Charge behavior in/on polymer films by simultaneous LIPP and TSDC method

T various polymer films with high resistivity are developed for various usage. Because of that excellent electric properties (high resistivity, in practice), it is very easy to accumulate the charge accidentally. That charge causes various electrostatic hazards including the electrostatic discharge. To prevent those electrostatic problems, charge behavior on/in the polymer film must be identified. The authors have already constructed the simultaneous TSDC (thermally stimulated discharge current) and LIPP (laser-induced pressure pulse) measuring system to investigate those problems. Tested samples are polyethylenetelephtalate and naphthalate (PEN) which are charged by the corona discharge. Some charge is injected from the back side (grounded side) and from the top side. There are some difference between those charges (TSDC peak temperature is not unique). Some charge change without TSDC flow is also identified near the room temperature indicating the mechanical contact change with the temperature and the surface leakage of the charge.