Novel scanning electron microscope bulge test technique integrated with loading function.

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Micro-scale membranes are crucial for electronics and Micro Electro Mechanical Systems (MEMS).
• Conventional mechanical property testing methods are inadequate for micrometer and nanometer scale structures.
• Accurate characterization of thin film mechanical properties is essential for device performance and reliability.

Purpose of the Study:

• To present a novel bulge test method for evaluating the mechanical properties of micro thin membranes.
• To address the challenges in measuring mechanical properties at micro and nano scales.
• To determine the biaxial and Young's modulus of polyimide films using the developed method.

Main Methods:

• A novel bulge test integrated with a Scanning Electron Microscope (SEM) for simultaneous loading and measurement.
• A simplified Digital Image Correlation (DIC) technique for precise height measurement during the bulge test.
• Introduction of a scanning Moiré method for correcting imaging distortions.
• Auxiliary standard tensile tests were performed for validation.

Main Results:

• The integrated bulge test, DIC, and Moiré methods enable simultaneous loading and precise measurement.
• Accurate determination of biaxial modulus and Young's modulus for polyimide films.
• Validation of the novel bulge test method's feasibility through comparison with standard tensile tests.

Conclusions:

• The proposed novel bulge test method effectively characterizes the mechanical properties of micro thin membranes.
• The combination of SEM, DIC, and Moiré methods offers a robust solution for micro-scale material analysis.
• This technique provides a reliable approach for evaluating critical mechanical parameters in microelectronic and MEMS devices.