Systems and methods for encapsulating electronics in a mountable device

• US 9,009,958 B2
• Filed: 09/23/2013
• Issued: 04/21/2015
• Est. Priority Date: 03/27/2013
• Status: Active Grant

• Current Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Etzkorn, James
• Primary Examiner(s): Vo, Peter DungBa
• Assistant Examiner(s): Carley, Jeffrey T
• Application Number:
  US14/034,303
• Publication Number:
  US 20140296674A1
• Time in Patent Office: 575 Days
• Field of Search: 298/32, 298/41, 298/46, 298/48, 298/51, 600/319, 600/345, 600/347, 600/365
• US Class Current: 29/841
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 3/101 for examining the tear film
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: A61B 5/6813 Specially adapted to be attached to a specific body part A61B5/6802 takes precedence
• CPC Class Codes: A61B 5/6821 Eye
• CPC Class Codes: B29D 11/00817 Producing electro-active lenses or lenses with energy receptors, e.g. batteries or antennas
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/3272 Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels optical biosensors G01N33/52
• CPC Class Codes: G02B 1/043 Contact lenses
• CPC Class Codes: G02C 7/04 Contact lenses for the eyes disinfection or sterilisation of contact lenses A61L12/00
• CPC Class Codes: G02C 7/049 Contact lenses having special fitting or structural features achieved by special materials or material structures
• CPC Class Codes: G02C 7/083 Electrooptic lenses
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2924/18162 of a chip with build-up interconnect
• CPC Class Codes: H05K 1/185 Components encapsulated in the insulating substrate of the printed circuit or incorporated in internal layers of a multilayer circuit semiconductor chips encapsulated by interconnect and support structures H01L23/5389, H01L24/00
• CPC Class Codes: H05K 2201/10098 : Components for radio transmission, e.g. radio frequency identification [RFID] tag, printed or non-printed antennas
• CPC Class Codes: H05K 2201/10151 : Sensor
• CPC Class Codes: H05K 2203/1469 : Circuit made after mounting or encapsulation of the components
• CPC Class Codes: H05K 3/32 : electrically connecting electric components or wires to printed circuits
• CPC Class Codes: Y10T 29/49018 : with other electrical component
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/49163 : with sintering of base

Abstract

A mountable device includes a bio-compatible structure embedded in a polymer that defines at least one mounting surface. The bio-compatible structure includes an electronic component having electrical contacts, sensor electrodes, and electrical interconnects between the sensor electrodes and the electrical contacts. The bio-compatible structure is fabricated such that it is fully encapsulated by a bio-compatible material, except for the sensor electrodes. In the fabrication, the electronic component is positioned on a first layer of bio-compatible material and a second layer of bio-compatible material is formed over the first layer of bio-compatible material and the electronic component. The electrical contacts are exposed by removing a portion of the second layer, a conductive pattern is formed to define the sensor electrodes and electrical interconnects, and a third layer of bio-compatible material is formed over the conductive pattern. The sensor electrodes are exposed by removing a portion of the third layer.

Claims

1. A method for fabricating a mountable device, the method comprising:

fabricating a bio-compatible structure that includes an electronic component and a conductive pattern, wherein the electronic component has a first surface and a second surface opposite the first surface and includes electrical contacts on the second surface, wherein fabricating the bio-compatible structure comprises;

forming a first layer of a bio-compatible material;

positioning the first surface of the electronic component on the first layer of the bio-compatible material;

forming a second layer of the bio-compatible material over the first layer of the bio-compatible material and the second surface of the electronic component;

exposing the electrical contacts on the second surface of the electronic component by removing a portion of the second layer of the bio-compatible material;

after exposing the electrical contacts, forming the conductive pattern, wherein the conductive pattern defines sensor electrodes on the second layer of the bio-compatible material and electrical interconnects between the sensor electrodes and the electrical contacts;

forming a third layer of the bio-compatible material over the conductive pattern, wherein the third layer of the bio-compatible material includes a portion covering the sensor electrodes; and

exposing the sensor electrodes by removing the portion of the third layer of the bio-compatible material covering the sensor electrodes; and

surrounding the bio-compatible structure with a polymer, wherein the polymer defines at least one mounting surface of the mountable device.

2. The method of claim 1, wherein forming the first layer of the bio-compatible material comprises forming the first layer of the bio-compatible material on a working substrate.

3. The method of claim 2, wherein fabricating the bio-compatible structure further comprises:

after exposing the sensor electrodes, releasing the first layer of the bio-compatible material from the working substrate.

4. The method of claim 1, wherein fabricating the bio-compatible structure further comprises:

after exposing the sensor electrodes, annealing the first, second, and third layers of the bio-compatible material so that the layers are sealed together.

5. The method of claim 4, wherein the annealing fully encapsulates the bio-compatible structure with the bio-compatible material, except for the sensor electrodes.

6. The method of claim 1, wherein removing the portion of the second layer of the bio-compatible material comprises:

forming a masking layer on the second layer of the bio-compatible material, wherein the masking layer exposes the portion of the second layer of the bio-compatible material;

etching the portion of the second layer of the bio-compatible material exposed by the masking layer to provide a remaining portion of the second layer that is covered by the masking layer; and

removing the masking layer from the remaining portion of the second layer.

7. The method of claim 6, wherein the remaining portion of the second layer of the bio-compatible material is substantially flush with the second surface of the electronic component.

8. The method of claim 1, wherein removing the portion of the third layer of the bio-compatible material covering the sensor electrodes comprises:

forming a masking layer on the third layer of the bio-compatible material, wherein the masking layer exposes the portion of the third layer of the bio-compatible material;

etching the portion of the third layer of the bio-compatible material exposed by the masking layer to provide a remaining portion of the third layer that is covered by the masking layer; and

removing the masking layer from the remaining portion of the third layer.

9. The method of claim 8, wherein the remaining portion of the third layer of the bio-compatible material covers all of the conductive pattern except for the sensor electrodes.

10. The method of claim 1, wherein the sensor electrodes include a working electrode, a reference electrode, and a counter electrode of an electrochemical sensor.

11. The method of claim 10, wherein fabricating the bio-compatible structure further comprises:

forming a reagent layer proximal to the sensor electrodes.

12. The method of claim 1, wherein the electronic component further includes additional electrical contacts on the second surface, and wherein the conductive pattern further defines an antenna on the second surface of the bio-compatible material and electrical interconnects between the antenna and the additional electrical contacts.

13. The method of claim 1, wherein the bio-compatible structure is ring shaped.

14. The method of claim 1, wherein the bio-compatible material comprises parylene.

15. The method of claim 1, wherein the mountable device is an eye-mountable device, and wherein the polymer defines a concave surface configured to mount the mountable device on a corneal surface and a convex surface configured to be compatible with eyelid movement when the concave surface is so mounted.