Abstract: A pick-up head assembly comprises a body of a liquid crystalline elastomer (LCE) that undergoes a reversible expansion when exposed to a first frequency of light and contracts when exposed to a second frequency of light. Selective portions of the LCE in the pick-up head assembly are irradiated with the first frequency to cause an expansion in the selective portions. The adhesive forces of the expanded portions of the LCE are used to pick-up semiconductor devices from a first substrate. The semiconductor devices are placed on a second substrate by exposing the expanded portions of the LCE to the second frequency of light, causing the expanded portions to contract.

Abstract: A light-emitting diode (LED) array is formed by bonding an LED chip or wafer to a backplane substrate via curved interconnects. The backplane substrate may include circuits for driving the LED's. One or more curved interconnects are formed on the backplane substrate. A curved interconnect may be electrically connected to a corresponding circuit of the backplane substrate, and may include at least a portion with curvature. The LED chip or wafer may include one or more LED devices. Each LED device may have one or more electrical contacts. The LED chip or wafer is positioned above the backplane substrate to spatially align electrical contacts of the LED devices with the curved interconnects on the backplane substrate. The electrical contacts are bonded to the curved interconnects to electrically connect the LED devices to corresponding circuits of the backplane substrate.

Abstract: A method and system for assembling a device by picking up semiconductor devices from a carrier substrate and placing the semiconductor devices onto a target substrate. The transfer of the semiconductor devices uses fluid as a transfer medium. The fluid enters a fluid channel of a pickup head, causing the pickup head to expand, make contact with, and attach to an aligned semiconductor device. After the semiconductor device is aligned with and placed onto the target substrate, at least a portion of the fluid is removed from the pickup head to release the semiconductor device onto the target substrate. The semiconductor device bonds to the target substrate.