Multilayer substrate module and portable wireless terminal

Abstract

In a multi-layer substrate module receiving from an external earth node supply of a reference potential for grounding, a plurality of ground lines are provided respectively corresponding to a plurality of internal circuits. Moreover, a common node for coupling the ground lines is provided in an insulating layer of the multi-layer substrate module. The common node is electrically coupled to the earth node through a ground pin terminal shared by the plurality of internal circuits. Preferably, the common node is provided in the lowest insulating layer of the multi-layer substrate module. Thus, parasitic inductance of the portion through which an earth current flows, that is, the portion common to the plurality of internal circuits, can be suppressed with a small number of ground pin terminals. Accordingly, the inflow phenomenon of the earth current between the plurality of internal circuits is prevented, enabling stable operation.