A connection assembly includes a sensor substrate, a layer substrate coupled to the sensor substrate so as to face an upper surface of the sensor substrate, and a wire connected between the sensor substrate and the layer substrate. The sensor substrate includes first and second projections provide on the upper surface of the sensor substrate and extending in an extension direction along the upper surface of the sensor substrate. The wire has a first end sandwiched between the layer substrate and the first projection, and a second end sandwiched between the layer substrate and the second projection. The connection assembly provides reliable connection.