EMI filter feedthrough terminal assembly having a capture flange to facilitate automated assembly

• US 20010050837A1
• Filed: 03/16/2001
• Published: 12/13/2001
• Est. Priority Date: 11/13/1997
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch-Sierra, Inc.
• Inventors: Brendel, Richard L., Stevenson, Robert A., Haskell, Donald K.
• Granted Patent: US 6,643,903 B2
• Time in Patent Office: Days
• US Class Current: 361/306.1
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 29/435 Solid dielectric type
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49139 by inserting component lead or terminal into base aperture
• CPC Class Codes: Y10T 29/49147 Assembling terminal to base

Abstract

An EMI filter feedthrough terminal assembly includes at least one conductive terminal pin, a feedthrough filter capacitor which has a passageway through which the terminal pin extends, and a conductive substrate through which the terminal pin passes in non-conductive relation. The conductive substrate includes a capture flange having a height that is less than an axial thickness of the capacitor and which is configured to at least partially surround an outer periphery of the capacitor. The height of the capture flange is preferably one-quarter to three-quarters of the axial thickness of the capacitor. A first set of capacitor electrodeplates is conductively coupled to the terminal pin, and a second set of electrode plates is conductively coupled to the capture flange by means of a thermal-setting conductive material disposed between the outer periphery of the capacitor and the capture flange. A related process is provided for manufacturing an EMI filter feedthrough terminal assembly that advantageously utilizes the capture flange.

Claims

1. An EMI filter feedthrough terminal assembly, comprising:

at least one conductive terminal pin;

a feedthrough filter capacitor having first and second sets of electrode plates and a passageway through which the terminal pin extends in conductive relation the first set of electrode plates; and

a conductive substrate through which the terminal pin passes in non-conductive relation, the conductive substrate including a capture flange having a height that less than an axial thickness of the capacitor and configured to at least partially surround an outer periphery of the capacitor.

2. The assembly of

claim 1

, wherein the height of the capture flange is one-quarter to three-quarters of the axial thickness of the capacitor.

3. The assembly of

claim 1

, wherein the second set of electrode plates is conductively coupled to the capture flange.

4. The assembly of

claim 3

, including a conductive material disposed between the outer periphery of the capacitor and the capture flange, to conductively couple the second set of electrode plates to the conductive substrate.

5. The assembly of

claim 4

, wherein the conductive material is a thermal-setting material taken from the group of conductive epoxy, conductive polyimide, or solder paste, a solder preform, a solder paste, or a braze alloy.

6. The assembly of

claim 1

, including an insulator supported by the conductive substrate through which the at least one terminal pin passes, the insulator being spaced from a face of the capacitor to form an air gap therebetween.

7. The assembly of

claim 6

, wherein the capture flange entirely surrounds the outer periphery of the capacitor, and wherein the assembly includes a conductive material disposed between discrete segments of the outer periphery of the capacitor and the capture flange.

8. The assembly of

claim 6

, including a first noble metal hermetic terminal seal joint between the terminal pin and the insulator, and a second noble metal hermetic seal joint between the insulator and the conductive substrate.

9. The assembly of

claim 1

, wherein the capture flange includes a countersink to facilitate robotic dispensing of a thermal-setting material between the capacitor and the capture flange.

10. The assembly of

claim 9

, wherein peripheral edges of the capacitor are axially rounded.

11. The assembly of

claim 1

, including a first noble metal hermetic terminal seal joint between the terminal pin and the feedthrough filter capacitor, and a second noble metal hermetic seal joint between the feedthrough filter capacitor and the conductive substrate.

12. An EMI filter feedthrough terminal assembly, comprising:

at least one conductive terminal pin;

a feedthrough filter capacitor having first and second sets of electrode plates and a passageway through which the terminal pin extends in conductive relation with the first set of electrode plates;

a conductive substrate through which terminal pin passes in non-conductive relation, the conductive substrate including a capture flange having a height that is less than an axial thickness of the capacitor and configured to at least partially surround an outer periphery of the capacitor, wherein the second set of electrode plates is conductively coupled to the capture flange; and

an insulator supported by the conductive substrate through which the at least one terminal pin passes, the insulator being positioned adjacent to a face of the capacitor.

13. The assembly of

claim 12

, wherein the insulator is spaced from the face of the capacitor to form an air gap therebetween.

14. The assembly of

claim 13

, wherein the capture flange entirely surrounds the outer periphery of the capacitor, and wherein the assembly includes a conductive material disposed between discrete segments of the outer periphery of the capacitor and the capture flange.

15. The assembly of

claim 14

, including a first noble metal hermetic terminal seal joint between the terminal pin and the insulator, and a second noble metal hermetic seal joint between the insulator and the conductive substrate.

16. The assembly of

claim 13

, wherein the height of the capture flange is one-quarter to three-quarters of the axial thickness of the capacitor.

17. The assembly of

claim 16

, including a thermal-setting conductive material disposed between the outer periphery of the capacitor and the capture flange, to conductively couple the second set of electrode plates to the conductive substrate.

18. The assembly of

claim 12

, including a first noble metal hermetic terminal seal joint between the terminal pin and the feedthrough filter capacitor, and a second noble metal hermetic seal joint between the feedthrough filter capacitor and the conductive substrate.

19. The assembly of

claim 12

, wherein the capture flange includes a countersink to facilitate robotic dispensing of a thermal-setting material between the capacitor and the capture flange, and wherein peripheral edges of the capacitor are axially rounded.

20. A process for manufacturing an EMI filter feedthrough terminal assembly, comprising the steps of:

placing a conductive ferrule having a capture flange into a holding fixture;

forming a seat of non-conductive thermal-setting material onto the ferrule within the capture flange;

loading a feedthrough filter capacitor into the capture flange on top of the seat;

dispensing a conductive thermal-setting material between an outer diameter of the feedthrough filter capacitor and the capture flange; and

curing the conductive thermal-setting material between the outer diameter of the feedthrough filter capacitor and the capture flange.

21. The process of

claim 20

, wherein the height of the capture flange is one-quarter to three-quarters of the axial thickness of the capacitor.

22. The process of

claim 20

, including the step of curing the seat subsequent to the loading step and prior to the dispensing step.

23. The process of

claim 20

, including the step of curing the seat concurrently with the step of curing the conductive thermal-setting material.

24. The process of

claim 20

, including the step of centrifuging the assembly subsequent to the dispensing step and prior to the curing step, to pack the conductive thermal-setting material.

25. The process of

claim 20

, including the step of conductively coupling the inside diameter(s) of the feedthrough filter capacitor to one or more feedthrough lead wires.

26. The process of

claim 25

, wherein the conductive coupling is accomplished by an automated soldering process wherein the solder is reflowed in a box oven-type furnace.

27. The process of

claim 26

, wherein the soldering process comprises the step of reflowing solder preform(s) in a furnace comprising a moving conveyer belt.

28. The process of

claim 27

, wherein the furnace is of the multi-heat zone radiant type.

29. The process of

claim 27

, wherein the furnace is of the heat conduction type employing moving hot plates on a conveyer belt.

30. The process of

claim 26

wherein the furnace is backfilled with an inert gas.

31. The process of

claim 30

, wherein the gas is of a reducing type.

32. The process of

claim 27

, wherein the solder preform(s) is replaced by a robot dispensed solder paste.

33. A process for manufacturing an EMI filter feedthrough terminal assembly, comprising the steps of:

placing an hermetic terminal assembly having a capture flange into a holding fixture;

forming a seat of non-conductive thermal-setting material onto the terminal assembly within the capture flange;

loading a feedthrough filter capacitor into the capture flange on top of the seat;

dispensing a conductive thermal-setting material between an outer diameter of the feedthrough filter capacitor and the capture flange; and

curing the conductive thermal-setting material between the outer diameter of the feedthrough filter capacitor and the capture flange.

34. The process of

claim 33

, wherein the hermetic terminal assembly comprises a ferrule and one or more lead wires which extend through the ferrule in non-conductive relation.

35. The process of

claim 34

, wherein the height of the capture flange is one-quarter to three-quarters of the axial thickness of the capacitor.

36. The process of

claim 35

, including the step of curing the seat subsequent to the loading step and prior to the dispensing step.

37. The process of

claim 36

, including the step of centrifuging the assembly subsequent to the dispensing step and prior to the curing step, to pack the conductive thermal-setting material.

38. The process of

claim 37

, including the step of conductively coupling the inside diameter(s) of the feedthrough filter capacitor to the one or more feedthrough lead wires.