IC Probing Assembly Compliance via Flexible Trace Support
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Solution Overview
Problem
Conventional probing assemblies for testing integrated circuits on wafers face challenges due to the high forces required to maintain compliance, which shorten the service life of the membrane assembly.
Innovation Solution
A probing assembly comprising an interface board, a structural support element, a trace support element with flexible conductive trace lines, and a probe support element with micro probes, where the structural support element provides mechanical stability and the trace support element's compliance allows for independent adjustment of the gram force applied by the micro probes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If more forces are exerted on the membrane assembly to maintain good compliance, then the compliance is improved, but the service life of the membrane assembly is shortened
Solution Approach 1:
The probing assembly is divided into separate functional components: a probe support element holding multiple contacts, a trace support element with conductive traces, and a structural support element. This segmentation allows each component to be optimized independently, with the trace support element providing compliance through its trace geometry rather than requiring excessive force on a membrane assembly.
Solution Approach 2:
The invention changes the compliance mechanism from force-dependent membrane deflection to geometry-dependent trace flexibility. The conductive traces are designed with specific patterns and dimensions that provide inherent compliance, allowing the system to maintain good electrical contact without exerting excessive forces that would shorten service life.
2Adaptability or versatility
If the wafer is moved in X, Y and Z directions to achieve consecutive engagement with bond pads, then the testing coverage is improved, but the complexity of the probing system increases
Solution Approach 1:
The probing assembly incorporates dynamic elements including the flexible trace support element that can deflect to accommodate wafer position variations, and the mechanism for moving the wafer or probe head in X, Y, and Z directions. This dynamic capability enables consecutive engagement with multiple bond pads while maintaining reliable electrical contact through the compliant trace design.
Solution Approach 2:
The trace support element acts as an intermediary between the rigid structural support element and the contacts. It provides a compliant interface that accommodates position variations during wafer movement, enabling testing coverage across multiple bond pads without requiring the entire probing system to be overly complex.
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
The solution extends the service life of the probing assembly by reducing the need for excessive force, enabling efficient and precise testing of integrated circuits while maintaining compliance and adjusting the gram force applied to the micro probes.
Implementation Method 1
The compliance of the elastomeric layer enables relative displacement of the respective contact bumps and facilitates simultaneous engagement with multiple bond pads that may have respective contact surfaces that lie in different planes
Implementation Method 2
The resilience of an elastomeric layer of the membrane assembly controls the force exerted by the contacts and returns the contacts to the at-rest position when the probe is withdrawn from pressing engagement with the DUT
Data Source
AI summary
A probing assembly is disclosed. The probing assembly includes an interface board, a structural support element, a trace support element and a probe support element. The structural support element provides structural and mechanical support to the trace support element. The trace support element includes a body and multiple trace lines located on the body. The probe support element includes a plate having multiple guide holes in which micro probes are inserted. At least one of the micro pins is in contact with one of the trace lines within the trace support element. A set of rails are utilized to secure the probe support element, the trace support element and the structural support element to the interface board.