Electrode array microchip

• US 5,388,577 A
• Filed: 05/04/1993
• Issued: 02/14/1995
• Est. Priority Date: 06/08/1990
• Status: Expired due to Fees

• Current Assignee: Boston University
• Original Assignee: Boston University
• Inventors: Hubbard, Allyn E.
• Primary Examiner(s): Nguyen, Viet Q.
• Application Number:
  US08/057,692
• Time in Patent Office: 651 Days
• Field of Search: 257/734, 257/784, 257/736, 257/448, 126/639, 126/640, 126/642, 126/644
• US Class Current: 600/377
• CPC Class Codes: G01N 33/4836 using multielectrode arrays
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 24/10 Bump connectors bumps on insulating substrates, e.g. chip carriers, H01L23/49816; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/13 of an individual bump connector
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01023 Vanadium [V]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/10329 Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/14 Integrated circuits

Abstract

An electrode array microchip, fabricated preferrably using CMOS technology, comprising electrodes made with overglass cuts over metal2 regions is disclosed. Overglass cuts of dimensions approximately an order of magnitude smaller than dimensions quoted in current design rules for CMOS technology are successfully employed to make exposed electrodes of dimensions on the order of microns. Thus, the electrode array chip can be produced cheaply on commercial fabrication lines. The invention finds many uses in biology and medicine, particularly when applied to the measurement of neural electrical activity.

Claims

1. An electrode army microchip for receiving biological electrical signals comprising:

a plurality of substantially planar metal regions supported on a surface of a substrate, insulating material covering said plurality of metal regions and said surface,

cuts in said insulating material, at least one of said cuts having a width of at least one micron, said cuts arranged to expose portions of said metal regions, whereby each exposed portion forms a substantially planar electrode for engagement with a biological material, and

regions of metal electrically connected to said electrodes to form electrical connections from said electrodes to wire bonding or probe sites on a surface of said microchip or to integrated circuitry within said microchip, whereby biological electrical signals from said biological material detectable at said electrodes are transmitted to said wire bonding or probe sites or to said integrated circuitry.

3. The microchip of claims 1 or 2 wherein said insulating material is comprised of silicon dioxide.

4. The microchip of claims 1 or 2 wherein said substrate is comprised of silicon.

5. The microchip of claims 1 or 2 wherein said microchip comprises integrated circuitry.

6. The microchip of claim 5 wherein said integrated circuitry provides multiplexing means for electrical signals between the electrodes and wire bonding or probe pads.

7. The microchip of claims 1 or 2 attached to a support, whereby said support permits manual manipulation of said microchip.

8. The microchip of claim 7 further comprising means for electrically connecting said wire bonding or probe sites or said integrated circuitry of said microchip to a display or recording device, whereby said electrical signals are displayed or recorded.

9. The microchip of claims 1 or 3 further comprising a conducting material deposited on each said electrode, whereby the resulting electrode is made to extend to the surface or above the surface of said microchip.

10. The microchip of claim 9 wherein said conducting material is gold, deposited to form a point on each said electrode.

11. The microchip of claim 9 further comprising a post fabrication line insulating coating over the surface of said microchip, said coating being removed over a portion of each extended electrode, whereby effective electrode surface area is reduced.

2. A CMOS electrode array microchip for receiving biological electrical signals comprising:

a pattern of adjacently arranged and substantially planar metal regions on a surface of a substrate, adjacent regions separated by a distance,

insulating material covering said pattern of metal regions and said surface,

a plurality of cuts in said insulating material, said cuts arranged to expose portions of said metal regions, whereby each exposed portion forms a substantially planar electrode for engagement with a biological material, at least one cut of said plurality of cuts having a width of three microns, said width at least equal to the distance between two adjacent metal regions, and

regions of metal electrically connected to said electrodes to form electrical connections from said electrodes to wire bonding or probe sites on a surface of said microchip or to integrated circuitry within said microchip, whereby biological electrical signals from said biological material detectable at said electrodes are transmitted to said wire bonding or probe sites or to said integrated circuitry.

12. The microchip of clam 9 wherein said-conducting material is platinum black electrochemically deposited on each said electrode, whereby effective electrode surface area is increased.