Li Te Fan

US Patent:

6498870, Dec 24, 2002

Filed:

Apr 20, 1998

Appl. No.:

09/063644

Inventors:

Ming Wu - Pacific Palisades CA
Li Fan - San Diego CA
Anis Husain - San Diego CA

Assignee:

OMM, Inc. - San Diego CA

International Classification:

G02B 626

US Classification:

385 18, 385 16, 385 25

Abstract:

A micromachined plate called a torsion plate, selectively pivots upon a substrate responsively to electrical force so as to move an attached micromirror in a same plane; thereby to accurately selectively intercept, and to reflect, a light beam that is moving parallel to the substrate; forming thus an optomechanical switch The electrical force may be electromagnetic in nature or, preferably, electrostatic. In various embodiments the pivoting torsion plate with the micromirror affixed may be (i) biased off the substrate by a three-dimensional structure and/or by a âreshapedâ torsion beam (ii) bent as plate and operated push OR pull, push AND pull, or push AND push, in a rocking operation, (iii) elevated above the substrate upon a self-assembling âmicro-elevator structureâ and/or (iv) moved greatly in angular position by action of a âmicro-flapâ A new design spring-loaded landing electrode and a torsion microhinge - further enhance performance. The micromachined, or Micro Electro Mechanical Systems (MEMS), optomechanical switch so formed is both fast and accurate to switch light over large angles up to 180Â while being highly resistant to sticking, or âstictionâ.

US Patent:

6526198, Feb 25, 2003

Filed:

Jan 17, 2002

Appl. No.:

10/053399

Inventors:

Ming C. Wu - Pacific Palisades CA
Li Fan - Rowland Heights CA
Anis Husain - San Diego CA

Assignee:

OMM, Inc. - San Diego CA

International Classification:

G02B 626

US Classification:

385 18, 385 16, 385 25

Abstract:

In at least one embodiment, a MEMS optomechanical switch in accordance with the present invention includes a substrate, a signal source capable of transmitting a radiation signal, an electrode coupled to the substrate, and a micromachined plate rotatably coupled to the substrate about a pivot axis. The switch further includes a micromirror having an orientated reflective surface, mounted to the micromachined plate and an electrical source coupled to at least one of the electrode and the micromachined plate.

US Patent:

7782072, Aug 24, 2010

Filed:

Sep 27, 2006

Appl. No.:

11/535859

Inventors:

Li Fan - San Ramon CA, US
John K. Gritters - Livermore CA, US

Assignee:

FormFactor, Inc. - Livermore CA

International Classification:

G01R 31/02

US Classification:

324762

Abstract:

A probe group can include multiple probes for testing devices having contact pads. The probes can comprise beams, contact tip structures, and mounting portions. The beams can provide for controlled deflection of the probes. The contact tip structures can be connected to the beams and can include contact portions for contacting with the devices. The mounting portions of the beams can be attached to support structures, which can be arranged in a staggered pattern. The beams located in a first row of the staggered pattern can include narrowing regions that lie substantially in line with the mounting portions of a second row of the beams.

US Patent:

7872394, Jan 18, 2011

Filed:

Dec 12, 2002

Appl. No.:

10/319403

Inventors:

John Gritters - Livermore CA, US
Christopher A. Bang - Glendale CA, US
Erno Klaassen - Los Altos CA, US
Li Fan - San Ramon CA, US
Richard Chen - Woodland Hills CA, US
Hsin-Chih Yeh - College Park MD, US
Ezekiel John Joseph Kruglick - San Diego CA, US

International Classification:

H02N 1/00
G02B 26/08

US Classification:

310309, 3592251, 359291, 257414, 216 6

Abstract:

In certain embodiments, a MEMS actuator is provided comprising a frame and a movable structure coupled to the frame. A vertical comb drive is provided between the frame and the movable structure to actuate the movable structure.

US Patent:

8148646, Apr 3, 2012

Filed:

Sep 29, 2008

Appl. No.:

12/240505

Inventors:

Li Fan - San Ramon CA, US
Michael J. Armstrong - Danville CA, US
John K. Gritters - Livermore CA, US

Assignee:

FormFactor, Inc. - Livermore CA

International Classification:

H05K 1/11

US Classification:

174261, 361760, 439 66, 32475403

Abstract:

A contact apparatus can be made by providing a first substrate with electrically conductive terminals and second substrates each of which can have contact structures. Each of the contact structures can have a contact tip. The second substrates can be aligned such that contact tips of the contact structures are aligned substantially in a plane. An optical system can be used to monitor an actual position of the second substrates, and a mechanical system can be used to move the second substrates to aligned positions. The contact structures can be attached to ones of the terminals on the first substrate while the second substrates are in the aligned positions.

US Patent:

8203352, Jun 19, 2012

Filed:

Aug 24, 2010

Appl. No.:

12/861984

Inventors:

Li Fan - San Ramon CA, US
John K. Gritters - Livermore CA, US

Assignee:

FormFactor, Inc. - Livermore CA

International Classification:

G01R 31/00
G01R 1/067

US Classification:

32475401, 32475507

Abstract:

A probe group can include multiple probes for testing devices having contact pads. The probes can comprise beams, contact tip structures, and mounting portions. The beams can provide for controlled deflection of the probes. The contact tip structures can be connected to the beams and can include contact portions for contacting with the devices. The mounting portions of the beams can be attached to support structures, which can be arranged in a staggered pattern. The beams located in a first row of the staggered pattern can include narrowing regions that lie substantially in line with the mounting portions of a second row of the beams.

US Patent:

20100140793, Jun 10, 2010

Filed:

May 22, 2009

Appl. No.:

12/470971

Inventors:

Li Fan - San Ramon CA, US
John K. Gritters - Livermore CA, US

Assignee:

FORMFACTOR, INC. - Livermore CA

International Classification:

H01L 23/48
C23F 1/00

US Classification:

257734, 216 18, 216 11, 257E2301

Abstract:

A process for making contact elements for a probe card assembly includes steps of forming a first continuous trench in a substrate along a first direction, and forming simultaneously a plurality of tip structures adjacent one to another in the first continuous trench in a second direction substantially normal to the first direction, each of the tip structures being part of, or adapted to be part of at least one corresponding contact element capable of forming an electrical contact with a terminal of an electronic device.

US Patent:

20130082729, Apr 4, 2013

Filed:

Sep 30, 2011

Appl. No.:

13/250756

Inventors:

Li Fan - Livermore CA, US
Rui Xu - Livermore CA, US

Assignee:

FORMFACTOR, INC. - Livermore CA

International Classification:

G01R 1/067

US Classification:

32475507

Abstract:

An electrically conductive probe can comprise a post to which a beam structure is attached. The beam structure can comprise a cantilevered portion that extends away from the post to a free end to which a contact structure can be attached. The cantilevered portion of the beam can include both a solid section and a hollow section. Multiple such probes can be used in a test contactor to make electrical connections with an electronic device such as a semiconductor die or dies to be tested.