Claims
- 1. An implantable sensor for sensing a specified parameter or substance to which the sensor is exposed, comprising:
an integrated circuit (IC), said IC comprising a semiconductor substrate having an active surface on which electronic circuitry is formed and a non-active surface where electronic circuitry is not formed; sensor electrodes formed on the non-active surface of the semiconductor substrate; means for electrically connecting the sensor electrodes with the electronic circuitry formed on the active surface of the IC; a protective coating that covers all areas of the surface of the semiconductor substrate except for selected portions of the sensor electrodes; and means for making electrical connection with and providing operating power to the electronic circuitry formed on the semiconductor substrate.
- 2. The implantable sensor of claim 1 wherein the means for electrically connecting the sensor electrodes with the electronic circuitry formed on the active surface of the IC comprises vias that pass through the body of the semiconductor substrate.
- 3. The implantable sensor of claim 2 wherein the vias that electrically connect the sensor electrodes with the electronic circuitry through the body of the semiconductor substrate comprise stair-stepped vias.
- 4. The implantable sensor of claim 1 wherein the protective coating comprises at least one layer of a biocompatible encapsulation material selected from the group comprising alumina, zirconia, or alloys of alumina and/or zirconia.
- 5. The implantable sensor of claim 1 wherein the means for making electrical connection with and providing operating power to the electronic circuitry comprises:
a plurality of conductive pads formed on the semiconductor substrate which are not covered by the protective coating; and a plurality of non-straight vias that respectively electrically connect each of the plurality of pads with the electronic circuitry formed on the active surface of the semiconductor substrate.
- 6. The implantable sensor of claim 5 wherein each end of the substrate includes a pair of said conductive pads.
- 7. The implantable sensor of claim 1 wherein the electronic circuitry formed on the active surface of the semiconductor substrate includes at least one built-in capacitor, said at least one built-in capacitor comprising a first conductive layer formed on the substrate, a dielectric layer deposited over the first conductive layer, a second conductive layer deposited over the dielectric layer, and conductive means for making electrical connection with the first and second conductive layers.
- 8. The implantable sensor of claim 7 wherein a plurality of built-in capacitors are formed on the surface of the substrate at locations where electronic circuitry and electrodes and not present.
- 9. The implantable sensor of claim 1 wherein said electrodes and electronic circuitry include means for operating said sensor as an electrochemical sensor.
- 10. The implantable sensor of claim 9 wherein said electrodes formed on the non-active surface of the substrate include first and second working electrodes, each of the first and second working electrodes having an exposed surface area which is not covered by the protective coating.
- 11. The implantable sensor of claim 10 further including:
a first membrane covering said substrate and electrodes, a saline solution held within said first membrane, said saline solution being in contact with the exposed surface areas of said electrodes, a second membrane covering the first membrane, said second membrane having a window pocket formed therein above the exposed surface area of the first working electrode, and a prescribed enzyme placed within the window pocket of the second membrane; whereby said implantable sensor comprises an enzyme electrode sensor.
- 12. An implantable sensor assembly comprising:
a first substrate sensor having an electrode surface and a circuit surface; a second substrate sensor also having an electrode surface and a circuit surface, the circuit surface of the second substrate sensor being placed against the circuit surface of the first substrate sensor, whereby the electrode surfaces of both the first and second substrate sensors face out from the sensor assembly; each of the first and second substrate sensors comprising:
an integrated circuit (IC), said IC comprising a semiconductor substrate having an active surface on which electronic circuitry is formed and a non-active surface where electronic circuitry is not formed, the active surface of the substrate comprising the circuit surface of the sensor, sensor electrodes formed on the non-active surface of the semiconductor substrate, the non-active surface comprising the electrode surface of the sensor, means for electrically connecting the sensor electrodes with the electronic circuitry formed on the active surface of the IC, a protective coating that covers all areas of the surface of the semiconductor substrate except for selected portions of the sensor electrodes; and means for making electrical connection with and providing operating power to the electronic circuitry formed on-the semiconductor substrate from a location outside of the implantable sensor.
- 13. A substrate sensor for immersion or implantation in a saline solution comprising:
a semiconductor substrate having front and back surfaces; at least one working electrode formed on the front side of the semiconductor substrate; electronic circuitry formed on the back side of the semiconductor substrate; a via that passes through the semiconductor substrate and electrically connects the at least one working electrode with the electronic circuitry; a coating that covers the semiconductor substrate with a biocompatible protective layer except for an exposed area of the at least one working electrode; and means for coupling operating signals with the electronic circuitry.
- 14. The substrate sensor of claim 13 wherein electronic circuitry comprises a CMOS integrated circuit, and wherein the semiconductor substrate comprises a portion of a semiconductor wafer on which the CMOS integrated circuit is formed.
- 15. The substrate sensor of claim 14 wherein said protective coating comprises at least one layer of a biocompatible encapsulation material selected from the group comprising alumina, zirconia, or alloys of alumina and/or zirconia.
- 16. The substrate sensor of claim 15 wherein the means for coupling operating signals with the electronic circuitry comprises:
a plurality of conductive pads formed on the semiconductor substrate which are not covered by the protective coating; and a plurality of non-straight vias that respectively electrically connect each of the plurality of pads with the electronic circuitry formed on the back surface of the semiconductor substrate.
- 17. The substrate sensor of claim 16 wherein the electronic circuitry formed on the back surface of the semiconductor substrate includes at least one built-in capacitor, said at least one built-in capacitor comprising a first conductive layer formed on the substrate, a dielectric layer deposited over the first conductive layer, a second conductive layer deposited over the dielectric layer, and conductive means for making electrical connection with the first and second conductive layers.
- 18. A method of making an implantable sensor, said implantable sensor including a substrate, electrodes formed on one side of the substrate, and electrical circuitry formed on the other side of the substrate, said method comprising:
forming the electrical circuitry on an active surface of a semiconductor substrate forming electrodes on a non-active surface of the semiconductor substrate; electrically interconnecting the electrodes with the electrical circuitry through the use of stair-stepped conductive vias that pass through the body of the semiconductor substrate; and depositing a protective layer of a biocompatible material over the entire surface area of the substrate except for an exposed area of the electrodes, whereby all but the exposed area of the electrodes is sealed and protected.
- 19. The method of claim 18 wherein the step of, depositing a protective layer over the entire surface area of the substrate except for an exposed area of the electrodes comprises
plating the electrodes with a biocompatible metal; masking the area of the electrodes to be exposed with a suitable masking material; sputtering a layer of a biocompatible encapsulation material over the entire surface area of the substrate and masking material, the biocompatible encapsulation material being selected from the group comprising alumina, zirconia, or alloys of alumina and/or zirconia; and removing the masking material to expose the plated electrodes.
- 20. The method of claim 19 wherein the plating step comprises plating the electrodes with a metal selected from the group comprising platinum, iridium or alloys thereof.
Parent Case Info
[0001] This application is a continuation-in-part of application Ser. No. 08/928,867, filed Sep. 12, 1997.
Divisions (1)
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Number |
Date |
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Parent |
09100310 |
Jun 1998 |
US |
Child |
10288038 |
Nov 2002 |
US |
Continuations (2)
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Number |
Date |
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Parent |
09360342 |
Jul 1999 |
US |
Child |
10288038 |
Nov 2002 |
US |
Parent |
09718782 |
Nov 2000 |
US |
Child |
10288038 |
Nov 2002 |
US |
Continuation in Parts (1)
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Number |
Date |
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Parent |
08928867 |
Sep 1997 |
US |
Child |
10288038 |
Nov 2002 |
US |