Bonding dummy electrodes of light emitting diode chip to substrate
A light emitting diode (LED) chip is bonded to a substrate. The LED chip includes one or more dummy electrodes that corresponds to one or more contacts on the substrate. The one or more dummy electrodes are exposed to a laser beam for coupling the one or more dummy electrodes to the one or more contacts. The one or more dummy electrodes may be positioned along edges of the LED chip that surround a display area of the LED chip and provide bonding strength between the LED chip and the substrate.
1. A light emitting diode (LED) assembly comprising:
a substrate having a surface with a plurality of contacts; and
an LED chip attached to the surface of the substrate, the LED chip comprising:
an array of LEDs in a display area, electrodes of the array of LEDs bonded to a subset of the plurality of contacts of the substrate to receive electrical signals, and
at least one dummy electrode in an edge area surrounding the display area for securely attaching the LED chip to the substrate, the at least one dummy electrode bonded to at least one contact of the plurality of contacts without conducting electrical signals from the substrate.
2. The LED assembly of claim 1 , wherein the at least one dummy electrode is laser bonded with the at least one contact on the substrate.
3. The LED of claim 1 , wherein one or more dummy electrodes are on each edge of the edge area.
4. The LED assembly of claim 1 , wherein each LED of the array of LEDs is configured to emit light of a same color.
5. The LED assembly of claim 1 , wherein the LED chip further comprises at least one testing electrode in the edge area for testing operability of at least a subset of the array of LEDs.
6. The LED assembly of claim 5 , wherein the at least one testing electrode is disposed at a corner of the LED chip where two edges of the edge area intersect.
7. The LED assembly of claim 1 , wherein the LED chip further comprises at least one common electrode in the edge area for operating a plurality of the LEDs in the array of LEDs.
8. The LED assembly of claim 1 , wherein the LED chip further comprises at least one active electrode in the display area, the at least one active electrode configured to bond with at least one contact of the plurality of contacts on the substrate.
9. The LED assembly of claim 8 , wherein the at least one active electrode is configured to supply an electrical signal to at least one LED of the array of LEDs for emitting light.
10. The LED assembly of claim 8 , wherein the at least one active electrode is bonded with the at least one contact of the plurality of contacts at edges or corners of the at least one active electrode.