ATR/IR spectroscopic method for following photo-polymer curing

A method for examining the photo-induced polymerization of photoresists and solder masks, at the substrate/photopolymer interface, using attenuated total reflectance (ATR) and infrared spectroscopy is discussed. The method is especially useful for dry film photoresists and gives information concerning cure levels affected by exposure dose and photoresist thickness. The photoprocessing of Vacrel® 8100 series solder mask and Riston® 3100 series photoresists from Dupont are used as examples.