Flip-chip packaging structure for light emitting diode and method thereof
View Patent ↗A packaging structure and method for a light emitting diode is provided. The present invention uses flip-chip and eutectic bonding technology to attach a LED to a thermal and electrical conducting substrate. The flip-chip packaging structure comprises a thermal and electrical conducting substrate having an insulating layer formed in an appropriate area on the top surface of the substrate and a bonding pad formed on top of the insulating layer; and a LED reversed in a flip-chip style and joined to the substrate by eutectic bonding. A first electrode of the LED is eutectically bonded to an appropriate area on the top surface of the substrate via a eutectic layer, while a second electrode of the LED is electrically connected to the bonding pad.
1. A packaging structure for LEDs, comprising:
a thermal and electrical conducting substrate;
an insulating layer in an appropriate area on the top surface of said substrate;
a bonding pad on top of said insulating layer;
an eutectic layer in an appropriate area not overlapping said insulating layer on the top surface of said substrate; and
a LED having a first electrode and a second electrode on a top side of said LED, said LED being reversed so that said first and second electrodes facing the top surface of said substrate, said first electrode being joined to said eutectic layer, and said second electrode being joined to said bonding pad.
2. The packaging structure as claimed in claim 1 , wherein said thermal conducting substrate made of Al.
3. The packaging structure as claimed in claim 1 , wherein said thermal conducting substrate is made of Cu.
4. The packaging structure as claimed in claim 1 , wherein said insulating layer is made of SiO 2 .
5. The packaging structure as claimed in claim 1 , wherein said eutectic layer is eutectic Cu/Au.
6. The packaging structure as claimed in claim 1 , wherein said eutectic layer is eutectic Cu/Au/Al.