Capacitors with sprayed electrode terminals

• US 3,891,901 A
• Filed: 08/05/1971
• Issued: 06/24/1975
• Est. Priority Date: 02/24/1970
• Status: Expired due to Term

• Current Assignee: Yosemite, Investment, Inc.
• Original Assignee: James M. Booe, Lawrence A. Landry
• Inventors: Booe, James M., Landry, Lawrence A.
• Primary Examiner(s): Goldberg, E. A.
• Application Number:
  US05/169,554
• Time in Patent Office: 1,419 Days
• Field of Search: 317/258,260,261
• US Class Current: 361/309
• CPC Class Codes: H01G 4/232 electrically connecting two or more layers of a stacked or rolled capacitor
• CPC Class Codes: H01G 4/2325 characterised by the material of the terminals
• CPC Class Codes: H01G 4/32 Wound capacitors

Abstract

In an electrostatic capacitor the edges of one electrode or set of electrodes are exposed at one portion of the capacitor and the edges of the other electrode or set of electrodes are exposed at another portion of the capacitor. At least one dielectric separates adjacent electrodes. A coating of nickel-aluminum material is applied to the exposed edges of both electrodes or sets of electrodes at different portions of the capacitor.

Claims

1. A capacitor comprising:

at least two adjacent, spaced apart, first and second metal electrodes;

at least one separating dielectric layer in contact with at least a portion of said electrodes;

said layer having a first extension beyond a first edge of said first electrode to define, at the edge of said first extension, a first separator surface;

said second electrode extending to said first separator surface, but having essentially no protrusion beyond said first separator surface, thereby defining a first electrode surface;

a dielectric material covering said first edge of said first electrode and filling any void space between the first edge of said first electrode and said first separator;

said separator layer having a second extension beyond a first edge of said second electrode to define at the edge of said second extension, a second separator surface;

said first electrode extending to said second separator surface but having essentially no protrusion beyond said second separator surface, thereby defining a second electrode surface;

a dielectric material covering said first edge of said second electrode and filling any void space between the first edge of said second electrode and said second separator surface;

a first deposit of nickel-aluminum material consisting essentially of about 50 to 98 weight percent nickel, weldbonded to said first electrode surface to provide a terminal; and

a second deposit of nickel-aluminum material consisting essentially of about 50 to 98 weight percent nickel, weldbonded to said second electrode surface to provide a terminal, the terminal to electrode bond strength being at least about 300 psi.

2. A capacitor comprising:

at least two adjacent, spaced apart, first and second metal electrodes;

at least one separating dielectric layer in contact with at least a portion of said electrodes;

said layer having a first extension beyond a first edge of said first electrodE to define, at the edge of said first extension, a first separator surface;

said second electrode extending to said first separator surface, but having essentially no protrusion beyond said first separator surface, thereby defining a first electrode surface;

a dielectric material covering said first edge of said first electrode and filling any void space between the first edge of said edge of said first electrode and said first separator surface;

said separator layer having a second extension beyond a first edge of said second electrode to define at the edge of said second extension, a second separator surface;

said first electrode extending to said second separator surface but having essentially no protrusion beyond said second separator surface, thereby defining a second electrode surface;

a dielectric material covering said first edge of said second electrode and filling any void space between the first edge of said second electrode and said second separator surface;

a first deposit of nickel-aluminum material consisting essentially of about 50 to 98 weight percent nickel, weld-bonded to said first electrode surface;

a second deposit of nickel-aluminum material consisting essentially of about 50 to 98 weight percent nickel, weld-bonded to said second electrode surface; and

a layer of readily solderable material over at least one of said deposits of nickel-aluminum material, said solderable material having a melting point above about 775*C.

3. A capacitor according to claim 1 in which said nickel aluminum material is coated with a relatively high melting point readily solderable material and an electrode to terminal bond strength of at least about 500 psi is obtained.

4. A capacitor according to claim 1 in which said electrodes are made of tantalum, said nickel-aluminum material is coated with a relatively high melting point readily solderable material and an electrode to terminal bond strength of at least about 1,000 psi is obtained.

5. A capacitor according to claim 1 in which said electrodes are made of tantalum, said nickel-aluminum material is coated with a relatively high melting point readily solderable material and an electrode to terminal bond strength of at least about 2,000 psi is obtained.

6. The capacitor of claim 1, wherein the metal of said electrodes is selected from the group consisting of film-forming metals, noble metals and copper.

7. The capacitor of claim 6, wherein at least one of said electrodes is a film-forming metal selected from the group consisting of aluminum, tantalum, titanium, zirconium, hafnium and niobium.

8. The capacitor of claim 7, wherein said capacitor is an electrostatic capacitor having electrodes selected from the group consisting of aluminum and tantalum.

9. A capacitor according to claim 1, wherein said electrodes are swaged.

10. The capacitor of claim 1, wherein said electrostatic capacitor is convolutely wound.

11. The capacitor of claim 1, wherein said electrostatic capacitor includes substantially flat, stacked electrode plates.

12. A capacitor according to claim 1, wherein said electrodes do not project from the capacitor body.

13. A capacitor according to claim 12, wherein attachment is made to the edge portion only of said electrodes.

14. A capacitor according to claim 1, in which a lead is attached directly to said nickel-aluminum material.

15. A capacitor according to claim 14, in which said attachement is a welded joint.

16. A capacitor according to claim 14, in which said attachment is a solder joint.

17. A capacitor according to claim 1, in which said dielectric layer is at least in part a formed oxide on a film-forming metal.

18. A capacitor according to claim 1, in which said dielectric layer is at least in part on a polymeric film on a formed oxide.

19. A capacitor according to claim 10, having little increase in dissipation factor with increase in frequency.

20. A capaCitor according to claim 8, wherein the electrodes are made of aluminum.

21. A capacitor according to claim 8, wherein the electrodes are made of tantalum.

22. A capacitor according to claim 1, wherein a layer of readily solderable material overlies each of said deposits of nickel-aluminum material.

23. A capacitor according to claim 6, wherein said electrodes are made of a noble metal selected from the group consisting of platinum, silver, gold, and palladium and alloys thereof.

24. A capacitor according to claim 23, wherein said electrodes are platinum.