US Patent 7989837 Light chain

A light chain includes a plurality of light emitting diodes (LEDs) electrically connected to each other. Each LED includes an LED chip having a first pole and a second pole, and a packaging layer encapsulating the LED chip. A first electrode has an inner end connected to the first pole, and an outer end extending to the outside of the packaging layer. A second electrode has an inner end connected to the second pole, and an outer end extending to the outside of the packaging layer. A third electrode has a first outer end and a second outer end located at the outside. The outer end of the first electrode and the first outer end cooperatively form a first plug; the outer end of the second electrode and the second outer end cooperatively form a second plug configured to attach to a first plug of an adjacent LED.