Patent ID: 8592690

Claim:
A circuit board comprising: a first shielding layer extending horizontally; an accessorial shielding layer; a signal circuit layer disposed between the first shielding layer and the accessorial shielding layer, said signal circuit layer having a plurality of signal traces; and a circumferential shielding layer surrounding the circuit board and electrically connecting with the first shielding layer and the accessorial shielding layer, wherein said circumferential shielding layer is separated into a first part and a second part, the first part surrounding one side of the circuit board, each side of the first part has an extension, the extension surrounding the other oppositely sides, the second part surrounding one side of the circuit board, each side of the second part has an extension, the extension surrounding said other oppositely sides, the other oppositely sides are only partly surrounded by the extensions of the first part and the second part with a gap.