Systems and methods for removing undesired metal within vias from printed circuit boards
AssigneeTTM Technologies, Inc.
InventorsMace Lehrer, James McKay, Charles Blessing
Life of this patent
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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.
Claims12
A drill for use in back drilling of a PCB, the drill comprising:
- an inner core comprising a solid cylindrical body having an outer cylindrical surface and a closed planar end surface coupled to the outer cylindrical surface, the closed planar end surface being substantially perpendicular to a vertical central axis of the solid cylindrical body;
- a continuous outer coating layer disposed over the outer cylindrical surface and the closed planar end surface of the inner core, the outer coating layer comprising a first cutting portion, a second cutting portion opposite to the first cutting portion, and an inner middle portion coupled between the first and second cutting portions, the first and second cutting portions comprising a conductive material and extending outwardly from the closed planar end surface of the inner core;
- and
- a non-conductive coating disposed over the inner middle portion of the outer coating layer between the first and second cutting portions.
Dependencies are inferred from the claim text.