Electronic Component Termination and Assembly by Means of Transient Liquid Phase Sintering Metalurgical Bonds

• US 20140177132A1
• Filed: 02/28/2014
• Published: 06/26/2014
• Est. Priority Date: 05/26/2010
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Inventors: MCCONNELL, JOHN E., RENNER, GARRY L., BULTITUDE, JOHN
• Granted Patent: US 9,881,744 B2
• Time in Patent Office: Days
• US Class Current: 361/305
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 1/0053 soldering by means of I.R.
• CPC Class Codes: B23K 1/008 Soldering within a furnace B23K1/012 takes precedence
• CPC Class Codes: B23K 1/203 Fluxing, i.e. applying flux onto surfaces
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 35/0227 Rods, wires B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/286 Al as the principal constituent
• CPC Class Codes: B23K 35/3613 Polymers, e.g. resins
• CPC Class Codes: H01G 4/005 Electrodes
• CPC Class Codes: H01G 4/2325 characterised by the material of the terminals
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01G 9/0029 Processes of manufacture
• CPC Class Codes: H01G 9/0032 formation of the dielectric layer
• CPC Class Codes: H01G 9/008 Terminals
• CPC Class Codes: H01G 9/045 based on aluminium
• CPC Class Codes: H01G 9/07 Dielectric layers
• CPC Class Codes: H01L 2224/83825 Solid-liquid interdiffusion
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: Y10T 29/435 : Solid dielectric type

Abstract

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.

Claims

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 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 10 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.

21. An MLCC capacitor comprising:

first planer internal aluminum or aluminum alloy electrodes in electrical contact with a first external termination;

second planer internal aluminum or aluminum alloy electrodes interleaved with said first planer electrodes wherein said second internal electrodes are in electrical contact with a second external termination;

a dielectric between said first planer internal electrodes and said second planer internal electrodes; and

at least one of said first external termination or said second external termination comprises a transient phase sintering metallurgical bond.

22. The MLCC capacitor of claim 21 wherein said first external termination is a metallurgical bond to said first planer internal aluminum electrodes.

23. The MLCC capacitor of claim 21 wherein said transient liquid phase sintered conductive material has at least 90 wt % metal.

24. The MLCC capacitor of claim 23 wherein said transient liquid phase sintered conductive material has at least 95 wt % metal.

25. The MLCC capacitor of claim 21 wherein said transient liquid phase sintered conductive material has no more than 98 wt % metal.

26. The MLCC capacitor of claim 21 wherein said wherein said transient liquid phase sintered conductive adhesive comprises copper and tin.

27. The MLCC capacitor of claim 26 wherein said 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.

28. The MLCC capacitor of claim 27 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 % tin to no more than 90 wt % tin.

29. The MLCC capacitor of claim 27 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.

30. The method for forming a capacitor of claim 29 wherein said non-volatile filler is selected from ceramics, glasses and polymers with a melting point such above 300°

C.

31. An electrical component comprising:

an aluminum or aluminum alloy layer;

a lead in contact with said aluminum or aluminum alloy layer; and

wherein said contact comprises a metallurgical bond with said aluminum or aluminum alloy layer wherein said metallurgical bond comprises transient liquid phase sintering material.

32. The electrical component of claim 31 wherein said aluminum is an electrical or conductive layer or a thermally conductive layer.

33. The electrical component of claim 31 wherein said thermally conductive layer is a heat sink.

34. The electrical component of claim 31 wherein said transient liquid phase sintered conductive material has at least 90 wt % metal.

35. The electrical component claim 34 wherein said transient liquid phase sintered conductive material has at least 95 wt % metal.

36. The electrical component claim 31 wherein said transient liquid phase sintered conductive material has no more than 98 wt % metal.

37. The electrical component of claim 31 wherein said metallurgical bond comprises a copper aluminum alloy.

38. The electrical component of claim 31 wherein said transient liquid sintering material comprises a high melting temperature component and a low melting temperature component.

39. The electrical component of claim 31 wherein said transient liquid phase sintering conductive material comprises copper and tin.

40. The electrical component of claim 39 wherein said transient liquid phase sintered conductive material comprises at least 60 wt % of a copper/tin portion and no more than 40 wt % of a secondary portion.

41. The electrical component of claim 40 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.

42. The electrical component of claim 40 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.

43. The electrical component of claim 42 wherein said non-volatile filler is selected from ceramics, glasses and polymers with a melting point such above 300°

C.

44. An MLCC capacitor comprising:

first planer internal electrodes in electrical contact with a first external termination wherein said first external termination comprises aluminum or aluminum alloy;

second planer internal electrodes interleaved with said first planer electrodes wherein said second internal electrodes are in electrical contact with a second external termination;

a dielectric between said first planer internal electrodes and said second planer internal electrodes;

a first lead in electrical contact with said first external termination; and

wherein said first external termination is attached to said first lead by a transient liquid phase sintering material.

45. The MLCC capacitor of claim 44 wherein said first planer internal electrodes are aluminum or aluminum alloy and said first external termination is a metallurgical bond to said first planer internal electrodes.

46. The MLCC capacitor of claim 45 wherein said metallurgical bond comprises a copper aluminum alloy.

47. The MLCC capacitor of claim 44 wherein said transient liquid phase sintered conductive material has at least 90 wt % metal.

48. The MLCC capacitor of claim 47 wherein said transient liquid phase sintered conductive material has at least 95 wt % metal.

49. The MLCC capacitor of claim 44 wherein said transient liquid phase sintered conductive material has no more than 98 wt % metal.

50. The MLCC capacitor of claim 44 wherein said wherein said transient liquid phase sintered conductive material comprises copper and tin.

51. The MLCC capacitor of claim 44 wherein said wherein said transient liquid phase sintered conductive material comprises at least 60 wt % of a copper/tin portion and no more than 40 wt % of a secondary portion.

52. The MLCC capacitor of claim 51 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 % tin to no more than 90 wt % tin.

53. The MLCC capacitor of claim 51 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.

54. The MLCC capacitor of claim 44 wherein said first lead is plated with a material comprising at least one of nickel, copper, gold, silver, tin, palladium and lead.

55. The MLCC capacitor of claim 44 wherein at least one of said anode lead or said cathode lead is a non-ferrous material or a ferrous material.

56. The MLCC capacitor of claim 55 wherein said non-ferrous material is selected from copper, phosphor bronze, brass and beryllium copper.

57. The MLCC capacitor of claim 55 wherein said ferrous material is selected from Alloy 42 and Kovar.