Analysis of wirebonding techniques for contacting high concentrator solar cells

The results of the wirebonding technique application to make connections on high concentrator solar cells are presented in this paper. The most usual wirebonding techniques in current microelectronic industry have been analyzed (i.e., aluminum wedge bonding and thermosonic gold ball bonding). In the first part of the paper the influence of wirebonding processes on solar cell performance is discussed theoretically. The theoretical approach is followed by a comprehensive experimental analysis, which focuses on: a) the influence of mechanical damage on the device I-V curve; b) bondability analysis; c) the influence of wirebonding damage on device lifetime; d) analysis of the electrical resistance of the connection. Finally some conclusions of practical interest are drawn and the main results of the work are summarized.