Electronic component termination and assembly by means of transient liquid phase sintering metallurgical bond
An improved method for forming a capacitor is provided as is a capacitor, or electrical component, formed by the method. The method includes providing an aluminum containing anode with an aluminum oxide dielectric thereon; forming a cathode on a first portion of the aluminum oxide dielectric; bonding an anode lead to the aluminum anode on a second portion of the aluminum oxide by a transient liquid phase sintered conductive material thereby metallurgical bonding the aluminum anode to the anode lead; and bonding a cathode lead to said cathode.
1. A method for forming a capacitor comprising:
providing an aluminum containing anode with an aluminum oxide dielectric thereon;
forming a cathode on a first portion of said aluminum oxide dielectric;
bonding an anode lead to said aluminum anode on a second portion of said aluminum oxide by a transient liquid phase sintered conductive material thereby metallurgical bonding said aluminum anode to said anode lead; and
bonding a cathode lead to said cathode.
2. The method for forming a capacitor of claim 1 wherein said transient liquid phase sintered conductive material has at least 90 wt % metal.
3. The method for forming a capacitor of claim 2 wherein said transient liquid phase sintered conductive adhesive has at least 95 wt % metal.
4. The method for forming a capacitor of claim 1 wherein said bonding of said anode lead includes heating to a first temperature followed by heating to a second temperature.
5. The method for forming a capacitor of claim 1 wherein said metallurgical bond comprises a copper aluminum alloy.
6. The method for forming a capacitor of claim 1 wherein said transient liquid sintering material comprises a high melting temperature component and a low melting temperature component.
7. The method for forming a capacitor of claim 6 wherein said high melting temperature component of the transient liquid phase sintering material comprises at least one member selected from the group consisting of copper, silver, aluminum, gold, platinum, palladium, beryllium, rhodium nickel, cobalt, iron and molybdenum or an alloy of said member.
8. The method for forming a capacitor of claim 6 wherein said low melting temperature component of the transient liquid phase sintering material comprises at least one member selected from the group consisting of tin, antimony, bismuth, cadmium, zinc, gallium, indium, tellurium, mercury, thallium, selenium and polonium or an alloy said member.
9. The method for forming a capacitor of claim 1 wherein said transient liquid phase sintered conductive material comprises copper and tin.
10. The method for forming a capacitor of claim 9 wherein said transient liquid phase sintered conductive material comprises at least 60 wt % a copper/tin portion and no more than 40 wt % as secondary portion.
11. The method for forming a capacitor of claim 9 wherein said transient liquid phase sintered conductive material comprises at least 10 wt % to no more than 70 wt % copper and at least 30 wt % to no more than 90 wt % tin.
12. The method for forming a capacitor of claim 11 wherein said secondary portion comprises a material selected from the group consisting of silver, aluminum, gold, platinum, palladium, beryllium, rhodium, nickel, cobalt, iron, molybdenum, antimony, bismuth, cadmium, zinc, gallium, indium, tellurium, mercury, thallium, selenium, polonium, and a non-volatile filler.
13. The method for forming a capacitor of claim 12 wherein said non-volatile filler is selected from ceramics, glasses and polymers with a melting point such above 300° C.
14. The method for forming a capacitor of claim 1 wherein at least one of said anode lead or said cathode lead is plated with a material comprising at least one of nickel, copper, gold, silver, tin, palladium and lead.
15. The method for forming a capacitor of claim 1 wherein at least one of said anode lead or said cathode lead is a non-ferrous material or a ferrous material.
16. The method for forming a capacitor of claim 15 wherein said non-ferrous material is selected from aluminum, copper, phosphor bronze, brass and beryllium copper.
17. The method for forming a capacitor of claim 15 wherein said ferrous material is selected from Alloy 42 and Kovar.
18. The method for forming a capacitor of claim 1 wherein said transient liquid phase sintering material does not comprise lead.
19. The method for forming a capacitor of claim 1 wherein said bonding does not include removing said aluminum oxide dielectric.
20. The method for forming a capacitor of claim 1 wherein said cathode comprises a conductive polymer.