Preparation method of rewiring layer and packaging structure

The invention provides a preparation method of a rewiring layer and a packaging structure, and the preparation method comprises the steps: firstly operating an insulating layer, making a patterned first hole, then filling the first hole with a conductive layer, making a flat embedded structure through a planarization technology, forming a sputtering layer on the surface of the flat embedded structure, and finally forming a rewiring layer on the surface of the sputtering layer. A sputtering layer is formed on the sputtering layer, a photoresist layer is operated on the sputtering layer, the photoresist layer is patterned to form a second opening, the position of the second opening corresponds to the arrangement position of the planarized conductive layer, metal is electroplated in the second opening to form a metal interconnection layer, and finally the photoresist layer and the sputtering layer covered by the photoresist layer are removed to form a rewiring layer. In the finally formed packaging structure, th