The invention discloses a method for drilling a multilayer board through hole by
carbon dioxide laser, which comprises the following steps of:
etching and removing a
copper layer corresponding to all drilling positions when an inner layer circuit is manufactured on a core board, and manufacturing a hole ring arranged around the drilling positions on an inner layer needing to be connected with a hole wall
copper layer;
coating the surface of the hole ring of the core plate with a layer of alkali-soluble light-cured
printing ink with the outer
diameter larger than that of the drilling position, curing the alkali-soluble light-cured
printing ink, and filling the hollow window of the hole ring with the alkali-soluble light-cured
printing ink to form a printing ink disc; the core plate and the outer layer
copper foil are laminated according to the lamination sequence through PP and then are pressed to form a production plate;
etching and windowing are carried out on the drilling positions on the outer layer
copper foil of the production board; a through hole is drilled in the position, corresponding to the drilling position, of the production board through
laser, and the ink disc in the inner layer forms an ink ring; and dissolving and removing the ink ring on the hole wall by adopting an alkaline solution so as to
expose the hole ring on the inner layer. The method can solve the problem that the
carbon dioxide laser cannot ablate the
copper foil, and the purpose of drilling the through holes in the multi-layer board through the
carbon dioxide laser is achieved.