Dynamic Probe Tip Misalignment Compensation for IC Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional methods for inspecting integrated circuits (ICs) require repeated manual alignment of probe tips with wafer pads at different temperatures, making reliability testing time-consuming due to the need for manual re-alignment at each temperature step.
Innovation Solution
A method and system that dynamically compensates for probe tip misalignment by recording and adjusting probe tip positions in real-time, allowing the wafer to remain in the handler while automatically correcting for thermal changes, ensuring accurate contact with wafer pads across varying temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual alignment is repeated at each temperature step, then alignment accuracy is maintained, but testing time increases significantly
Solution Approach 1:
The system performs preliminary alignment at a reference temperature and records the probe card position. This preliminary alignment data is then used to calculate and apply compensation for subsequent temperature steps, eliminating the need to repeat manual alignment at each temperature.
Solution Approach 2:
The system changes the temperature parameter while maintaining the same physical alignment. By recording the relationship between temperature changes and probe card expansion/contraction, the system dynamically adjusts probe positions through calculation rather than physical re-alignment, allowing accurate testing across multiple temperatures without repeated manual intervention.
2Adaptability or versatility
If the wafer is removed and re-positioned at each temperature, then alignment can be adjusted, but the process becomes time-consuming and complex
Solution Approach 1:
The system replaces the mechanical process of physically removing and re-positioning the wafer with a computational approach. The probe card position is calculated and adjusted based on temperature-dependent expansion models, substituting mechanical re-alignment operations with automated computational compensation.
Solution Approach 2:
The alignment system serves multiple temperature conditions using a single alignment procedure. The recorded probe card position and thermal expansion characteristics create a universal alignment solution that works across the entire temperature range, eliminating the need for separate alignment processes at each temperature step.
3Device complexity
If probe card position is not adjusted for thermal expansion, then the system remains simple, but misalignment occurs at elevated temperatures
Solution Approach 1:
The system uses feedback from recorded probe card positions at known temperatures to calculate thermal expansion effects. This feedback loop allows the system to dynamically compensate for thermal expansion by comparing the recorded reference position with the expected position at elevated temperatures, maintaining alignment accuracy without adding complex hardware.
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 approach significantly reduces testing time by eliminating the need for repeated manual alignment, enabling efficient reliability testing and maintaining accurate electrical connectivity across multiple temperature tests.
Implementation Method 1
adjusting the semiconductor wafer to a first temperature... adjusting the semiconductor wafer and the probe tips to a second temperature
Data Source
AI summary
Method for dynamically compensating probe tip misalignment with a semiconductor wafer. The wafer is located on a handler and the wafer is adjusted to a first temperature. Probe tips of an inspection system are moved to a first position centered above pads of a test module on the wafer. The first position is recorded in a memory of the inspection system at the first temperature. The wafer and the probe tips are adjusted to a second temperature while the wafer remains in the inspection system. A second position of the probe tips is recorded in the memory while the probe tips and the wafer are equilibrated at the second temperature. A difference between the first and second position is calculated. Relative positions of the probe tips or the wafer is compensated based on the calculated difference, such that the probe tips are re-centered above the pads at the second temperature.