Анализ стойкости сверл при обработке отверстий в печатных платах

Abstract

В работе рассмотрено влияние режимов сверления на долговечность работы сверл. Показано, что подача, скорость резания и количество просверленных отверстий оказывают существенное влияние на износ сверл. Так, при одинаковых условиях обработки до 1400 отверстий износ сверл практически одинаков, с увеличением подачи, скорости резания и количества отверстий (свыше 2100) износ интенсивно увеличивается.

In electronic equipment, practically at all levels, printed circuit boards (PCB) are widely used, the manufacture of which is impossible without drilling operations. Analysis of modern literature [1-3] and PCB production technologies has shown that the quality of the drilled holes depends on the base material and foil, tools, equipment and cutting modes. Moreover, it is necessary to analyze more thoroughly the bunch of processed material - cutting modes, since it directly affects the quality and productivity of the holes being processed. Experiments on testing the durability of drills were carried out on the machine tool with numerical control ICV 4030. As the material to be processed, a 4-layer PCB made of Fr 4 textolite, rigidly fastened to the table with the help of tackers (plates). As a research object, drills were chosen for PCB, 1.0 mm in diameter made of hard alloy (analog VK 6). At the first stage, the influence of the cutting speed (speed) on the wear of the drills on the front and rear surfaces was determined for longitudinal feed S = 0.05 mm / rev and two values of rotation speed of 10000 and 15000 min-1. Drilling holes was carried out in one pass. After processing 200 holes, the working surfaces of the drills were examined with an instrumental microscope, measuring wear along the transverse edge and back surfaces. The experiments were repeated three times, the results were averaged. The influence of the drilling modes on the durability of drill work is considered in this paper. It is shown that the feed, cutting speed and number of drilled holes have a significant effect on the wear of drills. At the end of the processing cycle, at each of the speeds, the boards were removed and inspected on both sides. Analyzing the obtained results, it can be concluded that the drill wear is affected by the feed rate, the cutting speed and the number of drilled holes in the PCB. With an increase in the number of holes (more than 2000), the wear rate of the drill increases, so it becomes necessary to replace or re-sharpen the drills.