Abstract: Provided is an electromagnetic wave shielding sheet, a flexible printed circuit board attached with the electromagnetic wave shielding sheet, and a manufacturing method thereof. The flexible printed circuit board attached with the electromagnetic wave shielding sheet comprises: an electromagnetic wave shielding sheet including a nonwoven fabric having a plated surface and including an adhesive layer adsorbed therein without containing conductive particles, and a nonwoven fabric layer including a first insulating layer formed on the nonwoven fabric; and a flexible printed circuit board attached with the electromagnetic wave shielding sheet, wherein the flexible printed circuit board includes: a base film having a wiring pattern and a ground pattern formed on one side; and a second insulating layer covering the wiring pattern and exposing the ground pattern, and the nonwoven fabric layer having the adhesive layer adsorbed therein is in direct contact with the ground pattern.

Abstract: Disclosed herein is a ZnO-based varistor composition including zinc oxide (ZnO) as a main component and a calcium (Ca)-containing compound as an accessory component. The varistor composition provides excellent electrostatic discharge (ESD) characteristics because it has excellent physical properties, such as a nonlinear coefficient, a clamping voltage ratio, a surge absorbance and the like, and, particularly, does not include Bi2O3. Further, the varistor composition provides high work safety because it does not include Sb2O3 that is regulated for environmental purposes. Further, the varistor composition can reduce the manufacturing cost of a varistor because it does not Pr-based components that require high-temperature sintering and increase the manufacturing cost of a varistor. Particularly, the varistor composition has a low clamping voltage as well as a low capacitance.

Abstract: A stacked piezoelectric speaker device having a structure where a piezoelectric ceramic plate and an internal electrode plate are stacked, in which an inactive dummy electrode is disposed around an active internal electrode on the same layer to ensure uniform plastic shrinkage. The stacked piezoelectric speaker device has a structure in which an inactive dummy electrode that does not contribute to polarization is disposed around an active internal electrode that contributes to the polarization, the active internal electrode and the inactive dummy electrode being stacked on the same layer.

Abstract: Disclosed herein is a ZnO-based varistor composition including zinc oxide (ZnO) as a main component and a calcium (Ca)-containing compound as an accessory component. The varistor composition provides excellent electrostatic discharge (ESD) characteristics because it has excellent physical properties, such as a nonlinear coefficient, a clamping voltage ratio, a surge absorbance and the like, and, particularly, does not include Bi2O3. Further, the varistor composition provides high work safety because it does not include Sb2O3 that is regulated for environmental purposes. Further, the varistor composition can reduce the manufacturing cost of a varistor because it does not Pr-based components that require high-temperature sintering and increase the manufacturing cost of a varistor. Particularly, the varistor composition has a low clamping voltage as well as a low capacitance.