Electrochemical Fabrication Process for Forming Multilayer Multimaterial Microprobe Structures

• US 20090320990A1
• Filed: 04/28/2009
• Published: 12/31/2009
• Est. Priority Date: 02/04/2003
• Status: Active Grant

• Current Assignee: University of Southern California
• Original Assignee: Microfabrica Incorporated (Technoprobe S.P.A.)
• Inventors: Smalley, Dennis R., Cohen, Adam L., Lockard, Michael S., Kumar, Ananda H.
• Granted Patent: US 9,244,101 B2
• Time in Patent Office: Days
• US Class Current: 156/150
• CPC Class Codes: C23C 18/1605 by masking
• CPC Class Codes: C23C 18/1651 Two or more layers only obtained by electroless plating
• CPC Class Codes: C25D 1/003 3D structures, e.g. superposed patterned layers
• CPC Class Codes: C25D 5/02 Electroplating of selected surface areas
• CPC Class Codes: C25D 5/10 Electroplating with more than one layer of the same or of different metals for bearings C25D7/10
• CPC Class Codes: G01R 1/06716 Elastic
• CPC Class Codes: G01R 1/06744 Microprobes, i.e. having dimensions as IC details
• CPC Class Codes: G01R 1/06755 Material aspects
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• CPC Class Codes: H01L 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps

Abstract

Some embodiments of the invention are directed to the electrochemical fabrication of microprobes which are formed from a core material and a material that partially coats the surface of the probe. Other embodiments are directed to the electrochemical fabrication of microprobes which are formed from a core material and a material that completely coats the surface of each layer from which the probe is formed including interlayer regions. These first two groups of embodiments incorporate both the core material and the coating material during the formation of each layer. Still other embodiments are directed to the electrochemical fabrication of microprobe arrays that are partially encapsulated by a dielectric material during a post layer formation coating process. In even further embodiments, the electrochemical fabrication of microprobes from two or more materials may occur by incorporating a coating material around each layer of the structure without locating the coating material in inter-layer regions.

Claims

1. A fabrication process for forming a multi-layer three-dimensional probe structure or array of probe structures, comprising:

(a) forming and adhering a layer of material to a previously formed layer and/or to a substrate;

(b) repeating the forming and adhering operation of (a) to build up a three-dimensional structure from a plurality of adhered layers, wherein the formation of at least a plurality of layers comprises the deposition of at least two structural materials, at least one of which is a dielectric material, and the deposition of a sacrificial material; and

(c) after formation of a plurality of layers, separating at least a portion of the sacrificial material on a plurality of layers from the structural materials on those layers.

2. The process of claim 1 wherein one of the structural materials is the same material as the sacrificial material.

3. The process of claim 1 wherein each of the structural materials is different from the sacrificial material.

4. The process of claim 1 wherein the forming and adhering comprise electrodepositing at least one material.

6. The process of claim 1 wherein one of the structural materials is the same material as the sacrificial material.

7. The process of claim 1 wherein each of the structural materials is different from the sacrificial material.

8. The process of claim 1 wherein the forming and adhering comprise electrodepositing at least one material.

5. A fabrication process for forming an array of multi-layer three-dimensional probes, comprising:

(a) forming and adhering a layer of material to a previously formed layer and/or to a substrate;

(b) repeating the forming and adhering operation of (a) to build up a three-dimensional structure from a plurality of adhered layers, wherein a plurality of layers comprise a desired pattern of at least one structural material and at least one sacrificial material;

(c) after formation of a plurality of layers, separating at least a portion of the sacrificial material on a plurality of layers from the structural material on those layers; and

(d) at least partially surrounding a plurality of probe elements of the probe array with a dielectric material in regions removed from tips of the probe elements.

9. A fabrication process for forming a multi-material, multi-layer three-dimensional probe structure or array of probe structures, comprising:

(a) forming and adhering a layer of material to a previously formed layer and/or to a substrate;

(b) repeating the forming and adhering operation of (a) to build up a three-dimensional structure from a plurality of adhered layers, wherein the formation of each of at least a plurality of layers comprises the deposition a sacrificial material and at least two structural materials, a first of which encapsulates a second wherein the encapsulating first material does not completely isolate regions of the second material from regions of second material on successive layers in regions where the second material overlap on the successive layers; and

(c) after formation of a plurality of layers, separating at least a portion of the sacrificial material on a plurality of layers from the first and second structural materials on those layers to reveal the multi-material, multi-layer three-dimensional probe structure formed from the at least two structural material, wherein the first structural material fully encapsulates the second structural material.

10. The process of claim 9 wherein one of the structural materials is the same material as the sacrificial material.

11. The process of claim 9 wherein each of the structural materials is different from the sacrificial material.

12. The process of claim 9 wherein the forming and adhering comprise electrodepositing at least one material.