Influence of Micro End Mill Tool Run-Out on Machining Accuracy

摘要

Micro-channel chips used in micro total analysis systems have been attracting attention in the medical field. Photolithography, which is a technology used in semiconductor manufacturing, is used to manufacture micro-channel chip dies. This technology requires many processes, such as making photomasks, applying photoresist to a substrate, and the availability of expensive clean-room facilities. Micro-channel chips have 'micro-channels,' which are micro-grooves having a width of 30-100 urn. These fine grooves require high accuracy in manufacture; for example, the surface roughness on the bottom face is 1.0 μm Rz. A previous study showed how tool run-out on the order of several urn incurred during micro-groove milling, reduced machining accuracy, and tool life. To bridge that gap, this study investigated how to form a fine groove by using micro end milling. Specifically, a method was experimentally examined for reducing the influence of tool run-out on machining accuracy by using two types of end mill-two-tooth square and ball-by modifying the tool setting angle. Modifying the tool setting angle improved the surface roughness of one side of the groove, and reduced change of cutting force in two-tooth square-end milling. In addition, it was able to reduce the influence of groove width on tool run-out by up to 1/10. A modification of tool setting angle in ball end milling reduced the influence of tool run-out on machining accuracy.