Prognostic Monitoring of Power QFN Packages with Silver Sintered Die-Attach Materials
H.A. Martin (TU Delft - Electronic Components, Technology and Materials, Chip Integration Technology Center)
Dong Hu (TU Delft - Electronic Components, Technology and Materials)
X. Liu (Nexperia B.V., TU Delft - Electronic Components, Technology and Materials)
R.H. Poelma (Nexperia B.V., TU Delft - Electronic Components, Technology and Materials)
Edsger C.P. Smits (Chip Integration Technology Center (CITC))
Willem van Driel (Signify, TU Delft - Electronic Components, Technology and Materials)
G. Zhang (TU Delft - Electronic Components, Technology and Materials)
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Abstract
Prognostic monitoring of power quad flat no-lead (PQFN) packages with four distinct silver pastes, each varying in material composition (pure-Ag and resin-reinforced hybridAg) and sintering processes (pressure-assisted and pressureless), was investigated in this study. The PQFN packages with silver sintered die-attach materials were subjected to thermal cycling tests (?55 ° C to 150 ° C), and the performance degradation was evaluated based on the following metrics: 1) electrical ON-state resistance RDSon monitored periodically at specific thermal cycling intervals and 2) transient thermal impedance Zth(t = 0.1 s) monitored online during thermal cycling. These measurements were further validated using acoustic microscopy imaging and cross-sectional inspection. The pressureless Ag-sintering material demonstrated comparable performance to pressure-assisted Agsintering, with a dense microstructure, and consistent electrical and stable thermal performance. Whereas the pressureless resinreinforced hybrid-Ag material exhibited degradation with a relative increase of 33% in RDSon, 38% in Zth(t = 0.1 s), and 67% delamination of the die-attach interface over 1000 cycles. These findings suggest that pressureless Ag-sintering may offer a viable alternative to pressure-assisted methods for lead (Pb)- free die-attachments, while resin-reinforced hybrid-Ag requires further development for improved thermomechanical reliability..