thickened conductive layer application_number US 60572800 A description referring initially to fig1 there is depicted an existing integrated circuit ic u201c chip u201d 1 in cross section without a plastic casing comprising a plurality of semiconductive layers 2 separated by thin layers of silicon nitride 6 in the ic art each layer includes a u201c front end u201d which refers to the actual circuitry and a u201c back end u201d which refers to conductive structures 3 for bringing signals into and out of the layer generally these conductive structures 3 will be of copper and will connect to the conductive structures of the u201c back ends u201d of immediately adjacent layers fig1 further depicts a dv level a tv level and an mt level known in the art the depiction of these particular layers in the drawings are for exemplary purposes only it not being necessary to have these specific layers in the order or arrangement shown most complex ics will have many more layers also shown in fig1 is a covering layer 7 that usually comprises a photosensitive polyimide polymer pspi and is commonly referred to as the u201c dv u201d or covering level this layer is not semiconductive and contains no circuitry below this layer is the topmost semiconductive layer the tv level 2 u2032 by u201c topmost u201d it is meant that in the art of ic chip manufacture this layer is actually physically facing upward and u201c topmost u201d on the assembly line and its fabrication is usually the final step of chip manufacture before laying down.