top plate and a face of the flow channel closer to the bottom plate bend in a synchronized manner toward the top plate and the bottom plate.

Abstract: Provided is a cooler having high cooling efficiency and low pressure loss of fluid. A cooler includes: a flow-channel part at least including a plate-like fin (top plate) and a plate-like fin (bottom plate); and a continuous groove-like flow channel defined between the top plate and the bottom plate to flow fluid, the cooler being configured to cool semiconductor elements. When the flow-channel part is viewed from the direction parallel to the top plate and intersecting the flow channel, the flow channel has a corrugated shape so that a face of the flow channel closer to the top plate and a face of the flow channel closer to the bottom plate bend in a synchronized manner toward the top plate and the bottom plate.