Synthesis of a Nano-Silver Metal Ink for Use in Thick Conductive Film Fabrication Applied on a Semiconductor Package

Abstract

The success of printing technology in the electronics industry primarily depends on the availability of metal printing ink. Various types of commercially available metal ink are widely used in different industries such as the solar cell, radio frequency identification (RFID) and light emitting diode (LED) industries, with limited usage in semiconductor packaging. The use of printed ink in semiconductor IC packaging is limited by several factors such as poor electrical performance and mechanical strength. Poor adhesion of the printed metal track to the epoxy molding compound is another critical factor that has caused a decline in interest in the application of printing technology to the semiconductor industry. In this study, two different groups of adhesion promoters, based on metal and polymer groups, were used to promote adhesion between the printed ink and the epoxy molding substrate. The experimental data show that silver ink with a metal oxide adhesion promoter adheres better than silver ink with a polymer adhesion promoter. This result can be explained by the hydroxyl bonding between the metal oxide promoter and the silane grouping agent on the epoxy substrate, which contributes a greater adhesion strength compared to the polymer adhesion promoter. Hypotheses of the physical and chemical functions of both adhesion promoters are described in detail.

Characterization of Thermoplastic Polyurethane (TPU) and Ag-Carbon Black TPU Nanocomposite for Potential Application in Additive Manufacturing

“…There are many benefits associated with inkjet printing (compared to other deposition methods) including low-cost, its additive nature, efficient handling of expensive materials, one-step processing, cheap and compact equipment, and applicability to various substrates [ 7 , 8 ]. The availability of metal printing ink and its performance is key to the success of printing technology in the electronics industry [ 9 ]. Commonly used inks for the inkjet printing of conductive components are conducting polymers and nanoparticle (NP) solutions with dispersants all of which have associated drawbacks [ 7 ].…”

“…Nanomaterials are currently not used extensively in AM processes due to their cost, their environmental stability, their tendency to agglomerate and settle, and the need to “tune” the AM processing conditions [ 10 ]. Development and optimization of a successful ink for ink jet printing is complex and expensive and involves selection of the proper metal particles (<5 nm size for depressed melting temperature and low annealing temperature), solvent, surfactant, and adhesion promoter (unique to each substrate) [ 9 ].…”

“…Poor electrical performance, mechanical strength, and adhesion (e.g., to epoxy molding compounds) limits interest in printing technology for the semiconductor industry [ 9 ]. Simple and inexpensive pre-screening, property evaluation, and development of AM electronic materials at the free-standing film level seems prudent so that expensive and complicated ink development is performed for only the most promising materials.…”

Recent developments of inkjet-printed flexible sensing electronics for wearable device applications: a review

“…The studies were focused by various researchers on the formation of droplets, accurate control of dropping location and printing parameters (Meinhart and Zhang, 2000; Huang and Kim, 2001; Tseng et al , 2002; Perçin and Khuri-Yakub, 2003; Azucena et al , 2008; Yang et al , 2009; Ahn et al , 2011; Yung et al , 2014; Huang et al , 2014; Dang et al , 2014). On the research of conductive ink, several materials were studied including molten metal, conductive polymer and metallic nanoparticle suspension (Calvert, 2001).…”

“…Due to their high conductivity and thermal stability, gold and silver nanoparticle suspensions were widely adopted in the studies of conductive ink. The operating parameters considered in prior works (Fuller et al , 2002; Szczech et al , 2002; Bieri et al , 2003; Chung et al , 2004; Bieri et al , 2004; Szczech et al , 2004; Azucena et al , 2008; Ahn et al , 2011; Huang et al , 2014; Yung et al , 2014; Dang et al , 2014; Lee et al , 2005) are listed in the following Table 2 for comparison.…”