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

• US 7,570,996 B2
• Filed: 02/07/2006
• Issued: 08/04/2009
• Est. Priority Date: 04/30/2003
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Norton, John D., Crespi, Ann M., Duva, Frank A.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US11/348,681
• Publication Number:
  US 20060126265A1
• Time in Patent Office: 1,274 Days
• Field of Search: 607/9, 737/18, 29/254.2, 295/95, 296/021
• US Class Current: 607/9
• 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 first layer of cast tape formed by a casting and screen printing process;

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

c. reversing the print pattern having said electrode material by 180°

;

d. applying a second layer of cast tape having a print pattern over the first layer of electrode material; and

e. creating a stack by applying alternating layers of cast tape and electrode material by repeating steps b., c., and d., above 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 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.

7. 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.

8. 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.

9. The method of claim 1 wherein the number of layers of cast tape and electrode material ranges from about 20 to about 50.

10. 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 first layer of cast tape formed by a casting and screen printing process;

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

c. reversing the print pattern by 180°

;

d. applying a second layer of cast tape having a print pattern over the first layer of electrode material;

e. creating a plurality of stacks applying alternating layers of cast tape and electrode material by repeating steps b., c., and d., above for each stack so that the rotation and applying steps creates adjacent terminals on the same side of the capacitors;

f. laminating the stacks at high pressure;

g. 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;

h. 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

i. 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.

11. The capacitor of claim 10, in which the shape of the new full capacitor stacks includes compound surfaces shaped for conformal fit with another component or housing.

12. The capacitor of claim 10 wherein the number of layers of cast tape and electrode material ranges from about 20 to about 50.

13. 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;

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

reversing the print pattern having said electrode material by 180°

;

casting a second wet film over the first layer of electrode material; and

applying alternating layers of wet layers and electrode materials with reversing the print patterns by 180°

between each layer application to form a stack having lenticular layers to build the capacitor of a desired capacitance value.

14. The method of claim 13 wherein one of a wet cast, wet printing and waterfall process is used in lieu of the tape process.

15. The capacitor of claim 13 wherein the number of layers of cast tape and electrode material ranges from about 20 to about 50.