Patent ID: 6985659
Filing Date: 2006-01-10
Classification: G02B,H05K

Abstract:
1. An optical transmission module comprising a substrate having an electronic part mounted on the substrate and a terminal area for inputting/outputting an electric signal into/from the electronic part, wherein: an electrical connection to a terminal area of the substrate is made by use of a flexible substrate having a structure constituted of at least two layers, said flexible substrate comprising a signal conductor; ground conductors that are placed on both sides of the signal conductor while keeping a distance from the signal conductor; a ground plane provided on an upper layer or a lower layer of the signal conductor across a dielectric; and a conductor that electrically connects between the ground conductor and the ground plane; a connection section of the flexible substrate has a structure whereby the electric field density observed in an area from the signal conductor to the upper-layer ground plane or the low-layer ground plane is gradually decreased from inside toward an edge of the flexible substrate in a longitudinal direction; and an electric signal is transmitted between the electronic part mounted on the substrate and the flexible substrate.