Infinera Corporation
Printed circuit board having a differential pair routing topology with negative plane routing and impedance correction structures

Abstract:

A printed circuit board including a set of five layers encompassing a breakout area is described. The set includes a first ground layer, a first signal layer having a first conductive layer within the breakout area, a second ground layer having conductive material, a second signal layer having a second conductive layer within the breakout area, and a third ground layer. The second ground layer having a void forming a differential pair being two parallel traces, and being separated into a first portion positioned within the breakout area and a second portion outside of the breakout area. The differential pair having a first width and a first spacing within the breakout area and a second width and second spacing outside of the breakout area, with the second width greater than the first width. The first and second conductive layers forming a first ground plane and a second ground plane.