Pb-Free Component & Board Finish Reliability
Wednesday, December 7, 2022

Section: Board Assembly

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Project Leader

Qinglei Zhang, IntelĀ 

Final Report

Statement of Work


The transition to Pb-free solder alloys introduces new concerns regarding solder joint reliability.  The implementation of alternative surface finishes for circuit boards and package substrates/leadframes compounds these reliability concerns.  Although multiple studies are investigating the impact of Pb-free solder and alternative board finishes on board-level temperature cycling lifetime, few studies have dealt with the impact of these new material sets on solder joint reliability.

Scope of Work

Comparative reliability testing will be conducted on Pb-free components assembled on test boards. Test board assemblies will be configured to evaluate multiple component surface finishes and 2 circuit board surface finishes.  The reliability testing will be conducted with mechanical testing - with and without aging. Mechanical testing will consist of 4-point monotonic bend testing (IPC/JEDEC-9702) and drop testing.

The component surface finishes to be evaluated are listed below:
  1. Electrolytic Ni/Au
  2. Electroless Ni/Au (ENIG)
  3. SnAgCu solder over Cu
  4. Matte Sn over Cu
  5. Matte Sn over Ni/Cu
  6. Au/Pd/Ni
  7. SnBi over Cu
The two printed wiring board (PWB) surface finishes will be evaluated as follows:
  1. Electrolytic NiAu
  2. Organic Solderability Preservative (OSP)