A spool for optical fiber ribbon or other flexible media has an opening communicating with an interior of the spool in which a first end of a helical guide is located. The operator motor is drivingly connected to a speed change transmission which is connected to the barrier. Each wafer has a wafer body, a number of signal contacts and a grounding bus. A plurality of wiring patterns are formed on the top surface of the resin-sealing layer such that each of the wiring patterns is allocated to a corresponding semiconductor device, and such that electrical connections are established between each of the wiring patterns and the tips of the metal bumps formed on the corresponding semiconductor device. During heating, the viscosities of the resins are reduced to cause the wavelength conversion material to migrate and deposit around the light emitting element. 1 \u03bcm or more and 4 \u03bcm or less, and a specific surface area of 400 m2g or more and 1000 m2g or less, the compound-A is a tertiary amine compound andor a urea compound, and the compound-A has a molecular weight of 150 or more and 550 or less.