Thermal-Expansion-Matched Probe Card Interposer for Wafer Contact
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Solution Overview
Problem
The challenge of achieving known-good-die (KGD) testing for advanced SiPs with ultrafine pitches and ultrahigh-I/O, particularly in wafer-level components, is exacerbated by the limitations of existing probe cards in ensuring uniform and consistent contact at sub-40 μm pitches, leading to yield and reliability issues in high-end applications like HPC and AI.
Innovation Solution
A probe card system utilizing a reusable interposer with closely matched thermal expansion coefficients to silicon, employing adhesion or direct bonding forces for uniform contact across the wafer, combined with a sacrificial layer for probe tip removal and reusability, enabling full-wafer probing at sub-10 μm pitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional probe cards are used for sub-40 μm pitch testing, then existing testing capability is maintained, but uniform and consistent contact cannot be achieved leading to yield and reliability issues
Solution Approach 1:
The patent changes the material parameter of the interposer from conventional materials to silicon or silicon-like materials with specific thermal expansion coefficients (2-10 ppm/°C) that closely match silicon wafers. This parameter change enables thermal expansion-matched bonding that maintains precise probe tip-to-pad alignment across the full wafer surface during temperature variations, resolving the contradiction between alignment accuracy and testing consistency.
Solution Approach 2:
The patent employs composite material structures including silicon interposers bonded to probe card substrates, creating a hybrid system that combines the dimensional stability of silicon with the electrical and mechanical properties of probe card materials. This composite approach enables both high precision alignment and reliable consistent contact across ultrahigh-I/O configurations.
2Productivity
If full-wafer probing at sub-10 μm pitches is implemented, then testing capability for advanced ICs is enabled, but probe tip damage and contact consistency become critical issues
Solution Approach 1:
The patent changes the thermal expansion parameter of the interposer material to match silicon wafers within 2-10 ppm/°C, which prevents differential thermal expansion during testing. This parameter change reduces mechanical stress on probe tips during contact with sub-10 μm pitch structures, preventing probe tip damage while maintaining high test efficiency across full wafers.
Solution Approach 2:
The silicon interposer acts as an intermediary between the probe card substrate and the silicon wafer under test. This intermediary layer with matched thermal expansion properties mediates the mechanical and thermal interactions, protecting probe tips from damage while enabling consistent contact across ultrahigh-I/O configurations at sub-10 μm pitches.
3Measurement precision
If reusable interposers with thermal expansion matching are used, then probe tip alignment accuracy is improved, but device complexity increases
Solution Approach 1:
The patent changes the material composition parameter of the interposer to silicon or silicon-like materials with specifically controlled thermal expansion coefficients (2-10 ppm/°C). This parameter change provides inherent thermal compensation that maintains alignment accuracy without requiring complex active control mechanisms, thus improving measurement precision while limiting the increase in device complexity to material selection rather than structural complexity.
4Reliability
If adhesion or direct bonding forces are employed for uniform contact, then contact consistency is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent changes the bonding interface parameters by using silicon-silicon direct bonding or adhesion bonding with controlled surface preparation and bonding conditions. This parameter change enables uniform contact across the full wafer surface through material property optimization rather than complex bonding process equipment, improving contact consistency while managing manufacturing process complexity through material science approaches.
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
Enables reliable, high-yield testing of advanced ICs and SiPs by ensuring precise alignment and consistent contact of probe tips with micro-bumps or metal pads, reducing damage and improving test efficiency and cost-effectiveness.
Implementation Method 1
The sacrificial layer allows removal of the bonding layer and the plurality of probe tips via an etching operation
Implementation Method 2
employing adhesion or direct bonding forces for uniform contact across the wafer
Implementation Method 3
employing adhesion or direct bonding forces for uniform contact across the wafer
Implementation Method 4
A probe card system utilizing a reusable interposer with closely matched thermal expansion coefficients to silicon
Data Source
AI summary
A probe card system is provided. The probe card system, including a tester assembly, a probe head body configured to couple with the tester assembly, a first interconnection structure on a first side of the probe head body, and a probe layer structure on the first interconnection structure on the first side of the probe head body which is configured to engage with a wafer under test (WUT). The probe layer structure includes a sacrificial layer in connection with the first interconnection structure, a bonding layer in connection with the sacrificial layer, and a plurality of probe tips each in connection with respective conductive patterns exposed from the bonding layer and electrically coupled to the first interconnection structure. The sacrificial layer allows removal of the bonding layer and the plurality of probe tips via an etching operation. A method of manufacturing a probe card system is also provided.