Circuitized substrate with conductive polymer and seed material adhesion layer
View Patent ↗A method of making a circuitized substrate such as a laminate chip carrier in which a polymer, e.g., Teflon, is used as a dielectric layer and a promotion adhesion layer of a polymer is used to securely adhere a conductive layer thereto which is deposited by plating. The resulting product is thus able to provide extremely narrow conductive circuitry for subsequent connections, e.g., to a semiconductor chip. Electroless plating is the preferred plating method with the dielectric immersed in a solution of conductive monomers, e.g., pyrrole monomer, the solution also possibly containing a seed material such as palladium-tin.
1. A circuitized substrate comprising:
a polytetrafluoroethylene dielectric layer;
an adhesion promoting layer on said polytetrafluoroethylene dielectric layer and including a quantity of seed material and a conductive monomer; and
an electrolessly plated copper layer bonded to said adhesion promoting layer, said electrolessly plated copper layer being a circuit including a plurality of lines each having a peel strength within the range of from about 2.3 pounds per square inch to about 3.5 pounds per square inch.
2. The circuitized substrate of claim 1 wherein said conductive monomer is selected from the group of monomers consisting of pyrrole monomer, aniline monomer, thiophene monomer and combinations thereof.
3. The circuitized substrate of claim 2 wherein said seed material comprises palladium-tin.
4. The circuitized substrate of claim 1 wherein each of said lines of said circuit of said electrolessly plated copper layer is only about 0.001 inch thick.
5. The circuitized substrate of claim 4 including at least one additional substrate bonded to said circuitized substrate.
6. The circuitized substrate of claim 1 wherein said conductive monomer is oxidatively polymerized.