Complex-shaped ceramic capacitors for implantable cardioverter defibrillators and method of manufacture

• US 20040220627A1
• Filed: 04/30/2003
• Published: 11/04/2004
• Est. Priority Date: 04/30/2003
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Norton, John D., Crespi, Ann M., Duva, Frank A.
• Application Number:
  US10/426,680
• Publication Number:
  US 20040220627A1
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion
• CPC Class Codes: A61N 1/3968 Constructional arrangements, e.g. casings A61N1/375 takes precedence

Abstract

An improved manufacturing and packaging process for optimizing the size of various implanted medical devices is disclosed. Specifically, complex shapes involving ceramic capacitors with various other shapes are manufactured to optimize fit and shapes within the device housing. The manufacturing process includes various techniques and electrode material selections, including manufacturing processes that enable high energy discharge capacitors to be made in compliant shapes to fit in small ICD footprints.

Claims

1. An implantable cardioverter defibrillator having at least one capacitor manufactured by a process including the following method steps:

a. providing at least one print pattern for a capacitor to a tape casting and screen printing process;

b. applying a first layer of electrode material onto portions of the print pattern; and

c. creating a stack by applying at least one additional layer of electrode material onto portions of the print pattern after first reversing the print pattern by 180°

between each layer application so that the rotation and applying steps creates adjacent terminals on the same side of the capacitor.

2. The method of claim 1, further comprising the step of laminating the stack at high pressure.

3. The method of claim 2, further comprising the step of removing a portion of the stack comprising at least one print pattern of a capacitor forming a capacitor stack.

4. The method of claim 3, further comprising the step of cutting the capacitor stack into at least two parts.

5. The method of claim 4, further comprising the steps of locating the center of the print pattern and cutting the capacitor stack in half through the center of the stack between upper and lower surfaces to create half portions.

6. The method of claim 1, in which the step of providing the at least one print pattern includes creating a generally U-shaped area along a centerline of the pattern in which no electrode is material is applied.

7. The method of claim 5, in which the step of providing the at least one print pattern includes creating a generally D-shaped print pattern with a generally U-shaped area along a centerline of the pattern in which no electrode is material is applied.

8. The method of claim 5, in which the half portion of the stacks are then processed, joined, partially rotated and then reassembled to form new full D-shaped capacitor stacks in which the orientation of the half portions is different than in the original half portions.

9. A capacitor manufactured by a process including the following method steps:

a. providing at least one print pattern for a capacitor to a tape casting and screen printing process;

b. applying a first layer of electrode material onto portions of the print pattern; and

c. creating a stack by applying at least one additional layer of electrode material onto portions of the print pattern after first reversing the print pattern by 180°

between each layer application so that the rotation and applying steps creates adjacent terminals on the same side of the capacitor.

10. The method of claim 9, further comprising the step of laminating the stack at high pressure.

11. The method of claim 10, further comprising the step of removing a portion of the stack comprising at least one print pattern of a capacitor forming a capacitor stack.

12. The method of claim 11, further comprising the step of cutting the capacitor stack into at least two parts.

13. The method of claim 12, further comprising the steps of locating the center of the print pattern and cutting the capacitor stack in half through the center of the stack between upper and lower surfaces to create half portions.

14. The method of claim 9, in which the step of providing the at least one print pattern includes creating a generally U-shaped area along a centerline of the pattern in which no electrode is material is applied.

15. The method of claim 13, in which the step of providing the at least one print pattern includes creating a generally D-shaped print pattern with a generally U-shaped area along a centerline of the pattern in which no electrode is material is applied.

16. The method of claim 13, in which the half portion of the stacks are then processed, joined, partially rotated and then reassembled to form new full D-shaped capacitor stacks in which the orientation of the half portions is different than in the original half portions.

17. A capacitor manufactured by a process including the following method steps:

a. providing a plurality of print patterns for at least one capacitor to a tape casting and screen printing process;

b. applying a first layer of electrode material onto portions of the print patterns;

c. creating a plurality of stacks each having a plurality of layers forming chips by applying at least one additional layer of electrode material onto portions of the print patterns after first reversing the print patterns by 180°

between each layer application so that the rotation and applying steps creates adjacent terminals on the same side of the capacitors;

d. laminating the stacks at high pressure;

e. removing a portion of at least one of the stacks in a manner which alters the shape of a portion of the at least one stack from the original print pattern;

f. locating a cut line on the print pattern in each stack and cutting the capacitor stacks through the cut line between upper and lower surfaces to create portions of the pattern in which at least two chips have different sizes; and

g. processing the chips, and partially rotating at least some of the chips and then assembling various chips to form new full capacitor stacks in which the orientation of the portions is different than in the original portions and the shape of the new full capacitor stacks are different than in the initial print pattern.

18. The capacitor of claim 17, in which the shape of the new full capacitor stacks includes compound surfaces shaped for conformal fit with another component or housing.

19. An implantable cardioverter defibrillator comprising at least one capacitor with outer surfaces which conform in shape to adjacent components or housing walls, said outer surfaces comprising a plurality of ceramic chips which do not all have the same aspect ratio.

20. An implantable cardioverter defibrillator device comprising:

a. at least one capacitor for storing and delivering electrical energy on demand, the capacitor having at least a 30 Joule capacity and a volumetric energy density of at least about 5 Joules/cubic centimeter; and

b. said at least one capacitor has outer surfaces which conform in shape to adjacent components or housing walls, said outer surfaces comprising a plurality of ceramic chips which do not all have the same aspect ratio.

21. The device of claim 20 in which the device volume is less than about 5 cubic centimeters.

22. A tape process method of manufacture for a capacitor for use in implantable medical devices, the method comprising:

casting a wet film for casting tape on a surface;

forming a desired thickness of the film;

drying the film;

applying a print pattern to the film; and

forming a stack having lenticular layers to build the capacitor of a desired capacitance value.

23. The method of claim 22 wherein one of a wet cast, wet printing and waterfall process is used in lieu of the tape process.