Japan Aviation Electronics Industry, Limited

Nippon Telegraph and Telephone Corporation

Senju Metal Industry Co., Ltd.

Kokusai Denshin Denwa Co., Ltd.

Masato Shimamura

Hiroyuki Sasaki

Juichi Noda

Yoshiaki Takeuchi

Hiroaki Hanafusa

Shuichi Aihara

Mitsuru Koike

Takeo Kaharu

Yuzo Kohsaka

Kousuke Maezawa

Masayuki A Suzuki

Ryoichi Suzuki

Yoshihiro Yoshida

Shunsaku Yoshikawa

Tsukasa Ohnishi

Toshihiko Taguchi

Ken Tachibana

Yoshie Yamanaka

Kazuyori Takagi

Seiko Ishibashi

Yoshinori Namihira

Toru Hayashida

Tomoko Nonaka

Satoru Akita

Tetsuya Okuno

Mitsuhiro Kosai

Takayuki Hori

By using a solder alloy consisting essentially of 0.2-1.2 mass % of Ag, 0.6-0.9 mass % of Cu, 1.2-3.0 mass % of Bi, 0.02-1.0 mass % of Sb, 0.01-2.0 mass % of In, and a remainder of Sn, it is possible to obtain portable devices having excellent resistance to drop impact and excellent heat cycle properties without developing thermal fatigue even when used in a high-temperature environment such as inside a vehicle heated by the sun or in a low-temperature environment such as outdoors in snowy weather.

Lead-free solder alloy

Even if the strength of a solder composition close to a SnBi eutectic composition was improved, it was brittle, so when it was used for small electronic devices such as mobile phones or notebook computers, the resistance to drop impacts when the small electronic equipment was dropped was low. Therefore, interface peeling often took place between the soldered surface and a printed circuit board, resulting in the devices being destroyed. As disclosed, when soldering using a solder paste containing a SnBi-based low-temperature solder, at least one type of solder composition selected from a Sn&#x2014;Ag, a Sn&#x2014;Cu, and a Sn&#x2014;Ag&#x2014;Cu solder composition is diffused into the solder paste by simultaneously supplying at least one type of preform selected from a Sn&#x2014;Ag, a Sn&#x2014;Cu, and a Sn&#x2014;Ag&#x2014;Cu solder composition, whereby resistance to drop impacts is improved.

Soldering method using a low-temperature solder paste

A lead-free solder paste suitable for reflow soldering includes a plurality of different types of metal powder mixed with a flux. One of the metal powders is a Sn alloy powder. Another of the metal powders is selected from a Sn alloy powder, elemental Ag powder, elemental Cu powder, and elemental Sn powder. Each Sn alloy powder includes 0-8 mass % of Ag, 0-5 mass % of Cu, and at least 80 mass % of Sn. The plurality of metal powders have a composition when melted of 1-5 mass % Ag, 0.5-3 mass % Cu, and a remainder of Sn.

Lead-free solder paste for reflow soldering

In each terminal connected to an optical bus a narrow pulse synchronized with the rise of a pre-synchronizing pulse appended to the head of the one digital signal TXN of Manchester-biphase signals, a narrow pulse synchronized with the rise of each pulse of the other Manchester-biphase digital signal TXO and a narrow pulse occurring every fixed period of time during the duration of each pulse are produced, and these narrow pulses are converted into optical signals, which are provided as an optical pulse train to the optical bus. In each terminal optical pulses received from the optical bus are converted into an electric signal, which is separated into its leading pulse and the subsequent pulses, a synchronizing pulse is produced in synchronization with the leading pulse, the subsequent pulses are each converted into a pulse of a fixed width to regenerate the signal TXO, and the regenerated signal TXO is polarity inverted and then combined with the pre-synchronizing pulse to regenerate the signal TXN.

Optical bus transmission method and transmitting-side encoder and

In an optical fiber coupler there is provided, in an optical coupling portion between cores of two partly fused together and extended optical fiber, an optical coupling control portion which has a refractive index different from those of claddings covering the cores.

Optical fiber coupler and its manufacturing Method

In each terminal connected to an optical bus a narrow pulse synchronized with the rise of a pre-synchronizing pulse appended to the head of the one digital signal TXN of Manchester-biphase signals, a narrow pulse synchronized with the rise of each pulse of the other Manchester-biphase digital signal TXO and a narrow pulse occurring every fixed period of time during the duration of each pulse are produced, and these narrow pulses are converted into optical signals, which are provided as an optical pulse train to the optical bus. In each terminal optical pulses received from the optical bus are converted into an electric signal, which is separated into its leading pulse and the subsequent pulses, and the synchronizing pulse is produced in synchronization with the leading pulse and the subsequent pulses are each converted into a pulse of a fixed width to regenerate the signal TXO, and the regenerated signal TXO is polarity inverted and is then combined with the pre-synchronizing pulse to regenerate the signal TXN.

Two single mode optical fibers are reduced in diameter over a predetermined length to form reduced-diameter portions whose center portions have different diameters. The two optical fibers are intersected at a small angle to each other substantially centrally of their reduced-diameter portions and then are fused together at the intersecting portions and the fused portions of the two optical fibers are heated and stretched to provide an optical coupler having a desired coupling ratio.

Wide-band optical fiber coupler and its manufacturing method

Two single mode optical fibers are stretched to form prestretched portions of different diameters, and then the optical fibers are fused together at their prestretched portions to form a coupling region which is stretched to obtain a wide-band optical fiber coupler of a desired splitting ratio.

In a method of making an optical fiber coupler through heat elongation of optical fibers, the performance of the coupled optical fibers is measured after the optical fibers are heat elongated at least once, and based on the measured elongation length and the performance of the coupled optical fibers, a functional equation representing their relationship is determined by approximate calculation. The functional equation is used to calculate an elongation length which provides the intended performance of the coupled optical fibers, and then the optical fibers are heat elongated to the calculated length.

Method for the manufacture of an optical fiber coupler

Growing community of inventors

Tokyo, Japan

Masato Shimamura