Development of micro-diamond tools through electroless composite plating and investigation into micro-machining characteristics

Abstract This research deals with the development of micro-diamond tools through electroless Ni–P composite plating and micro-machining in single-crystalline silicon. The purpose of this paper is to testify the application of electroless plating to micro-tool fabrication. In this study, we investigated the effects of various plating parameters and diamond grit size on the tool fabrication process. The plating parameters are composite plating time, embedding time, solution stirring speed, and rotation speed of substrate. The substrate material of micro-tools is cemented carbide and its tip has basically a cylindrical shape with a diameter of 100 μm and a length of 500 μm. We fabricated micro-tools using three kinds of diamond grits with sizes of 0.5–2 μm, 2–4 μm, and 5–10 μm. The tool diameter was about 115–120 μm after fabrication for each diamond size. Tool life was investigated in micro-grooving in silicon. According to the results, the bigger the diamond grit was, the longer the life of the tool was. When the 5–10 μm-grit tool was used, micro-grooving with a groove depth of 100 μm could be performed up to more than 550 mm in length under a grinding speed of 11.3 m/min and a feed rate of 2.4 mm/min. We also applied the 2–4 μm-grit tool for the fabrication of a few micro-channel devices.