Are Sintered Silver Joints Ready for Use as Interconnect Material in Microelectronic Packaging?

Abstract

Silver (Ag) has been under development for use as interconnect material for power electronics packaging since the late 1980s. Despite its long development history, high thermal and electrical conductivities, and lead-free composition, sintered Ag technology has limited market penetration. This review sets out to explore what is required to make this technology more viable. This review also covers the origin of sintered Ag, the different types and application methods of sintered Ag pastes and laminates, and the long-term reliability of sintered Ag joints. Sintered Ag pastes are classified according to whether pressure is required for sintering and further classified according to their filler sizes. This review discusses the main methods of applying Ag pastes/laminates as dieattach materials and the related processing conditions. The long-term reliability of sintered Ag joints depends on the density of the sintered joint, selection of metallization or plating schemes, types of substrates, substrate roughness, formulation of Ag pastes/laminates, joint configurations (i.e., joint thicknesses and die sizes), and testing conditions. This paper identifies four challenges that must be overcome for the proliferation of sintered Ag technology: changes in materials formulation, the successful navigation of the complex patent landscape, the availability of production and inspection equipment, and the health concerns of Ag nanoparticles. This paper is expected to be useful to materials suppliers and semiconductor companies that are considering this technology for their future packages.

Low-temperature Cu-to-Cu bonding using silver nanoparticles stabilised by saturated dodecanoic acid

“…Currently, the development of a bonding method that works at temperatures below 300 1C is important for electronic packaging and interconnections [1][2][3][4][5][6][7]. In this study, we developed a process that possesses the benefits of a lower processing temperature and the adoption of more conductive materials.…”

Rapid formation of intermetallic joints through ultrasonic-assisted die bonding with Sn–0.7Cu solder for high temperature packaging application

“…Good candidates for high temperature applications are eutectic alloys of Au-Sn (280°C) and Au-Ge (356°C), but it is not rational to apply Au to a large area die attach due to its extremely high cost. Although a new die-attachment structure using pure zinc solder for SiC die attachment was proposed [11], it has certain drawbacks: a high bonding temperature (more than 420°C) causing irreversible damage or accelerated aging affects to the electronic devices [12]; a poor ductility and limited oxidation resistance due to Zn [13].Many researchers have investigated bonding techniques that involve sintering of Ag nanoparticles, because Ag has high thermal and electrical conductivity, and Ag nanoparticles can be produced easily and be sintered at relatively low temperatures due to their high stability against oxidation [14][15][16][17]. However, Ag is expensive and is poorly resistant to migration.…”

Investigation of Thermoelectric Parameters of Bi2Te3: TEGs Assembled using Pressure-Assisted Silver Powder Sintering-Based Joining Technology

“…Additional advantages are the high electrical and thermal conductivity of the sintered silver layer, high adhesive strength of the interconnect, as well as good stability at thermal cycling load. 5,6 Another feature of PASPS is its high potential for automation in combination with a proprietary foil transfer method. 7 First, ceramics are metalized using electron beam physical vapor deposition (EBPVD).…”