At present, LED chips are of a single light-emitting wavelength range specification, a packaging factory will package this chip of the single light-emitting wavelength range specification or needs to package two or more chips within different light-emitting wavelength ranges into an identical packaging body, the completed packaging bodies are arranged and assembled as required, a single chip or a single LED assembly is controlled by a control circuit, and LEDs having different light-emitting wavelengths generate mixed light to than a full-color display picture effect. But the prior art and structure will generate a large clearance between LEDs, thus being adverse to miniaturization.

Due to variation influences of manufacturing procedures and materials, main wavelength distributions of LED chips produced in each batch are different. When light having specific wavelength characteristics needs to be emitted, demands of light emission in different lighting occasions need to be met or a specific color for full-color display needs to be formed, in order to meet requirements for color accuracy, the earliest prior art refers to: binning many LED grains by utilizing spot measurement, sorting and binning programs to sort out LED grains close to the main wavelength distributions to result in considerable cost and time consumption of applications having different wavelength characteristic demands.