Process for manufacturing an EMI filter feedthrough terminal assembly

• US 6,643,903 B2
• Filed: 03/16/2001
• Issued: 11/11/2003
• Est. Priority Date: 11/13/1997
• Status: Expired due to Term

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch-Sierra, Inc.
• Inventors: Haskell, Donald K., Brendel, Richard L., Stevenson, Robert A.
• Primary Examiner(s): Vo, Peter
• Assistant Examiner(s): KIM, PAUL D
• Application Number:
  US09/812,371
• Publication Number:
  US 20010050837A1
• Time in Patent Office: 970 Days
• Field of Search: 29/254.1, 29/254.2, 295/921, 298/32, 298/37, 361/302, 361/303, 361/306.1, 361/309, 607/2, 607/5, 174/256, 174/257, 174/259
• US Class Current: 29/25.42
• 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

A process for manufacturing an EMI filter feedthrough terminal assembly is provided for mating a feedthrough filter capacitor with an hermetic terminal assembly including a ferrule and one or more lead wires which extend through the ferrule in non-conductive relation. The process includes the steps of placing the hermetic terminal assembly, having a capture flange, into a holding fixture, and forming a seat of non-conductive thermal-setting material onto the terminal assembly within the capture flange. A feedthrough filter capacitor is loaded into the capture flange on top of the seat, and then the seat is cured. A conductive thermal-setting material is dispensed between an outer diameter of the feedthrough filter capacitor and the capture flange. The assembly is then centrifuged to pack the conductive thermal-setting material. The conductive thermal-setting material is then cured between the outer diameter of the feedthrough filter capacitor and the capture flange. Preferably, the height of the capture flange is one-quarter to three-quarters of an axial thickness of the capacitor.

Claims

1. 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;

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

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

2. The process of claim 1, wherein a height of the capture flange is one-quarter to three-quarters of an axial thickness of the capacitor.

3. The process of claim 1, including the step of curing the seat subsequent to the loading step and prior to the dispensing step.

4. The process of claim 1, 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.

5. The process of claim 1, including the step of conductively coupling an inside diameter of the feedthrough filter capacitor to one or more feedthrough lead wires.

6. The process of claim 5, wherein the conductive coupling is accomplished by an automated soldering process wherein solder is reflowed in a box oven-type furnace.

7. The process of claim 6, wherein the soldering process comprises the step of reflowing a solder preform in a furnace comprising a moving conveyer belt.

8. The process of claim 7, wherein the furnace is of a multi-heat zone radiant type.

9. The process of claim 7, wherein the furnace is of a heat conduction type employing moving hot plates on the conveyer belt.

10. The process of claim 7, wherein the solder preform is replaced by a robot dispensed solder paste.

11. The process of claim 6, wherein the furnace is backfilled with an inert gas.

12. The process of claim 11, wherein the gas is of a reducing type.

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

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

curing the seat;

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

centrifuging the assembly to pack the conductive thermal-setting material; and

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

14. The process of claim 13, including the step of conductively coupling an inside diameter of the feedthrough filter capacitor to the one or more feedthrough lead wires.

15. 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;

curing the seat;

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

centrifuging the assembly to pack the conductive thermal-setting material; and

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

16. The process of claim 15, wherein the hermetic terminal assembly comprises a ferrule and one or more lead wires which extend through the ferrule in non-conductive relation.

17. The process of claim 16, including the step of conductively coupling an inside diameter of the feedthrough filter capacitor to the one or more feedthrough lead wires.

18. The process of claim 17, wherein the conductive coupling is accomplished by an automated soldering process wherein solder is reflowed in a box over-type furnace.

19. The process of claim 18, wherein the soldering process comprises the step of reflowing a solder preform in a furnace comprising a moving conveyer belt.

20. The process of claim 19, wherein the furnace is of a multi-heat zone radiant type.

21. The process of claim 19, wherein the furnace is of a heat conduction type employing moving hot plates on the conveyor belt.

22. The process of claim 19, wherein the solder preform is replaced by a robot dispensed solder paste.

23. The process of claim 18, wherein the furnace is backfilled with an inert gas.

24. The process of claim 23, wherein the gas is of a reducing type.

25. The process of claim 15, wherein a height of the capture flange is one-quarter to three-quarters of an axial thickness of the capacitor.