Dynex’s Senior Principle Engineer, Muhammad Morshed along with Yangang Wang, Laxma R. Billa, Thomas Grant, Maryam Mat, Dean Payne will be presenting their paper on the ‘High temperature lead free solder alloy for high power semiconductor device packaging applications’ at PCIM in Nuremberg, 9 - 11 May 2023. In addition Dynex will be exhibiting at PCIM again this year and hope to welcome you to our stand 9 - 311, Nuremberg, Germany.
Abstract
Power semiconductor modules typically undergo extreme temperature swings and are subjected to fast switching applications. SAC and SnSb alloys are popular material choices of Pb-free type for die attach applications. The melting temperature of SAC and SnSb alloys are typically around 2200C and 2400C respectively. These solder materials have the disadvantages of a poor reliability against thermomechanical stress at elevated temperature. In this paper, Pb free solder alloy which has a melting temperature more than 3000C has considered for die attach. This solder alloy exhibits significantly higher shear strength and more reliable than base line solders. The solder material after isothermal aging at high temperature (2000C) and thermal shock test for 1000 cycles (with a ∆T=2250C) maintains their superior shear strength. The substrate level power cycling with deltaT=1200C confirmed the solder material performs 135k cycles without die solder degradation. The SEM/EDS microstructural analysis confirmed the various intermetallic phases of the soldered material improved the bond strength.
The Durfuse HT Pb-free solder material could replace the usage of high Pb content solder alloys and a cost effecive solution over sinteri ng for die attach applications in power module packaging.The die attach process upto 105.27 mm2 die size optmised by minimising the perc entage of void level. The die bond shear stre ngth remained above 50MPa after the induced thermomechanical (thermal shock) and thermal stresses (thermal aging) confirmed the HT Pbfree solder material is capable to use die atta chment for high tempeature power module pac kaging applications. Power cycling with deltaT =1200C maintained the thermal resistance of die attachment without significant change of die solder degradation.
To receive a copy of Muhammad Morshed and Co's research paper and for an opportunity to discuss in detail the 'High temperature lead free solder alloy for high power semiconductor device packaging applications', sign up to attend the PCIM conference or contact us to arrange a meeting with our team at powersolutions@dynexsemi.com