Publication Date

1988

Document Type

Dissertation/Thesis

First Advisor

Genis, Alan P.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Technology

LCSH

Thick films; Resistance furnaces; Electronic industries; Thermistors

Abstract

The United States' electronic industry continues to look for better methods to control processes in order to improve yields and reduce costs. One area of concern in the thick film portion of the industry is the question of what effect the standard resistor printing and firing variables have on the negative Beta thick film thermistor. This study is an analysis of the effects on resistance and Beta with common variations in firing furnace characteristics. The changes in firing furnace characteristics which would commonly vary during day-to-day operations are the peak temperature and the volume of air flow. In addition, the time at peak temperature and the effects of palladium silver versus gold for use as a terminating conductor were also studied. A total of seven thermistor pastes ranging in value from 1000 ohms to 6000 ohms and from -350 to -2600 Beta were studied under the different conditions. The study attempted to control all other possible parameters, such as printed thickness variations, to reasonable, but not perfect, conditions. This permitted the study to take on the appearance of actual production conditions rather than looking like a laboratory experiment. Once samples had been printed under these conditions, sets were processed under the five different furnace variables to be studied. The fired parts were then measured for resistance and Beta was calculated. The results were summarized in tabular form and statistical comparisons were made. The study concluded that most of the pastes tested were relatively unaffected by the realistic changes that occur in furnace peak temperature and air flow on a daily basis. Changes in time at peak temperature, specifically changing from a 30-minute profile to a 60-minute profile did not significantly change the Beta but did cause a large increase in resistance which is undesirable. The comparison of palladium silver to gold for termination also showed no significant changes. The study showed that standard furnace parameters and the use of either conductor for termination were acceptable in daily operations without loss of control of the thermistor.

Comments

Bibliography: leaf [70]

Extent

vii, 74 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

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Text

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