No.25(AUGUST 2006)

The use of connectors in automobiles and consumer appliances such as cellular phones and PCs has been increasing. In addition, connectors smaller than conventional ones are now required. Novel connectors have been actively developed by connector manufacturers in response to this trend. Meanwhile, higher strength and electrical conductivity are required for Cu-alloy strips as connector materials.
Against this background, we have improved a Corson alloy, HCL305, which is currently in mass production for lead-frame application, by equipping it with properties suitable for connector application. Additionally, we have developed HCL307, a Cu-alloy coil strip with still higher strength, using HCL305 as a base material. The developed material has high strength as well as excellent bending workability. We expect it will be widely utilized as a material to replace phosphor bronze and low-beryllium copper alloy.

GaAs compound semiconductors are widely used as optoelectronic and electronic devices. As these devices have made rapid progress, the uniformity, reproducibility and controllability of thickness and composition of the epitaxial layers have become more important than before. To improve these properties, we developed simulation techniques including a chemical model of deposition of a GaAs compound and applied it to the MOVPE (Metal Organic Vapor Phase Epitaxy) system. In the present paper, we report an example whereby the dispersion of layers is improved from ±1.6% to ±0.8% in our commercial MOVPE system.

We have developed a highly-precise micro/nano-processing technologies of synthetic quartz glass, through developing the planar lightwave circuit (PLC) device. The aim of the development is to apply the micro/nano-processing technologies for a new field, such as bio-technology and nano-technology. We have utilized micro/nano-processing technologies to fabricate bio-technology devices such as synthetic quartz glass type micro fluid devices and the same type of micro reactor devices, and nano-technology devices such as a synthetic quartz glass type mold for nano-imprint lithography. As a result, we achieved processing precision from a few nm to 10 nm.

In recent years, lightweight aluminum alloy conductor with high electrical conductivity characteristics is expected. Al-Fe-Zr alloy wire was developed industrially, although without having the tensile strength and elongation and spoiling electrical conductivity characteristics.

The coauthors have developed two kinds of 10GBASE-LX4 fiber-optic transceivers. These transceivers comply with the IEEE802.3 10GBASE-LX4 specifications [the only standard that allows existing MMFs (Multi Mode Fibers) and SMFs (Single mode Fibers) to transmit 10 Gbits of Ethernet signals per sec. over distance of up to 300 m and 10km respectively] and conform to the XENPAK and X2 form factors. The LX4 performs wavelength multiplexing at 3.125 gigabits per second x 4 by using four wavelengths near 1,310 nm, thus alleviating the effects of mode distribution delay peculiar to MMF and enabling the transmission of 10 gigabits of data per second. The recently developed models are: (1) the LX4-TOSA (Transmitter Optical Sub Assembly) that integrates four kinds of LDs (the keys to the LX4) with a multiplexer; and (2) the LX4-ROSA (Receiver Optical Sub Assembly) that integrates a wavelength separate filter with a 4-channel PD and a preamplifier. The small-sized X2 consumes as little as 4 W of power or less thanks to a metal die-cast case design based on a unique latch/release mechanism, and as a result of reviewing the LSI and other parts of the main circuit. The development of these LX4 optical transceivers meeting both form factors will hopefully accelerate the hitherto-pending upgrade of MMF networks from 1 gigabit to 10 gigabits.

Currently, electrical gas detectors are used to detect gas leaks in LNG-fired thermal power stations. The detector installation with the explosion proof for the power supply and its quarterly regular inspection and correction are considered as cost factors. To reduce the costs, a fiber optic gas detection system has been developed because its sensor heads do not need explosion protection and their maintenance is low. The system meets the Japanese Industrial Standards (error-less than ±25% of the pointing, response time-less than 30 seconds) and its stability under assumed environmental conditions for LNG pipelines is confirmed. Also, the mean time between failures of each of system part is investigated and the environmental tests such as dust resistance test, and damp and temperature tests were performed. The results show that the system is applicable to LNG pipelines with long inspection intervals.