In this exemplary embodiment, the first contact electrode 406 includes a primary contact electrode 4061, and two auxiliary contact electrodes 4062 that are isolated from the primary contact electrode 4061. The primary contact electrode 4061 is an electrode having a large contact area and corresponding to the soldering position.

The primary contact electrode 4061 and the auxiliary contact electrode 4062 are isolated from each other and distributed at different positions of the LED chip, which can increase the current distribution in the LED chip and enhance the uniformity of the light emitted from the LED chip.

It should be noted that, in this exemplary embodiment, the number of the auxiliary contact electrodes 4062 is two. In other exemplary embodiments, the number of the auxiliary contact electrodes 4062 is at least one in order to increase the current distribution.

The first extension electrode 411 includes a primary extension electrode 4111 covering the primary contact electrode 4061, a secondary extension electrode 4112 covering the auxiliary contact electrode 4062, and a linear extension electrode 4113 connecting the primary extension electrode 4111 and the auxiliary extension electrode 4112. A circular area (shown by a broken line) of the primary extension electrode 4111 above the primary contact electrode 4061 is formed with a plurality of concave spots 430 for achieving soldering.

In the subsequent soldering process, the solder easily is likely to form a circular extension surface, and a circular area in which a plurality of concave spots 430 are formed in the first extension electrode 411 matches the shape of the circular extension surface.