Printed circuit dielectric foil and embedded capacitors
A dielectric circuit board foil ( 400, 600 ) includes a conductive metal foil layer ( 210, 660 ), a crystallized dielectric oxide layer ( 405, 655 ) disposed adjacent a first surface of the conductive metal foil layer, a lanthanum nickelate layer ( 414, 664 ) disposed on the crystallized dielectric oxide layer, and an electrode layer ( 415, 665 ) that is substantially made of one or more base metals disposed on the lanthanum nickelate layer. The foil ( 400, 600 ) may be adhered to a printed circuit board sub-structure ( 700 ) and used to economically fabricate a plurality of embedded capacitors, including isolated capacitors of large capacitive density (>1000 pf/mm 2 ).
1. A dielectric circuit board foil, comprising:
a conductive metal foil layer;
a crystallized dielectric oxide layer disposed adjacent a first surface of the conductive metal foil layer;
a lanthanum nickelate layer disposed on the crystallized dielectric oxide layer;
an electrode layer substantially comprising at least one base metal disposed on the lanthanum nickelate layer; and
a high temperature anti-oxidant barrier disposed between and contacting the crystallized dielectric oxide layer and the conductive metal foil layer, wherein the high temperature anti-oxidant barrier is formed from a material effective to prevent any substantial oxidation of the conductive metal foil layer during pyrolysis and crystallization of the crystallized dielectric oxide layer.
2. The dielectric circuit board foil according to claim 1 , wherein the high temperature anti-oxidant barrier is formed from palladium, platinum, iridium, nickel, or alloys or compositions that include any combination of these metals.
3. A method for fabricating a circuit board foil, comprising:
forming a crystallized dielectric oxide layer on a conductive metal foil layer;
forming a lanthanum nickelate layer on the crystallized dielectric oxide layer; and
forming an electrode layer on the lanthanum nickelate layer, the electrode layer substantially comprising one or more base metals; and
coating a surface of the conductive metal foil layer with a high temperature anti-oxidant barrier, wherein the coated surface has a surface roughness that is less than 0.05 microns root mean square (RMS).