Boonmi A Mekdhanasarn

US Patent:

6344412, Feb 5, 2002

Filed:

Mar 10, 2000

Appl. No.:

09/522725

Inventors:

Steven Ichikawa - Fremont CA
Boonmi Mekdhanasarn - Sunnyvale CA
Abdul R. Ahmed - Morgan Hill CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2144

US Classification:

438661, 438681

Abstract:

An ESD structure is created on an integrated circuit by providing a conductive polymer material between a signal line and a supply node or ground reference. The conductive polymer material becomes conductive when an electric field of sufficient intensity is applied. In one embodiment, the concentration of conductive particles of the conductive polymer material is empirically determined so that the resulting film becomes conducting at a predetermined threshold voltage. The conductive polymer is applied in liquid form on the wafer surface using a silk-screen printing process or a spin-on process and then cured. The conductive polymer layer can be adapted for use in multilevel metallization systems.

US Patent:

6357763, Mar 19, 2002

Filed:

Nov 4, 1998

Appl. No.:

09/186297

Inventors:

Ranjan J. Mathew - San Jose CA
Boonmi Mekdhanasarn - Sunnyvale CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G02F 113

US Classification:

277628, 349155, 349190, 277233, 350160

Abstract:

The present invention provides an improved seal for sealing a liquid crystal display (LCD) device. An improved seal is formed between a transparent plate and a die having a pixel array. The improved seal is configured to encircle the pixel array of the die when the die and the transparent plate are joined. The die and the transparent plate are joined together such that the improved seal is disposed between the transparent plate and the die. In one embodiment, the improved seal is a hybrid seal. The hybrid seal includes a first seal encircling the pixel array of the die and adhesively coupling the transparent plate and the die. The hybrid seal further includes a second seal encircling the second seal. In another embodiment, the first seal lacks a characteristic necessary for an effective seal. The second seal possesses the characteristic, such that the hybrid seal possesses the necessary characteristic.

US Patent:

6479323, Nov 12, 2002

Filed:

Jul 10, 1997

Appl. No.:

08/891025

Inventors:

Boonmi Mekdhanasarn - Sunnyvale CA
Daniel P. Tracy - San Jose CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2148

US Classification:

438111, 438118, 438122, 438123, 438124, 438127, 257675

Abstract:

A method and structure for attaching a lead frame to a heat sink are provided. In one embodiment, a layer of thermally conductive, electrically insulating epoxy is formed on a heat sink and the epoxy layer is fully cured. A thermoplastic adhesive layer is formed on the epoxy layer, and the heat sink is clamped to the lead frame such that the thermoplastic layer contacts the lead frame. The thermoplastic layer is heated to its melting point and then cooled, thereby joining the heat sink and the lead frame. In a variation, a partially cured B-stage epoxy layer is used to replace the thermoplastic layer. The B-stage epoxy layer is fully cured to connect the lead frame to the heat sink.

US Patent:

6534422, Mar 18, 2003

Filed:

Jun 10, 1999

Appl. No.:

09/330255

Inventors:

Steven Ichikawa - Fremont CA
Boonmi Mekdhanasarn - Sunnyvale CA
Abdul R. Ahmed - Morgan Hill CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2131

US Classification:

438780, 438781, 438778

Abstract:

An ESD structure is created on an integrated circuit by providing a conductive polymer material between a signal line and a supply node or ground reference. The conductive polymer material becomes conductive when an electric field of sufficient intensity is applied. In one embodiment, the concentration of conductive particles of the conductive polymer material is empirically determined so that the resulting film becomes conducting at a predetermined threshold voltage. The conductive polymer is applied in liquid form on the wafer surface using a silk-screen printing process or a spin-on process and then cured. The conductive polymer layer can be adapted for use in multilevel metallization systems.

US Patent:

56915675, Nov 25, 1997

Filed:

Sep 19, 1995

Appl. No.:

8/530772

Inventors:

Boonmi Mekdhanasarn - Sunnyvale CA
Daniel P. Tracy - San Jose CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 23495
H01L 2348

US Classification:

257675

Abstract:

A method and structure for attaching a lead frame to a heat sink are provided. In one embodiment, a layer of thermally conductive, electrically insulating epoxy is formed on a heat sink and the epoxy layer is fully cured. A thermoplastic adhesive layer is formed on the epoxy layer, and the heat sink is clamped to the lead frame such that the thermoplastic layer contacts the lead frame. The thermoplastic layer is heated to its melting point and then cooled, thereby joining the heat sink and the lead frame. In a variation, a partially cured B-stage epoxy layer is used to replace the thermoplastic layer. The B-stage epoxy layer is fully cured to connect the lead frame to the heat sink.

US Patent:

57738769, Jun 30, 1998

Filed:

Nov 6, 1996

Appl. No.:

8/744681

Inventors:

Boonmi Mekdhanasarn - Sunnyvale CA
Randy Hsiao-Yu Lo - Campbell CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2348

US Classification:

257665

Abstract:

A lead frame having protection against electrostatic discharge is disclosed. The lead frame having protection against electrostatic discharge includes a multiplicity of leads and an electrostatic discharge protection device. The electrostatic discharge protection device includes a conductive layer and a protection layer. The protection layer is arranged to contact a plurality of leads and is formed from an electrostatic discharge protection material, which insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.

US Patent:

57965706, Aug 18, 1998

Filed:

Sep 19, 1996

Appl. No.:

8/724305

Inventors:

Boonmi Mekdhanasarn - Sunnyvale CA
Randy Hsiao-Yu Lo - Campbell CA
Steve M. Ichikawa - Fremont CA
Abdul Rahim Ahmed - Morgan Hill CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H02H 100

US Classification:

361126

Abstract:

Described is a circuit board having protection against electrostatic discharge. The board includes a plurality of interconnect traces and an electrically conductive ground plane formed on a substrate such that a gap is created between the interconnect traces and the ground plane. A resistive electrostatic discharge protection material is positioned to bridge the gaps between the ground plane and the interconnect traces, such that the electrostatic discharge protection material electrically insulates the interconnect traces from the ground plane at voltages below a predefined threshold voltage and establishes an electrical connection between the interconnect traces and the conductive plane at voltages above the threshold voltage. A process of manufacturing the circuit board includes forming interconnect traces and a ground plane such that there is a gap between the ground plane and the interconnect traces. A resistive electrostatic discharge protection material is placed in the gap between the ground plane and the traces for protection against electrostatic discharge.

US Patent:

58917608, Apr 6, 1999

Filed:

Mar 25, 1998

Appl. No.:

/047884

Inventors:

Boonmi Mekdhanasarn - Sunnyvale CA
Randy Hsiao-Yu Lo - Campbell CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

H01L 2144
H01L 2148
H01L 2150

US Classification:

438123

Abstract:

A lead frame having protection against electrostatic discharge is disclosed. The lead frame having protection against electrostatic discharge includes a multiplicity of leads and an electrostatic discharge protection device. The electrostatic discharge protection device includes a conductive layer and a protection layer. The protection layer is arranged to contact a plurality of leads and is formed from an electrostatic discharge protection material, which insulates the leads from the conductive layer at voltages below a predefined threshold voltage and establishes an electrical connection between the leads and the conductive layer at voltages above the threshold voltage.