Abstract
We have proposed a low-temperature bonding technology utilizing the sintering of Cu particles with transient liquid-phase of Sn-based solder, called transient liquid-phase sintering (TLPS), as a die-attach solution for high-temperature power modules. A copper-intermetallic compound-resin (Cu-IMC-resin) microstructure, which consists of Cu particles connected with Cu–Sn intermetallic compounds (IMCs) partially filled with polyimide resin, is obtained by the pressureless TLPS process at 250 °C for 1 min using a novel Cu-solder-resin composite as the bonding material in a nitrogen atmosphere. Macro- and micro-deformation properties of the unique microstructure of the TLPS Cu-IMC-resin are evaluated by finite element analysis using a three-dimensional image reconstruction model. The macroscopic computational uniaxial tensile tests of the Cu-IMC-resin model reveal that the utilization of the IMCs and the addition of the easily-deformable resin facilitates the temperature-stability and low-stiffness of the mechanical properties. The microstructure exhibits a significantly low homogenized Young’s modulus (11 GPa). Microscopic investigations show that the local stresses are broadly distributed on the IMC regions under uniaxial macroscopic tensile displacement, indicating highly reliable performance of the joint within a specific macroscopic strain condition. Numerical and experimental investigations demonstrate the excellent thermal cyclic reliability of die-attached joints between silicon carbide chips and directly bonded copper substrate.
Highlights
The rapid advancement of hybrid electric vehicles (HEVs) and other power electronic systems has increased the demand of highly reliable bonding technologies in the power modules
We evaluated an inherent microstructure of the transient liquid-phase sintering (TLPS) joint, skeleton-shaped Cu-intermetallic compounds (IMCs)-resin microstructure, using finite element (FE) simulations based on a 3D image reconstruction model to elucidate its macro- and micro-deformation properties
The Cu-IMC-resin microstructure showed temperature-stable and low-stiffness mechanical characteristics because the Cu and IMC primarily acted as the load-carrying phases, and the embedded -deformable resin acted as the spacer
Summary
The rapid advancement of hybrid electric vehicles (HEVs) and other power electronic systems has increased the demand of highly reliable bonding technologies in the power modules. The operation of power modules at high powers and frequencies, along with high integrability and miniaturization capability is highly desired [1]. The utilization of next-generation semiconductor material; silicon carbide (SiC), instead of the conventional materials offers lower power loss, higher switching speed, and higher operating temperature, which has recently exceeded 175 ◦ C and even reached. As the bonding layers are exposed to such high temperatures, the performance metrics and reliability of joints should be improved. Alternative bonding technologies with higher heat tolerance are in great demand. Silver sinter bonding technologies are representative technologies for next-generation power modules, which have been reported to provide outstanding thermal and electrical conductivity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
