The present invention discloses a light mixing structure and a preparation method thereof for a
phosphor-free multi-primary-color
LED lamp. The light mixing structure includes a bottom plate, a substrate, a
first light mixing unit, and a second light mixing unit. The
first light mixing unit includes
phosphor-free multi-primary-color
LED lamp beads, and the
phosphor-free multi-primary-color
LED lamp beads include four different main
wavelength LED chips. The second light mixing unit is composed of the
first light mixing units distributed in a
quadrilateral shape, and a complementary color unit is arranged therein. When preparing the light mixing structure, different LED
chip arrangement structures are designed according to the complementary color unit, and the first light mixing unit is fabricated by using
die bonding,
soldering, and encapsulation processes. Then, according to the design of the complementary color unit, the second light mixing unit is fabricated and arranged by using
reflow soldering and installation processes. The present invention can eliminate the obvious light mixing color deviation phenomenon in some areas of the lamp caused by the enrichment of different monochromatic lights in different directions in the phosphor-free multi-primary-color LED lamp, and improve the color uniformity of the emitted light.