Leadless multi-layered ceramic capacitor stacks

• US 9,472,342 B2
• Filed: 08/06/2013
• Issued: 10/18/2016
• 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, Hill, Allen
• Primary Examiner(s): THOMAS, ERIC W
• Application Number:
  US13/959,954
• Publication Number:
  US 20140002952A1
• Time in Patent Office: 1,169 Days
• Field of Search: 361/306.3, 361/308.1, 361/309, 361/311
• US Class Current: 1/1
• 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 2101/40 Semiconductor devices
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 35/0227 Rods, wires B23K35/0244 takes precedence
• CPC Class Codes: B23K 35/3613 Polymers, e.g. resins
• CPC Class Codes: H01G 4/0085 Fried electrodes
• CPC Class Codes: H01G 4/12 Ceramic dielectrics H01G4/085 takes precedence
• CPC Class Codes: H01G 4/228 Terminals
• 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 4/38 Multiple capacitors, i.e. structural combinations of fixed capacitors
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00015 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• 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 2924/1461 : MEMS
• CPC Class Codes: Y10T 29/435 : Solid dielectric type

Abstract

A stacked MLCC capacitor is provided wherein the capacitor stack comprises multilayered ceramic capacitors wherein each multilayered ceramic capacitor comprises first electrodes and second electrodes in an alternating stack with a dielectric between each first electrode and each adjacent second electrode. The first electrodes terminate at a first side and the second electrodes second side. A first transient liquid phase sintering conductive layer is the first side and in electrical contact with each first electrode; and a second transient liquid phase sintering conductive layer is on the second side and in electrical contact with each second electrode.

Claims

1. A capacitor stack comprising:

multilayered ceramic capacitors wherein each multilayered ceramic capacitor of said multilayered ceramic capacitors comprises;

first electrodes and second electrodes in an alternating stack with a dielectric between each first electrode of said first electrodes and each adjacent second electrode of said second electrodes wherein said first electrodes have a first polarity and terminate at a first side of said multilayered ceramic capacitor and said second electrodes have a second polarity and terminate at a second side of said multilayered ceramic capacitor;

a first layer of transient liquid phase sintering compatible material on said first side and in electrical contact with each said first electrode; and

a second layer of transient liquid phase sintering compatible material on said second side and in electrical contact with each said second electrode.

2. The capacitor stack of claim 1 further comprising a conductive layer between said first side and said first transient liquid phase sintering conductive layer.

3. The capacitor stack of claim 2 wherein said first layer of transient liquid phase sintering compatible material comprises at least one low melting point metal selected from indium, tin, antimony, bismuth, cadmium, zinc, gallium, tellurium, mercury, thallium, selenium, or polonium, lead.

4. The capacitor stack of claim 2 wherein said conductive layer comprises a high temperature metal selected from the group consisting of silver, copper, aluminum, gold, platinum, palladium, beryllium, rhodium, nickel, cobalt, iron and molybdenum.

5. The capacitor stack of claim 2 wherein said conductive layer comprises nickel plated with an element selected from the group consisting of Ag, Sn, Au or SnPb.

6. The capacitor stack of claim 1 further comprising an external termination comprises nickel plated with an element selected from the group consisting of Ag, Sn, Au or SnPb.

7. The capacitor stack of claim 1 further comprising a lead frame.

8. The capacitor stack of claim 7 wherein said first layer of transient liquid phase sintering compatible material comprising a low melting metal where said low melting metal is diffused into said lead frame.

9. The capacitor stack of claim 8 wherein said low melting metal is also diffused into said first electrodes.

10. The capacitor stack of claim 8 further comprising an external termination between said first side and said first layer of transient liquid phase sintering compatible material.

11. The capacitor stack of claim 10 wherein said low melting metal is also diffused into said external termination.

12. The capacitor stack of claim 7 wherein said first layer of transient liquid phase sintering compatible material further comprises a high melting metal.

13. The capacitor stack of claim 1 further comprising a first lead frame in electrical contact with said first layer of transient liquid phase sintering compatible material and a second lead frame in electrical contact with said second layer of transient liquid phase sintering compatible material.

14. The capacitor stack of claim 13 wherein said first lead frame or said second lead frame comprises a material selected from the group consisting of phosphor bronze, copper, and ferrous alloys.

15. The capacitor stack of claim 14 wherein said first lead frame or second lead frame comprises a lead frame surface finish of Cu, Ag, Sn, Au, Ni, or Pb.

16. The capacitor stack of claim 13 wherein said first lead frame or said second lead frame comprises a material selected from the group consisting beryllium copper, Cu194 and Cu192.

17. The capacitor stack of claim 16 wherein said first lead frame or second lead frame comprises a lead frame surface finish of Cu, Ag, Sn, Au, Ni, or Pb.

18. The capacitor stack of claim 13 wherein said first lead or said second lead comprises a material selected from the group consisting of alloys of copper, Alloy 42 and Kovar.

19. The capacitor stack of claim 18 wherein said first lead frame or second lead frame comprises a lead frame surface finish of Cu, Ag, Sn, Au, Ni, or Pb.

20. The capacitor stack of claim 1 wherein said first layer of transient liquid phase sintering compatible material comprises a low melting metal and a high melting metal.

21. The capacitor stack of claim 20 wherein said low melting metal is diffused into both said high melting metal and said first electrodes.

22. The capacitor stack of claim 20 wherein said low melting metal is selected from the group consisting of indium, tin, antimony, bismuth, cadmium, zinc, gallium, tellurium, mercury, thallium, selenium, polonium and lead.

23. The capacitor stack of claim 20 wherein said high melting metal is selected from the group consisting of silver, copper, aluminum, gold, platinum, palladium, beryllium, rhodium, nickel, cobalt, iron and molybdenum.

24. The capacitor stack of claim 20 wherein said low melting metal is selected from the group consisting of indium, tin or bismuth and said high melting metal is selected from the group consisting of silver, copper or nickel.

25. The capacitor stack of claim 1 further comprising an insulator between adjacent multilayered ceramic capacitors.

26. The capacitor stack of claim 1 further comprising a sacrificial chip at the bottom of the stack to absorb flexure.

27. A capacitor stack comprising:

multilayered ceramic capacitors wherein each multilayered ceramic capacitor of said multilayered ceramic capacitors comprises;

first electrodes and second electrodes in an alternating stack with a dielectric between each first electrode of said first electrodes and each adjacent second electrode of said second electrodes wherein said first electrodes have a first polarity and terminate at a first side of said multilayered ceramic capacitor and said second electrodes have a second polarity and terminate at a second side of said multilayered ceramic capacitor;

a first transient liquid phase sintering conductive layer on said first side and in electrical contact with each said first electrode; and

a second transient liquid phase sintering conductive layer on said second side and in electrical contact with each said second electrode wherein said first transient sintering conductive layer further comprises a non-metallic filler.

28. The capacitor stack of claim 27 wherein said non-metallic filler is glass frit.