Planar Ring Radiation Barrier for Cryogenic Wafer Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Testing of superconducting circuits at cryogenic temperatures is expensive and labor-intensive due to the need for individual die to be cooled in liquid helium, making it inefficient for high-volume throughput.
Innovation Solution
A cryogenic wafer test system with a radiation barrier that maintains a cryogenic temperature in one chamber while allowing translational and rotational motion of a wafer chuck through a thermally conductive radiation barrier with overlapping planar rings, preventing direct radiation heat transfer from a non-cryogenic chamber, thus enabling efficient testing of multiple superconducting die on a wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If individual superconducting die are cooled in liquid helium Dewars for testing, then the testing can be performed at cryogenic temperatures, but the process becomes time-consuming and helium-intensive, reducing throughput
Solution Approach 1:
The system segments the wafer into multiple individual die that can be tested separately on the wafer substrate, allowing parallel testing of multiple die simultaneously. The wafer chuck can hold and position multiple die on its surface, enabling batch processing rather than individual die testing in separate Dewars.
Solution Approach 2:
The system merges multiple individual die testing operations into a single integrated wafer-level testing platform. By combining multiple die on one wafer substrate and providing a unified cryogenic environment for the entire wafer, the system achieves parallel testing of multiple die without requiring separate cooling processes for each die.
2Temperature
If a radiation barrier is used to maintain cryogenic temperature in the first chamber, then thermal isolation from the non-cryogenic second chamber is achieved, but mechanical linkage motion through the barrier becomes complex
Solution Approach 1:
The radiation barrier incorporates movable elements that can dynamically adjust their position to accommodate the motion of the mechanical linkage. The barrier structure includes components that can translate or rotate along with the wafer chuck movement, maintaining thermal isolation while allowing mechanical motion through the barrier without requiring complex sealed transmission mechanisms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system significantly reduces testing time and helium consumption by allowing sequential testing of multiple superconducting die on a wafer, maintaining the cryogenic temperature while facilitating mechanical motion, thus enhancing efficiency and scalability.
Implementation Method 1
a radiation barrier arranged between the first chamber and the second chamber and through which the mechanical linkage extends, the radiation barrier being configured to provide a thermal gradient between the cryogenic temperature of the first chamber and the non-cryogenic temperature of the second chamber
Implementation Method 2
at least one of the overlapping planar rings of the radiation barrier is configured to slide along a next contiguous one of the overlapping planar rings in response to lateral motion of the mechanical linkage along a plane that is parallel with each of the overlapping planar rings of the radiation barrier
Data Source
AI summary
One example includes a cryogenic wafer test system. The system includes a first chamber that is cooled to a cryogenic temperature and a wafer chuck confined within the first chamber. The wafer chuck can be configured to accommodate a wafer device-under-test (DUT) comprising a plurality of superconducting die. The system also includes a second chamber that is held at a non-cryogenic temperature and which comprises a wafer chuck actuator system configured to provide at least one of translational and rotational motion of the wafer chuck via mechanical linkage interconnecting the wafer chuck and the wafer chuck actuator system. The system further includes a radiation barrier arranged between the first chamber and the second chamber and through which the mechanical linkage extends, the radiation barrier being configured to provide a thermal gradient between the cryogenic temperature of the first chamber and the non-cryogenic temperature of the second chamber.