Drilling method for improving drilling accuracy of high-thickness-diameter PCB

Abstract

The invention discloses a drilling method for improving the drilling accuracy of a high-thickness-diameter PCB. The method comprises the following steps that a front side pre-drilling file, a front side resin drilling file, a reverse side pre-drilling file and a reverse side resin drilling file of the PCB are prepared; a pin hole is formed in the PCB edge according to the front resin drilling file, and the front side of the PCB is subjected to pre-drilling slotting process to form a front side pre-drilling hole according to the front pre-drilling file; the front side of PCB is subjected to drilling process according to the front side resin hole drilling file and the front side pre-drilling hole; a pin hole is formed in the PCB edge according to the reverse side resin drilling file, and thereverse side of the PCB is subjected to pre-drilling process to form a reverse side pre-drilling hole according to the reverse side pre-drilling file; and the reverse side of the PCB is subjected tothe drilling process according to the reverse side resin drilling file and the reverse side pre-drilling hole. A pre-drilling process is introduced, cutting force resistance produced in the resin drilling process is greatly reduced, and the yield of production quality is improved.

Description

Technical field [0001] The invention relates to a drilling technology, in particular to a drilling method for improving the drilling accuracy of a high-thickness PCB board. Background technique [0002] At present, with the rapid development of electronic products in the direction of miniaturization, high density, high integration and multi-function, the requirements for printed circuit boards are getting higher and higher, with high density, complex structure, and high Features such as layering, high thickness-to-diameter ratio, and small porosity In the current industry, the resin drilling process mainly includes two drilling methods: ordinary resin drilling and elongated drill vertical drilling. Among them, ordinary resin drilling is more common in the industry, and the length of ordinary drills is consistent with one-time drilling and printing. The condition of the board (general drill length-printed board thickness-aluminum sheet thickness (thickness is generally 0.2mm) ≥ 0...

AI Technical Summary

Problems solved by technology

The disadvantages of the method of lengthening the drill are: 1. During the process of clamping the drill 2, the drill spindle 1 will inevitably produce an offset angle α (the angle between the spindle centerline 3 and the drill tip), when the drill 2 The longer the length, the greater the offset angle α, and the worse the drilling accuracy (the position of the angle between the drill spindle 1 and the drill 2 is as follows figure 1 ); 2. After the main shaft of the drilling rig clamps the drill bit, the drill bit will rotate at a high speed. During the high-speed rotation and drilling process, it will contact the aluminum sheet 4 and the printed board 5 successively. It touches the aluminum sheet 4 and the printed board 5 At this time, a large cutting force resistance will be generated, which will cause the drill bit 2 to shift, resulting in the deviation of the drill hole 6 (the longer the length of the drill bit, the greater the offset), and even broken tool, printed board The blast hole is scrapped, so the length of the drill bit cannot be extended infinitely

[0009] (1) Errors such as machine accuracy and equipment accuracy can easily lead to misalignment of the drill connection in the middle of the printed board;

[0010] (2) During the process of high-speed rotating and drilling, the drill tool contacts the aluminum sheet and the printed board in turn. When it touches the aluminum sheet and the printed board, a large cutting force resistance will be generated. The cutting force resistance will make the drill The tool is offset, resulting in the deviation of the drilling (and the smaller the tool diameter, the longer the length of the drill, the higher the thickness-to-diameter ratio, the more obvious the deviation); The misalignment of the middle drill connection can reach 2-3mil, and for printed boards with high hole position accuracy, it may eventually lead to misalignment and scrapping

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