A Novel Seedless TSV Process Based on Room Temperature Curing Silver Nanowires ECAs for MEMS Packaging

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Through-silicon-via (TSV) technology is crucial for microelectromechanical systems (MEMS) packaging.
• Conventional copper electroplating for TSV filling presents challenges like multi-step processes, complex equipment, low throughput, and potential device damage.

Purpose of the Study:

• To develop a novel, seedless, room-temperature curable TSV filling process.
• To create a cost-effective and efficient alternative to traditional TSV filling methods for MEMS packaging.

Main Methods:

• A one-step TSV filling process was developed using novel electrically conductive adhesives (ECAs).
• ECAs were formulated with silver nanowires and polymethyl methacrylate (PMMA).
• The ECAs were cured at room temperature, and their conductivity was evaluated.

Main Results:

• Complete filling of TSVs was achieved using ECAs with 30 wt% silver nanowires.
• The developed ECAs exhibited excellent conductivity, with a resistivity as low as 10^-3 Ω·cm.
• The process demonstrated room-temperature treatability and high efficiency.

Conclusions:

• A novel, seedless TSV filling process using silver nanowire-based ECAs is presented as a viable alternative for MEMS packaging.
• The room-temperature curable ECAs offer a low-cost, high-efficiency solution with excellent conductivity.
• This technique shows broad applicability across various substrates, including flexible microsystems.