Implantable medical device having an improved electronic assembly for increasing packaging density and enhancing component protection

• US 6,324,428 B1
• Filed: 03/30/1999
• Issued: 11/27/2001
• Est. Priority Date: 03/30/1999
• Status: Expired due to Fees

• Current Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Pacesetter Incorporated (Abbott Laboratories Incorporated)
• Inventors: Weinberg, Alvin, Yang, Min-Yaug, Silvian, Sergiu
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US09/281,424
• Time in Patent Office: 973 Days
• Field of Search: 607/1, 607/2, 607/9, 607/36
• US Class Current: 607/36
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence

Abstract

An implantable cardiac stimulation device having an improved multi-level electronic module is disclosed. The multi-level module comprises at least two stacked internal substrates for mounting electronic components within a confined region formed between the two stacked substrates. Placement of the two stacked substrates creates an opening establishing fluid communication between the confined region and an exterior of the electronic module. A polymer dielectric coating, such as parylene, is vapor deposited over the entire electronic module which penetrates the confined region via the opening. The parylene provides enhanced protection against dielectric breakdown between the electronic components and their interconnections thereby enabling smaller separation distances between the electronic components. The parylene also provides support for the electronic components and their interconnections while acting as a moisture barrier and a particle getter.

Claims

1. An implantable cardiac stimulation device for stimulating a patient'"'"'s heart, comprising:

a housing for implantation in the human body and for containing electronic components of the stimulation device therein;

a multi-level high density electronic module mounted within the housing for controlling pulse generating functions of the stimulation device, the electronic module comprising;

a first substrate having a cavity formed therein for mounting within the cavity electronic circuitry including components and electrical interconnections therebetween;

an intermediate substrate having first and second opposed surfaces, the intermediate substrate mounted in vertical registration above the first substrate wherein the first opposed surface is placed atop the cavity formed in the first substrate, and wherein the first opposed surface is positioned to form an opening establishing a communication path for fluid between the cavity and the second opposed surface of the intermediate substrate; and

wherein, the opening between the cavity and intermediate substrate permits fluid comprising a vaporized polymer material, to penetrate the interior of the cavity for coating the electronic circuitry mounted on the first substrate within the cavity.

2. The implantable cardiac stimulation device, as set forth in claim 1, wherein placement of the intermediate substrate atop the first substrate leaves an end portion of the cavity uncovered and the opening is formed along an edge of the cavity at the end portion.

3. The implantable cardiac stimulation device, as set forth in claim 1, wherein the opening formed by the positioning of the intermediate substrate atop the first substrate is characterized by first and second apertures created at opposite ends of the cavity.

4. The implantable cardiac stimulation device, as set forth in claim 1, wherein the opening is formed within the intermediate substrate.

5. The implantable cardiac stimulation device, as set forth in claim 1, wherein the high-density electronic module further comprises a protective lid mounted atop the first and intermediate substrates, the lid having apertures formed therein for establishing fluid communication between an exterior surface of the lid, the intermediate substrate, and the cavity.

6. The implantable cardiac stimulation device, as set forth in claim 1, wherein the high-density electronic module further comprises a layer of polymer material deposited over the intermediate and first substrates and within the cavity.

7. The implantable cardiac stimulation device, as set forth in claim 6, wherein the polymer material is parylene.