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Accelerated testing of metal foil tape joints and their effect of photovoltaic module reliability

Proceedings of SPIE - The International Society for Optical Engineering

Sorensen, N.R.; Quintana, Michael A.; Puskar, J.D.; Lucero, Samuel J.

A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a Reliability Block Diagram (RBD), which models system behavior. Because this model is based mainly on field failure and repair times, it can be used to predict current reliability, but it cannot currently be used to accurately predict lifetime. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape joint degradation, a possible failure mode, can be incorporated into the model. © 2009 SPIE Victor Karpov.

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The effects of long-term storage on the solderability of immersion silver coatings

Proceedings of the 3rd International Brazing and Soldering Conference

Lopez, Edwin P.; Vianco, Paul T.; Lucero, Samuel J.; Buttry, R.W.; Rejent, Jerome A.; Martin, Joseph

The solderability of an immersion Ag finish was evaluated after the exposure of test specimens to a Battelle Class II environment, which accelerates the storage conditions of light industrial surroundings. The solderability metric was the contact angle, (θC), as determined by the meniscometer/wetting balance technique. Auger surface and depth profile analyses were utilized to identify changes in the coating chemistry. The solderability test results indicate that there was no appreciable loss in solderability when the immersion Ag coated coupons were packaged in vapor phase corrosion (VPC) inhibitor bags and/or inhibitor bags with VPC inhibitor paper and aged for 8 hours, 1 week or 2 weeks in the Battelle Class II environment. An increase in surface carbon concentration after aging did not appear to significantly affect solderability. Copyright © 2006 ASM International®.

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Mechanisms of Atmospheric Copper Sulfidation and Evaluation of Parallel Experimentation Techniques

Barbour, J.C.; Breiland, William G.; Moffat, Harry K.; Sullivan, John P.; Campin, Michael J.; Wright, Alan F.; Missert, Nancy A.; Braithwaite, J.W.; Zavadil, Kevin R.; Sorensen, Neil R.; Lucero, Samuel J.

A physics-based understanding of material aging mechanisms helps to increase reliability when predicting the lifetime of mechanical and electrical components. This report examines in detail the mechanisms of atmospheric copper sulfidation and evaluates new methods of parallel experimentation for high-throughput corrosion analysis. Often our knowledge of aging mechanisms is limited because coupled chemical reactions and physical processes are involved that depend on complex interactions with the environment and component functionality. Atmospheric corrosion is one of the most complex aging phenomena and it has profound consequences for the nation's economy and safety. Therefore, copper sulfidation was used as a test-case to examine the utility of parallel experimentation. Through the use of parallel and conventional experimentation, we measured: (1) the sulfidation rate as a function of humidity, light, temperature and O{sub 2} concentration; (2) the primary moving species in solid state transport; (3) the diffusivity of Cu vacancies through Cu{sub 2}S; (4) the sulfidation activation energies as a function of relative humidity (RH); (5) the sulfidation induction times at low humidities; and (6) the effect of light on the sulfidation rate. Also, the importance of various sulfidation mechanisms was determined as a function of RH and sulfide thickness. Different models for sulfidation-reactor geometries and the sulfidation reaction process are presented.

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13 Results
13 Results