Flexible Cryo-packages for Josephson Devices

Published

June 1, 2005

Author(s)

Charles J. Burroughs, Samuel Benz, Paul Dresselhaus, Yonuk Chong, Hirotake Yamamori

Abstract

We have developed a method of bonding superconductive integrated-circuit chips to interchangeable, microwave-compatible, flexible cryo-packages. This new 'flip-chip on flex' technology will greatly improve the service life and reliability of our Josephson systems because the present press-contacts to the chip are replaced with directly soldered connections. The new method eliminates the most common failure mode for our Josephson chips which has been the degradation and variation of the contact resistances of the chip pads due to mechanical wear upon repeated thermal cycles from 4K to room temperature. The superior microwave properties of this packaging provides improved operating margins for our devices. We have demonstrated the reliability of the bonds with repeated thermal cycling for 100% functional chips with 40 connections (67 410 Josephson junctions).

Citation

IEEE Transactions on Applied Superconductivity

Volume

15

Issue

2

Pub Type

Journals

Download Paper

Local Download

Keywords

Chip Bonding, Cryo-Packaging, Josephson Arrays, Josephson Voltage Standard

Citation

Burroughs, C. , Benz, S. , Dresselhaus, P. , Chong, Y. and Yamamori, H. (2005), Flexible Cryo-packages for Josephson Devices, IEEE Transactions on Applied Superconductivity, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=31828 (Accessed October 11, 2025)