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Polycrystalline Semiconductor Power Diodes

IP.com Disclosure Number: IPCOM000095594D
Original Publication Date: 1964-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Delaney, RA: AUTHOR [+2]

Abstract

This diode employs polycrystalline material to perform electrical rectification. The diode is easily fabricated and is insensitive to environmental variations.

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Polycrystalline Semiconductor Power Diodes

This diode employs polycrystalline material to perform electrical rectification. The diode is easily fabricated and is insensitive to environmental variations.

A fabrication cycle for these diodes is as follows. Ceramic substrate 20 receives metal electrode 22, typically a platinum-gold paste silk screened on the substrate and fired at 800 degrees C for approximately one-half an hour. Zinc oxide is pulverized and doped with a metal oxide having a valence of 2 or 3, typically 3-5% bismuth trioxide or 2-1/4% lead oxide. The doped zinc oxide is made into a slurry and coated over electrode 22 by a screening technique. The sample is fired at 1000 degrees C for fifteen minutes followed by quenching on a cold aluminum plate. Thus, dielectric 24 is formed.

A second layer 26 of dielectric corresponding to dielectric 24 is screened on the sample. The sample is fired at 1000 degrees C for thirty minutes and quenched as previously indicated. A top metal electrode 28 is screened on the dielectric 26 in a manner corresponding to that described for the electrode 22 fired at 1000 degrees C for fifteen minutes and quenched. The electrode 28 may be of the same metal as the electrode 22 or a metal different from the electrode
22. When the top electrode 28 is of a different metal, a lead-tin solder is satisfactory.

The dielectric serves as a semiconductor medium separating metals of different work functions. As a rectifying element, the dio...