Test Vehicle/Meseran Method for Measuring the Interfacial Crosslink Density of Photolytically Cured Solder Masks and Other Protective Coatings
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
A method of enabling the use of a modified Meseran technique to measure crosslinking at the top and underside of photolytically cured solder mask adhesive layers is disclosed. The Meseran technique involves tracking the penetration of a solvent, such as methyl chloroform, into photoresist and then measuring the degree in which the photoresist swells. The Test Vehicle/Meseran technique may be used to periodically monitor the steps in the photoresist or solder mask process, such as exposure, development, and thermal cure or UV cure, to assure that they are within control limits. A critical parameter in the performance of photoresist protective coatings is the crosslink density of the cured material.