Fujitsu Corporation

Kaoru Sugimoto

Takashi Kanda

Yasutomo Maehara

Hitoshi Suzuki

Takashi Nakagawa

Kishio Yokouchi

Shigenori Aoki

Alexei L Glebov

Kenji Fukuzono

Katsuhiko Kobayashi

Kenji Iida

Hiroshi Nagaeda

Kiyotaka Seyama

Hiroaki Date

Tomohisa Yagi

Kazuya Arai

Kenji Takano

Junichi Kanai

Souichi Obata

Seiichi Sugano

Munekazu Shibata

A coupon board is cut out together with a printed wiring board from a sheet material in which a solder resist film is formed on a surface of a glass cloth fiber. The coupon board is for evaluating characteristics of the printed wiring board. The coupon board includes a region on which the solder resist film is not formed, and which extends parallel with one side of the printed wiring board.

Coupon board and manufacturing method of printed board

A process for producing a multilayer board includes the steps of applying a bonding ink to the terminal of the first substrate, the bonding ink including a thermosetting resin containing a filler and a curing agent, the filler being formed of metal particles plated with solder, the metal particles each having a first melting point, and the solder having a second melting point lower than the first melting point; bonding the second substrate to a bonding sheet composed of a thermosetting resin and having a through hole disposed in a portion corresponding to the terminal of the second substrate; and heating and pressurizing the first and second substrates with the bonding sheet in such a manner that the terminals are opposite each other to effect curing of the bonding sheet and the bonding ink and to form an integral structure.

Process for producing multilayer board

A process for producing a circuit board includes the steps of etching the third metal layer of a three-layer metal laminate into a predetermined interconnection pattern by photolithography; forming a laminate on the interconnection pattern by a buildup method, the laminate including interconnection patterns with insulating layers provided therebetween, the interconnection patterns being electrically connected to each other; separating a first metal layer from a supporting substrate to detach the laminate; removing the first metal layer of the three-layer metal laminate by etching using a second metal layer as a barrier layer; and removing the exposed second metal layer by etching.

Process for producing circuit board

The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having a cladding that includes an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The VOA also includes a layer that is parallel to the core of the waveguide and that optically couples to the core to receive light from the attenuated signal. A power meter receives light from the layer as an indication of the amount of light attenuated from the signal and for controlling the voltage to the electrodes.

Variable optical attenuator having a waveguide and an optically coupled layer with a power monitor

It is an object of the present invention to enhance laser beam transmitting efficiency by accurately controlling an interval between a light emitting (light receiving) element () and an optical wave-guide substrate () without causing any fluctuation in the interval in a mounting structure of the light transmitting element in which the light emitting (light receiving) element () is mounted on the optical wave-guide substrate (). When the light emitting (light receiving) element is joined to the sub-mount chip () and when the sub-mount chip () is joined to the optical wave-guide while the element is being directed to the substrate side, the sub-mount chip and the optical wave-guide substrate are joined to each other by the solder bump (). A post () is arranged for regulating an interval between the light emitting (light receiving) element and the optical wave-guide substrate.

Printed board unit for optical transmission and mounting method

Growing community of inventors

Kawasaki, Japan

Kaoru Sugimoto