Integration of microdevices into system substrate
In a micro-device integration process, a donor substrate is provided on which to conduct the initial manufacturing and pixelation steps to define the micro devices, including functional, e.g. light emitting layers, sandwiched between top and bottom conductive layers. The microdevices are then transferred to a system substrate for finalizing and electronic control integration. The transfer may be facilitated by various means, including providing a continuous light emitting functional layer, breakable anchors on the donor substrates, temporary intermediate substrates enabling a thermal transfer technique, or temporary intermediate substrates with a breakable substrate bonding layer.
1 . A method of forming a cartridge from microdevices, the method comprising:
preparing the microdevices on a donor substrate;
forming and post-processing the microdevices;
preparing the microdevices to be separated from the donor substrate;
forming the cartridge from the microdevices;
identifying defective microdevices; and
removing or fixing the defective microdevices.
2 . The method of claim 1 , wherein the removing includes removing a set of microdevices from the cartridge if a number of defects in the set of microdevices in the cartridge is more than a threshold value.
3 . The method of claim 1 , wherein the removing includes removing one or more layers, or adding an electrical contact or an optical layer, after forming the cartridge from the microdevices.
4 . The method of claim 1 , further comprising testing a set of microdevices with a predetermined number of the microdevices, and if a number of defects exceeds a predetermined threshold, removing all of the set of microdevices.
5 . The method of claim 1 , further comprising testing a set of microdevices with a predetermined number of the microdevices, and if a number of defects exceeds a predetermined threshold, removing at least some of the defective microdevices and/or fixing at least some of the defective microdevices.
6 . The method of claim 1 , further comprising moving the cartridge to a receiver substrate to transfer a set of the microdevices to a part of the receiver substrate.
7 . The method of claim 6 , further including stretching the cartridge to increase a pitch of the microdevices in the cartridge.
8 . The method of claim 6 , further comprising picking or loading a cartridge and aligning a part or all of the receiver substrate and the cartridge.
9 . The method of claim 8 , wherein the aligning includes using a dedicated alignment mark on the cartridge and the receiver substrate.
10 . The method of claim 8 , wherein the aligning includes using the microdevices and landing areas on the receiver substrate.
11 . The method of claim 10 , further comprising transferring the microdevices to selected landing areas and, if the receiver substrate is fully populated, moving the cartridge to another receiver substrate.
12 . The method of claim 11 , further comprising, if further population is needed for the receiver substrate, conducting further transferring with one or more additional cartridges.
13 . The method of claim 11 , further comprising, before the transferring and if the cartridge does not have enough microdevices, picking or loading the cartridge and aligning a part or all of the receiver substrate and the cartridge.
14 . The method of claim 11 , further comprising before the transferring and if the cartridge has enough microdevices, offsetting, or moving and aligning, the cartridge to a new area of the receiver substrate.
15 . The method of claim 6 , further comprising during the moving:
loading or picking the cartridge;
selecting the set of microdevices for transfer in the cartridge, wherein a number of defects in the set of microdevices is less than a threshold;
aligning the cartridge with a part of, or all of, the receiver substrate, wherein the aligning is done through using dedicated alignment marks on the cartridge and/or the receiver substrate, or through using the microdevices and selected landing areas on the receiver substrate; and
transferring the microdevices to the selected landing areas.
16 . The method of claim 15 , further comprising connecting the set of microdevices in the cartridge to the receiver substrate.
17 . The method of claim 15 , further comprising turning on the microdevices by biasing through the receiver substrate to test microdevice connections with the receiver substrate, and if a one or more individual microdevices are found to be defective, adjusting a one or more bonding parameters to correct or fix a one or more non-functional microdevices.
18 . The method of claim 15 , further comprising transferring the microdevices to the selected landing areas, and if the receiver substrate is fully populated, moving the cartridge to another receiver substrate.
19 . The method of claim 18 , further comprising, if further population is needed for the receiver substrate, conducting further transferring with a one or more additional cartridges.
20 . The method of claim 18 , further comprising, before further transferring and if the cartridge does not have enough microdevices, loading or picking the cartridge.
21 . The method of claim 18 , further comprising, before further transferring and if the cartridge has enough microdevices, offsetting, or moving and aligning, the cartridge to a new area of the receiver substrate.