Identifying and repairing defects micro-device integrated system
What is disclosed are structures and methods for testing and repairing emissive display systems. Systems are tested with use of temporary electrodes which allow operation of the system during testing and are removed afterward. Systems are repaired after identification of defective devices with use of redundant switching from defective devices to functional devices provided on repair contact pads. Time varying signals coupled to a capacitor are used as well.
1. A method of extracting and identify defects in at least one microdevice parameter, the method comprising:
having a carrying substrate comprising at least one electrode and a dielectric layer covering at least part of the electrode;
forming one or more microdevices on top of the dielectric;
having additional layers between the dielectric and the microdevices;
having a first pad of the microdevice facing the electrode of the carrying substrate;
having another test substrate comprising another electrode and a dielectric layer, wherein the test substrate is close to a second pad of microdevice, and forming two test capacitors with the two electrodes, the two dielectric layers and the two microdevice pads;
coupling a micro device to the two test capacitors through respective electrodes;
coupling the two test capacitors to a time varying test signals;
measuring at least one signal from the microdevice; and
extracting at least one microdevice parameter.
2. The method of claim 1 , wherein one of the time varying test signals is a voltage.
3. The method of claim 1 , wherein the microdevice signal is one of the time varying test signals, and is a current.
4. The method of claim 1 , wherein the microdevice signal is an electromagnetic signal.
5. The method of claim 1 , wherein the microdevice parameter is an external efficiency.
6. The method of claim 1 , where in the microdevice parameter is a color point.
7. The method of claim 1 , wherein the microdevice parameter is a state of microdevice.
8. The method of claim 1 , wherein the microdevice parameter is a functional parameter of the device.
9. The method of claim 1 , wherein more than one microdevice parameter is extracted.
10. The method of claim 1 , wherein the second and the first time varying signals are out of a phase.
11. The method of claim 10 , wherein the out of phase is 90 degrees.