Reduced circuit trace roughness for improved signal performance

Abstract

Exemplary techniques for improving the performance of signals transmitted by conductive circuit traces are disclosed. The techniques may be realized as a method comprising the step of reducing a surface roughness of at least one surface of a conductive circuit trace. Alternatively, the techniques may be realized as a circuit board for transmitting at least one signal, the circuit board comprising at least one conductive circuit trace for carrying at least one signal, the at least one conductive circuit trace having at least one polished surface. Further, the technique may be realized as a conductive circuit trace for carrying a signal, the conductive circuit trace comprising conductive material having a plurality of surfaces substantially parallel with a direction of propagation of the signal, wherein the plurality of surfaces includes at least one polished surface having a reduced surface roughness.

1 - 18 . (canceled) 
     
     
         19 . A method of manufacturing a circuit board, comprising:
 providing a first circuit board layer of a circuit board, the first circuit board layer having a conductive circuit trace on a surface of the first circuit board layer;   reducing a surface roughness of at least one surface of the conductive circuit trace by vacuum depositing conductive material on the at least one surface; and   laminating the first circuit board layer with a second circuit board layer.   
     
     
         20 . The method of  claim 19 , wherein the step of reducing the surface roughness comprises a lateral smoothing technique operable to reduce surface roughness in a direction along the circuit trace. 
     
     
         21 . The method of  claim 19 , wherein the step of reducing the surface roughness comprises a transverse smoothing technique operable to reduce surface roughness in a direction across the circuit trace. 
     
     
         22 . The method of  claim 19 , wherein the step of reducing the surface roughness reduces the surface roughness to no more than 20 microinches root-mean-squared (RMS). 
     
     
         23 . The method of  claim 19 , wherein the step of reducing the surface roughness reduces the surface roughness to no more than 10 microinches root-mean-squared (RMS). 
     
     
         24 . The method of  claim 19 , wherein the step of reducing the surface roughness reduces the surface roughness to no more than 5 microinches root-mean-squared (RMS). 
     
     
         25 . The method of  claim 19 , further comprising forming the circuit trace on the surface of the first circuit board layer. 
     
     
         26 . The method of  claim 19 , further comprising affixing the circuit trace on the surface of the first circuit board layer. 
     
     
         27 . The method of  claim 26 , further comprising reducing a surface roughness of a surface of the circuit trace before affixing that surface of the circuit trace to the surface of the first circuit board layer. 
     
     
         28 . The method of  claim 27 , further comprising applying an adhesion promoter to strengthen adhesion between the surface of the circuit trace and the surface of the first circuit board layer. 
     
     
         29 . The method of  claim 19 , comprising reducing a roughness of at least one side surface of the circuit board trace. 
     
     
         30 . A circuit board manufactured by:
 providing a first circuit board layer of a circuit board, the first circuit board layer having a conductive circuit trace on a surface of the first circuit board layer;   reducing a surface roughness of at least one surface of the conductive circuit trace by vacuum depositing conductive material on the at least one surface; and   laminating the first circuit board layer with a second circuit board layer.   
     
     
         31 . The circuit board of  claim 30 , wherein the surface roughness of the circuit trace is no more than 20 microinches root-mean-squared (RMS). 
     
     
         32 . The circuit board of  claim 30 , wherein the surface roughness of the circuit trace is no more than 10 microinches root-mean-squared (RMS). 
     
     
         33 . The circuit board of  claim 30 , wherein the surface roughness of the circuit trace is no more than 5 microinches root-mean-squared (RMS). 
     
     
         34 . A method of manufacturing a circuit board, comprising:
 providing a first circuit board layer of a circuit board, the first circuit board layer having a conductive circuit trace on a surface of the first circuit board layer;   reducing a surface roughness of at least one surface of the conductive circuit trace;   applying an adhesion promoter to the at least one surface of the conductive circuit trace; and   laminating the first circuit board layer with a second circuit board layer.   
     
     
         35 . The method of  claim 34 , further comprising affixing the circuit trace on the surface of the first circuit board layer. 
     
     
         36 . The method of  claim 35 , further comprising reducing a surface roughness of a surface of the circuit trace before affixing that surface of the circuit trace to the surface of the first circuit board layer. 
     
     
         37 . The method of  claim 36 , further comprising applying an adhesion promoter to strengthen adhesion between the surface of the circuit trace and the surface of the first circuit board layer. 
     
     
         38 . The method of  claim 34 , wherein reducing surface roughness comprises at least one method in a group consisting of electropolishing the at least one surface, chemical polishing the at least one surface, electroplating the at least one surface; and vacuum depositing conductive material on the at least one surface.