Sensor substrate and method of fabricating same

• US 7,514,038 B2
• Filed: 06/04/2004
• Issued: 04/07/2009
• Est. Priority Date: 09/07/2001
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Shah, Rajiv, Pendo, Shaun, Chernoff, Edward
• Primary Examiner(s): Griffin; Walter D
• Assistant Examiner(s): Mui; Christine T
• Application Number:
  US10/861,976
• Publication Number:
  US 20040223875A1
• Time in Patent Office: 1,768 Days
• Field of Search: 204/430, 204/195, 438/622, 438/648, 438/762, 438/584, 128/899, 422/56, 422/94, 422/82.05, 257/698, 174/262
• US Class Current: 422/502
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/0175 Inorganic, non-metallic layer, e.g. resist or dielectric for printed capacitor
• CPC Class Codes: H05K 2201/0179 Thin film deposited insulating layer, e.g. inorganic layer for printed capacitor
• CPC Class Codes: H05K 2201/0317 Thin film conductor layer; Thin film passive component
• CPC Class Codes: H05K 2201/09472 Recessed pad for surface mounting; Recessed electrode of component
• CPC Class Codes: H05K 2203/082 Suction, e.g. for holding solder balls or components
• CPC Class Codes: H05K 2203/085 Using vacuum or low pressure
• CPC Class Codes: H05K 2203/1147 Sealing or impregnating, e.g. of pores
• CPC Class Codes: H05K 2203/1476 Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning
• CPC Class Codes: H05K 2203/1572 Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 2203/308 Sacrificial means, e.g. for temporarily filling a space for making a via or a cavity or for making rigid-flexible PCBs
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673
• CPC Class Codes: H05K 3/4061 for via connections in inorganic insulating substrates

Abstract

A substrate with hermetically sealed vias extending from one side of the substrate to another and a method for fabricating same. The vias may be filled with a conductive material such as, for example, a fritless ink. The conductive path formed by the conductive material aids in sealing one side of the substrate from another. One side of the substrate may include a sensing element and another side of the substrate may include sensing electronics.

Claims

1. A method of forming an hermetically sealed substrate comprising:

obtaining a substrate material;

forming a via from a first side of the substrate to a second side of the substrate;

filling the via with a conductive material such that an hermetic seal forms between the first side of the substrate and the second side of the substrate to form a filled via; and

depositing a pillar on top of the filled via,

wherein depositing a pillar on top of the filled via comprises;

depositing a metal on at least one of the substrate and the filled via;

coating the substrate with a ceramic; and

removing the metal after the substrate has been coated with the ceramic.

2. The method according to claim 1, wherein forming a via comprises laser drilling the via.

3. The method according to claim 1, wherein forming a via further comprises annealing the substrate.

4. The method according to claim 1, wherein filling the via comprises

placing a screen on a surface of the substrate;

pushing the conductive material through the screen such that the conductive material proceeds into the via; and

pulling a vacuum on a side of the substrate opposite the side on which the conductive material has been pushed into the via such that the conductive material coats a wall of the via.

5. The method according to claim 4, wherein filling the via further comprises filling a meniscus that forms within the via.

6. The method according to claim 5, wherein filling a meniscus comprises

putting the substrate into a vacuum;

printing a conductive material into the meniscus; and

venting the substrate to atmosphere.

7. The method according to claim 6, wherein filling a meniscus further comprises firing the substrate.

8. The method according to claim 1, wherein removing the metal comprises dissolving the metal after the substrate has been coated with the ceramic.

9. The method according to claim 1, wherein the ceramic coating is shorter than the pillar.

10. The method according to claim 1, further comprising covering the filled via with a cap.

12. The method according to claim 4, wherein a stencil is used in place of the screen.

13. The method according to claim 1, wherein depositing a metal comprises:

affixing a mask to the substrate before depositing the metal; and

removing the mask after depositing the metal.

14. The method according to claim 1, wherein depositing a pillar on top of the filled via comprises:

applying a metalized pattern on the substrate.

15. The method according to claim 14, wherein the metal is deposited on the metalized pattern on the substrate.

11. A method of forming an hermetically sealed substrate comprising:

obtaining a substrate material;

forming a via from a first side of the substrate to a second side of the substrate;

filling the via with a conductive material such that an hermetic seal forms between the first side of the substrate and the second side of the substrate to form a filled via; and

covering the filled via with a nonconductive cap,

wherein covering the filled via is done using an ion beam assist deposition process.