Abstract: The invention relates to joining of fine wires, and more particularly to a wire bonding method suitable for connecting a number of wires within a narrow area. A first wire is bonded on a pad, and a second wire is bonded on the position where the first wire has been bonded. Bonding of a subsequent wire is performed in that the wire is stacked and bonded in similar manner mentioned above. Thus a plurality of repair wires can be bonded within one pad even if the pad area is very small.

Abstract: A bundle of optical fibers is disclosed in which optical fibers each provided with a cladding layer are stacked tier upon tier in a close-packed hexagonal structure and the ratio of a radius of the core of each optical fiber to a radius of the optical fiber including the cladding layer ranges from 0.55 to 0.65.

Abstract: When a composite material comprising a nylon non-woven fabric as a substrate and a paper material for cleaning a magnetic tape which has been stuck onto one surface or both surfaces of said nylon non-woven fabric is used as a ribbon used in a tape cleaning device for cleaning a magnetic tape and/or for cleaning a magnetic converter or a magnetic head for sending a magnetic tape, a decrease in a reproduction output due to static charge can be prevented, the generation of dust and the damage of the tape can be decreased, and a cleaning effect for the magnetic tape and/or the magnetic head can be improved.