Alumina insulation for coating implantable components and other microminiature devices

• US 6,844,023 B2
• Filed: 09/20/2002
• Issued: 01/18/2005
• Est. Priority Date: 12/20/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Schulman, Joseph H., Lucisano, Joseph Y., Byers, Charles L., Pendo, Shaun M.
• Primary Examiner(s): Huff, Mark F.
• Assistant Examiner(s): CHACKO DAVIS, DABORAH
• APPLICATION: US 20030087197A1
• Time in patent office: 851 Days
• Field of Search: 257/698, 257/702, 174/505, 156/89.16, 607/2, 607/116, 204/298.04, 427/2.24, 427/2.1, 427/2.12
• US Class Current: 427/2.24
• CPC Class Codes: A61N 1/02 Details
• CPC Class Codes: C23C 14/042 using masks
• CPC Class Codes: G03F 7/70641 Focus focus measurement prior to exposure G03F9/7026
• CPC Class Codes: H01L 21/308 using masks H01L21/3063, H01L21/3065 take precedence
• CPC Class Codes: H01L 23/291 Oxides or nitrides or carbides, e.g. ceramics, glass
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: Y10T 29/49144 by metal fusion
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24917 including metal layer
• CPC Class Codes: Y10T 428/24926 including ceramic, glass, porcelain or quartz layer
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A protective, biocompatible coating or encapsulation material protects and insulates a component or device intended to be implanted in living tissue. The coating or encapsulation material comprises a thin layer or layers of alumina, zirconia or other ceramic, less than 25 microns thick, e.g., 5-10 microns thick. The alumina layer(s) may be applied at relatively low temperature. Once applied, the layer provides excellent hermeticity, and prevents electrical leakage. Even though very thin, the alumina layer retains excellent insulating characteristics. In one embodiment, an alumina layer less than about 6 microns thick provides an insulative coating that exhibits less than 10 pA of leakage current over an area 75 mils by 25 mils area while soaking in a saline solution at temperatures up to 80° C. over a three month period.

Claims

1. An implantable component comprising:

a substrate;

conductive patterns formed on a surface of the substrate, the conductive patterns having at least one layer of titanium formed thereon; and

at least one layer of a ceramic material formed on the at least one layer of titanium, the at least one layer of the ceramic material having a thickness of about 5-10 microns.

2. The implantable component recited in claim 1, wherein the conductive patterns are metallized traces.

3. The implantable component recited in claim 2, wherein the metallized traces are formed by thin film deposition.

4. The implantable component recited in claim 2, wherein the metallized traces are formed by thin film deposition and etching.

5. The implantable component recited in claim 1, wherein the at least one layer of titanium is about 300 angstroms thick.

6. The implantable component recited in claim 1, wherein the ceramic material is selected from the group consisting essentially of alumina, zirconia, magnesium oxide, alloy of alumina, alloy of zirconia, and alloy of magnesium oxide.

7. The implantable component recited in claim 1, wherein the ceramic material is formed in successive layers.

8. The implantable component recited in claim 7, wherein each of the successive layers is about 1-2 microns thick.

9. The implantable component recited in claim 1, wherein the at least one layer of ceramic material is formed using an ion-enhanced deposition technique.

10. The implantable component recited in claim 1, wherein the layer of ceramic material is formed using an ion-beam deposition (IBD) technique.