The invention discloses a method for drilling a high-precision large-aperture hole in a printed board. When the
diameter of the large-aperture hole is larger than and equal to 3.0 millimeters and is smaller than and equal to 6.5 millimeters, a straight drilling method is adopted. When the
diameter of the large-aperture hole is larger than 6.5 millimeters, a
counterbore drilling method is adopted. The straight drilling method includes the steps of firstly drilling three first
pilot holes on three 120-degree-angle radiuses of the large-aperture hole to be drilled, and then drilling the large-aperture hole with the required
diameter by using a
drill bit with the center of the large-aperture hole to be drilled as the circle center, wherein the centers of the three first
pilot holes coincide with the midpoints of the radiuses where the three first
pilot holes are located on respectively. The
counterbore drilling method includes the steps of firstly drilling a second
pilot hole in the center of the large-aperture hole to be drilled, then drilling a plurality of counterbores between the periphery of the large-aperture hole to be drilled and the second
pilot hole, and finally obtaining the large-aperture hole. According to the method for drilling the high-precision large-aperture hole in the printed board, the different drilling methods are adopted according to the aperture range of the large-aperture hole to be drilled, so the drilling accuracy is greatly improved, the requirements of the printed boards for the drilling accuracy are met, and the quality of the printed boards is promoted.