Method of making circuitized substrate
A method of making a circuitized substrate in which the substrate's commoning bar, used during the plating of the circuitry on the substrate, is terminated from the various conductors using a laser. In a preferred embodiment, the laser acts through a dielectric layer (soldermask) which is applied over the circuitry, including the commoning bar and connected parts. The laser may also be used to expose selected ones of the circuit's other parts, including various pads used to accommodate a wirebond (from a chip) and also solder balls for eventual placement of the substrate on a larger circuit board.
1. A method of making a circuitized substrate, said method comprising:
providing a first dielectric layer having a first surface;
forming a first pattern of conductors and a second pattern of conductors spaced from said first pattern and electrically coupled thereto on said first surface of said first dielectric layer;
forming a common conductive line on said first surface of said first dielectric layer electrically connected to each of said conductors of said second pattern of conductors;
providing a second dielectric layer in liquid form and flowing said second dielectric layer onto said first dielectric layer and substantially over said first and second patterns of conductors; and
thereafter terminating said electrical connections between each of said conductors of said second pattern of conductors and said common conductive line using a laser.
2. The method of claim 1 wherein said second dielectric layer comprises a soldermask.
3. A method of making a circuitized substrate, said method comprising:
providing a first dielectric layer having a first surface;
forming a first pattern of conductors and a second pattern of conductors spaced from said first pattern and electrically coupled thereto on said first surface of said first dielectric layer;
forming a common conductive line on said first surface of said first dielectric layer electrically connected to each of said conductors of said second pattern of conductors;
thereafter terminating said electrical connections between each of said conductors of said second pattern of conductors and said common conductive line using a laser; and
positioning a semiconductor chip on said first dielectric layer and electrically coupling said semiconductor chip to said first pattern of conductors.
4. The method of claim 3 wherein said electrically coupling of said semiconductor chip to said first pattern of conductors is accomplished using a wirebonding operation.
5. The method of claim 3 wherein said semiconductor chip is electrically coupled to said first pattern of conductors using a plurality of solder balls.
6. A method of making a circuitized substrate, said method comprising:
providing a first dielectric layer having a first surface;
forming a first pattern of conductors and a second pattern of conductors spaced from said first pattern and electrically coupled thereto on said first surface of said first dielectric layer;
forming a common conductive line on said first surface of said first dielectric layer electrically connected to each of said conductors of said second pattern of conductors;
positioning a second dielectric layer substantially over said first and second patterns of conductors; and
thereafter terminating said electrical connections between each of said conductors of said second pattern of conductors and said common conductive line using a laser while simultaneously using said laser to provide openings in said second dielectric layer above respective ones of said electrical connections.
7. The method of claim 6 wherein said laser also partially removes some of said first dielectric layer immediately below said electrical connections during said terminating of said connections.