Abstract: Display structures and methods of fabrication are described. In an embodiment, a display structure includes an array of pixel driver chips embedded in an insulation layer, a redistribution layer (RDL) over and in electrical contact with the array of pixel driver chips, and an array of light emitting diodes (LEDs) over and in electrical contact with the RDL, where the array of LEDs includes different groups of LEDs designed for different wavelength emission spectra, and the top surfaces of the LEDs are coplanar.

Abstract: Conformable transfer devices and micro-transfer printing methods are described. In an embodiment, a conformable transfer devices includes first and second arrays of transfer heads with differential lengths to support a micro-transfer printing sequence including a single pick operation and multiple placement operations.

Abstract: An optical verification method and mass transfer system described. In an embodiments, a mass transfer sequence may be accompanied by optical imaging and inspection to detect pick and place errors. The optical imaging and inspection techniques may be performed in-situ.

Abstract: Multi-port polishing fixture assemblies, pick and place bond heads, split holders, and conditioning methods are described. In an embodiment, a multi-port polishing fixture assembly includes a fixture base, a plurality of split holders fastenable to a perimeter surface with a plurality of kinematic plurality of kinematic clamps. The pick and place bond heads may be secured inside the plurality of split holders to reduce edge-fast polishing during conditioning of the distal bond surfaces of the pick and place bond heads.

Abstract: Structures and methods to actively control the shape of a micro pickup array (MPA) during micro device transfer are described. In an embodiment, a strain is applied to the MPA counteractive to strain arising during micro device transfer operations. For example, strain may be applied by a piezoelectric actuator element bonded to a back side of the base substrate to control a curvature of base substrate, and by extension the MPA.

Abstract: An electrostatic cleaning device, mass transfer tool, and method of operation are disclosed. In an embodiment an electrostatic cleaning device includes a cleaning electrode area including a first electrode pattern, a first trace line connected to the first electrode pattern, and a dielectric layer covering the cleaning electrode and the first trace line. In an embodiment, a mass transfer tool includes a translatable transfer head assembly that is translatable over a carrier substrate stage, a receiving substrate stage, and an electrostatic cleaning stage.

Abstract: An optical verification method and mass transfer system described. In an embodiments, a mass transfer sequence may be accompanied by optical imaging and inspection to detect pick and place errors. The optical imaging and inspection techniques may be performed in-situ.

Abstract: An optical verification method and mass transfer system described. In an embodiments, a mass transfer sequence may be accompanied by optical imaging and inspection to detect pick and place errors. The optical imaging and inspection techniques may be performed in-situ.

Abstract: Systems and methods for transferring a micro device or an array of micro devices to or from a substrate are disclosed. In an embodiment, a remote center robot allows on-the-fly alignment between a micro pick up array and a target substrate. The remote center robot may include a plurality of symmetric linkages that move independently and share a remote rotational center. In an embodiment, the remote rotational center may be positioned at a surface of the micro pick up array to prevent damage to the array of micro devices during transfer.

Abstract: Systems and methods for aligning a transfer head assembly with a substrate are disclosed. In an embodiment a pivot mount is used for generating a feedback signal in a closed-loop motion control system. In an embodiment, the pivot mount includes a plurality of spring arms, with each spring arm including a switch-back along an axial length of the spring arm such that a pair of first and second lengths of the spring arm are immediately adjacent the switch-back and are parallel to each other. A first strain sensing element is located at the first length, and a second strain sensing element is located at the second length.

Abstract: Structures and methods to actively control the shape of a micro pickup array (MPA) during micro device transfer are described. In an embodiment, a strain is applied to the MPA counteractive to strain arising during micro device transfer operations. For example, strain may be applied by a piezoelectric actuator element bonded to a back side of the base substrate to control a curvature of base substrate, and by extension the MPA.

Abstract: An electrostatic cleaning device, mass transfer tool, and method of operation are disclosed. In an embodiment an electrostatic cleaning device includes a cleaning electrode area including a first electrode pattern, a first trace line connected to the first electrode pattern, and a dielectric layer covering the cleaning electrode and the first trace line. In an embodiment, a mass transfer tool includes a translatable transfer head assembly that is translatable over a carrier substrate stage, a receiving substrate stage, and an electrostatic cleaning stage.

Abstract: A compliant electrostatic transfer head and method of forming a compliant electrostatic transfer head are described. In an embodiment, a compliant electrostatic transfer head includes a base substrate, a cavity template layer on the base substrate, a first confinement layer between the base substrate and the cavity template layer, and a patterned device layer on the cavity template layer. The patterned device layer includes an electrode that is deflectable toward a cavity in the cavity template layer. In an embodiment, a second confinement layer is between the cavity template layer and the patterned device layer.

Abstract: Systems and methods for aligning a transfer head assembly with a substrate are disclosed. In an embodiment a pivot mount is used for generating a feedback signal in a closed-loop motion control system. In an embodiment, the pivot mount includes primary spring arms and secondary spring arms extending between a pivot platform and a base of the pivot mount. The secondary spring arms are characterized by a lower stiffness than the primary spring arms, and strain sensing elements are located along the secondary spring arms.

Abstract: Systems and methods for aligning a transfer head assembly with a substrate are disclosed. In an embodiment a pivot mount is used for generating a feedback signal in a closed-loop motion control system. In an embodiment, the pivot mount includes a plurality of spring arms, with each spring arm including a switch-back along an axial length of the spring arm such that a pair of first and second lengths of the spring arm are immediately adjacent the switch-back and are parallel to each other. A first strain sensing element is located at the first length, and a second strain sensing element is located at the second length.

Abstract: Systems and methods for aligning a transfer head assembly with a substrate are disclosed. In an embodiment a pivot mount is used for generating a feedback signal in a closed-loop motion control system. In an embodiment, the pivot mount includes a plurality of spring arms, with each spring arm including a switch-back along an axial length of the spring arm such that a pair of first and second lengths of the spring arm are immediately adjacent the switch-back and are parallel to each other. A first strain sensing element is located at the first length, and a second strain sensing element is located at the second length.

Abstract: Systems and methods for transferring a micro device or an array of micro devices to or from a substrate are disclosed. In an embodiment, a remote center robot allows on-the-fly alignment between a micro pick up array and a target substrate. The remote center robot may include a plurality of symmetric linkages that move independently and share a remote rotational center. In an embodiment, the remote rotational center may be positioned at a surface of the micro pick up array to prevent damage to the array of micro devices during transfer.

Abstract: Systems and methods for transferring a micro device or an array of micro devices to or from a substrate are disclosed. In an embodiment, a remote center robot allows on-the-fly alignment between a micro pick up array and a target substrate. The remote center robot may include a plurality of symmetric linkages that move independently and share a remote rotational center. In an embodiment, the remote rotational center may be positioned at a surface of the micro pick up array to prevent damage to the array of micro devices during transfer.

Abstract: A compliant electrostatic transfer head and method of forming a compliant electrostatic transfer head are described. In an embodiment, a compliant electrostatic transfer head includes a cavity in a base substrate, a spring support layer on the base substrate, and a patterned device layer on the spring support layer. The spring support layer includes a spring support layer beam profile that extends over and is deflectable toward the cavity, and the patterned device layer includes an electrode beam profile that is supported by the spring support layer beam profile and extends over and is deflectable toward the cavity.

Abstract: A compliant electrostatic transfer head and method of forming a compliant electrostatic transfer head are described. In an embodiment, a compliant electrostatic transfer head includes a base substrate, a cavity template layer on the base substrate, a first confinement layer between the base substrate and the cavity template layer, and a patterned device layer on the cavity template layer. The patterned device layer includes an electrode that is deflectable toward a cavity in the cavity template layer. In an embodiment, a second confinement layer is between the cavity template layer and the patterned device layer.