No abstract

Due to the severe wear of micro drill and the difficulty in controlling of hole quality, high speed drilling process of high frequency printed circuit board (PCB) was attracted comprehensive attention. In this investigation, the wear width of drills’ primary face was measured, and the wear morphologies of micro drills were studied at once. Furthermore, regularity of micro hole quality concerning drilling burr and nail heading while drilling with different types of drills were analyzed. The research results indicated that the wear width of diamond coating drill reduced slightly. Abrasive wear and adhesive wear were mainly occurred on uncoated drill and diamond like carbon coating drill, but some micro breaches and pits appeared on uncoated drill. Meanwhile, drilling with diamond like carbon coating drill could obtain better hole quality than drilling with uncoated ones. However, diamond coating drill performed well in terms of ability of wear resistance, as well as micro hole quality.

High frequency printed circuit board (PCB), as the significant support for 5G technology, has been receiving intense attention from the increasing number of scholars. Concerning precision fabrication of high frequency PCBs, micro hole drilling is deemed as one of the extremely crucial challenges. In this study, the coated drill bits’ wear and micro hole quality were investigated through the drilling experiments of high frequency PCBs. Results showed that two kinds of coated drill bits exhibited well in terms of hole registration accuracy. Using diamond like carbon coated drill bits could obtain fewer burrs than drilled with diamond coated drill bits before drilling 200 holes, but the burr height increased very slowly with the increment of hole number when using diamond coated drill bits. Taking the combination of aluminum sheet and phenolic aldehyde board as the entry board was conducive to obtaining less burr, and the micro drill bits with helix angles of 40° and 42° were contributed to achieving less burr too. Additionally, decreasing the feed rate could lessen the hole blocking.

No abstract