The water break test

Purpose To discuss the validity of the water break test, commonly used as a means of cleanliness determination in the printed circuit fabrication industry. Design/methodology/approach To examine qualitatively the physics of water‐wetting of solid substrates and their energy levels and the conditions under which cohesion may occur. Findings It would seem that conditions could occur, which would render the likelihood of the test being valid problematic. Practical implications Technical managers of fabricators using the test may wish to re‐examine whether it is valid under their particular circumstances. If it were replaced by a more scientific test covering their particular needs, it is possible that the reliability of subsequent operations may be improved, increasing production yield. Originality/value The author previously cast doubts on the test validity but this is the first physical analysis of the situation, confirming prior statements. The value of this paper is to demonstrate that a long‐standing practice may be either meaningless or of significantly reduced usefulness.