Substrate with embedded patterned capacitance
View Patent ↗A process for forming a laminate with capacitance and the laminate formed thereby. The process includes the steps of providing a substrate and laminating a conductive foil on the substrate wherein the foil has a dielectric. A conductive layer is formed on the dielectric. The conductive foil is treated to electrically isolate a region of conductive foil containing the conductive layer from additional conductive foil. A cathodic conductive couple is made between the conductive layer and a cathode trace and an anodic conductive couple is made between the conductive foil and an anode trace.
1. A layered substrate comprising:
a first substrate;
a valve metal conductive foil laminated to said first substrate wherein said valve metal conductive foil comprises a valve metal oxide dielectric thereon;
a cathode on said dielectric;
a second substrate forming a layered structure with said valve metal conductive foil and said cathode between said first substrate and said second substrate;
a first trace on at least one of said first substrate and said second substrate;
a first via forming an electrical connection between said cathode and said first trace;
a second trace on at least one of said first substrate and said second substrate; and
a second via forming an electrical connection between said valve metal conductive foil and said second trace.
2. The layered substrate of claim 1 further comprising an isolation dam between said first substrate and said second substrate.
3. The layered substrate of claim 2 wherein a via or plated through hole passes through said isolation dam.
4. The layered substrate of claim 2 wherein said isolation dam circumvents said cathode.
5. The layered substrate of claim 1 wherein said cathode comprises a solid electrolyte layer.
6. The layered structure of claim 5 wherein said solid electrolyte layer comprises at least one conductor selected from the group consisting of conductive polymeric materials and manganese dioxide.
7. The layered structure of claim 6 wherein said conductive polymeric material comprises at least one material selected from the group consisting of polypyrrole, polyaniline, and polythiophene.
8. The layered structure of claim 1 wherein said valve metal conductive foil comprises one material selected from aluminum, tantalum, niobium, titanium and NbO.
9. The layered structure of claim 8 wherein said valve metal conductive foil comprises aluminum.
10. The layered structure of claim 8 wherein said dielectric comprises at least dielectric oxide selected from aluminum, tantalum, titanium and niobium.
11. The layered structure of claim 1 wherein said substrate comprises a glass-reinforced polymer.
12. A layered substrate comprising:
an embedded capacitor comprising:
a first substrate wherein said first substrate comprises a material selected from the group consisting of copper, copper coated circuit substrate, polyimide, phenolic and glass reinforced polymer;
a valve metal conductive foil laminated to said first substrate wherein said valve metal conductive foil comprises a valve metal oxide dielectric thereon;
a cathode on said dielectric;
a second substrate forming a layered structure with said valve metal conductive foil and said cathode between said first substrate and said second substrate and wherein said second substrate comprises a material selected from the group consisting of copper, copper coated circuit substrate, polyimide, phenolic and glass reinforced polymer;
a first trace on at least one of said first substrate and said second substrate;
a first via forming an electrical connection between said cathode and said first trace;
a second trace on at least one of said first substrate and said second substrate; and
a second via forming an electrical connection between said valve metal conductive foil and said second trace.