Nthdegree Technologies Worldwide Inc.

Printed Energy Pty Ltd

Bradley Steven Oraw

Richard A Blanchard

William Johnstone Ray

Mark David Lowenthal

Tricia Youngbull

Thomas Frederick Soules

Brian D Ogonowsky

Xiaorong Cai

Lixin Zheng

Reuben Rettke

Alexander Ray

Eric Kahrs

Travis Thompson

Bemly Sujeewa Randeniya

Jeff Baldridge

Marc Oliver Meier

Rodger Whitby

Richard Austin Blanchard

An LED sticker is disclosed that receives an NFC transmission from a nearby smartphone to energize LEDs in the sticker. A spiral (or loop) antenna is used in the sticker to generate power from the NFC transmission. The NFC signal is at 13.56 MHz, which is the resonant frequency of the NFC antenna circuit in the smartphone. The LED portion is formed by sandwiching pre-formed microscopic LEDs between two conductive layers to connect the LEDs in parallel. The conductive layers form a relatively large integral capacitor that is used to achieve the 13.56 MHz resonant frequency. So no additional capacitor is needed in the circuit to achieve a resonance of 13.56 MHz. This greatly reduces the design requirements of the antenna. The LED sticker may also contain an NFC tag having its own independent loop antenna and NFC chip. Various practical applications of the LED sticker are disclosed.

NFC-powered LED sticker with integral capacitor

A programmable circuit includes an array of printed groups of microscopic transistors or diodes. The devices are pre-formed and printed as an ink and cured. The devices in each group are connected in parallel so that each group acts as a single device. In one embodiment, about 10 devices are contained in each group so the redundancy makes each group very reliable. Each group has at least one electrical lead that terminates in a patch area on the substrate. An interconnection conductor pattern interconnects at least some of the leads of the groups in the patch area to create logic circuits for a customized application of the generic circuit. The groups may also be interconnected to be logic gates, and the gate leads terminate in the patch area. The interconnection conductor pattern then interconnects the gates for form complex logic circuits.

Method for forming complex electronic circuits by interconnecting groups of printed devices

A programmable circuit includes an array of printed groups of microscopic transistors or diodes. The devices are pre-formed and printed as an ink and cured. A patterned hydrophobic layer defines the locations of the printed dots of the devices. The devices in each group are connected in parallel so that each group acts as a single device. Each group has at least one electrical lead that terminates in a patch area on the substrate. An interconnection conductor pattern interconnects at least some of the leads of the groups in the patch area to create logic circuits for a customized application of the generic circuit. The groups may also be interconnected to be logic gates, and the gate leads terminate in the patch area. The interconnection conductor pattern then interconnects the gates for form complex logic circuits.

Printing complex electronic circuits using a printable solution defined by a patterned hydrophobic layer

Active LEDs have a control transistor in series with an LED and have a top electrode, a bottom electrode, and a control electrode. The active LEDs are microscopic and dispersed in an ink. A substrate has column lines, and the active LEDs are printed at various pixel locations so the bottom electrodes contact the column lines. A hydrophobic mask defines the pixel locations. Due to the printing process, there are different numbers of active LEDs in the various pixel locations. Row lines and control lines contact the top and control electrodes so that the active LEDs in each single pixel location are connected in parallel. If the LEDs emit blue light, red and green phosphors are printed over various pixel locations to create an ultra-thin color display. Any active LED may be addressed using row and column addressing, and the brightness may be controlled using the control lines.

Ultra-thin display using printed printed light emitting diodes

A PV module is formed having an array of PV cells, where the cells are separated by gaps. Each cell contains an array of small silicon sphere diodes (10-300 microns in diameter) connected in parallel. The diodes and conductor layers may be patterned by printing. A continuous metal substrate supports the diodes and conductor layers in all the cells. A dielectric substrate is laminated to the metal substrate. Trenches are then formed by laser ablation around the cells to sever the metal substrate to form electrically isolated PV cells. A metallization step is then performed to connect the cells in series to increase the voltage output of the PV module. An electrically isolated bypass diode for each cell is also formed by the trenching step. The metallization step connects the bypass diode and its associated cell in a reverse-parallel relationship.

Photovoltaic module having printed PV cells connected in series by printed conductors

Printing complex electronic circuits using a patterned hydrophobic layer

An initially flat light sheet is formed by printing conductor layers and microscopic LEDs over a flexible substrate to connect the LEDs in parallel. The light sheet is then subjected to a molding process which forms 3-dimensional features in the light sheet, such as bumps of any shape. The features may be designed to create a desired light emission profile, increase light extraction, and/or create graphical images. In one embodiment, an integrated light sheet and touch sensor is formed, where the molded features convey touch positions of the sensor. In one embodiment, a curable resin is applied to the light sheet to fix the molded features. In another embodiment, optical features are molded over the flat light sheet. In another embodiment, each molded portion of the light sheet forms a separate part that is then singulated from the light sheet.

Molded LED light sheet

LED modules are disclosed having a control MOSFET, or other transistor, in series with an LED. In one embodiment, a MOSFET wafer is bonded to an LED wafer and singulated to form thousands of active 3-terminal LED modules with the same footprint as a single LED. Despite the different forward voltages of red, green, and blue LEDs, RGB modules may be connected in parallel and their control voltages staggered at 60 Hz or greater to generate a single perceived color, such as white. The RGB modules may be connected in a panel for general illumination or for a color display. A single dielectric layer in a panel may encapsulate all the RGB modules to form a compact and inexpensive panel. Various addressing techniques are described for both a color display and a lighting panel. Various circuits are described for reducing the sensitivity of the LED to variations in input voltage.

Full color LED module having integrated driver transistors

A method of forming a light sheet includes depositing a reflective conductor layer over a substrate, printing a layer of microscopic inorganic LEDs on the conductor layer, depositing a first dielectric layer, having a first index of refraction, over the conductor layer and along sidewalls of the LEDs, and depositing a transparent conductor layer over the LEDs so that the LEDs are connected in parallel. The transparent conductor layer may be a wire mesh with openings. A liquid or paste polymer layer is then deposited over the transparent conductor layer and directly contacts the first dielectric layer. The indices of refraction of both layers are similar to reduce TIR. The top surface of the polymer layer is then molded to contain light extraction features to reduce waveguiding in the light sheet. In another embodiment, the substrate surface is the light exit surface that has the light extraction features.

Geometrical light extraction structures for printed LEDs

An LED module is disclosed containing an integrated driver transistor (e.g, a MOSFET) in series with an LED. In one embodiment, LED layers are grown over a substrate. The transistor regions are formed over the same substrate. After the LED layers, such as GaN layers, are grown to form the LED portion, a central area of the LED is etched away to expose a semiconductor surface in which the transistor regions are formed. A conductor connects the transistor in series with the LED. Another node of the transistor is electrically coupled to an electrode on the bottom surface of the substrate. In one embodiment, an anode of the LED is connected to one terminal of the module, one current carrying node of the transistor is connected to a second terminal of the module, and the control terminal of the transistor is connected to a third terminal of the module.

Active LED module with LED and transistor formed on same substrate

Active LED module having integrated limiter

Printing complex electronic circuits

Relatively small, electrically isolated segments of LED light sheets are fabricated having an anode terminal and a cathode terminal. The segments contain microscopic printed LEDs that are connected in parallel by two conductive layers sandwiching the LEDs. The top conductive layer is transparent. Separately formed from the light sheet segments is a flexible, large area conductor backplane having a single layer or multiple layers of solid metal strips (traces). The segments are laminated over the backplane's metal pattern to supply power to the segment terminals. An adhesive layer secures the segments to the backplane. The metal pattern may connect the segments in series, or parallel, or form an addressable circuit for a display. The segments may be on a common substrate or physically separated from each other prior to the lamination.

Multi-layer conductive backplane for LED light sheet segments

A first layer of inorganic first vertical LED dies (VLEDs) of a first color is printed on a conductor surface. A first transparent conductor layer is deposited over the first VLEDs to electrically contact top electrodes of the first VLEDs. An electrically insulated second layer of second VLEDs of a second color is printed over the first transparent conductor layer, and an electrically insulated third layer of third VLEDs of a third color is printed over the first transparent conductor layer. For a color display, the VLEDs are printed in an addressable pixel array. Since the VLEDs are printed as an ink, the overlying VLEDs in a pixel are not vertically aligned, so there is little blockage of light. If the structure is used for general illumination, the VLEDs do not need to be printed in pixel areas.

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Chandler, AZ, United States of America

Bradley Steven Oraw