Abstract: A method is provided for modifying a via from a PCB including a plurality of subassemblies comprising a plurality of layers. The method may include drilling a via of the PCB to form a through-hole to remove an unwanted material in the via of the PCB. The method may also include depositing a carbon-based material over an inner wall of the through-hole. The method may further include back drilling a first portion of the through-hole by a drill from the top of the PCB to form a first blind via. The method may also include selectively plating a conductive material over the carbon-based material to form a plated through-hole.

Abstract: The disclosure provides a multilayer structure for a printed wiring board (PWB). The multilayer structure may include a plurality of insulating layers interleaved with a plurality of conductive layers comprising at least one inner conductive layer. The multilayer structure may also include one or more stub-less plated through-holes through the plurality of insulating layers and the plurality of conductive layers. The multilayer structure may include at least one secondary material layer formed on the at least one inner conductive layer. The secondary material layer defines a void that creates a discontinuity in the plated through-hole to achieve segmented metallization of the plated through-hole. The disclosure also provides a method of forming the multilayer structure.

Abstract: A method is provided for modifying a via from a PCB including a plurality of subassemblies comprising a plurality of layers. The method may include drilling a via of the PCB to form a through-hole to remove an unwanted material in the via of the PCB. The method may also include depositing a carbon-based material over an inner wall of the through-hole. The method may further include back drilling a first portion of the through-hole by a drill from the top of the PCB to form a first blind via. The method may also include selectively plating a conductive material over the carbon-based material to form a plated through-hole.