IP Library Granted Patent US 10,056,320
Granted Patent B2
US 10,056,320 · App. 14/525,603 · Granted Aug 21, 2018

Ceramic capacitors with improved lead designs

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Quick Facts
Patent No.
US 10,056,320
App. No.
14/525,603
Granted
Aug 21, 2018
Kind
B2
Abstract

An electronic component is provided with improved thermal stability. The electronic component comprises at least one capacitive element wherein the capacitive element comprises internal electrodes of alternating polarity separated by a dielectric. External terminations with a first external termination of the external terminations are in electrical contact with internal electrodes of a first polarity and a second external termination of the external terminations are in electrical contact with internal electrodes of a second polarity. A first external lead frame is in electrical contact with the first external termination with a conductive bond there between wherein the first external lead frame comprises at least one feature selected from the group consisting of a perforation, a protrusion and an edge indentation.

Claims (99)

1. An electronic component comprising:

capacitive elements wherein a first capacitive element of said capacitive elements comprises internal electrodes of alternating polarity separated by a dielectric; and

said first capacitive element comprises external terminations with a first external termination of said external terminations in electrical contact with internal electrodes of a first polarity and a second external termination of said external terminations in electrical contact with internal electrodes of a second polarity; and

a first external lead frame in electrical contact with said first external termination with a conductive bond there between wherein said first external lead frame comprises protrusions wherein a first set of said protrusions are adjacent protrusions which are parallel and each protrusion of said adjacent protrusions extends a length of said first external lead frame and form an adhesive channel on said first capacitive element wherein said adhesive channel is between said adjacent protrusions and adhesive is in said adhesive channel.

2. The electronic component of claim 1 comprising at least 2 to no more than 50 said capacitive elements.

3. The electronic component of claim 1 wherein said first external lead frame further comprises at least one feature selected from the group consisting of a perforation, and an edge indentation.

4. The electronic component of claim 3 wherein said first external lead frame comprises said protrusions and said edge indentation.

5. The electronic component of claim 3 wherein said first external lead frame has a width W L and a number of perforations selected from the group consisting of:

W L of no more than 3.175 mm at least one perforation;

W L of over 3.175 to no more than 6.35 mm at least 2 perforations; and

W L of over 6.35 mm n perforations where n is defined by the equation 2<n≤W L /0.07 wherein W L is defined in inches.

6. The electronic component of claim 3 wherein said first external lead frame has a width W L and wherein said perforation has a longest length, D O , defined by the equation W L /5<D O <W L /2.5.

7. The electronic component of claim 3 wherein at least one said perforation overlaps a separation between adjacent capacitive elements.

8. The electronic component of claim 1 further comprising a vacant channel between a second set of adjacent said protrusions.

9. The electronic component of claim 1 wherein said adjacent protrusions are stamped from said first external lead frame or attached to said first external lead frame.

10. The electronic component of claim 1 wherein at least one said protrusion of said adjacent protrusions abuts said first external termination.

11. The electronic component of claim 3 wherein said conductive bond has a thickness, h, which meets the criteria defined by:

a

h

=

Δγ

YLD

MAXT

β

ΔαΔ

T

wherein:

a is a longest continuous length of said lead frame between adjacent perforations in said lead frame taken from a neutral expansion point of said longest continuous length;

YLD MAXT is a corresponding strain for a bonding material at its yield point when measured at an operating temperature range;

β is a critical design factor defined from 0 to 1;

Δα is a difference in coefficient of thermal expansion between said first capacitive element and said lead frame; and

ΔT is said operating temperature range.

12. The electronic component of claim 11 wherein said ß is defined as being from 0.002<ß<1.

13. The electronic component of claim 12 wherein said ß is defined as being from 0.01<ß<0.05.

14. The electronic component of claim 11 wherein said a/h is defined as being from

2< a/h< 100.

15. The electronic component of claim 11 wherein said a/h is ß is defined as being from 5<a/h<30.

16. The electronic component of claim 11 wherein said a and h are related by the relationship 0.01a<h<0.5a.

17. The electronic component of claim 16 wherein said a and h are related by the relationship 0.033a<h<0.2a.

18. The electronic component of claim 1 wherein said first external lead frame comprises a mounting component selected from the group consisting of a foot, a pin and a crimp.

19. The electronic component of claim 1 wherein said first external lead frame comprises at least one metal selected from the group consisting of Cu, Ni, Ag, Pd, Fe, Al and Au, and alloys thereof.

20. The electronic component of claim 19 wherein said first external lead frame is non-ferrous.

21. The electronic component of claim 1 wherein said first external lead frame has a coefficient of thermal expansion of at least 13 to no more than 30 ppm/° C.

22. The electronic component of claim 1 wherein said first capacitive element has a principal dimension of greater than about 2.54 mm.

23. An electronic device comprising:

a component comprising:

a substrate;

capacitive elements mounted on said substrate wherein a first capacitive element of said capacitive elements comprises internal electrodes of alternating polarity separated by a dielectric; and

said first capacitive element comprises external terminations with a first external termination of said external terminations in electrical contact with internal electrodes of a first polarity and a second external termination of said external terminations in electrical contact with internal electrodes of a second polarity; and

a first external lead frame in electrical contact with said first external termination with a conductive bond there between wherein said first external lead frame comprises protrusions extending a length of said first external lead frame wherein a first pair of said protrusions are adjacent protrusions forming an adhesive channel on said first capacitive element with adhesive in said adhesive channel.

24. The electronic device of claim 23 wherein said component comprises at least 2 to no more than 50 said capacitive elements.

25. The electronic device of claim 23 wherein said first external lead frame further comprises at least one feature selected from the group consisting of a perforation and an edge indentation.

26. The electronic device of claim 25 wherein said first external lead frame comprises said perforation and said edge indentation.

27. The electronic device of claim 25 wherein said first external lead frame has a width W L and a number of perforations selected from the group consisting of:

W L of no more than 3.175 mm at least one perforation;

W L of over 3.175 to no more than 6.35 mm at least 2 perforations; and

W L of over 6.35 mm n perforations where n is defined by the equation 2<n≤W L /0.07 wherein W L is defined in inches.

28. The electronic device of claim 25 wherein at least one said perforation overlaps a separation between adjacent capacitive elements.

29. The electronic device of claim 25 wherein said first external lead frame has a width W L and wherein said perforation has a longest length, D O defined by the equation W L /5<D O <W L /2.5.

30. The electronic device of claim 23 further comprising a vacant channel between a second set of said protrusions.

31. The electronic device of claim 23 wherein said adjacent protrusions are stamped from said first external lead frame or attached to said first external lead frame.

32. The electronic device of claim 23 wherein a protrusion of said adjacent protrusions abuts said first external termination.

33. The electronic device of claim 25 wherein said conductive bond has a thickness, h, which meets the criteria defined by:

a

h

=

Δγ

YLD

MAXT

β

ΔαΔ

T

wherein:

a is a longest continuous length of said lead frame between adjacent perforations in said lead frame taken from a neutral expansion point of said longest continuous length;

YLD MAXT is a corresponding strain for a bonding material at its yield point when measured at an operating temperature range;

β is a critical design factor defined from 0 to 1;

Δα is a difference in coefficient of thermal expansion between said first capacitive element and said lead frame; and

ΔT is said operating temperature range.

34. The electronic device of claim 33 wherein said ß is defined as being from 0.002<β<1.

35. The electronic device of claim 34 wherein said ß is defined as being from 0.01<ß<0.05.

36. The electronic device of claim 33 wherein said a/h is defined as being from

2 <a/h< 100.

37. The electronic device of claim 33 wherein said a/h is ß is defined as being from 5<a/h<30.

38. The electronic device of claim 33 wherein said a and h are related by the relationship 0.01a<h<0.5a.

39. The electronic device of claim 38 wherein said a and h are related by the relationship 0.033a<h<0.2a.

40. The electronic device of claim 23 wherein said first external lead frame has a mounting component selected from the group consisting of a foot, a pin and a crimp.

41. The electronic device of claim 23 wherein said first external lead frame comprises at least one metal selected from the group consisting of Cu, Ni, Ag, Pd, Fe, Al and Au, and alloys thereof.

42. The electronic device of claim 41 wherein said first external lead frame is non-ferrous.

43. The electronic device of claim 23 wherein said first external lead frame has a coefficient of thermal expansion of at least 13 to no more than 30 ppm/° C.

44. The electronic device of claim 23 wherein said substrate is selected from the group consisting of glass epoxy substrate, flexible substrate and metal clad substrate.

45. The electronic device of claim 23 wherein said substrate has a coefficient of thermal expansion of from 13 to 30 ppm/° C.

46. The electronic device of claim 23 wherein said internal electrodes are either parallel or perpendicular to said substrate.

47. The electronic device of claim 23 wherein said first capacitive element has a principal dimension of greater than about 2.54 mm.

Assignments (3)
RELEASE OF SECURITY INTEREST Recorded Nov 8, 2018
From: BANK OF AMERICA, N.A.
To: KEMET CORPORATION,; KEMET ELECTRONICS CORPORATION; KEMET BLUE POWDER CORPORATION
Reel/Frame 047450/0926 →
SECURITY AGREEMENT Recorded May 22, 2017
From: KEMET CORPORATION; KEMET ELECTRONICS CORPORATION; KEMET BLUE POWDER CORPORATION
To: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
Reel/Frame 042523/0639 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 28, 2014
From: MURRELL, JEFFREY S; JONES, LONNIE G; BELL, JEFFREY W
To: KEMET ELECTRONICS CORPORATION
Reel/Frame 034050/0658 →