Hitoshi Yokono

Thick-Film Zirconia Air-Fuel Ratio Sensor with a Heater for Lean Mixture Control Systems

This paper describes the design and operation of a thick-film zirconia air-fuel ratio sensor with a heater. This sensor is composed of two zirconia plate cells, a stoichiometric cell and a lean cell, laminated on the platinum heater. It is fabricated as one body using a thick-film process. The pair of cells has a gas diffusion chamber and a slit type gas diffusion aperture. The sensing principle is based on the rate-determining diffusion of oxygen molecules at the gas diffusion aperture. By using an oxygen pumping phenomenon, air- fuel ratios of the stoichiometric and lean regions can be detected. As this sensor is heated to a high constant temperature, it has sufficient accuracy without any additional temperature compensation. Its starting time is short and response time is very quick.

Highly sensitive self developing electron-beam resist of aldehyde copolymer

SummaryThe copolymers of aliphatic aldehydes were prepared in toluene with diethylaluminum diphenylamide at −78°C. It was found that the copolymer was depolymerized into monomeric aldehydes on the exposure to electron-beam or X-ray. When the copolymer was used as an electron-beam resist, almost complete development was accomplished by exposure alone. No development step was required. The sensitivities of poly(ethanal-co-propanal), poly(ethanal-co-butanal), poly(ethanal-co-heptanal) and poly(ethanal-co-3-phenylpropanal) at the film thickness of 0.4∼0.7 μm were 8×10−7, 7×10−7, 1.7×10−6 and 6.5× 10−6 c/cm2, respectively. The copolymer acts also as an X-ray resist of high sensitivity.

New heat resistant “DP resin”

The cost of electrical equipments can be lowered by reducing the size and weight of the equipment. This has led to the need for the development of inexpensive heat resistant polymers having high mechanical strength at elevated temperatures.