Manufacturing method of any layer of high-density interconnected flexible board

The invention discloses a method for manufacturing any layer of high-density interconnected flexible board, and the method comprises the following steps: drilling a first blind hole in a double-sided copper-clad flexible substrate, manufacturing an inner-layer circuit on the board, filling conductive ink in the first blind hole, and performing curing to form a first sub-board; pasting a protective film on the non-copper surface of the single-sided copper-clad flexible substrate, drilling a second blind hole corresponding to the first blind hole in position on the surface pasted with the protective film, and manufacturing an inner-layer circuit on the substrate; filling conductive ink in the second blind hole and curing, and then tearing off the protective film to form a second sub-board; laminating the second daughter board and the first daughter board in sequence through a PP sheet and pressing the first and second daughter boards into a production board, and enabling the conductive ink in the first daughter