Patent ID: 6835897
Filing Date: 2004-12-28
Classification: H01L,H05K

Abstract:
A warpage preventing substrate, comprising:a core layer having a first surface and a second surface opposed to the first surface; a plurality of first conductive traces and second conductive traces respectively formed on the first surface and the second surface of the core layer, each of the conductive traces having a terminal; a plurality of first non-functional traces and second non-functional traces respectively formed on the first surface and the second surface of the core layer at area free of the conductive traces, wherein the first non-functional traces are arranged in different density from the second non-functional traces, wherein the first conductive traces and the first non-functional traces deform to an extent substantially equivalent to deformation of the second conductive traces and the second non-functional traces under temperature variation, thereby preventing warpage of the substrate; and an insulating layer applied over each of the first and second surfaces of the core layer, for covering the conductive traces and non-functional traces, with the terminals of the conductive traces being exposed to outside of the insulating layers.