The region of the perforation hole which is established in the sealed board, the portable communications terminal, and the sealed board IC where the methodological

摘要

PROBLEM TO BE SOLVED: To prevent electromagnetic wave noise, which is generated from a digital circuit in a digital/analog mixed IC when inserting a shield plate and propagated through the shield plate, from being fed back to the analog circuit in the same digital/analog mixed IC, thereby preventing the degradation of performance of the analog circuit.;SOLUTION: A through hole is pieced into a portion of the shield plate, which is opposed to an area of a digital/analog mixed IC wherein the performance of an analog circuit is deteriorated by application of electromagnetic wave noise propagated into the shield plate. Further, a chucking plate to be used for carrying a shield frame is arranged on a position not covering the through hole but covering part of the digital/analog mixed IC.;COPYRIGHT: (C)2011,JPO&INPIT