Journal of Applied Polymer Science, Vol.59, No.13, 2029-2037, 1996
Debonding of Photoresists by Organic-Solvents
Chlorofluorocarbons (CFCs) have been widely used in the printed circuit board industry for many decades. However, the growing concern regarding their ozone depleting properties has demanded a ban on these solvents and consequently brought forth the search for environmentally friendly alternatives. In printed circuit board technology, methyl chloroform and methylene chloride have been widely utilized as solvents for developing and stripping, respectively, radiation sensitive materials useful in creating fine line circuitry patterns. The solubility of unexposed and exposed T168 resist in selected solvents or solvent mixtures at various temperatures is described here. Results addressing the ease of removal of such solvent based resists using environmentally friendly alternatives are presented. Debonding of the polymer layer from the underlying substrate was observed by monitoring the deflection of the composite strip immersed in the solvent using a Fotonic Sensor accessory. Debonding time, identified as the necessary time to remove the photoresist from such surfaces, can vary with temperature, solvent, photoresist type or thickness, and exposure energy.