High-density fan-out packaging structure and preparation method thereof

The invention provides a high-density fan-out packaging structure and a preparation method thereof, and the method comprises the steps: providing a silicon substrate, and pasting a passive surface of a to-be-packaged chip on the silicon substrate; the chip to be packaged is subjected to plastic packaging, a plastic packaging layer is prepared, and the top face of the plastic packaging layer and the top ends of the interconnection columns on the active face of the chip to be packaged are located on the same horizontal plane; preparing a plurality of wiring layers on the top surface of the plastic packaging layer, and enabling the plurality of wiring layers to be connected with the interconnection columns; preparing a welding component which is conducted and interconnected with the packaging interconnection body on the multi-layer wiring layer; carrying out thinning treatment on the silicon substrate to obtain a high-density fan-out packaging structure; the problem that in the prior art, a high-density fan-out