The invention discloses a three-dimensional fan-out packaging structure and a preparation method thereof, and the method comprises the steps: digging a groove in a carrier plate, preparing a
metal wiring layer at the groove and the periphery of the groove, then pasting a
core particle, leading out a part of pins of the
core particle to the front surface of the carrier plate through the
metal wiring layer, carrying out the
plastic packaging, preparing a conductive column at a
plastic packaging layer, and leading out the part of pins. Then preparing a first rewiring layer and a first
dielectric layer on the
plastic packaging layer to complete front packaging; and
thinning the back surface of the carrier plate until the
metal wiring layer is formed and the other part of pins of the core particles are exposed, then preparing a second rewiring layer and a second
dielectric layer, completing preparation of fan-out packaging units of double-sided fan-out, stacking the fan-out packaging units according to needs, and then connecting the fan-out packaging units by adopting solder balls to obtain the three-dimensional fan-out packaging structure. According to the fan-out packaging unit with the two fan-out surfaces, the
interconnection distance can be effectively reduced, three-dimensional stacking is facilitated, the fan-out packaging unit has great advantages in electrical
interconnection performance, the loss is smaller, the efficiency is higher, the packaging process difficulty is greatly reduced, and the packaging cost is reduced.