A 64-pin Nanowire Surface Fastener Like a Ball Grid Array Applied for Room-temperature Electrical Bonding

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Traditional soldering faces challenges including rare metal recycling, thermal issues, and lead (Pb) toxicity.
• Developing lead-free and environmentally friendly assembly methods is crucial for sustainable electronics manufacturing.

Purpose of the Study:

• To develop and demonstrate a metallic nanowire surface fastener (NSF) as a room-temperature, solder-free alternative for electronic component interconnection.
• To investigate the adhesion strength and electrical properties of the NSF by optimizing nanowire parameters.

Main Methods:

• Fabrication of a 64-pin NSF mimicking a ball grid array (BGA) structure using a simple template method.
• Systematic investigation of nanowire parameters: diameter, length, density, preload, and shape.
• Evaluation of adhesion strength and contact resistivity of the developed NSF.

Main Results:

• A maximum adhesion strength of 16.4 N/cm² was achieved with bent, hook-like NSFs, significantly outperforming straight NSFs (4-5 times higher).
• The NSF demonstrated a contact resistivity of 2.98 × 10⁻² Ω∙cm².
• The developed NSF exhibited room-temperature bonding capability and adaptability to highly ordered electrodes like BGA.

Conclusions:

• The metallic nanowire surface fastener (NSF) presents a viable, high-performance alternative to traditional soldering for electronic assembly.
• Optimizing nanowire shape, particularly creating hook-like structures, significantly enhances adhesion strength.
• The NSF technology offers a sustainable and efficient solution for connecting electronic components at room temperature.