Hot Embossing to Fabricate Parylene-Based Microstructures and Its Impact on the Material Properties.

Area of Science:

• Materials Science
• Polymer Engineering
• Microfabrication

Background:

• Parylene C is a biocompatible polymer widely used in microelectronics and biomedical applications.
• Existing patterning techniques for Parylene C, such as plasma etching and laser ablation, have limitations in achieving high resolution and structural integrity.
• There is a need for advanced fabrication methods to create complex 3D microstructures from Parylene C for emerging applications.

Purpose of the Study:

• To establish and optimize a hot embossing process for fabricating 3D microstructures using Parylene C.
• To adapt the hot embossing technique for silicon chip platforms and assess its compatibility with embedded metal layers for printed circuit board applications.
• To evaluate the morphological, chemical, and structural properties of the fabricated microstructures.

Main Methods:

• Optimization of hot embossing process parameters: embossing temperature, force, demolding temperature/speed, and release agent usage.
• Adaptation of hot embossing from stainless steel to silicon substrates, including investigation of effects on embedded metal layers.
• Characterization of embossed Parylene C microstructures using light microscopy (LM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR).

Main Results:

• Optimized hot embossing process parameters for Parylene C fabrication.
• Successful adaptation of the process to silicon chip platforms, demonstrating compatibility with embedded metal layers.
• Characterization confirmed superior structural integrity, feature resolution, and sidewall smoothness compared to plasma etching and laser ablation.

Conclusions:

• Hot embossing is a highly effective method for fabricating high-resolution 3D microstructures from Parylene C.
• The developed process is compatible with semiconductor fabrication techniques and suitable for advanced applications.
• This technique offers significant advantages over existing methods for patterning Parylene C, enabling new possibilities in micro-device design.