Abstract: A common-anode micro-LED device includes an array of micro light-emitting diodes (micro-LEDs) characterized by a pitch less than 20 ?m and including a first common anode for the first array of micro-LEDs, and a backplane wafer including pixel drive circuits configured to individually address micro-LEDs of the array of micro-LEDs through cathodes of the micro-LEDs. Each pixel drive circuit of the pixel drive circuits includes an analog current drive circuit connected to a cathode of a micro-LED of the first array of micro-LEDs, a storage circuit for storing pixel data, and a timing control circuit configured to control the analog current drive circuit based on the pixel data.

Abstract: Techniques disclosed herein relate to micro light emitting diodes (micro-LEDs) for a display system. A display system includes an array of micro light emitting diodes (micro-LEDs), an array of output couplers optically coupled to the array of micro-LEDs and configured to extract light emitted by respective micro-LEDs in the array of micro-LEDs, a waveguide display, and display optics configured to couple the light emitted by the array of micro-LEDs and extracted by the array of output couplers into the waveguide display. Each output coupler in the array of output couplers is configured to direct a chief ray of the light emitted by a respective micro-LED in the array of micro-LEDs to a different respective direction.

Abstract: Disclosed herein are techniques relating to wafer-to-wafer bonding for manufacturing light-emitting diodes (LEDs). In some embodiments, a method includes reducing bowing present in a semiconductor material and a substrate on which the semiconductor material is formed. The reducing involves segmenting the semiconductor material through etching the semiconductor material to form gaps between adjacent segments. The semiconductor material includes an n-type layer, a quantum well layer, and a p-type layer. The method further includes bonding a base wafer to the semiconductor material, removing the substrate from the semiconductor material, and forming a plurality of trenches. The trenches extend through the semiconductor material within each of the segments, thereby singulating the LEDs. In some embodiments, the method is performed in the following order: reducing bowing, bonding the base wafer, removing the substrate, forming the trenches.

Abstract: Disclosed herein are techniques relating to wafer-to-wafer bonding for manufacturing light-emitting diodes (LEDs). In some embodiments, a method includes reducing bowing of a layered structure including a semiconductor material and a substrate on which the semiconductor material is formed by generating breakages, fractures, or at least one region of weakened bonding within the layered structure. The method also includes bonding a base wafer to the semiconductor material, removing the substrate from the semiconductor material, and forming a plurality of trenches through the semiconductor material to produce a plurality of LEDs.

Abstract: Techniques disclosed herein relate to micro light emitting diodes (micro-LEDs) for a display system. A display system includes an array of micro light emitting diodes (micro-LEDs), an array of output couplers optically coupled to the array of micro-LEDs and configured to extract light emitted by respective micro-LEDs in the array of micro-LEDs, a waveguide display, and display optics configured to couple the light emitted by the array of micro-LEDs and extracted by the array of output couplers into the waveguide display. Each output coupler in the array of output couplers is configured to direct a chief ray of the light emitted by a respective micro-LED in the array of micro-LEDs to a different respective direction.

Abstract: Disclosed herein are techniques for wafer-to-wafer bonding for manufacturing light emitting diodes (LEDs). In some embodiments, a method of manufacturing LEDs includes etching a semiconductor material to form a plurality of adjacent mesa shapes. The semiconductor material includes one or more epitaxial layers. The method also includes forming a passivation layer to fill gaps between the adjacent mesa shapes, planarizing the passivation layer to expose a contact layer formed on a first surface of the semiconductor material, and bonding a base wafer to the contact layer.

Abstract: Disclosed herein are techniques for wafer-to-wafer bonding for manufacturing light emitting diodes (LEDs). In some embodiments, a method of manufacturing LEDs includes modifying a p-type layer of a semiconductor material to form a plurality of alternating high resistivity areas and low resistivity areas, wherein the low resistivity areas correspond to light emitters; bonding a base wafer to a first surface of the p-type layer; removing a substrate from a second surface of the semiconductor material, wherein the second surface of the semiconductor material is opposite to the first surface of the p-type layer; and patterning a trench between each adjacent pair of the light emitters.

Abstract: Disclosed herein are techniques for wafer-to-wafer bonding for manufacturing light emitting diodes (LEDs). In some embodiments, a method of manufacturing LEDs includes etching a semiconductor material to form a plurality of adjacent mesa shapes. The semiconductor material includes one or more epitaxial layers. The method also includes forming a passivation layer within gaps between the adjacent mesa shapes and bonding a base wafer to a first surface of the semiconductor material.

Abstract: Techniques disclosed herein relate to micro light emitting diodes (micro-LEDs) for a display system. A display system includes an array of micro light emitting diodes (micro-LEDs), an array of output couplers optically coupled to the array of micro-LEDs and configured to extract light emitted by respective micro-LEDs in the array of micro-LEDs, a waveguide display, and display optics configured to couple the light emitted by the array of micro-LEDs and extracted by the array of output couplers into the waveguide display. Each output coupler in the array of output couplers is configured to direct a chief ray of the light emitted by a respective micro-LED in the array of micro-LEDs to a different respective direction.

Abstract: A light emitting diode (LED) includes an elastomeric material that facilitates adhesive attachment with a pick-up head for pick and place operations. The LED includes an epitaxial layer defining a mesa structure and a light emitting surface. The mesa structure includes an active layer to emit light, and the emitted light is reflected at the mesa structure toward a light emitting region of the light emitting surface and transmitted at the light emitting region. An elastomeric material is on a portion of the light emitting surface, such as the light emitting region or a passive region. At the light emitting region, the elastomeric material may be shaped as a lens that collimates light transmitted from the light emitting region, and also facilitates adhesion to the pick-up head. At the passive region, the elastomeric material facilitates adhesion to the pick-up head without interfering with light emitted from the light emitting region.

Abstract: Embodiments relate to transferring dies or other electronic components from a carrier substrate to a target substrate of a device as part of chip assembly for the device. Bonding material is applied to selected dies on a carrier substrate by direct boning, or to corresponding die transfer locations on a target substrate. The carrier substrate is then brought into contact with the target substrate to transfer each of the selected dies to the carrier substrate. Dies can also be directly bonded to the target substrate even in the presence of other die in situ (e.g., from a previous bonding cycle), hence, enables more than one direct bond cycle to be carried out for a target substrate. As such, multi-color (RGB) display elements can be assembled in stages (e.g., separate bonding cycles) in a flexible manner to provide redundancy or to replace inoperative LED dies.

Abstract: Methods and apparatus for use in the manufacture of a display element. Some embodiments include a method for selective pick up of a subset of a plurality of electronic devices adhered to a handle layer. The method comprises modifying a level of adhesion between one or more electronic devices of the plurality of electronic devices adhered to the handle layer, such that the subset of the plurality of electronic devices has a level of adhesion to the handle layer that is less than a force applied by a pick up tool, PUT. This enables selective pick up of the subset of the plurality of electronic devices from the handle layer by the PUT.

Abstract: A method for directly bonding semiconductor devices from multiple carrier substrates to a target substrate using relative alignments of semiconductor contacts to substrate contacts, as well as relative heights of semiconductor contacts to substrate contacts. The method may include directly bonding a subset of semiconductor devices on a first carrier substrate with a first alignment to a subset of substrate contacts, and directly bonding a subset of second semiconductor device on a second carrier substrate with a second alignment to a subset of substrate contacts. The method may include directly bonding a subset of semiconductor devices with a first height on a first carrier substrate to a first subset of substrate contacts, followed by directly bonding a second subset of second semiconductor devices with a second height on a second carrier substrate to a second subset of substrate contacts.

Abstract: Embodiments described herein relate to maintaining alignment between materials having different coefficients of thermal expansion during a bonding process of a light emitting diode (LED) device. The LED device includes a LED array and a backplane. The LED array and the blackplane each include a plurality of electrodes. During a bonding process where the electrodes of the LED array and electrodes of a backplane are bonded together, an alignment material having a coefficient of thermal expansion different than a coefficient of thermal expansion of the material of the LED array is deposited between LEDs of the LED array.

Abstract: Methods and apparatus for use in the manufacture of a display device including pixels. Each pixel includes a plurality of sub-pixels, each sub-pixel configured to provide light of a given wavelength. The method may include: performing, using a pick up tool (PUT), a first placement cycle comprising picking up first light emitting diode (LED) dies, and placing a first LED die on a substrate of the display device at a location corresponding to a sub-pixel the display device. The method further includes performing one or more subsequent placement cycles comprising picking up a second LED die, and placing the second LED die on the substrate of the display device at a second location corresponding to the sub-pixel of the display device. Multiple first and second LED dies may be picked and placed during each placement cycle to populate each pixel of the display device to provide redundancy of LED dies at each sub-pixel.

Abstract: A method and system for calibrating brightness variation in a display involve measuring brightness levels of light emitters in the display. The light emitters are divided into different groups based on the measured brightness levels. Each group is assigned a sub-frame duration. Groups with higher brightness are assigned shorter sub-frame durations than groups with lower brightness. Calibration information is stored for driving the light emitters such that during a frame period of the display, the light emitters are activated for durations corresponding to the sub-frame duration of their corresponding group.

Abstract: A light emitting diode (LED) includes an elastomeric material that facilitates adhesive attachment with a pick-up head for pick and place operations. The LED includes an epitaxial layer defining a mesa structure and a light emitting surface. The mesa structure includes an active layer to emit light, and the emitted light is reflected at the mesa structure toward a light emitting region of the light emitting surface and transmitted at the light emitting region. An elastomeric material is on a portion of the light emitting surface, such as the light emitting region or a passive region. At the light emitting region, the elastomeric material may be shaped as a lens that collimates light transmitted from the light emitting region, and also facilitates adhesion to the pick-up head. At the passive region, the elastomeric material facilitates adhesion to the pick-up head without interfering with light emitted from the light emitting region.

Abstract: To manufacture a device by picking and placing semiconductor devices from a carrier substrate to a target substrate using suction force, a subset of pick-up heads of an array of pick-up heads is selectively operated to attach a subset of the semiconductor devices to the subset of pick-up heads by a suction force. The subset of semiconductor devices attached with the pick-up heads are placed over or on a target substrate, and releasing onto the target substrate. The semiconductor devices may be detached from the pick-up heads by releasing or reversing the suction force. The suction force may be created by controllable membranes in the pick-up heads, such as piezoelectric benders.

Abstract: Disclosed herein are techniques for wafer-to-wafer bonding for manufacturing light emitting diodes (LEDs). In some embodiments, a method of manufacturing LEDs includes etching a semiconductor material to form a plurality of adjacent mesa shapes. The semiconductor material includes one or more epitaxial layers. The method also includes forming a passivation layer within gaps between the adjacent mesa shapes and bonding a base wafer to a first surface of the semiconductor material.

Abstract: Disclosed herein are techniques relating to wafer-to-wafer bonding for manufacturing light-emitting diodes (LEDs). In some embodiments, a method includes reducing bowing of a layered structure including a semiconductor material and a substrate on which the semiconductor material is formed by generating breakages, fractures, or at least one region of weakened bonding within the layered structure. The method also includes bonding a base wafer to the semiconductor material, removing the substrate from the semiconductor material, and forming a plurality of trenches through the semiconductor material to produce a plurality of LEDs.