Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Flexible Cryo-packages for Josephson Devices



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


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).
IEEE Transactions on Applied Superconductivity


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


Burroughs, C. , Benz, S. , Dresselhaus, P. , Chong, Y. and Yamamori, H. (2005), Flexible Cryo-packages for Josephson Devices, IEEE Transactions on Applied Superconductivity, [online], (Accessed April 16, 2024)
Created May 31, 2005, Updated October 12, 2021