Cryogenic Testing of Josephson Chips
Original Publication Date: 1981-Feb-01
Included in the Prior Art Database: 2005-Feb-10
In the testing of Josephson device chips, it is necessary to provide a contactor package which will work well at 4.2 degrees K. Such a package has to have minimal length contact paths and in conjunction avoid the problem of differential contraction between different materials. If undue contraction occurs, it will not be possible to align contacts to pads on the chip under test. It is also desirable to minimize stray magnetic fields at the chip since Josephson circuits depend upon magnetic fields for their switching properties. The package shown in Figs. 1 and 2 uses miniature contacts, a silicon space transformer, and a molybdenum alignment frame to solve these problems.