Circuit apparatus having a rounded differential pair trace

Abstract

A first artwork layer having a first adaptable-mask section allows a graded amount of light to pass into an underlying first photoresist layer. Subsequent to developing the first photoresist layer, the graded amount of light creates a rounded geometric void used as a mold or sidewall for the creation of at least a lower portion of a rounded trace. A dielectric layer is laminated upon the lower portion and a second artwork layer having an second adaptable-mask section allows a graded amount of light to pass into a second photoresist layer. Subsequent to developing the second photoresist layer, the graded amount of light creates a rounded geometric void used as a mold or sidewall for the creation of at least an upper portion of a rounded trace. The photoresist and dielectric layers are removed resulting in a circuit apparatus having a rounded differential pair trace.

The invention claimed is: 
     
         1 . A circuit apparatus having a rounded electrically conductive differential pair trace comprising:
 a dielectric layer;   a lower portion of the rounded electrically conductive trace having a first rounded sidewall and a first flat sidewall, the lower portion of the electrically conductive trace joined to the dielectric layer; and   an upper portion of the rounded electrically conductive trace having a second rounded sidewall and a second flat sidewall, the lower portion of the electrically conductive trace joined to an opposing side of the dielectric layer aligned with the lower portion of the rounded electrically conductive trace.   
     
     
         2 . The apparatus of  claim 1  wherein the first rounded sidewall and the second rounded side wall are aligned to form a circular geometry. 
     
     
         3 . The apparatus of  claim 1  wherein the first rounded sidewall and the second rounded side wall are aligned to form an elliptical geometry. 
     
     
         4 . The circuit apparatus of  claim 1  further comprising a first photoresist layer having a geometrical void used to create the lower portion of the rounded electrically conductive trace. 
     
     
         5 . The circuit apparatus of  claim 4  further comprising a second photoresist layer having a geometrical void used to create the lower portion of the rounded electrically conductive trace. 
     
     
         6 . The circuit apparatus of  claim 5  wherein the first photoresist layer has an opposite tone relative to the second photoresist layer. 
     
     
         7 . The circuit apparatus of  claim 1  further comprising:
 a substrate layer. 
 
     
     
         8 . The circuit apparatus of  claim 7  wherein the first rounded sidewall is mechanically supported by the substrate layer. 
     
     
         9 . The circuit apparatus of  claim 1  wherein the first flat sidewall and the second flat sidewall are joined to the dielectric layer. 
     
     
         10 . A design structure embodied in a non-transitory machine readable medium for designing, manufacturing, or testing a circuit apparatus having a rounded electrically conductive differential pair trace, the design structure comprising:
 a dielectric layer;   a lower portion of the rounded electrically conductive trace having a first rounded sidewall and a first flat sidewall, the lower portion of the electrically conductive trace joined to the dielectric layer; and   an upper portion of the rounded electrically conductive trace having a second rounded sidewall and a second flat sidewall, the lower portion of the electrically conductive trace joined to an opposing side of the dielectric layer aligned with the lower portion of the rounded electrically conductive trace.   
     
     
         11 . The design structure of  claim 10  wherein the first rounded sidewall and the second rounded side wall are aligned to form a circular geometry. 
     
     
         12 . The design structure of  claim 10  wherein the first rounded sidewall and the second rounded side wall are aligned to form an elliptical geometry. 
     
     
         13 . The design structure of  claim 10  further comprising a first photoresist layer having a geometrical void used to create the lower portion of the rounded electrically conductive trace. 
     
     
         14 . The design structure of  claim 13  further comprising a second photoresist layer having a geometrical void used to create the lower portion of the rounded electrically conductive trace. 
     
     
         15 . The design structure of  claim 14  wherein the first photoresist layer has an opposite tone relative to the second photoresist layer. 
     
     
         16 . The design structure of  claim 10  further comprising:
 a substrate layer. 
 
     
     
         17 . The design structure of  claim 16  wherein the first rounded sidewall is mechanically supported by the substrate layer. 
     
     
         18 . The design structure of  claim 10  wherein the first flat sidewall and the second flat sidewall are joined to the dielectric layer. 
     
     
         19 . The design structure of  claim 10 , wherein the design structure comprises a netlist. 
     
     
         20 . The design structure of  claim 10 , wherein the design structure resides on storage medium as a data format used for the exchange of layout data of a circuit apparatus.