Patent ID: 9519308
Filing Date: 2016-12-13
CPC Classification: G06F,H05K

Claim Text:
1. A printed circuit board, comprising outer surface layers and at least two inner layers between the outer surface layers, wherein: signal lines are arranged on an area basis on the at least two inner layers; each of the outer surface layers of the printed circuit board is arranged with a metal sheet, wherein each of the outer surface layers is disposed on an outer surface of the printed circuit board; the outer surface layers are interconnected by at least one through via, so that the outer surface layers function as a primary ground; the printed circuit board does not include a ground plane at any of the at least two inner layers; an interlayer distance between two adjacent inner layers is at least twice a distance from each of the two adjacent inner layers to a corresponding one of the outer surface layers closest to an inner layer; the printed circuit board comprises at least three base plates and the outer surface layers and the at least two inner layers are formed on surfaces of the base plates; and a number of layers of the at least two inner layers in the printed circuit board is two, and at least one BGA-packaged device is provide on the printed circuit board, a blind via in a BGD area is arranged below a pad of the BGA-packaged device, and a ground copper sheet with a large area in the BGA area is a mesh copper sheet.