Selective micro device transfer to receiver substrate
A method of selectively transferring micro devices from a donor substrate to contact pads on a receiver substrate. Micro devices being attached to a donor substrate with a donor force. The donor substrate and receiver substrate are aligned and brought together so that selected micro devices meet corresponding contact pads. A receiver force is generated to hold selected micro devices to the contact pads on the receiver substrate. The donor force is weakened and the substrates are moved apart leaving selected micro devices on the receiver substrate. Several methods of generating the receiver force are disclosed, including adhesive, mechanical and electrostatic techniques.
1. A method of transferring micro devices into a system substrate, the method comprising:
aligning selected micro devices in a donor substrate with the system substrate;
reducing, with a laser, a force of the selected micro devices with the donor substrate;
selectively blocking, with a shadow mask, non-selected micro devices from the laser;
aligning the shadow mask with a receiver substrate or the donor substrate depending on a direction of the laser; and
applying a raster scan or a step-and-repeat process to cover an entire intended area on the receiver substrate.
2. The method of claim 1 , wherein the laser covers either the receiver substrate or the donor substrate partially.
3. The method of claim 1 , wherein the laser covers either the receiver substrate or the donor substrate fully.
4. The method of claim 1 , further comprising:
adding a layer with a higher laser absorption rate to a force modulation element for improving a heat transfer from the laser.
5. A method of transferring micro devices into a system substrate, the method comprising:
aligning selected micro devices in a donor substrate with the system substrate;
reducing, with a laser, a force of the selected micro devices with the donor substrate;
selectively blocking, with a shadow mask, non-selected micro devices from the laser; and
aligning the shadow mask with a receiver substrate or the donor substrate depending on a direction of the laser,
wherein the laser covers either the receiver substrate or the donor substrate fully.
6. The method of claim 5 , further comprising:
adding a layer with a higher laser absorption rate to a force modulation element for improving a heat transfer from the laser.
7. A method of transferring micro devices into a system substrate, the method comprising:
aligning selected micro devices in a donor substrate with the system substrate;
reducing, with a laser, a force of the selected micro devices with the donor substrate;
selectively blocking, with a shadow mask, non-selected micro devices from the laser;
aligning the shadow mask with a receiver substrate or the donor substrate depending on a direction of the laser; and
adding a layer with a higher laser absorption rate to a force modulation element for improving a heat transfer from the laser.
8. The method of claim 7 , wherein the laser covers either the receiver substrate or the donor substrate partially.