CAPACITOR WITH IMPROVED VOLUMETRIC EFFICIENCY AND REDUCED COST

• US 20080247122A1
• Filed: 05/11/2007
• Published: 10/09/2008
• Est. Priority Date: 04/06/2007
• Status: Abandoned Application

• Current Assignee: Vishay Sprague Inc. (Vishay Intertechnology Incorporated)
• Original Assignee: Vishay Sprague Inc. (Vishay Intertechnology Incorporated)
• Inventors: PETUHOV, EVGENY, VAISMAN, PAVEL, EIDELMAN, ALEX
• Application Number:
  US11/747,335
• Publication Number:
  US 20080247122A1
• Time in Patent Office: Days
• US Class Current: 361/533
• CPC Class Codes: H01G 2/065 for surface mounting, e.g. chip capacitors
• CPC Class Codes: H01G 9/012 specially adapted for solid capacitors
• CPC Class Codes: H01G 9/15 Solid electrolytic capacitors H01G11/00 takes precedence

Abstract

A surface mount capacitor is provided. The surface mount capacitor includes a capacitive element including an anode and a cathode, the anode having an exposed portion, an encapsulation material partially surrounding the capacitive element, a non-conductive substrate in contact with the encapsulation material, an anode termination connected to the non-conductive substrate, a cathode termination connected to the non-conductive substrate, and a first conductive path between the exposed portion of the anode and the anode termination comprising a first external conductive connection on a first external surface of the capacitor. The capacitor may also include a second conductive path between the cathode and the cathode termination. The second conductive path includes a second external conductive connection on a second external surface of the capacitor. The second conductive path may further include a conductive adhesive between the cathode and the second external conductive connection.

Claims

1. A surface mount capacitor, comprising:

a capacitive element including an anode and a cathode, the anode having an exposed portion;

an encapsulation material partially surrounding the capacitive element;

a non-conductive substrate in contact with the encapsulation material;

an anode termination connected to the non-conductive substrate;

a cathode termination connected to the non-conductive substrate;

a first conductive path between the exposed portion of the anode and the anode termination comprising a first external conductive connection on a first external surface of the capacitor.

a second conductive path between the cathode and the cathode termination comprising a second external conductive connection on a second external surface of the capacitor.

2. The surface mount capacitor of claim 1 wherein the second conductive path between the cathode and the cathode termination further comprises a conductive adhesive between the cathode and the second external conductive connection.

3. The surface mount capacitor of claim 1 wherein the first external surface of the capacitor and the second external surface of the capacitor are on opposite ends of the capacitor.

4. The surface mount capacitor of claim 1 wherein the capacitor includes a top side, a bottom side, a first side between the top and bottom sides, a second side between the top and bottom sides, a first end side and a second end side and wherein the first external surface of the capacitor is on the first side and the second external surface of the capacitor is on the second side.

5. The capacitor of claim 1 wherein the first external conductive connection and the second external conductive connection are plated with an electrically conductive plating material.

6. The capacitor of claim 1 wherein the capacitive element comprises a solid body.

7. The capacitor of claim 6 wherein the solid body is a pellet.

8. The capacitor of claim 7 wherein the pellet comprises tantalum, niobium, or niobium oxide.

9. The capacitor of claim 8 wherein the anode comprises the pellet and a wire having a portion embedded in or welded to the pellet and a portion outside of the pellet, and a dielectric layer formed by oxidation of anode material, and the cathode comprises an electrolyte layer on an exterior of the pellet.

10. The capacitor of claim 1 wherein the first external surface of the capacitor is generally orthogonal to the anode termination and the second external surface of the capacitor is generally orthogonal to the cathode termination.

21. The capacitor of claim 11 wherein the first external surface of the capacitor is generally orthogonal to the anode termination and the second external surface of the capacitor is generally orthogonal to the cathode termination.

11. A surface mount capacitor comprising:

a) a capacitive element including an anode and a cathode;

b) an encapsulation material forming a case around the capacitive element except for an exposed portion of the anode;

c) an electrically conductive planar substrate comprising anode and cathode terminations having surface mounting portions on a single exterior side of the case and to which the capacitive element is mounted;

d) a first conductive path between the exposed portion of the anode and the anode termination comprising a first external conductive connection on a first external surface of the case;

e) a second conductive path between the cathode and the cathode termination comprising a second external conductive connection on a second external surface of the case.

12. The surface mount capacitor of claim 11 wherein the second conductive path between the cathode and the cathode termination further comprises a conductive adhesive between the cathode and the second external conductive connection.

13. The surface mount capacitor of claim 11 further comprising a non-conductive substrate, the anode and cathode terminations operatively connected to the non-conductive substrate, the non-conductive substrate separating the encapsulation material from the anode and cathode terminations.

14. The surface mount capacitor of claim 11 wherein the first external surface of the capacitor and the second external surface of the capacitor are on opposite ends of the capacitor.

15. The surface mount capacitor of claim 11 wherein the case of the capacitor includes a top side, a bottom side, a first side between the top and bottom sides, a second side between the top and bottom sides, a first end side and a second end side and wherein the first external surface of the case is on the first side and the second external surface of the case is on the second side.

16. The capacitor of claim 11 wherein the first external conductive connection and the second external conductive connection are plated with an electrically conductive plating material.

17. The capacitor of claim 11 wherein the capacitive element comprises a solid body.

18. The capacitor of claim 17 wherein the solid body is a pellet.

19. The capacitor of claim 18 wherein the pellet comprises tantalum, niobium, or niobium oxide.

20. The capacitor of claim 18 wherein the anode comprises the pellet and a wire having a portion embedded in or welded to the pellet and a portion outside of the pellet, and a dielectric layer formed by oxidation of anode material, and the cathode comprises an electrolyte layer on an exterior of the pellet.

23. The surface mount capacitor of claim 11 further comprising a non-conductive substrate, the anode and cathode terminations operatively connected to the non-conductive substrate, the non-conductive substrate separating the encapsulation material from the anode and cathode terminations.

24. The circuit board of claim 23 wherein the first external conductive path allows an improvement in volumetric efficiency by allowing a larger capacitive element in the case than if the anode termination was electrically connected to the capacitive element through the case.

22. An electrical circuit board comprising:

a) an electrical circuit board;

b) an electrical circuit on the circuit board including at least one surface mount capacitor;

c) each of the at least on surface mount capacitor comprising a capacitive element including an anode and a cathode, an encapsulation material forming a case around the capacitive element except for an exposed portion of the anode, an electrically conductive planar substrate comprising anode and cathode terminations having surface mounting portions on a single exterior side of the case and to which the capacitive element is mounted, a first conductive path between the exposed portion of the anode and the anode termination comprising a first external conductive connection on a first external surface of the case, and a second conductive path between the cathode and the cathode termination comprising a second external conductive connection on a second external surface of the case.

25. The circuit board of claim 22 further comprising minimizing volume of the case around the capacitive element relative to the volume of the capacitive element.

26. The circuit board of claim 25 wherein volume of the case is minimizing by minimizing wall thickness of the case by high precision molding and singulation of the case.

27. The circuit board of claim 22 further comprising a plurality of said capacitors.

28. The circuit board of claim 22 wherein the capacitive element comprises a solid pellet anode body, an embedded or welded wire partially in the anode body, a dielectric layer formed by oxidation of the anode body, and an electrolyte layer over the dielectric layer.

29. An electrical or electronic device comprising:

a) a housing and a user interface;

b) an electrical circuit board in the housing including at least one surface mount capacitor;

c) the surface mount capacitor comprising a capacitive element including an anode and a cathode, an encapsulation material forming a case around the capacitive element except for an exposed portion of the anode, an electrically conductive planar substrate comprising anode and cathode terminations having surface mounting portions on a single exterior side of the case and to which the capacitive element is mounted, a first conductive path between the exposed portion of the anode and the anode termination comprising a first external conductive connection on a first external surface of the case, and a second conductive path between the cathode and the cathode termination comprising a second external conductive connection on a second external surface of the case.

30. The surface mount capacitor of claim 29 further comprising a non-conductive substrate, the anode and cathode terminations operatively connected to the non-conductive substrate, the non-conductive substrate separating the encapsulation material from the anode and cathode terminations.

31. The device of claim 29 further comprising a plurality of said capacitors.

32. The device of claim 29 wherein the capacitive element comprises a solid pellet anode body, an embedded or welded wire in the anode body, a dielectric layer formed by oxidation of the anode body, and an electrolyte layer over the dielectric layer.

33. A method of manufacturing a surface mount capacitor, comprising:

substantially encapsulating a capacitive element including an anode and a cathode while leaving an exposed portion of the anode;

forming a cathode termination and an anode termination on an insulating substrate separated from the capacitive element;

forming a first conductive path between the exposed portion of the anode and an anode termination, the first conductive path comprising a first external conductive connection on a first external surface of the capacitor;

forming a second conductive path between the cathode and a cathode termination, the second conductive path comprising a second external conductive connection on a second external surface of the capacitor.

34. The method of claim 33 wherein the second conductive path further comprises a conductive adhesive between the second external conductive connection and the cathode.

35. The method of claim 33 wherein the anode termination and the cathode termination are not formed from a lead frame.