an exterior layer of flexible substrate 106 see description of shield layer 164 below to form a faraday cage that surrounds and protects boosting component 152 by preventing the passage of emi through shield 112 with the faraday cage alternatively a bottom side of the faraday cage can be formed by a grounding layer within flexible substrate 106 or by stiffener 118 when stiffener 118 is formed of electrically conductive material in some embodiments gasket 116 can form a grounding pathway for shield 112 gasket 116 can be adhesively secured to an internal surface of a device housing to help secure flexible circuit assembly 100 in place within the device housing gasket 116 can take the form of a conductive foam that increases in conductivity when compressed the conductive foam can be a foam infused with metals along the lines of aluminum copper steel or nickel in some embodiments shield 112 can also be grounded through grounding pads 114 fig1 b includes close up view 154 which shows a magnified detail of flexible substrate 106 which is made up of a number of discrete layers 156 158 160 162 and 164 in some embodiments flexible substrate 106 includes a number of signal layers depicted as high speed layer 156 and low speed layer 160 each of the signal layers can include various trace patterns that distribute discrete signals through the respective layer while high speed layer 156 can be configured to provide passage for a majority of higher bandwidth signals and low speed layer 160 can be configured for low bandwidth signals in certain embodiments high speed and low speed signals.