LED module and method of bonding thereof
View Patent ↗The present disclosure provides a method including providing a light-emitting diode (LED) device (e.g., a LED element and PCB) and a heat sink. The LED device is bonded to the heat sink by applying an ultrasonic energy. In an embodiment, the bonding may form a bond comprising copper and aluminum. The PCB may be a metal core PCB (MC-PCB).
1. A lighting apparatus, comprising:
a thermally conductive structure that contains a first material;
a printed circuit board disposed over the thermally conductive structure, wherein the printed circuit board includes:
a base layer that contains a second material, wherein the thermally conductive structure and the base layer are bonded together without a connective means or an adhesive;
a dielectric layer disposed over the base layer; and
a conductor layer disposed over the dielectric layer; and
a photonic device disposed over the printed circuit board.
2. The lighting apparatus of claim 1 , wherein the thermally conductive structure and the base layer of the printed circuit board are bonded together through a solid-state bond structure that contains a mixture of the first material and the second material.
3. The lighting apparatus of claim 2 , wherein the mixture of the first material and the second material includes a mixture of copper and aluminum.
4. The lighting apparatus of claim 2 , wherein the solid-state bond structure encircles the photonic device in a top view.
5. The lighting apparatus of claim 2 , wherein the solid-state bond structure has a lateral dimension that is greater than about 3 millimeters.
6. The lighting apparatus of claim 2 , wherein the solid-state bond structure includes a plurality of discrete segments that are separated from one another by non-bonded regions.
7. The lighting apparatus of claim 2 , further comprising: a thermally conductive interface material disposed between the thermally conductive structure and the printed circuit board.
8. The lighting apparatus of claim 7 , wherein the solid-state bond structure encircles the thermally conductive interface material in a top view.
9. The lighting apparatus of claim 1 , wherein the printed circuit board is a metal core printed circuit board (MCPCB).
10. The lighting apparatus of claim 1 , wherein:
the first material is a first metal; and
the second material is a second metal different from the first metal.
11. The lighting apparatus of claim 1 , wherein the dielectric layer contains a thermally conductive dielectric material.
12. The lighting apparatus of claim 1 , wherein the photonic device includes a light-emitting diode (LED), and wherein the LED is electrically coupled to the conductor layer of the printed circuit board.
13. A lighting apparatus, comprising:
a heat sink that contains a first metal;
a metal core printed circuit board (MCPCB) disposed over the heat sink, wherein the MCPCB includes:
a base metal layer that contains a second metal;
a thermally conductive dielectric layer disposed over the base metal layer; and
a conductor layer disposed over the thermally conductive dielectric layer;
a bond structure that bonds the heat sink and the base metal layer of the MCPCB together, wherein the bond structure contains a mixture of the first metal and the second metal; and
a light-emitting diode (LED) disposed over the conductor layer of the MCPCB, and wherein the LED is electrically coupled to the conductor layer.
14. The lighting apparatus of claim 13 , wherein the mixture of the first metal and the second metal includes a mixture of copper and aluminum.
15. The lighting apparatus of claim 13 , wherein the bond structure is continuous and encircles the LED in a top view.
16. The lighting apparatus of claim 13 , further comprising: a thermally conductive gel disposed between the heat sink and the base metal layer, wherein the thermally conductive gel is encircled by the bond structure in a top view.
17. A method, comprising:
providing a heat sink that contains a first metal;
providing a metal core printed circuit board (MCPCB) that includes:
a base metal layer that contains a second metal;
a thermally conductive dielectric layer disposed over the base metal layer; and
a conductor layer disposed over the thermally conductive dielectric layer; and
bonding the heat sink with the base metal layer of the MCPCB using ultrasonic energy to create a mixture of the first metal and the second metal between the heat sink and the base metal layer.
18. The method of claim 17 , further comprising: attaching a light-emitting diode (LED) to the MCPCB, wherein the LED is electrically coupled to the conductor layer of the MCPCB.
19. The method of claim 17 , wherein a frequency of the ultrasonic energy is one of: about 15 kHz, about 20 kHz, about 30 kHz, about 35 kHz, about 40 kHz, or about 70 kHz.
20. The method of claim 17 , further comprising: applying a pressure to the MCPCB and the heat sink during the bonding.