Substrate sensor
First Claim
1. 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.
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Accused Products
Abstract
An implantable substrate sensor has electronic circuitry and electrodes formed on opposite sides of a substrate. A protective coating covers the substrate, effectively hermetically sealing the electronic circuitry under the coating. Exposed areas of the electrodes are selectively left uncovered by the protective coating, thereby allowing such electrodes to be exposed to body tissue and fluids when the sensor is implanted in living tissue. The substrate on which the electronic circuitry and electrodes are formed is the same substrate or “chip” on which an integrated circuit (IC) is formed, which integrated circuit contains the desired electronic circuitry. Such approach eliminates the need for an hermetically sealed lid or cover to cover hybrid electronic circuitry, and allows the sensor to be made much thinner than would otherwise be possible. In one embodiment, two such substrate sensors may be placed back-to-back, with the electrodes facing outward. As required, capacitors that form part of the sensor'"'"'s electronic circuits are formed on the substrate by placing metalization layers and a dielectric in vacant areas of the substrate surface.
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Citations
43 Claims
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1. 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:
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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. - View Dependent Claims (2, 3)
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.
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3. The method of claim 2 wherein the plating step comprises plating the electrodes with a metal selected from the group comprising platinum, iridium or alloys thereof.
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4. A method for making an implantable electronic device comprising:
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forming an electronic circuit within a substrate;
forming an electrode on a surface of the substrate;
interconnecting the electronic circuit and the electrode with a via through the substrate; and
coating the substrate with an hermetic, biocompatible protective layer that covers the electronic circuit and at least a portion of the electrode. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 19, 20, 21, 22, 23, 24, 25)
sputtering a layer of titanium over those areas of the substrate that are to be coated with the alumina insulation.
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21. The method of claim 19, further comprising:
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spinning a photosensitive polyamide onto the substrate; and
illuminating the polyamide over a portion of the substrate that is not to be coated with said alumina insulation.
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22. The method of claim 4, further comprising:
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encapsulating the substrate with a saline solution inside a sheath;
surrounding the sheath with a membrane having a pocket positioned adjacent to the electrode;
filling the pocket with an enzyme; and
providing a window in the pocket to expose the enzyme to an external environment.
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23. The method of claim 4, further comprising:
forming one or more connection pads on the substrate to communicate operating signals with and provide power to the electronic circuit.
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24. The method of claim 23, further comprising:
forming a non-straight via in the substrate between the one or more connection pads and the electronic circuit.
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25. The method of claim 4 further comprising the step of plating the electrode with a biocompatible metal.
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14. A method for making an implantable electronic device comprising:
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forming a first electronic circuit within a first substrate;
forming a first electrode on a surface of the first substrate;
interconnecting the first electronic circuit and the first electrode with a first via formed through the first substrate;
coating the first substrate with an hermetic, biocompatible protective layer that covers the first electronic circuit and at least a portion of the first electrode;
forming a second electronic circuit within a second substrate;
forming a second electrode on a surface of the second substrate;
interconnecting the second electronic circuit and the second electrode with a second via formed through the second substrate;
coating the second substrate with an hermetic, biocompatible protective layer that covers the second electronic circuit and at least a portion of the second electrode; and
placing the first substrate against the second substrate so that the first electrode and the second electrode are exposed. - View Dependent Claims (15, 16, 17, 18, 26, 27, 28, 29, 30, 31, 32)
sputtering a layer of titanium over those areas of first and second substrates that are to be coated with the alumina insulation.
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28. The method of claim 26, further comprising:
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spinning a photosensitive polyamide onto the first and second substrates; and
illuminating the polyamide over a portion of the first and second substrates that is not to be coated with said alumina insulation.
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29. The method of claim 14, further comprising:
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encapsulating the first substrate and the second substrate with a saline solution inside a sheath;
surrounding the sheath with a membrane having a first pocket positioned adjacent to the first electrode and a second pocket positioned adjacent to the second electrode;
filling the first pocket and the second pocket with an enzyme; and
providing a first window in the first pocket and a second window in the second pocket to expose the enzyme to an external environment.
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30. The method of claim 14, further comprising:
forming one or more connection pads on the first substrate and the second substrate to communicate operating signals with and provide power to the first electronic circuit and the second electronic circuit, respectively.
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31. The method of claim 30, further comprising:
forming a non-straight via in the substrate between the one or more connection pads on the first substrate and the first electronic circuit.
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32. The method of claim 14, further comprising plating the first electrode and the second electrode with a biocompatible metal.
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33. A method for making an implantable electronic device comprising:
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forming an electronic circuit within a substrate;
forming an electrode on a surface of the substrate;
interconnecting the electronic circuit and the electrode with a via that is not straight; and
coating the substrate with a protective layer.
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34. A method of making a living tissue implantable device, comprising:
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forming electrical circuitry on a first side of a semiconductor substrate;
forming a plurality of electrodes on the semiconductor substrate, wherein at least a portion of the plurality are formed on a second side of the semiconductor substrate and wherein the second side is opposite to the first side;
electrically interconnecting the electrodes and the electrical circuitry using a plurality of conducting stair-stepped vias that extend from the first side to the second side of the substrate; and
forming a protective layer of biocompatible material over at least a portion of each of the first and second sides of the substrate such that at least a portion of the electrical circuitry and electrodes are covered by the protective layer. - View Dependent Claims (35, 36, 37, 38)
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39. A method of making a living tissue implantable device, comprising:
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forming electrical circuitry on a semiconductor substrate;
forming a plurality of electrodes on the semiconductor substrate;
electrically interconnecting the electrodes and the electrical circuitry using a plurality of conducting stair-stepped vias; and
hermetically sealing and insulating the electrical circuitry and a portion of the electrodes by applying a protective layer of a biocompatible, hermetic, non-conducting material over at least the circuitry and a portion of the electrodes. - View Dependent Claims (40, 41, 42, 43)
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Specification