Sheet Resistance Testing Using Dispersed Electrodes
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Solution Overview
Problem
Current methods for measuring sheet resistance and contact resistance of sheet materials are complex, require precise control, and are limited by the collinear four-probe array method, which affects measurement accuracy and does not account for sheet materials effectively.
Innovation Solution
A non-destructive testing method using dispersedly distributed electrodes to measure sheet resistance and contact resistance, calculating these values based on resistances between electrodes and distances, employing a theoretical model and least-squares linear fitting technique.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the collinear four-probe array method is used to measure sheet resistance, then measurement standards are established, but the process becomes complicated and demanding on measurement instruments and operation skills
Solution Approach 1:
The patent divides the measurement process into two independent parts: sheet resistance measurement and contact resistance measurement. By using separate measurement methods for each parameter, the complexity of simultaneously measuring both parameters with the traditional four-probe method is reduced, while maintaining measurement accuracy for both sheet resistance and contact resistance
Solution Approach 2:
The patent extracts the contact resistance measurement from the sheet resistance measurement process. By using a two-probe method specifically for contact resistance measurement, the influence of sheet resistance on contact resistance measurement is eliminated, simplifying the overall measurement process while improving accuracy
2Measurement precision
If the collinear four-probe array method is used, then sheet resistance can be measured, but the potential field is affected by middle measuring electrodes and requires repeated testing
Solution Approach 1:
The patent extracts the sheet resistance measurement from the complex four-probe array configuration and uses a simplified two-probe method. This extraction eliminates the interference from middle measuring electrodes on the potential field, allowing for accurate sheet resistance measurement in a single test without repeated testing
Solution Approach 2:
The patent applies different measurement strategies to different measurement objectives: using a two-probe method with specific electrode configurations that are optimized for each measurement type (sheet resistance vs. contact resistance), thereby achieving accurate local measurements without the need for complex global electrode arrangements
3Measurement precision
If the four-probe method with specific probe shapes is used, then measurement standards are established, but the indentation shape on the surface is difficult to control
Solution Approach 1:
The patent extracts the measurement process from dependence on precise probe indentation shapes. By using a two-probe method where the measurement principle does not rely on specific indentation geometries, the manufacturing precision requirements for probes are significantly reduced while maintaining measurement accuracy
Solution Approach 2:
The patent changes the measurement parameters from those requiring controlled indentation shapes to those that are independent of indentation geometry. By measuring resistance between two probes without requiring hemispherical or flat circular section shapes, the manufacturing precision burden is removed while preserving measurement accuracy
4Measurement precision
If the GB/T 15078-2008 standard is used for contact resistance measurement, then contact resistance between precious metals and bulk materials can be measured, but it does not apply to sheet materials due to high resistance
Solution Approach 1:
The patent creates a universal measurement method that can measure contact resistance for both bulk materials and sheet materials. By using a two-probe method that accounts for sheet resistance in the measurement model, the measurement technique becomes adaptable to different material types and configurations, significantly improving versatility
Solution Approach 2:
The patent changes the measurement parameters and model to accommodate sheet materials. By developing a measurement approach that explicitly considers and compensates for sheet resistance effects, the method becomes applicable to sheet materials while maintaining contact resistance measurement accuracy, unlike the traditional method designed for bulk materials
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 method simplifies and enhances the accuracy of sheet resistance and contact resistance measurements, reducing the influence of other electrodes on the potential field and allowing for flexible electrode distribution, suitable for various conductive materials and configurations.
Implementation Method 1
measuring the resistances between the electrodes; and calculating the sheet resistance and the electrode contact resistance of the sheet material on the basis of a theoretical model from the resistances measured between the electrodes
Data Source
AI summary
A testing method for the sheet resistance and contact resistance of connecting point of a sheet material, comprising: mounting at least four small electrodes on the surface of the sheet material; measuring the resistance between the electrodes; and calculating the sheet resistance and electrode contact resistance of the sheet material on the basis of a theoretical model from the resistance measured between the electrodes and the distances between the electrodes. As a main feature, the testing method is a convenient nondestructive testing method for the sheet resistance and electrode contact resistance of the sheet material, and has no strict requirement on the distribution of electrodes.