Abstract:
In a method for fabricating a flip-chip light emitting diode device, epitaxial layers (14, 114) are deposited on a growth substrate (16, 116) to produce an epitaxial wafer. A plurality of light emitting diode devices are fabricated on the epitaxial wafer. The epitaxial wafer is diced to generate a device die (10, 110). The device die (10, 110) is flip chip bonded to a mount (12, 112). The flip chip bonding includes securing the device die (10, 110) to the mount (12, 112) by bonding at least one electrode (20, 22, 120) of the device die (10, 110) to at least one bonding pad (26, 28, 126) of the mount (12, 112). Subsequent to the flip chip bonding, a thickness of the growth substrate (16, 116) of the device die (10, 110) is reduced.
Abstract:
At least two light emitting diodes emit a non-parallel light beam. A condensing system, operationally coupled with the light emitting diodes, receives the emitted non-parallel light beam and converts the received non-parallel light beam into a parallel light beam. A non-imaging concentrator includes an input surface which collects the parallel light beam, and an output surface, which includes phosphor material and outputs light.
Abstract:
An LED device including an LED chip and a lens positioned apart from the chip and coated with a uniform thickness layer of fluorescent phosphor for converting at least some of the radiation emitted by the chip into visible light. Positioning the phosphor layer away from the LED improves the efficiency of the device and produces more consistent color rendition. The surface area of the lens is preferably at least ten times the surface area of the LED chip. For increased efficiency, the reflector and submount can also be coated with phosphor to further reduce internal absorption.
Abstract:
A light emitting apparatus comprises: an LED-based light source; a spherical, spheroidal, or toroidal diffuser generating a Lambertian light intensity distribution output at any point on the diffuser surface responsive to illumination inside the diffuser; and a base including a base connector. The LED based light source, the diffuser, and the base are secured together as a unitary LED lamp installable in a lighting socket by connecting the base connector with the lighting socket. The diffuser is shaped and arranged respective to the LED based light source in the unitary LED lamp to conform with an isolux surface of the LED based light source. The base is operatively connected with the LED based light source in the unitary LED lamp to electrically power the LED based light source using electrical power received at the base connector.
Abstract:
A light source (10) comprises a light engine (16), a base (24), a power conversion circuit (30) and an enclosure (22). The light engine (16) comprises at least one LED (12) disposed on a platform (14). The platform (14) is adapted to directly mate with the base (24) which a standard incandescent bulb light base. Phosphor (44) receives the light generated by the at least one LED (12) and converts it to visible light. The enclosure (22) has a shape of a standard incandescent lamp.
Abstract:
A lighting apparatus includes a bilaterally symmetrical light engine comprising first and second light emitting diode (LED) devices or planar LED device arrays facing opposite directions, and an envelope including phosphor spaced apart from and surrounding the bilaterally symmetrical light engine. The phosphor is effective to convert light emitted by the light engine to emission light. The bilaterally symmetrical light engine may be configured to emit light having a bilaterally symmetrical intensity distribution that is uniform except at emission angles within 10° of the symmetry plane of the bilaterally symmetrical light engine. Each of the first and second LED devices or planar LED device arrays may comprise at least one hemispherically emitting LED device including an LED chip and an encapsulant encapsulating the LED chip and shaped to refract light emitted by the LED chip into a uniform distribution over a hemispherical solid angle.
Abstract:
Provided are a lighting device, a backlighting device, and a display device that comprise a radiation source such as LED and wavelength converting members comprising phosphors. In one embodiment, self-absorption within the devices is suppressed or reduced by placing a selective reflector between two wavelength converting members, and the wavelength converting member emitting light with longer peak wavelength is substantially isolated from the irradiation of another wavelength converting member emitting light with shorter peak wavelength. In other embodiments, the wavelength converting members are arranged in strip configuration; or in adjacent hexagons configuration.
Abstract:
A light source (10) comprises a light engine (16), a base (24), a power conversion circuit (30) and an enclosure (22). The light engine (16) comprises at least one LED (12) disposed on a platform (14). The platform (14) is adapted to directly mate with the base (24) which a standard incandescent bulb light base. Phosphor (44) receives the light generated by the at least one LED (12) and converts it to visible light The enclosure (22) has a shape of a standard incandescent lamp.
Abstract:
In a light emitting device, a light emitting chip (12, 112) includes a stack of semiconductor layers (14) and an electrode (24, 141, 142) disposed on the stack of semiconductor layers. A support (10, 10′, 110, 210) has a generally planar surface (30) supporting the light emitting chip in a flip-chip fashion. An electrically conductive chip attachment material (40, 41, 141, 142) is recessed into the generally planar surface of the support such that the attachment material does not protrude substantially above the generally planar surface of the support. The attachment material provides electrical communication between the electrode of the light emitting chip and an electrically conductive path (36, 36′) of the support. Optionally, at least the stack of semiconductor layers and the electrode of the light emitting chip are also recessed into the generally planar surface of the support.
Abstract:
Systems and methods are provided to mitigate excess die attachment material accrual, and parasitic conductive paths formed thereby. A die attachment material (e.g., solder) is melted using a combination of localized heat sources and ultrasonic energy. The heat sources bring the die attachment material close to its melting point, which reduces an amount of bonding force associated with purely ultrasonic bonding techniques. An ultrasonic transducer brings the die attachment material the rest of the way up to its melting point, which reduces the overall temperature that the die and/or sensitive components thereon endure during the bonding process.