Light-emitting device and lighting device provided with the same
A light-emitting device capable of ensuring an electric connection between a light-emitting element and an electrode without generating any problem in practical use, by both connecting methods with a solder and a connector, and a lighting device provided with the light-emitting device are provided. The light-emitting device according to the present invention has a plurality of LED chips, and a soldering electrode land and a connector connecting electrode land electrically connected to the chips, on a ceramic substrate. The soldering electrode land is formed of a first conductive material having a function to prevent diffusion to a solder, and the connector connecting electrode land is formed of a second conductive material having a function to prevent oxidation.
1. A light-emitting device comprising:
a substrate;
a resin dam formed on a primary surface of said substrate and provided so as to surround a mounting area around a center of said substrate;
a first electrode land and a second electrode land which are electrodes to be connected to a power supply, said first and second electrode lands being provided on the primary surface of said substrate and outside said resin dam;
a first wiring pattern provided on the primary surface of said substrate and electrically connected to said first electrode land, said first wiring pattern including a first portion located under said resin dam and curved along said resin dam;
a second wiring pattern provided on the primary surface of said substrate and electrically connected to said second electrode land, said second wiring pattern including a second portion located under said resin dam and curved along said resin dam;
a first series of LED chips provided on the mounting area and electrically connected in series between said first wiring pattern and said second wiring pattern,
a second series of LED chips provided on the mounting area and electrically connected in series between said first wiring pattern and said second wiring pattern, a number of LED chips in said first series being same number as the LED chips in said second series;
a first wire connected between the first portion of said first wiring pattern and the LED chip at the end of said first series, said first wire being contacted with the first portion at a first contact point;
a second wire connected between the second portion of said second wiring pattern and the LED at the other end of said first series, said second wire being contacted with the second portion at a second contact point;
a third wire connected between the first portion of said first wiring pattern and the LED chip at the end of said second series, said third wire being contacted with the first portion at a third contact point;
a fourth wire connected between the second portion of said second wiring pattern and the LED at the other end of said second series, said fourth wire being contacted with the second portion at a fourth contact point, a distance between the third and fourth contact points being smaller than a distance between the first and second contact points; and
a resin layer provided attaching to an inner side of said resin dam and covering said first and second series of LED chips and said first, second, third and fourth wires.
2. The light-emitting device of claim 1 , wherein
said substrate comprises a rectangular outer shape in a top view, and
said first and second electrode lands are located near corners of said substrate diagonally opposite to each other.
3. The light-emitting device of claim 2 , wherein
said substrate has first and second openings diagonally located at corners of said substrate other than the corners where said first and second electrode lands are located.
4. The light-emitting device of claim 1 , wherein said resin layer comprises a phosphor, and a color of said resin dam is white.
5. The light-emitting device of claim 4 , wherein
said substrate comprises ceramic, and
said first and second electrode lands include gold.
6. The light-emitting device of claim 5 , wherein said resin dam comprises silicon resin containing titanium oxide.
7. The light-emitting device of claim 5 , further comprising a resistive element inserted between said first and second wiring patterns and located under said resin dam.
8. The light-emitting device of claim 4 , wherein
said substrate comprises ceramic, and
said first and second electrode lands include silver.
9. The light-emitting device of claim 4 , wherein
said substrate comprises ceramic, and
said first and second electrode lands include platinum.
10. The light-emitting device of claim 1 , wherein the LED chips in said second series are arranged in a plurality of rows.
11. The light-emitting device of claim 10 , wherein the LED chips in said first series are arranged in a plurality of rows.
12. The light-emitting device of claim 11 , wherein
most of the LED chips in said first series are arranged in a first row,
most of the LED chips in said second series are arranged in a second row, and
a number of the LED chips arranged in the second row is smaller than a number of the LED chips arranged in the first row.