DocumentCode :
561051
Title :
Improved testing of soldered Busbar interconnects on silicon solar cells
Author :
Klengel, R. ; Petzold, M. ; Schade, D. ; Sykes, B.
Author_Institution :
Fraunhofer Inst. of Mech. of Mater. IWM, Halle, Germany
fYear :
2011
fDate :
12-15 Sept. 2011
Firstpage :
1
Lastpage :
5
Abstract :
The expected life of a PV solar cell is 20-25 years. To ensure this the quality and reliability of the material and process parameters of solder joints that connect single cells into strings has to be assured. A standardized test method or clearly defined good-bad-criteria are not available for PV products. Thus a product, manufacturer or joining technology comparison is not possible. Due to the lack of standards and commercial available test equipment PV module manufacturers often implement their own test solutions and specifications. However, these mostly have limited scientific proof, are difficult to interpret and lack optimisation. Because there is no standardization these solutions cannot be used for comparative characterization of different manufacturers, cell types, base- and joining materials or joining technologies. The most commonly used test for solar cell ribbon interconnects is the Pull test, as used in micro-electronics. For thin, brittle, large area silicon solar cells substantial modifications of the test equipment and methodology are required to realize a suitable metrology. In addition the factors influencing the defect conditions in multi crystalline material, high strains around the solder connect, inhomogeneous contact interfaces has to be considered. Results show the development, optimization and evaluation of a test method for soldered bus bar interconnects on silicon a solar cell that is independent of product, manufacturer and cell assembly. A comparison between this new method, its results and the previously mentioned issues is made. The test method demonstrates how cell breakage during a test can be avoided by optimising how it is mounted and guided.
Keywords :
elemental semiconductors; integrated circuit interconnections; integrated circuit testing; photovoltaic cells; silicon; solar cells; soldering; PV module manufacturers; PV products; PV solar cell; Si; base-materials; cell assembly; cell breakage; cell types; defect conditions; good-bad-criteria; inhomogeneous contact interfaces; joining materials; joining technologies; joining technology comparison; manufacturer technology comparison; microelectronics; multicrystalline material; process parameters; pull test; silicon solar cells; solar cell ribbon interconnects; solder connect; solder joints; soldered busbar interconnects; standardized test method; test equipment; test solutions; Bars; Force; Force measurement; Photovoltaic cells; Silicon; Soldering; Mechanical Testing; Photovoltaic; Quality Improvement; Solar Cell; Solder Joint Characterization;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Microelectronics and Packaging Conference (EMPC), 2011 18th European
Conference_Location :
Brighton
Print_ISBN :
978-1-4673-0694-2
Type :
conf
Filename :
6142434
Link To Document :
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