Patents by Inventor Ashok Narayan Prabhu

Ashok Narayan Prabhu 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).

  • Patent number: 6713862
    Abstract: Integrated packages incorporating multilayer ceramic circuit boards mounted on a metal support substrate can be used for temperature control by the metal support substrate. Various electronic components, as well as additional temperature control devices, can be connected to the circuit boards and to the metal support substrate to control or regulate the temperature of operation of the components. The integrated package can be hermetically sealed with a lid.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: March 30, 2004
    Assignee: Lamina Ceramics
    Inventors: Ponnuswamy Palanisamy, Attiganal Narayanaswamysreeram, Ellen Schwartz Tormey, Barry Jay Thaler, John Connolly, Ramon Ubaldo Martinelli, Ashok Narayan Prabhu, Mark Stuart Hammond, Joseph Mazzochette
  • Patent number: 6709749
    Abstract: A method of controlling shrinkage in aligned green tape stacks during firing comprises providing a topmost layer of a ceramic material having a sintering temperature higher than that of the ceramic used to make the green tapes and firing above the sintering temperature of the green tape ceramic but below the sintering temperature of the topmost layer ceramic. The method of the invention provides improved shrinkage control for green tape stacks on a support substrate.
    Type: Grant
    Filed: September 3, 1998
    Date of Patent: March 23, 2004
    Assignee: Lamina Ceramics, Inc.
    Inventors: Ananda Hosakere Kumar, Barry Jay Thaler, Ashok Narayan Prabhu
  • Publication number: 20030034564
    Abstract: Integrated packages incorporating multilayer ceramic circuit boards mounted on a metal support substrate can be used for temperature control by the metal support substrate. Various electronic components, as well as additional temperature control devices, can be connected to the circuit boards and to the metal support substrate to control or regulate the temperature of operation of the components. The integrated package can be hermetically sealed with a lid.
    Type: Application
    Filed: July 19, 2002
    Publication date: February 20, 2003
    Inventors: Ponnusamy Palanisamy, Attiganal Narayanaswamysreeram, Ellen Schwartz Tormey, Barry Jay Thaler, John Connolly, Ramon Ubaldo Martinelli, Ashok Narayan Prabhu, Mark Stuart Hammond, Joseph Mazzochette
  • Patent number: 6471805
    Abstract: A method of forming low resistance contact pads on a metal support substrate for a multilayer ceramic printed circuit board comprising forming a patterned layer of a conductive metal on the metal support substrate made of the same metal as that used to form the circuitry on the ceramic circuit board, and firing the support substrate. The patterned conductive metal can be formed by electroplating, by screen printing from a fritless conductor ink or by screen printing from a glass frit-containing conductor ink that includes a reducing agent.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: October 29, 2002
    Assignee: Sarnoff Corporation
    Inventors: Barry Jay Thaler, Ashok Narayan Prabhu
  • Patent number: 6455930
    Abstract: Integrated packages incorporating multilayer ceramic circuit boards mounted on a metal support substrate can be used for temperature control by the metal support substrate. Various electronic components, as well as additional temperature control devices, can be connected to the circuit boards and to the metal support substrate to control or regulate the temperature of operation of the components. The integrated package can be hermetically sealed with a lid.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: September 24, 2002
    Assignee: Lamina Ceramics, Inc.
    Inventors: Ponnuswamy Palanisamy, Attiganal Narayanaswamy Sreeram, Ellen Schwartz Tormey, Barry Jay Thaler, John Connolly, Ramon Ubaldo Martinelli, Ashok Narayan Prabhu, Mark Stuart Hammond
  • Patent number: 6399230
    Abstract: Resistors can be screen printed onto a green tape stack from a resistor ink comprising ruthenium oxide and a sufficient amount of a low melting temperature glass so that the resultant mixture fires at a temperature of 850-900° C. A conductive layer, as of silver, terminates the screen printed resistor layer and one or two green tapes are applied over the resistor layer to embed the resistors during firing. A final conductive layer is applied after firing.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: June 4, 2002
    Assignees: Sarnoff Corporation, Sharp Corporation
    Inventors: Ellen Schwartz Tormey, Ashok Narayan Prabhu, Ponnusamy Palinasamy
  • Patent number: 6361390
    Abstract: A plasma display device of the type having a composite back plate including a metal substrate and a ceramic barrier rib structure, is formed using a green ceramic tape which is a combination of two glasses, a primary glass which flows back during firing and a secondary glass that has a relatively high thermal coefficient of expansion. These glasses are combined in proportion to match the thermal coefficient of expansion of the metal substrate. Channels are formed on the inner surface of the back panel by laminating a green ceramic tape to the metal substrate and then soaking the laminated tape in a solvent before embossing the green tape to form the ribs. This soaking step enhances the flow of the green ceramic tape during the embossing process. The ceramic components of the green tape are formulated with a particle size 15 &mgr;m or more to enhance particle flow when the green tape is embossed.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: March 26, 2002
    Assignee: Sarnoff Corporation
    Inventors: Attiganal Narayanaswamy Sreeram, Ashok Narayan Prabhu, Les Hozer, Kalipada Palit
  • Patent number: 6321569
    Abstract: A method for forming a back panel for a plasma display includes preparing a green ceramic tape having a temperature coefficient of expansion (TCE) which matches the TCE of a metal core. Barrier ribs are formed on the back panel by embossing or scribing the green ceramic tape. The formed green ceramic tape is then bonded to the metal core. Finally, the bonded formed green ceramic tape and the metal core are cofired to form the back panel.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: November 27, 2001
    Assignee: Sarnoff Corporation
    Inventors: Attiganal Narayanswamy Sreeram, Robert L. Quinn, Ashok Narayan Prabhu
  • Patent number: 6286204
    Abstract: An integrated double sided metal supported display device has a green tape stack on both sides of the metal support. The green tape stacks incorporate circuitry and conductor filled vias to access the circuitry electrically on each green tape layer. The metal support has a plurality of openings to access both of the green tape stacks. These openings are made by forming the openings in the metal support, filling them with a dielectric that has a thermal coefficient of expansion close to that of the metal support, forming an opening in the dielectric and filling the opening with a conductive ink.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: September 11, 2001
    Assignee: Sarnoff Corporation
    Inventors: Attiganal Narayanaswamy Sreeram, Ashok Narayan Prabhu, Leszek Hozer, Kalipada Palit
  • Patent number: 6191934
    Abstract: High dielectric constant capacitors are made from a dielectric ink of lead-magnesium-niobate and lead oxide powders. Dielectric inks are made by mixing the dielectric powders with a suitable organic vehicle which can be used to coat one or more glass-based green tapes. Buried capacitors are made by coating an overlying and an underlying green tape with a conductor such as silver. Capacitors can also be made by adjusting the organic vehicle and forming a green tape from the dielectric powders. These dielectric green tapes each can be coated with a conductive layer and stacked, the conductive layers connected in parallel. The resultant multilayer capacitors have a very high dielectric constant, while eliminating the need for very large area capacitors, as compared to single layer capacitors.
    Type: Grant
    Filed: December 14, 1998
    Date of Patent: February 20, 2001
    Assignees: Sarnoff Corporation & Co., Ltd., Daewoo Electronics Co., Ltd.
    Inventors: Michael James Liberatore, Attiganal Narayanaswamy Sreeram, Ashok Narayan Prabhu, In-Tae Kim, Je-Do Mun, Sung-Dae Park, Yun-Hwi Park, Joo-Dong Yu, Ellen S. Tormey
  • Patent number: 6168490
    Abstract: A plasma display having a transparent front panel spaced from a back panel which is a metal core having layers of a dielectric material extending over and bonded to the core. Conductive electrodes are on the surface of or imbedded in the dielectric layer of the back panel. The materials of which the back panel is made are chosen to form a back panel having a thermal coefficient of expansion compatible with that of the front panel. Barrier ribs are formed on the back panel by embossing the green tape before cofiring the bonded assembly. The green tape is embossed using pulsed pressure and an embossing tool that is formed by assembling embossing members and spacing members in compression. The embossing tool further includes elastic spacers mounted outside of the embossing tool and in a position such that the elastic spacers are held in compression during the embossing operation to aid in releasing the embossed green tape from the embossing tool after the embossing operation.
    Type: Grant
    Filed: June 1, 1998
    Date of Patent: January 2, 2001
    Assignees: Sarnoff Corporation, LG Electronics, Inc.
    Inventors: Leszek Hozer, Kalipada Palit, Attiganal Narayanaswamy Sreeram, Robert L. Quinn, Ashok Narayan Prabhu
  • Patent number: 6140759
    Abstract: A plasma display device having a composite back panel including a metal substrate having a predetermined thermal coefficient of expansion (TCE) and a ceramic barrier rib structure which are co-fired at a pre-determined temperature, the ceramic barrier rib structure is composed from a first glass material having a TCE which is less than the TCE of the metal substrate, the first glass formulated to flow-back at the co-firing temperature; and a second glass material having a TCE which is greater than the TCE of the metal substrate, wherein the first and the second glass materials are mixed in a proportion to produce a composite ceramic material having a TCE which is substantially equal to the TCE of the metal substrate. The plasma display device having the ceramic barrier rib structure composed of the first and second glasses provides control of the TCE to minimize stresses in the final produce and assure panel flatness.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: October 31, 2000
    Assignee: Sarnoff Corporation
    Inventors: Attiganal Narayanaswamy Sreeram, Ashok Narayan Prabhu, Les Hozer, Kalipada Palit
  • Patent number: 6140767
    Abstract: A plasma display having a transparent front panel spaced from a back panel which is a metal core having layers of a dielectric material extending over and bonded to the core. Conductive electrodes are on the surface of or imbedded in the dielectric layer of the back panel. The materials of which the back panel is made are chosen to form a back panel having a thermal coefficient of expansion compatible with that of the front panel. The dielectric material is made from a green ceramic tape which is bonded to the core and cofired with the core to form the back panel. Barrier ribs are formed on the back panel by embossing or scribing the green tape before cofiring the bonded assembly. Slight differences in the TCEs of the front and back panels may be compensated for by heating the panel having the lower TCE to a temperature hotter than the panel having the lower TCE during the frit seal process.
    Type: Grant
    Filed: March 13, 1998
    Date of Patent: October 31, 2000
    Assignee: Sarnoff Corporation
    Inventors: Attiganal Narayanswamy Sreeram, Robert L. Quinn, Ashok Narayan Prabhu
  • Patent number: 6055151
    Abstract: Embedded passive components such as capacitors are formed in multilayer ceramic circuit boards by screen printing a component precursor compound ink sandwiched between conductor ink layers onto a green tape stack and covering the component ink layer with one or two green tape layers, aligning and laminating the green tapes and firing. Capacitor inks are made from dielectrics chosen from barium titanate, titanium oxide and lead-magnesium-niobate. The green tapes are made of a mixture of a crystallizing glass, a non-crystallizing glass and an oxide filler which does not shrink in the x and y dimensions during firing mounted on a metal support. Thus the embedded components can be made to close tolerances.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: April 25, 2000
    Assignees: Sarnoff Corp, Sharp K.K.
    Inventors: Ellen Schwartz Tormey, Ashok Narayan Prabhu, Attiganal Narayanaswamy Sreeram, Michael James Liberatore
  • Patent number: 6017642
    Abstract: High magnesium-content magnesium aluminosilicate glasses are used to form green tape compositions that are fired stepwise, i.e., first to about 500.degree. C. to remove organic materials, then to a temperature 10-30.degree. C. above the glass transition temperature for a time sufficient to nucleate the glass, and finally to a higher temperature near but below the softening temperature to complete crystallization of the glass. The resultant glass-ceramic may include substantial amounts of the forsterite crystalline phase. Multilayer ceramic printed circuit boards are made that are useful for high frequency, microwave applications. The fired high magnesium oxide content glasses have low dielectric constant and low dissipation loss factors, and they have a thermal coefficient of expansion that is compatible with metal or ceramic support substrates that impart mechanical strength to the printed circuit boards and that are thermally conductive. The boards are compatible with gallium arsenide devices.
    Type: Grant
    Filed: June 18, 1997
    Date of Patent: January 25, 2000
    Assignee: Sarnoff Corporation
    Inventors: Ananda Hosakere Kumar, Barry Jay Thaler, Ashok Narayan Prabhu, Ellen Schwartz Tormey
  • Patent number: 6011330
    Abstract: A power supply integrated module includes a metal substrate having a surface and a body of a dielectric material, such as a glass or ceramic, mounted on and bonded to the surface of the substrate. The body is formed of a plurality of layers of the dielectric material bonded together. Areas of a conductive material and a resistive material are coated on the surfaces of the layers of the body to form passive electronic components, such as capacitors, resistors and inductors. At least one transformer is on or in the body. The transformer and passive electronic components are electrically connected by conductive interconnects on the layers of the body and vias of a conductive material extending through the layers of the body to form a power supply integrated circuit. Active electronic components, such as diodes and transistors, may also be mounted on the body and electrically connected in the power supply circuit.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: January 4, 2000
    Assignee: Sarnoff Corporation
    Inventors: Lawrence Alan Goodman, Ashok Narayan Prabhu
  • Patent number: 5958807
    Abstract: High magnesium-content magnesium aluminosilicate glasses are used to form green tape compositions that are fired stepwise, i.e., first to about 500.degree. C. to remove organic materials, then to a temperature 10-30.degree. C. above the glass transition temperature for a time sufficient to nucleate the glass, and finally to a higher temperature near but below the softening temperature to complete crystallization of the glass. The resultant glass-ceramic may include substantial amounts of the forsterite crystalline phase. Multilayer ceramic printed circuit boards are made that are useful for high frequency, microwave applications. The fired high magnesium oxide content glasses have low dielectric constant and low dissipation loss factors, and they have a thermal coefficient of expansion that is compatible with metal or ceramic support substrates that impart mechanical strength to the printed circuit boards and that are thermally conductive. The boards are compatible with gallium arsenide devices.
    Type: Grant
    Filed: July 1, 1997
    Date of Patent: September 28, 1999
    Assignee: Sarnoff Corporation
    Inventors: Ananda Hosakere Kumar, Barry Jay Thaler, Ashok Narayan Prabhu, Ellen Schwartz Tormey
  • Patent number: 5953203
    Abstract: Embedded capacitors are formed in multilayer ceramic circuit boards by screen printing a capacitor ink sandwiched between conductor ink layers onto a green tape stack and covering the ink layer with one or two green tapes, and aligning the green tape layers, and firing. The green tapes are made of a mixture of a crystallizing glass, a non-crystallizing glass and an oxide filler which do not shrink in the x and y dimensions during firing. Thus the capacitors can be made to close tolerances.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: September 14, 1999
    Assignees: Sarnoff Corporation, Sharp Corporation
    Inventors: Ellen Schwartz Tormey, Ashok Narayan Prabhu, Attiganal Narayanaswamy Sreeram
  • Patent number: 5880705
    Abstract: An electroluminescent display formed on a ceramic substrate having a front ceramic surface and a back ceramic surface. The ceramic substrate includes a metal core that provides structural support, electrical ground, and heat dissipation. Electroluminescent cells are mounted on the front ceramic surface and driver circuits for driving the of electroluminescent cells are mounted on the back ceramic surface. The driver circuits are positioned directly behind said electroluminescent cells. Connectors extend through said ceramic substrate and the electroluminescent cells to different driver circuits. By positioning the driver circuits close to the EL cells, the drive lines from the drivers to the EL cells are short which allows for high refresh rates and low resistance losses. Each of the driver circuits can drive one electroluminescent cell or a group of electroluminescent cells. EL display cells coupled to a cermet electrode can also be driven by a field emission device or a low power electron beam.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: March 9, 1999
    Assignee: Sarnoff Corporation
    Inventors: Lubomyr Stephen Onyskevych, Satyam C. Cherukuri, Ashok Narayan Prabhu, P. Neil Yoc.o slashed.m, Kenneth E. Salsman
  • Patent number: 5876536
    Abstract: A method of controlling shrinkage in aligned green tape stacks during firing comprises providing a topmost layer of a ceramic material having a sintering temperature higher than that of the ceramic used to make the green tapes and firing above the sintering temperature of the green tape ceramic but below the sintering temperature of the topmost layer ceramic. The method of the invention provides improved shrinkage control for green tape stacks on a support substrate.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: March 2, 1999
    Assignee: Sarnoff Corporation
    Inventors: Ananda Hosakere Kumar, Barry Jay Thaler, Ashok Narayan Prabhu