Attenuation reduction grounding pattern structure for connection pads of flexible circuit board

摘要

An attenuation reduction grounding pattern structure for connection pads of a flexible circuit board includes a plurality of high frequency connection pads formed on a component surface of a substrate and a plurality of differential mode signal lines arranged on the substrate and connected to the high frequency connection pads. The substrate has a grounding surface forming a grounding layer. The grounding layer includes an attenuation reduction grounding pattern structure formed at a location corresponding to the transition zone and including a hollowed area and a protruded portion. The protruded portion extends a predetermined length in a direction from the grounding layer toward the high frequency connection pads and along the adjacent high frequency connection pads to reach the transition zone. The protruded portion and the high frequency connection pads form a polarization-direction-varying electric field in the transition zone.

主权项

1. An attenuation reduction grounding pattern structure for connection pads of a flexible circuit board, the flexible circuit board comprising:
a substrate, which includes a first end, a second end, and an extension section located between the first end and the second end and extending in an extension direction, the substrate having a surface forming a component surface and an opposite surface forming a grounding surface; at least a pair of high frequency connection pads, which are arranged on a connection pad laying zone defined by the component surface of the substrate to be adjacent to and insulated from each other and being adjacent to the first end of the substrate; at least a pair of differential mode signal lines, which are arranged on the extension section of the substrate to be adjacent to and insulated from each other and are respectively connected to the adjacent high frequency connection pads, the at least a pair of differential mode signal lines carrying at least one the high frequency differential mode signal, an area of connection between the differential mode signal lines and the high frequency connection pads being defined as a transition zone; the grounding surface of the substrate forming a grounding layer; wherein the grounding layer includes an attenuation reduction grounding pattern structure formed at a location corresponding to the transition zone, the attenuation reduction grounding pattern structure including:
a hollowed area, which corresponds to the connection pad laying zone, the hollowed area covering the transition zone; anda protruded portion, which extends a predetermined length in a protrusion direction from the grounding layer toward the high frequency connection pads and along the adjacent high frequency connection pads to reach the transition zone; wherein the protruded portion includes a gradually reduced width so that the protruded portion has a large width connected to the grounding layer and an increasingly reduced width in the extension direction toward the high frequency connection pads.