Conduction Conditions for Self-Healing of Metal Interconnect Using Copper Microparticles Dispersed with Silicone Oil

Area of Science:

• Materials Science
• Electrical Engineering
• Physics

Background:

• Metal interconnects are crucial for electronic devices.
• Bridging gaps in interconnects is essential for circuit continuity.
• Controlling microparticle behavior is key for novel conductive pathways.

Purpose of the Study:

• To determine the conditions for successful bridging and electrical conduction across a metal interconnect gap using copper microparticles.
• To investigate the role of dielectrophoretic forces in forming conductive microparticle chains.
• To establish the voltage and current thresholds for reliable conductivity and identify failure mechanisms.

Main Methods:

• Dispersing copper microparticles (3 µm) in silicone oil.
• Applying AC voltage (32 kHz) across a 10 µm gap on a metal interconnect.
• Utilizing dielectrophoretic forces to form microparticle chains.
• Varying external resistance to tune current independently of applied voltage.

Main Results:

• Copper microparticle chains successfully bridged the interconnect gap.
• Electrical conductivity was achieved at applied voltages of 14 Vrms or higher.
• Conductivity was contingent on post-bridging current being 350 mArms or lower.
• Low voltages, even with bridging, did not result in conductivity.
• Excessive voltage led to bubble formation and bridge destruction.

Conclusions:

• Dielectrophoretic forces enable the formation of conductive copper microparticle chains across interconnect gaps.
• Achieving reliable electrical conduction requires precise control over applied voltage and post-bridging current.
• Understanding these parameters is critical for preventing bridge failure and ensuring functional interconnects.