Thin Multilayer Analysis Using the Agilent 8700 LDIR Chemical Imaging System

Significance of the Topic

The analysis of thin multilayer materials is critical in various industries because layer interactions determine mechanical and barrier properties. Precise thickness measurement and chemical identification at micrometer resolution ensure product integrity and safety. The Agilent 8700 LDIR chemical imaging system addresses these needs by combining infrared imaging and spectroscopy for rapid, non-destructive characterization.

Objectives and Study Overview

This application note demonstrates the system's capability to:

• Build a reference spectral library from known polymer layers.
• Measure layer thickness and morphology using high-resolution visible and infrared imaging.
• Identify unknown polymer layers in validation and real-world samples.

Methodology and Instrumentation

Samples were prepared using an Agilent laminate holder and sample planer to produce flat cross-sections within minutes. The 8700 LDIR system acquired high-magnification visible images and IR images at 1442 cm-1 with 1 μm pixel size. Single-point spectra along line profiles were collected automatically and matched against the user-defined library.

Instrumentation

• Agilent 8700 LDIR Chemical Imaging System
• Agilent Clarity Software
• Agilent Laminate Holder
• Agilent Sample Planer (microtome accessory)

Key Results and Discussion

Using a three-layer reference sample of PP, PS, and PE, a spectral library was generated. The system measured 150 μm total thickness with equal 50 μm layers. In a validation sample, layers of 25, 40, and 25 μm were identified with Hit Quality Index (HQI) scores above 0.88. A lithium-ion battery separator (~25 μm total) was resolved into PP, PE, and PP layers with HQI scores above 0.80, confirming sub-10 μm resolution capability.

Benefits and Practical Applications of the Method

The workflow offers:

• Rapid, non-destructive sample preparation without resin embedding.
• High spatial resolution for thin-layer measurement and morphology.
• Custom spectral library creation for confident material identification.
• Applicability in quality control, failure analysis, and research of multilayer materials.

Future Trends and Potential Applications

Advancements may include integration with automated spectral libraries, improved resolution for nano-scale layers, and expanded use in emerging fields such as flexible electronics and advanced packaging. Combining machine learning algorithms with IR imaging could further enhance identification accuracy and throughput.

Conclusion

The Agilent 8700 LDIR system provides a robust solution for rapid, micrometer-scale multilayer analysis. Its combination of precise thickness measurement, high-resolution imaging, and customizable spectral libraries supports both R&D innovation and routine quality assurance across diverse industries.

References

• Agilent Technologies Application Note: Thin Multilayer Analysis Using the Agilent 8700 LDIR Chemical Imaging System.