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25 4 August, 2015
Ag Sintering I – Overview
 Principle
 Ag-sinter pastes: Ag particles (µm- and/or nm-scale) with organic coating, dispersants, & sintering
promoters
 Dispense, pick & place die, pressureless sintering in N2 or air in box oven
 Resulting die-attach layer is a porous network of pure, sintered Ag
 Advantages
 Fulfills many of the drop-in replacement requirements for a paste
 Better thermal and electrical performance than Pb-solder possible
 Disadvantages
 No self-alignment as with solder wetting
 nm-scale Ag particles are at risk of being banned
 New concept in molded packaging - no prior knowledge of feasibility, reliability or physics of failure
 Production equipment changes might be needed (low-O
2
ovens?)
 Elevated risks
 Potential limitations in die area/thickness, lead frame & die finishes
 Potential reliability issues: cracking (rigidity), delamination or bond lift (organic contamination,
thickness reduction due to continued sintering), interface degradation or electromigration of Ag
(O
2
or humidity penetration, unsintered Ag particles in die-attach layer)