Effects of Sintering Pressure on the Densification and Mechanical Properties of Nanosilver Double-Side Sintered Power Module

Abstract

Modern power electronics has the increased demands in current density and high temperature reliability. However, these performance factors are limited due to the die attach materials used to affix power dies microchips to electric circuitry. Although several die attach materials and methods exist, nanosilver sintering technology has received much attention in attaching power dies due to its superior high temperature reliability. This paper investigated the sintering properties of nanosilver film in double side sintered power packages. X-ray diffraction (XRD) results revealed that the size of nanosilver particles increased after pressure-free sintering. Comparing with the pressure-free sintered nanosilver particles, the 5 MPa sintered particles showed a higher density. When increasing sinte ring pressure from 5 to 30 MPa, the shear strength of the sintered package increased from 8.71 MPa to 86.26 MPa. When sintering at pressures below 20 MPa, the fracture areas are mainly located between the sintered Ag layer and the surface metallization layer on the fast recovery diode (FRD) die. The fracture occurs through the FRD die and the metallization layer on bottom Mo substrate when sintering at 30 MPa. Index Terms-power electronics, nanosilver sintering, shear strength, fracture I. INTRODUCTION HE rapid development of wide-band gap semiconductors have facilitated power electronics becoming key components in hybrid electric vehicles, traction, wind turbine and high-voltage power transmission systems due to their

Influence of sintering pressure on microstructure and tribological properties of Copper–Tin composites containing graphite and MoS2

“…Madeira et al [20] studied at how different sintering pressures (5-100 MPa) affected the microstructure and tribological characteristics of yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics, and they found that as pressure increased, the density, hardness, and tribological properties all improved. Zhang et al [21] investigated the effect of sintering pressure on the performance of nanosilver double-side sintered power modules, and found that nanosilver particles sintered at 5 MPa had higher density compared with the pressureless sintered nanosilver particles, and the shear strength of the sintered body increased from 8.71 to 86.26 MPa when the sintering pressure was increased from 5 to 30 MPa. Liu et al [22] discovered that the porosity of the sintered silver layer dropped by 17.99% as the sintering pressure increased from 5 MPa to 30 MPa.…”

In-air sintering of copper nanoparticle paste with pressure-assistance for die attachment in high power electronics

“…These advantages have encouraged the recent utilization of Ag NP paste as a die-attach material in power electronics applications [11][12][13]. The sintering parameters and materials were tuned to increase the mechanical strength of the sintered joints [14][15][16]. There have also been studies on the sintering mechanisms of Ag pastes [17][18][19].…”