Oki Electric Industry Co., Ltd.

Nippon Telegraph and Telephone Corporation

Jiro Utsunomiya

Kiyoshi Kurosawa

Ryo Nagase

Masao Kawachi

Akira Himeno

Kuniharu Kato

Hajime Hotta

Hisao Matsukura

Akio Hirakawa

Masaki Sugawara

Yasuhiko Kudou

Iida Saburo

Toshiyuki Kawashima

Ken-ichi Yukimatsu

Masayuki Okyno

Composite units of an optical semiconductor device and a supporting substrate are disclosed, in which the rear surface of the optical semiconductor device is provided with one or more electrode patterns and the top surface of the supporting substrate is provided with one or more electrode patterns. The optical semiconductor device and the supporting substrate are fixed to each other by once melting and solidifying one or more solder bumps which intervene between the one or more electrode patterns provided on the rear surface of the optical semiconductor device and the one or more electrode patterns provided on the top surface of the supporting substrate. A good grade of accuracy in the mutual geometric position of the optical semiconductor device and the supporting substrate is obtained in a horizontal direction due to a phenomenon called 'the self alignment results' in this specification, in which a molten metal is inclined to become a ball based on surface tension. Methods for mounting an optical semiconductor device on a supporting substrate with a good grade of accuracy in the mutual geometric position therebetween in the horizontal direction, based on the same technical principle, are also disclosed. To realize the foregoing results, each of the composite units of an optical semiconductor device and supporting substrate in accordance with this invention is given various structures specific to each of them, and each of the methods in accordance with this invention is given various steps or processes specific to each of them.

Composite unit of optical semiconductor device and supporting substrate

An optical switching module has an optical waveguide substrate mounted on an electronic circuit substrate. According to a first aspect of the invention, the optical waveguide substrate has thin-film heaters, and the electronic circuit substrate has trimmable thick-film resistors for adjusting current fed to the thin-film heaters. According to a second aspect of the invention, the optical switching module also has a pair of fiber pigtails butt-coupled to the optical waveguide substrate. The fiber pigtails are secured to the ends of a supporter, which is attached to a heat sink fastened below the electronic circuit substrate. According to a third aspect of the invention, the optical waveguide substrate is mounted in a depression in the electronic circuit substrate. The invention reduces the size of the optical switching module.

Compact optical switching module including thin-film heaters and trimmed

Growing community of inventors

Tokyo, Japan

Jiro Utsunomiya