EMI suppression effects of a magnetic composite sheet with an internal conductive layer

With continuing development in the field of digital high-frequency devices, the problems of EMI in the quasi-microwave band are becoming increasingly serious. The authors have previously proposed a noise suppressing sheet made of soft magnetic metal flakes, and its efficacy as a countermeasure for high frequency noise has been confirmed. This sheet is already in practical use in cellular-phones and notebook PCs, installed near radiation sources. This paper describes EMI suppression effects achieved with the use of a new EMI suppression sheet with an internal conductive layer, designed for use in interference suppression between printed circuit boards