Surface resistivity, mechanical strength and coating adhesion
were then measured. The study found that the electrical percolation threshold of the PVOH/GNP coating
is 9e13wt% GNP. GNP incorporated PVOH coatings with surface resistivity of 103e108 U/sq. generally
meet all of ESD packaging requirements. The humidity strongly affects the surface resistivity of the
coatings below the percolation threshold, but the change of the surface resistivity with humidity is less
significant above the percolation threshold.