Processing method of short slot hole in pcb board

Abstract

The invention discloses a machining method of a short slotted hole of a PCB (printed circuit board). The machining method prevents the slotted hole from deformation and deviation in a machining process of the short slotted hole with a short diameter less than 1.0mm. The machining method is characterized by comprising the following steps of: (1) drilling two guide holes in a corresponding edge in a length direction of the short slotted hole to be formed, (2) drilling a hole at one end, in the length direction, of the short slotted hole, and another hole at the other corresponding end with a drill point of which the diameter is equal to the short diameter of the slotted hole, allowing the two holes to be internally tangent with the edge of the short slotted hole in the length direction, and (3) carrying out overlap drilling in the length direction of the short slotted hole, wherein the diameter of the guide holes is (the short diameter of the slotted hole minus 0.1) / 2mm-(the short diameter of the slotted hole minus 0.25)mm; an anticlockwise included angle alpha between a line of centers of the two guide holes and a center line of the slotted hole in the length direction is 10-35 degrees; and a distance between the edges of each guide hole and the short slotted hole is 1-3mil. The method effectively avoids quality problems such as deformation of the short slotted hole in the machining process of the minor-diameter short slotted hole, increases a finished product yield of the PCB and lowers production cost of an enterprise.

Description

technical field [0001] The present invention relates to a method for processing slot holes in PCB boards, in particular to a method for processing short slot holes in PCB boards, in particular to a PCB board with short diameter < 1.0 mm and slot length / slot diameter < 2 Short slot machining method. Background technique [0002] In the slot hole processing of PCB board (printed circuit board), especially when processing short slot holes with slot length / slot diameter < 2 times, it is generally formed by overlapping drilling of multiple round holes, that is, when drilling, use The drill bit whose diameter is equal to the short diameter of the slot hole drills a hole at one end of the short slot along the length direction, then drills a hole at the corresponding other end, and then stacks drills along the length direction of the short slot. When drilling the other end of the short slot hole, one end of the short slot hole has already been drilled, and the drill bit ca...

AI Technical Summary

Problems solved by technology

Similarly, when stacking drills, one side of the slot hole has already been drilled, and the drill pin cannot take advantage of it. When the drill pin rotates clockwise at high speed (50,000 rpm to 60,000 rpm), the area of ​​the undrilled substrate will cause damage to the drill pin. The force on the right side is greater than that on the left side, which still causes deformation of the short slot hole after processing, and the center along the length direction of the slot hole is offset counterclockwise by about 5°~15°

At the same time, because the guide hole is inscribed with the edge of the short slot hole, after the first round hole of the short slot hole is drilled, when the second round hole is drilled down, the base material will be in the direction of the length of the short slot hole. The upper force is greater than the downward force, resulting in the length of the short slot hole being about 0.1 mm shorter than the original design length, so that the guide hole cannot be completely covered, and there are bumps on the edge of the short slot hole that are not completely drilled (that is, the position of the guide hole)

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