Fabrication of Micro-Punch Array by Plasma Printing for Micro-Embossing into Copper Substrates

Area of Science:

• Materials Science and Engineering
• Manufacturing Technology
• Surface Engineering

Background:

• Advanced packaging technologies require precise micro-scale features on substrates.
• Micro-stamping offers a potential method for creating these features, but requires robust tooling.
• Developing durable micro-punches with specific textures is crucial for micro-embossing processes.

Purpose of the Study:

• To develop and characterize a novel method for fabricating micro-textured punches from AISI316 stainless steel.
• To investigate the micro-embossing behavior of copper substrates using these fabricated micro-punches.
• To evaluate the fidelity of micro-texture transcription from the punch to the copper substrate.

Main Methods:

• Tailoring micro-texture patterns using CAD data and screen printing on AISI316 stainless steel dies.
• Plasma nitriding the die substrate to selectively harden specific areas.
• Sand-blasting to remove un-nitrided material, creating a 3D micro-textured punch array.
• Utilizing uniaxial compression testing to perform micro-embossing on copper substrates.

Main Results:

• Successfully fabricated a micro-punch array with closed-loop heads (75 µm width, 120 µm height) from plasma-nitrided and sand-blasted AISI316 stainless steel.
• Demonstrated the ability of the hardened micro-punch array to emboss micro-grooves onto copper substrates.
• Analyzed the geometric transcription of the micro-texture from the punch to the copper, confirming process viability.

Conclusions:

• The developed plasma nitriding and sand-blasting technique effectively creates durable, micro-textured AISI316 stainless steel punches.
• The micro-embossing process using these punches accurately replicates the designed micro-textures onto copper substrates.
• This method provides a viable route for manufacturing micro-structured components for packaging and other micro-fabrication applications.