Browse Prior Art Database

Superconducting MLC Module for Josephson Devices

IP.com Disclosure Number: IPCOM000044542D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Kaiser, HD: AUTHOR [+2]

Abstract

Disclosed is a process of forming a multilayer glass ceramic (MLC) substrate having superconducting interconnecting wiring therein. The substrate is formed by simultaneous in-situ firing of the glass-ceramic material and the components of the superconducting compound. Thin laminated green sheets are first prepared by a conventional doctor-blading technique using a crystallizable cordierite-type glass having the following illustrative composition, by weight percent: MgO - 20%, SiO2 - 55%, Al2O3 - 21.23%, P2O5 - 2.77% and B2O5 - 1.0%. The superconductive wiring can be formed using an A-15 type compound, such as Nb3Sn.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 93% of the total text.

Page 1 of 1

Superconducting MLC Module for Josephson Devices

Disclosed is a process of forming a multilayer glass ceramic (MLC) substrate having superconducting interconnecting wiring therein. The substrate is formed by simultaneous in-situ firing of the glass-ceramic material and the components of the superconducting compound. Thin laminated green sheets are first prepared by a conventional doctor-blading technique using a crystallizable cordierite-type glass having the following illustrative composition, by weight percent: MgO - 20%, SiO2 - 55%, Al2O3 - 21.23%, P2O5 - 2.77% and B2O5 - 1.0%. The superconductive wiring can be formed using an A-15 type compound, such as Nb3Sn. To form Nb3Sn wiring, a paste which is suitable for screening, is prepared using finely divided niobium and tin powders (in the weight ratio of Nb to Sn of 3 to
1) in combination with an appropriate organic screening vehicle.

Using the paste, the required interconnecting wiring pattern is screen printed on individual green sheets. The green sheets are then laminated together into a MLC substrate and subjected to a firing cycle, in a neutral or reducing atmosphere, reaching a temperature of up to about 965OEC. The glass-ceramic composition begins to sinter at about 600OEC with final recrystallization occurring at 965OEC. At the crystallization temperature, the Nb and Sn particles diffuse and react, forming the Nb3Sn intermetallic. The glass on recrystallization has a dielectric constant of about 5 and a ...