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Photovoltaic modules as well as automotive electronics are both designed to perform more than 20 years in the field. They show many similarities, for example the material combinations (Silicon, copper, lead free interconnection), the field loads, qualification tests, etc. Therefore knowledge obtained from designing automotive electronics can be used to design reliable photovoltaic modules. Tn the recent years many lifetime prediction methods have been developed to address a variety of different damage mechanisms observed in the field such as crack growth, delamination etc. by simulation. The paper describes various aspects of how the experiences gained in this field of research can be transferred to photovoltaic modules.Tn order to show a first application of the discussed issues, selected optimization measures on the basis of numerical results for photovoltaic modules on tabber stringer technology will be presented.

The electronics industry has successfully transitioned to lead free soldering for computer and consumer products while in the automotive industry due to the very high reliability requirements this step is still in an ongoing process. In order to ensure or even to enhance the reliability of electronics the improvement of lead free solder joints based on Sn-Ag-Cu (SAC) solder has been the focus of many research projects already. One approach to improve the thermal fatigue properties of these alloys is to add a further alloying element SAC + X. Until now, further elements have mainly been added by metallurgical alloying, requiring special equipment and conditions. The powder production is even more difficult. In this paper a new way how to add minor amounts around 0.1 wt.-% of a forth element to SAC solder joints is presented. One possibility is to do the doping during the reflow process adding the additional elements via the flux by incorporating Co-, Fe-, Al- or other metal compounds into the flux. Experiments have shown that Co and Fe were successfully added while for certain other elements like for example Al this was not possible until now. In comparison to standard SAC solder the Co containing solder shows a refined microstructure and Co is found in the intermetallic phase Cu6Sn5. Fe which has been found at gain boundaries is not only attractive as alloying element but as metallization layer, too. It is possible to deposit Fe on printed circuit boards using electroplating. During soldering the slowly growing FeSn2 phase forms between the solder and the Fe layer

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Purpose -The purpose of this paper is to develop a new alloying method for solders by using a metal organic modified flux in solder pastes. Design/methodology/approach -This paper presents the impact of six metal organic compounds (Co, Fe, Al; stearate, oxalate, citrate) on the melting and solidification behaviour in comparison to the revealed microstructure. Findings -It could be shown that Co and Al influence the supercooling whereas Fe exhibits no effect. Co reduces the supercooling of the cast of about 10 K and affects the nucleation. Al retards the solidification up to 1858C. Doping of the solder by flux containing metal organic compounds is successful and the alloying elements Co and Fe are found in the microstructure. Research limitations/implications -This paper provides a starting-point for the new alloying method -so far only fluxes for solder pastes have been investigated. Originality/value -The reactive alloying method enables the use of new alloying elements for solder pastes in unmodified soldering processes.