Printed circuit board

摘要

A printed circuit board is provided with a plurality of insulator layers and a plurality of conductor layers, and an outermost conductor layer has a plurality of foot patterns in outer and inner rows for mounting a BGA component and signal patterns. The width of at least a part of the signal pattern extending from the foot pattern in the outer row is greater than the width of the signal pattern extending from the foot pattern in the inner row. The printed circuit board further includes a protection layer for covering the signal patterns on the outermost conductor layer, and the protection layer has openings each for permitting the foot pattern to be exposed. At least a portion of the signal pattern appearing in the opening is widened.