Title:

Determination of Optimum Ink Viscosity Range and Standardization of Thinner Addition for the Reduction of Illegible Mark Defect

Author(s):

Ma. Christina Violante, Elizabeth Pulga, Lloyd Nino Unabia, Allegro Microsystems Phils., Inc.

Gist:

Ink viscosity, which greatly affects ink mark quality and permanency, is an important factor in the pad printing process. Ink viscosity that is too high or too low results in uncured or smeared marks. This study deals with the improvement of ink mark quality and permanency by controlling the ink film thickness on the package surface through optimization and standardization of the ink viscosity range. A system for the regular addition of thinner to the ink to maintain ink viscosity was also defined. To determine the optimum viscosity range, different ink viscosity values were evaluated using mark reliability testing and visual inspection results as output responses. After the optimum ink viscosity range was established, the rate of thinner evaporation was determined. From this, the amount and frequency of thinner addition to maintain the required ink viscosity was defined. The implementation of actions generated by this study reduced the occurrence level of illegible marks by 78%.

Published in :

ASEMEP 2001 Proceedings; June, 2001