Oculus Patent | Fluidic Pick-up Head For Small Semiconductor Devices
Publication Number: 20180351030
Publication Date: 2018-12-06
Applicants: Oculus VR, LLC
A method and system for manufacturing a device by picking and placing semiconductor devices from a carrier substrate to a target substrate using fluidic material as a transfer medium. The method may include releasing a first amount of fluidic material from a tip of a pick-up head to form a fluidic membrane on the tip, and bringing the fluidic membrane on the tip of the pick-up head in contact with a semiconductor device on a carrier substrate to attach the semiconductor device to the fluidic membrane. The method can further include releasing a second amount of the fluidic material from the tip of the pick-up head to separate the semiconductor device from the pick-up head and place the semiconductor device on a target substrate.
The present invention relates to a multi device pick-up head and assembly process for use in, but not exclusively limited to, pick and place of very small display element(s) that need to be transferred from an initial substrate to a receiving substrate using a micro fluidic pick-up and transfer process.
To populate a display with very small light emitting diodes (LEDs), such as micro-LEDs, there may be a need to transfer the LEDs from the native substrate on which they have been manufactured to a target substrate that forms part of a display, or “display substrate.” Such small semiconductor devices may be assembled with a defined separation distance between them or closely packed together on the target substrate. Because of the small size of these devices (e.g., smaller than 49.times.40 .mu.m), conventional pick and place techniques are unsuitable.
Vacuum pick-up, transfer printing, and electrostatic pick-up are some techniques that have been applied to the pickup and placement of small electronic devices. Each of these techniques has various drawbacks. For example, vacuum pick-up tools are typically limited to serial pick and place of individual devices. In another example, transfer printing uses direct contact (under high pressure) with the devices that are to be picked and placed, resulting in pick-up heads with limited work life or physical damage to the devices. In another example, the use of electrostatic forces to pick and transfer LED’s can result in potential to damage electrostatic discharge (ESD) sensitive devices.
Embodiments relate to using a fluidic material as a transfer medium for picking and placing a semiconductor device, such as a micro-LED. A first amount of fluidic material is released from a tip of a pick-up head to form a fluidic membrane on the tip. The fluidic membrane is brought on the tip of the pick-up head in contact with a semiconductor device on a carrier substrate to attach the semiconductor device to the fluidic membrane.
In one or more embodiments, a second amount of the fluidic material is released from the tip of the pick-up head to separate the semiconductor device from the pick-up head and place the semiconductor device on a target substrate.