In-depth characterization of screen-printed electrodes by laser-induced breakdown spectrometry and pattern recognition

The application of laser-induced breakdown spectrometry (LIBS) and chemomet rics [namely principal component analysis (PCA) and cluster analysis ICA)I is presented for the characterization of screen-printed electrodes with in- depth resolution. An Nd:YAG laser operating at the fundamental wavelength o f 1064 nm was focused on the sample and the plasma emission was collected b y a fibre-optic bundle coupled to a spectrograph-charge-coupled device syst em. The experimental variables were optimized for a satisfactory spatial ch aracterization. The different zones of the screen-printed electrode were st udied (working electrode, reference electrode and electrical contacts) in o rder to identify both the composition and distribution of the layers deposi ted on the inert support for the construction of the electronic device. Car bon, gold, silver, platinum, palladium, titanium and aluminium were identif ied as major components. The use of pattern recognition techniques (PCA and CA) for the statistical treatment of the spectroscopy data obtained by LIE S proved to be a powerful tool for the rapid analysis of miniaturized multi layer electronic devices. Copyright (C) 2001 John Wiley & Sons, Ltd.