Electrochemical fabrication process for forming multilayer multimaterial microprobe structures

• US 20050215023A1
• Filed: 01/03/2005
• Published: 09/29/2005
• 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 7,531,077 B2
• Time in Patent Office: Days
• US Class Current: 438/381
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• 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: G01R 1/0483 Sockets for un-leaded IC's having matrix type contact fields, e.g. BGA or PGA devices; Sockets for unpackaged, naked chips for IC's with connecting points around the edges only G01R1/0433
• CPC Class Codes: G01R 1/06716 Elastic
• CPC Class Codes: G01R 1/07357 with flexible bodies, e.g. buckling beams
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06

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 an 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 one sacrificial material and two structural materials at least one of which at least partially encapsulates the other; 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.

5. 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 isolates other from the 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.

6. The process of claim 5 wherein one of the structural materials is the same material as the sacrificial material.

7. The process of claim 5 wherein each of the structural materials is different from the sacrificial material.

8. The process of claim 5 wherein the forming and adhering comprise electrodepositing at least one material.

9. 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 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 form regions of second material on successive layers when those regions of second material at least partially overlap; 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 material on those layers.

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.