Silver oxalate: towards a new solder material for highly dissipative electronic assemblies

Abstract

This work presents a new route to obtain a highly conductive silver solder (with thermal conductivity around 100 W/m.K) by thermal decomposition of a silver oxalate precursor at moderate temperature (<300°C) and low pressure (<0.5MPa).

Bi2(C2O4)3·7H2O and Bi(C2O4)OH Oxalates Thermal Decomposition Revisited. Formation of Nanoparticles with a Lower Melting Point than Bulk Bismuth

“…Although low melting can be an issue for some applications of nanomaterials, this property is promising to offer answers to electronic packaging challenges. It is identified as a way to lower the joining process temperatures. , On the basis of this concept, a new kind of assembly method for power electronics was formerly developed with silver oxalate as a precursor for high thermal conductivity sintered silver interfaces. , The thermal decomposition of the silver oxalate into metal nanoparticles with a high propensity for sintering allows a low-temperature joining process. With the will to broaden the oxalate precursor route for low-temperature soldering, several compounds other than silver oxalate were studied.…”

Developing new joining materials for low-temperature electronics assembly

“…The present work focuses on a new kind of lead-free joining method for surface-mount technology based on precursor chemistry. The interest of metal oxalates as new soldering materials for die attachment (1 st level packaging) was previously demonstrated with silver oxalate [2], [3]. The thermal decomposition of metal oxalates under controlled atmosphere can be used to produce small metal particles below their melting point.…”