Lighting device and method of manufacturing the same
View Patent ↗A lighting device including a metal substrate to prevent temperature rise of LED chip is offered. The lighting device includes the metal substrate, an anode or cathode electrode of the LED chip disposed on the metal substrate, brazing materials connecting the LED chip and the metal substrate, and a groove formed in the anode or cathode electrode. Forming the groove can prevent an occurrence of a crack in the brazing materials. Also, a lighting device includes the metal substrate, an anode and cathode electrode of the LED chip disposed on the metal substrate and brazing materials connecting the LED chip and the metal substrate. Further, a slit is formed in the metal substrate between the anode and cathode electrode. Forming the slit in the metal substrate can prevent an occurrence of a crack in the brazing materials.
1. A lighting device comprising:
a metal substrate comprising aluminum;
a plurality of LED packages mounted on a top surface of the metal substrate, each package comprising a ceramic substrate, a LED chip mounted on a front surface of the ceramic substrate, an anode electrode, a cathode electrode and a heat release electrode, and the anode, cathode and heat release electrodes being disposed on a back surface of the ceramic substrate, a resin insulation film disposed on the top surface of the metal substrate so as to be between the LED packages and the top surface; and
a first electrode, a second electrode and a third electrode which are disposed on the insulation film, wherein the first, second and third electrodes are bonded to the anode, cathode and heat release electrodes, respectively;
wherein a shallow groove is formed in the first electrode or the second electrode; and
wherein the shallow groove extends from the inside toward the outside of the first electrode, or from the inside toward the outside of the second electrode in a plane view.
2. The lighting device according to claim 1 , wherein the metal substrate has an elongated shape, and the LED packages are disposed along a long side of the metal substrate.
3. The lighting device according to claim 1 , wherein the heat release electrode is smaller than the third electrode, and the anode electrode does not overlap completely the first electrode, or the cathode electrode does not overlap completely the second electrode.
4. The lighting device according to claim 1 , wherein a wiring is disposed on the metal substrate, and the plurality of the LED packages are electrically connected in series along a long side of the metal substrate.
5. The lighting device according to claim 1 , wherein the cathode electrode and the heat release electrode are the same electrode.
6. The lighting device according to claim 1 , wherein a thickness of the heat release electrode is thicker than the anode electrode or the cathode electrode.
7. A lighting device comprising:
a metal substrate comprising aluminum;
a plurality of LED packages mounted on a top surface of the metal substrate, each package comprising a ceramic substrate, a LED chip mounted on a front surface of the ceramic substrate, an anode electrode and a cathode electrode, and the anode and cathode electrodes being disposed on a back surface of the ceramic substrate, a resin insulation film disposed on the top surface of the metal substrate so as to be between the LED packages and the top surface; and
a first electrode and a second electrode which are disposed on the insulation film, wherein the first and second electrodes are bonded to the anode, and cathode electrodes, respectively, and
a slit is formed in the metal substrate between two neighboring anode and cathode electrodes;
wherein a heat release electrode which releases a heat of the LED chip is disposed between the neighboring anode and cathode electrode, and the slit is disposed between the anode electrode and the heat release electrode, or between the cathode electrode and the heat release electrode.
8. The lighting device according to claim 7 , wherein a wiring is disposed on the metal substrate, and the LED packages are electrically connected in series along a long side of the metal substrate.
9. The lighting device according to claim 7 , wherein the anode electrode or the cathode electrode doubles as a heat release electrode which releases a heat of the LED chip, and a via hole formed in the ceramic substrate doubles as a thermal via and a through hole via.