By Topic

Durability of Pb-Free solder connection between copper interconect wire and crystalline silicon solar cells

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

6 Author(s)
Cuddalorepatta, G. ; Dept. of Mech. Eng., Maryland Univ., College Park, MD ; Dasgupta, A. ; Sealing, S. ; Moyer, J.
more authors

The thermal cycling durability of large-area Pb-free (Sn3.5Ag) solder interconnects on photovoltaic (PV) solar laminates, has been studied and benchmarks against existing Sn36Pb2Ag interconnects, using a combination of accelerated testing and physics-of-failure (PoF) modeling. Accelerated thermal cycling tests conducted on photovoltaic laminates of both solder compositions, show that the interconnect resistance (measured from dark I-V curves) show that Pb-free laminates outperform Sn37Pb laminates with significantly different response history. Linear extrapolation of the trends from the firs 1000 cycles, suggests that Sn3.5Ag interconnects are 3.5 times more durable than Sn36Pb2Ag interconnects. Due to nonlinearities in the damage growth rate, this estimate may be non-conservative. Post failure analysis shows cracks close TO the interface between the solder and the Ag ink used on the Si wafer. Distributed solder damage is also evident in Sn36Pb2Ag specimens. Acceleration factors were estimated based on a two dimensional viscoplastic finite element analysis and damage predictions based on an energy-partitioning fatigue model. Error-seeded models reveal that process-induced voids, commonly encountered in this architecture can be detrimental to thermal cycling durability. Results suggest that even the worst case (highest void density) Pb-free specimen has a higher durability than the best case {void-tree} Sn37Pb specimen. For the worst void density configuration, accelerated test simulations predict that the Sn3.5Ag interconnects are 1.8 times as robust as the Sn36Pb2Ag interconnects. PoF modeling also shows that the Pb-free solder PV laminates have a higher acceleration factor than the Sn37Pb solder laminates

Published in:

Thermal and Thermomechanical Phenomena in Electronics Systems, 2006. ITHERM '06. The Tenth Intersociety Conference on

Date of Conference:

May 30 2006-June 2 2006