This paper investigates the experimental reliability of SN9000 ink on the chip on film and the axial and shear stress distributions across the squared and spew end of ink in single-lap joints. The glass transition temperature of SN9000 was analyzed by a regression analysis method. The results demonstrated that for the continuous heating of a single ink drop, the confidence level is more than 96.7%. The stress field in single-lap joints with square and spew geometries was simulated by the finite element method. The stress distribution across the lap length at the interface for joints with spew ends was compared to that of square ended single lap joints. The maximum magnitude of the von Mises stress was less than the yield strength of the substrate material. These results helped us to understand that the relationship between the glass transition temperature and von Mises stress is less than the yield strength of SN9000. (C) Koninklijke Brill NV, Leiden, 2011