Abstract: A packaged power device includes a ceramic package body having a top drain pad having a first area, a top source pad having a second area smaller than the first area, and a top gate pad having a third area smaller than the second area; a power device having a bottom surface affixed to a top drain pad, a die source pad coupled to the top source pad, and a die gate pad coupled to the top gate pad; and a ceramic lid affixed to the ceramic package body to form the packaged power device.

Abstract: A packaged power device includes a ceramic package body having a top drain pad having a first area, a top source pad having a second area smaller than the first area, and a top gate pad having a third area smaller than the second area; a power device having a bottom surface affixed to a top drain pad, a die source pad coupled to the top source pad, and a die gate pad coupled to the top gate pad; and a ceramic lid affixed to the ceramic package body to form the packaged power device.

Abstract: A packaged power device includes a ceramic package body having a top drain pad having a first area, a top source pad having a second area smaller than the first area, and a top gate pad having a third area smaller than the second area; a power device having a bottom surface affixed to a top drain pad, a die source pad coupled to the top source pad, and a die gate pad coupled to the top gate pad; and a ceramic lid affixed to the ceramic package body to form the packaged power device.

Abstract: A packaged power device includes a ceramic package body having a top drain pad having a first area, a top source pad having a second area smaller than the first area, and a top gate pad having a third area smaller than the second area; a power device having a bottom surface affixed to a top drain pad, a die source pad coupled to the top source pad, and a die gate pad coupled to the top gate pad; and a ceramic lid affixed to the ceramic package body to form the packaged power device.

Abstract: A semiconductor package for mounting to a printed circuit board (PCB) includes a case comprising a ceramic base, a semiconductor die in the case, a mounting pad under the ceramic base and coupled to the semiconductor die through at least one opening in the ceramic base. The mounting pad includes at least one layer having a coefficient of thermal expansion (CTE) approximately matching a CTE of the ceramic base. The mounting pad includes at least one layer having a low-yield strength of equal to or less than 200 MPa. The mounting pad includes at least one copper layer and at least one molybdenum layer. The semiconductor package also includes a bond pad coupled to another mounting pad under the ceramic base through a conductive slug in the ceramic base.

Abstract: A semiconductor package for mounting to a printed circuit board (PCB) includes a case comprising a ceramic base, a semiconductor die in the case, a mounting pad under the ceramic base and coupled to the semiconductor die through at least one opening in the ceramic base. The mounting pad includes at least one layer having a coefficient of thermal expansion (CTE) approximately matching a CTE of the ceramic base. The mounting pad includes at least one layer having a low-yield strength of equal to or less than 200 MPa. The mounting pad includes at least one copper layer and at least one molybdenum layer. The semiconductor package also includes a bond pad coupled to another mounting pad under the ceramic base through a conductive slug in the ceramic base.

Abstract: A semiconductor package for mounting to a printed circuit board (PCB) includes a semiconductor die in a ceramic case, a conductive base coupled to the semiconductor die at a top surface of the conductive base, where the conductive base includes a first layer having a first coefficient of thermal expansion (CTE), and a second layer having at least one mounting tab and a second CTE. The conductive base is configured to reduce thermal stress in the ceramic case, where the first CTE is equal to or slightly different than a CTE of the ceramic case, the second CTE is greater than the first CTE, and a CTE of the PCB is greater than or equal to the second CTE. The conductive base is configured to electrically couple a power electrode of the semiconductor die to the PCB.

Abstract: A semiconductor package for mounting to a printed circuit board (PCB) includes a semiconductor die in a ceramic case, a conductive base coupled to the semiconductor die at a top surface of the conductive base, where the conductive base includes a first layer having a first coefficient of thermal expansion (CTE), and a second layer having at least one mounting tab and a second CTE. The conductive base is configured to reduce thermal stress in the ceramic case, where the first CTE is equal to or slightly different than a CTE of the ceramic case, the second CTE is greater than the first CTE, and a CTE of the PCB is greater than or equal to the second CTE. The conductive base is configured to electrically couple a power electrode of the semiconductor die to the PCB.

Abstract: Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.

Abstract: Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.

Abstract: Embodiments of the invention include a system and method for color-coating an optical fiber. The system includes a flow controller that controllably delivers and mixes color concentrate from one or more color concentrate reservoirs with a coating material, which colored coating material is fed to a coating die through which optical fiber passes. The color concentrate reservoirs are more compact and can be made portable along with the flow controller. Thus, the entire color coating system can travel to any appropriate location in the fiber manufacturing facility, e.g., at any one of a number of draw towers. Such portability allows many different colors to be used at the same draw tower much more easily than conventional arrangements, which typically only have one color line per draw tower. The method includes providing an optical fiber, controllably delivering color concentrate with a coating material to a coating die, coating the optical fiber with the coating die, and curing the coated fiber.

Abstract: Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.

Abstract: Embodiments of the invention include an optical fiber preform assembly and a method for making optical fiber using the preform assembly. The assembly includes a preform core rod, at least one overclad tube formed around the preform core rod, a handle attached to one end of the overclad tube, and a refractory material positioned in the overclad tube between the preform core rod and the handle. The refractory material reduces if not prevents movement of the preform core rod into the handle during the fiber draw process. Preferably, the refractory material is made of, e.g., magnesium oxide and/or aluminum oxide, and has a melting point, e.g., greater than approximately 2000 degrees Celsius. Embodiments of the invention also include a method for making optical fiber using this preform assembly.

Abstract: Embodiments of the invention include a system and method for color-coating an optical fiber. The system includes a flow controller that controllably delivers and mixes color concentrate from one or more color concentrate reservoirs with a coating material, which colored coating material is fed to a coating die through which optical fiber passes. The color concentrate reservoirs are more compact and can be made portable along with the flow controller. Thus, the entire color coating system can travel to any appropriate location in the fiber manufacturing facility, e.g., at any one of a number of draw towers. Such portability allows many different colors to be used at the same draw tower much more easily than conventional arrangements, which typically only have one color line per draw tower. The method includes providing an optical fiber, controllably delivering color concentrate with a coating material to a coating die, coating the optical fiber with the coating die, and curing the coated fiber.

Abstract: Embodiments of the invention include an optical fiber preform assembly and a method for making optical fiber using the preform assembly. The assembly includes a preform core rod, at least one overclad tube formed around the preform core rod, a handle attached to one end of the overclad tube, and a refractory material positioned in the overclad tube between the preform core rod and the handle. The refractory material reduces if not prevents movement of the preform core rod into the handle during the fiber draw process. Preferably, the refractory material is made of, e.g., magnesium oxide and/or aluminum oxide, and has a melting point, e.g., greater than approximately 2000 degrees Celsius. Embodiments of the invention also include a method for making optical fiber using this preform assembly.

Abstract: Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. Prior to MCVD deposition on a starting tube, the outer diameter of the starting tube is altered by etching or a like process to modify its ovality. Additionally, after MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. Both methods may be used independently or in combination to modify the ovality and reduce PMD of optical fiber drawn from the core rod. An additional method includes etching the cladding material of a core rod having an oval or elliptical core such that the cladding material mirrors the shape of the oval core. During drawing, the perform created there from is placed under a surface tension, or pulled in a manner to generate a circular or near perfect circular optical fiber having desired ovality and low PMD.

Abstract: An optical fiber including a layer of primary coating material having a first modulus, a layer of color coating material having a second modulus, a layer of secondary coating having a third modulus, and wherein the first modulus, the second modulus, and the third modulus are different values.

Abstract: Apparatus and methods are provided for reducing end effect on a preform assembly during manufacture of optical fiber. The present invention provides apparatus and methods that apply a first vacuum pressure to a preform assembly during a first portion of the draw of optical fiber from the preform assembly and a second lesser vacuum pressure during a second portion of the draw. The second vacuum pressure may be a step down pressure or a gradual or an incremental decrease in pressure over time. The present invention further provides apparatus and methods that use an intermediate rod such as a dummy preform core rod and/or a support rod placed at the back of the preform core rod, wherein the preform end effect occurs on the dummy preform core rod, as opposed to the core rod of the preform assembly or is eliminated altogether by the support rod.

Abstract: The present invention provides coating methods for use in the manufacture of coated optical fibers. The coating methods of the present invention coat an optical fiber with a primary coating material that has a non-reactive colorant. A secondary coating material is applied over the primary coating material. The primary coating material may either be cured prior to application of the secondary coating material or both the primary and secondary coating materials may be cured at the same time to create primary and secondary coating layers over the optical fiber. In one embodiment, the secondary layer is formed of a substantially transparent material, visibly exposing the colored primary coating layer for inspection and/or measurement. The present invention further provides coated optical fibers made according to the coating methods of the present invention.