Patents by Inventor Boonmi Mekdhanasarn
Boonmi Mekdhanasarn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6534422Abstract: 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.Type: GrantFiled: June 10, 1999Date of Patent: March 18, 2003Assignee: National Semiconductor CorporationInventors: Steven Ichikawa, Boonmi Mekdhanasarn, Abdul R. Ahmed
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Patent number: 6479323Abstract: 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.Type: GrantFiled: July 10, 1997Date of Patent: November 12, 2002Assignee: National Semiconductor CorporationInventors: Randy H. Y. Lo, Boonmi Mekdhanasarn, Daniel P. Tracy
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Patent number: 6357763Abstract: 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.Type: GrantFiled: November 4, 1998Date of Patent: March 19, 2002Assignee: National Semiconductor CorporationInventors: Ranjan J. Mathew, Boonmi Mekdhanasarn
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Patent number: 6344412Abstract: 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.Type: GrantFiled: March 10, 2000Date of Patent: February 5, 2002Assignee: National Semiconductor CorporationInventors: Steven Ichikawa, Boonmi Mekdhanasarn, Abdul R. Ahmed
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Publication number: 20010045712Abstract: 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.Type: ApplicationFiled: November 4, 1998Publication date: November 29, 2001Inventors: RANJAN J. MATHEW, BOONMI MEKDHANASARN
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Patent number: 5891760Abstract: 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.Type: GrantFiled: March 25, 1998Date of Patent: April 6, 1999Assignee: National Semiconductor CorporationInventors: Boonmi Mekdhanasarn, Randy Hsiao-Yu Lo
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Patent number: 5796570Abstract: 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.Type: GrantFiled: September 19, 1996Date of Patent: August 18, 1998Assignee: National Semiconductor CorporationInventors: Boonmi Mekdhanasarn, Randy Hsiao-Yu Lo, Steve M. Ichikawa, Abdul Rahim Ahmed
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Patent number: 5773876Abstract: 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.Type: GrantFiled: November 6, 1996Date of Patent: June 30, 1998Assignee: National Semiconductor CorporationInventors: Boonmi Mekdhanasarn, Randy Hsiao-Yu Lo
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Patent number: 5691567Abstract: 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.Type: GrantFiled: September 19, 1995Date of Patent: November 25, 1997Assignee: National Semiconductor CorporationInventors: Randy H. Y. Lo, Boonmi Mekdhanasarn, Daniel P. Tracy