IMPLANTABLE MEDICAL DEVICE WITH IMPROVED BACK-FILL MEMBER AND METHODS OF MANUFACTURE THEREOF

• US 20100132184A1
• Filed: 01/27/2010
• Published: 06/03/2010
• Est. Priority Date: 11/29/2005
• Status: Active Grant

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Xie, Jian, Sahabi, Kavous
• Granted Patent: US 8,555,498 B2
• Time in Patent Office: Days
• US Class Current: 29/592.100
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49151 by deforming or shaping
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49169 Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49176 with molding of electrically insulating material

Abstract

An implantable medical device and methods of manufacture are provided for implantation in a body. The device includes a device housing having an interior cavity and electronic circuitry located in the interior cavity of the device housing. The electronic circuitry detects a physiologic condition of the body and delivers a therapy to the body. The device further includes a feed-through assembly having a feed-through housing that is joined to the device housing. The feed-through assembly includes conductors held in the feed-through housing and electronically connected to the electronic circuitry. A back-fill member is joined to the feed-through housing. The back-fill member has an opening there through communicating with the interior cavity of the device housing. A sealing element is hermetically secured in the opening through the back-fill member. The sealing element and back-fill member are formed of different first and second materials, respectively. The second material is generally harder than the first material. For example, the sealing element may constitute a titanium ball configured to be deformed when pressed into the opening in the back-fill member, where the first and second materials constitute titanium and a titanium alloy, respectively. The back-fill member is dimensioned relative to a support tool to permit the back-fill member to self-align during an initial sealing operation by shifting and/or tilting relative to a support tool.

Claims

1. A method for manufacturing an implantable medical device, comprising:

assembling a device housing defining an interior cavity;

joining a feed-through assembly to the device housing, the feed-through assembly including a feed-through housing and conductors held in the feed-through housing;

joining a back-fill member to the feed-through housing, the back fill member having an opening there through communicating with the interior cavity of the device housing;

back-filling the device housing with an inert gas through the opening in the back-fill member; and

hermetically sealing the interior cavity by closing the opening through the back-fill member with a sealing element, where the sealing element and back-fill member are formed of different first and second materials, respectively.

2. The method of claim 1, wherein the sealing further comprises holding the back-fill member in a support tool in a self-aligning manner when closing the opening with the sealing element, while permitting the back-fill member and device housing to self-align within the support tool while a press load is induced onto the sealing element.

3. The method of claim 1, wherein the sealing further comprises retaining the back-fill member with a support tool that defines a support X-Y plane, inducing a press load onto the sealing element in a direction that intersects the X-Y plane and permitting the device housing to shift in at least one of the X-Y plane and a tilting direction out of the X-Y plane while the press load is induced.

4. The method of claim 1, wherein the back-filling is performed while the device housing is in a nitrogen chamber and the inert gas is nitrogen.

5. The method of claim 1, wherein the sealing permits the back-fill member to at least one of linearly shift and tilt while a sealing force is applied to the sealing element to deform the sealing element into the opening in the back-fill member.

6. The method of claim 1, further comprising polishing an interior surface of the opening through the back-fill member prior to the sealing.

7. The method of claim 1, further comprising forming the back-fill member with a cylindrical body having distal and proximal ends relative to the feed-through housing, and a base platform extending about the body proximate the proximal end, the base platform abutting against, and being sealed to, an exterior surface of the feed-through housing during the joining.

8. The method of claim 1, further comprising loading a ceramic terminal into an aperture provided through the feed-through housing, and loading the conductors into the ceramic terminal.

9. The method of claim 1, wherein the first material constitutes titanium and the second material constitutes a titanium alloy.

10. The method of claim 1, wherein the sealing element constitutes a titanium ball and the sealing operation deforms the titanium ball when pressed into the opening in the back-fill member.

11. The method of claim 1, further comprising brazing a terminal holding the conductors to the feed-through housing.