Fabbrica Italiana Magneti Marelli, S.p.a.

Giovanni Fidanzati

Gianfranco Cirri

A process for the fabrication of thermistors is described. Conductive wires are positioned in a spaced fashion and are aligned so as to intersect one another. The wires are maintained in the above alignment and placed into a reaction chamber or other suitable environment in which chemical vapor deposition of a semiconductor material by a pyrolysis technique is produced. The temperature of the reaction chamber is preferably just below the temperature level needed to produce the vapor deposition. Electric current is preferably passed through the conductors causing them to heat at the region of the intersections to a level sufficient to induce vapor deposition. The semiconductor material is caused to be deposited upon the conductors in the region of the intersection and is continued until the semiconductor material substantially completely surrounds both of the wires in the region of the intersection so as to mechanically and electrically join the wires. The growth is continued until the thermistor of the desired characteristics is developed. Thereafter, two adjacent leads are removed leaving the remaining two leads projecting from the semiconductor material for use in coupling the thermistor to electrical circuits. The process when completed substantially provides a thermistor device which is ready for use without the need for performing additional steps of providing electrical terminations. The nature of the process also lends itself advantageously for producing thermistors on a large mass production scale.

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Florence, Italy

Giovanni Fidanzati