Conductive nanostructure-based films with improved ESD performance
Optical stacks containing one or more patterned transparent conductor layers may be damaged by electrostatic discharges that occur during the optical stack manufacturing process. Such damage may result in non-conductive conductors within the patterned transparent conductor layer. An electrostatic discharge protected optical stack may include a substrate layer, a first anti-static layer having a sheet resistance of from about 10 6 ohms per square (Ω/sq) to about 10 9 Ω/sq, and a patterned transparent conductor layer. Methods of testing and assessing damage to patterned transparent conductors are provided.
1. A method of assessing the effects of electrostatic discharge on a patterned transparent conductor, the method comprising:
depositing an anti-static substrate layer proximate at least a portion of a grounded counter electrode;
depositing a patterned transparent conductor layer at least partially across and proximate the anti-static substrate layer laterally opposite the grounded counter electrode;
disposing a charging inlet proximate the anti-static substrate layer at a first location on a side of the anti-static substrate layer including the patterned transparent conductor layer, the first location not in direct physical contact with either the patterned transparent conductor or the anti-static substrate layer;
disposing a drain outlet proximate the anti-static substrate layer at a second location on the side of the anti-static substrate layer including the patterned transparent conductor layer, the second location not in direct physical contact with either the patterned transparent conductor or a second surface of the anti-static substrate layer and at least a portion of the patterned transparent conductor between the first location and the second location; and
electrically coupling the drain outlet to the grounded counter electrode.
2. The method of claim 1 , further comprising:
electrically coupling a charged capacitor to the charging inlet; and
accumulating an electrical charge at the charging inlet;
dissipating the accumulated electrical charge at the charging inlet through at least one of either the anti-static substrate layer or patterned transparent conductor layer; and
determining the electrical conductivity of all or a portion of the patterned transparent conductor layer.
3. The method of claim 2 wherein electrostatically discharging the accumulated electrical charge at the charging inlet to the anti-static substrate layer comprises:
discharging the charged capacitor through a first external resistor placed in series with the charging inlet.
4. The method of claim 3 wherein discharging the charged capacitor through a first external resistor placed in series with the charging inlet comprises:
discharging the charged capacitor through the first external resistor, the first external resistor including at least one resistance value of one million ohms (1 MΩ) or greater.
5. The method of claim 4 wherein depositing a patterned transparent conductor layer at least partially across and proximate the anti-static substrate layer comprises:
depositing the patterned transparent conductor layer at least partially across and proximate a polyethylene terephthalate (PET) substrate layer that includes at least one of: one or more anti-static materials disposed within the substrate layer or one or more anti-static layers disposed proximate the anti-static substrate layer.