Gelcore, LLC

Lumination LLC

Emcore Corporation

Hari S Venugopalan

Ivan Eliashevich

Bryan S Shelton

Xiang Gao

Robert F Karlicek

Michael Sackrison

Prosanto K Mukerji

Shawn Gibb

Steven Francis LeBoeuf

Stanton Earl Weaver, Jr

Thomas Frederick Soules

Stephen Daley Arthur

Emil P Stefanov

Chen-Lun Hsing Chen

Michael G Brown

Sebastien Libon

Stanton Weaver

Chris Bohler

Michael Wang

Bob Karlicek

Keng Ouyang

A light emitting chip is disposed on a support surface. A plurality of bonding bumps are disposed in a gap between the light emitting chip and the support surface. The plurality of bonding bumps provide at least one electrical power input path to the light emitting chip. An underfill comprising underfill material is disposed in the gap between the light emitting chip and the support surface such that the underfill substantially fills the gap but does not form a fillet extending outside the gap over sidewalls of the light emitting chip. The underfill is configured to provide at least one of (i) mechanical support for the light emitting chip and (ii) a thermal conduction path from the light emitting chip to the support surface.

Underfill for light emitting device

A light emitting device (A) includes a semiconductor die (). The semiconductor die includes: an epitaxial structure () arranged on a substrate (), the epitaxial structure forming an active light generating region () between a first layer () on a first side of the active region and having a first conductivity type, and a second layer () on a second side of the active region and having a second conductivity type, the second side of the active region being opposite the first side of the active region and the second conductivity type being different that the first conductivity type; a first contact () in operative electrical communication with the active region via the first layer in the epitaxial structure, the first contact being arranged on a side of the epitaxial structure opposite the substrate; a second contact () in operative electrical communication with the active region via the second layer in the epitaxial structure, the second contact being arranged on a side of the epitaxial structure opposite the substrate; a first contact trace corresponding to the first contact and defined at a surface thereof distal from the substrate, the first trace including at least one area designated for bonding (); and, a second contact trace corresponding the second contact and defined at a surface thereof distal from the substrate, the second trace including at least one area () designated for bonding. Suitably, the first contact trace is substantially enclosed within the second contact trace.

Optimized contact design for thermosonic bonding of flip-chip devices

A p-type contact () is disclosed for flip chip bonding and electrically contacting a p-type group III-nitride layer () of a group III-nitride flip chip light emitting diode die () with a bonding pad (). A first palladium layer () is disposed on the p-type group III-nitride layer (). The first palladium layer () is diffused through a native oxide of the p-type group III-nitride layer () to make electrical contact with the p-type group III-nitride layer (). A reflective silver layer () is disposed on the first palladium layer (). A second palladium layer () is disposed on the silver layer (). A bonding stack () including at least two layers () is disposed on the second palladium layer (). The bonding stack () is adapted for flip chip bonding the p-type layer () to the bonding pad ().

Flip-chip light emitting diode with a thermally stable multiple layer reflective p-type contact

A flip chip light emitting diode die () includes a light-transmissive substrate () and a plurality of semiconductor layers () are disposed on the light-transmissive substrate (). The semiconductor layers () define a light-generating p/n junction. An electrode () is formed on the semiconductor layers () for flip-chip bonding the diode die () to an associated mount (). The electrode () includes an optically transparent layer () formed of a substantially optically transparent material adjacent to the semiconductor layers () that makes ohmic contact therewith, and a reflective layer () adjacent to the optically transparent layer () and in electrically conductive communication therewith.

Flip-chip light emitting diode with indium-tin-oxide based reflecting contacts

A light emitting semiconductor device die () includes an electrically insulating substrate (). First and second spatially separated electrodes () are disposed on the electrically insulating substrate. The first and second electrodes define an electrical current flow direction directed from the first electrode to the second electrode. A plurality of light emitting diode mesas () are disposed on the substrate between the first and second spatially separated electrodes. Electrical series interconnections () are disposed on the substrate between neighboring light emitting diode mesas. Each series interconnection carries electrical current flow between the neighboring mesas in the electrical current flow direction.

LED with series-connected monolithically integrated mesas

A light-emitting element () is disclosed. A light emitting diode (LED) includes a sapphire substrate () having front and back sides (), and a plurality of semiconductor layers () deposited on the front side () of the sapphire substrate (). The semiconductor layers () define a light-emitting structure that emits light responsive to an electrical input. A metallization stack () includes an adhesion layer () deposited on the back side () of the sapphire substrate (), and a solderable layer () connected to the adhesion layer () such that the solderable layer () is secured to the sapphire substrate () by the adhesion layer (). A support structure () is provided on which the LED is disposed. A solder bond () is arranged between the LED and the support structure (). The solder bond () secures the LED to the support structure ().

GaN LED with solderable backside metal

A light emitting diode () has a backside and a front-side with at least one n-type electrode () and at least one p-type electrode () disposed thereon defining a minimum electrodes separation (d). A bonding pad layer () includes at least one n-type bonding pad () and at least one p-type bonding pad () defining a minimum bonding pads separation (d) that is larger than the minimum electrodes separation (d). At least one fanning layer () interposed between the front-side of the light emitting diode () and the bonding pad layer () includes a plurality of electrically conductive paths passing through vias () of a dielectric layer () to provide electrical communication between the at least one n-type electrode () and the at least one n-type bonding pad () and between the at least one p-type electrode () and the at least one p-type bonding pad ().

Flip-chip light emitting diode device without sub-mount

In a method for fabricating a flip-chip light emitting diode device, a submount wafer is populated with a plurality of the light emitting diode dies. Each device die is flip-chip bonded to the submount. Subsequent to the flip-chip bonding, a growth substrate is removed. The entire submount is immersed in the etchant solution, exposed to the light for a prespecified period of time, removed from the solution, dried and diced into a plurality of LEDs. The LEDs are immediately packaged without any further processing.

Increased light extraction from a nitride LED

A flip chip light emitting diode () includes a light-transmissive substrate () with a base semiconducting layer () disposed thereupon. A conductive mesh () is disposed on the base semiconducting layer () and is in electrically conductive contact therewith. Light-emitting micromesas () are disposed in openings () of the conductive mesh (). Each light emitting micromesa () has a topmost layer () of a second conductivity type that is opposite the first conductivity type. A first conductivity type electrode () is disposed on the base semiconducting layer () and is in electrical communication with the electrically conductive mesh (). An insulating layer () is disposed over the electrically conductive mesh (). A second conductivity type electrode layer () is disposed over the insulating layer () and the light-emitting micromesas (). the insulating layer () insulates the second conductivity type electrode layer () from the electrically conductive mesh ().

Flip chip light emitting diode with micromesas and a conductive mesh

A flip-chip LED device () includes a plurality of group III-nitride semiconductor layers () defining a p/n junction and including a top p-type group III-nitride layer (), and a p-contact () for flip-chip bonding the top p-type group III-nitride layer. The p-contact includes an aluminum layer () disposed on the top p-type group III-nitride layer (), and an interface layer () disposed between the aluminum layer and the top p-type group III-nitride layer. The interface layer reduces a contact resistance between the aluminum layer () and the top p-type group III-nitride layer (). The interface layer comprises one or more group III-nitride layers.

Methods for forming aluminum-containing p-contacts for group III-nitride light emitting diodes

A light-emitting package includes a substantially transparent substrate having a first surface and a second surface including a lens. The package also includes a light-emitting diode (LED) adapted to emit light having a predetermined wavelength, the LED being secured over the first surface of the substantially transparent substrate. The second surface of the substrate defines a principal light emitting surface of the package. The lens at the second surface has a grating pattern that matches the predetermined wavelength of the light emitted from the LED for controlling the emission geometry of the light emitted by the package. The grating pattern has a radial configuration including a series of circles that are concentric.

Microelectronic package having improved light extraction

A light-emitting microelectronic package includes a light-emitting diode () having a first region () of a first conductivity type, a second region () of a second conductivity type, and a light-emitting p-n junction () between the first and second regions. The light-emitting diode defines a lower contact surface () and a mesa () projecting upwardly from the lower contact surface. The first region () of a first conductivity type is disposed in the mesa () and defines a top surface of the mesa, and the second region () of a second conductivity type defines the lower contact surface that substantially surrounds the mesa (). The mesa includes at least one sidewall () extending between the top surface () of the mesa and the lower contact surface (), the at least one sidewall () having a roughened surface for optimizing light extraction from the package.

Led packages having improved light extraction

Light emitting diodes are provided with electrode and pad structures that facilitate current spreading and heat sinking. A light emitting diode may be formed as a die with a stacked structure having a first region and a mesa projecting from a surface of the first region. A first electrode may substantially cover the mesa and have a plurality of pads disposed thereon maximizing a contact area in relation to the first electrode. A second electrode may be disposed as a trace on the surface of the first region, the trace having a spiral, segmented/interdigitated, loop or pattern. Optionally, the trace includes corner spikes projecting outwardly toward edges of the first electrode.

Optimized contact design for flip-chip LED

A light emitting diode incorporating an active emitting layer () overlying a transparent substrate () is provided with a reflective diffraction grating () on the bottom surface of the substrate. Emitted light passing downwardly through the substrate is diffracted outwardly toward edges () of the substrate and passes out of the die through the edges. This effect enhances the external quantum efficiency of the diode.

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Somerset, NJ, United States of America

Hari S Venugopalan