Miniaturization is the order of the day. Until recently a decade ago traditionally watch parts were considered to be the micro components one can think of. Recent changes in society’s demand have forced us to manufacture a variety of micro-components used in different fields starting from entertainment electronics to biomedical implants.
We are all familiar with the phrase “the world is getting smaller.” However, it is not just that the world is getting smaller, practically everything we use is getting smaller. Manufacturing technology has advanced to higher levels of precision to satisfy the increasing demand to reduce the size of parts and products in the electronics, computer, and biomedical industrial sectors. New processing concepts, procedures, and machines are thus needed to fulfill the increasingly stringent requirements and expectations.
In the traditional mechanical/manufacturing engineering communities it implies material removal processes at a certain scale (not clearly defined), while for others including those who were the principal force behind the development of micro-electro-mechanical-systems (MEMS) technologies, this term encompasses the universe of silicon processing techniques for MEMS devices that were adopted or suitably modified from lithography-based techniques that are prevalent in integrated circuit manufacture.
At this time, unfortunately, a convergence in terminology has not been forthcoming and, hence, a definition of the term Micro-Machining to be implied in the context of this assessment is in order.
In principle, one may take two viewpoints:
We are all familiar with the phrase “the world is getting smaller.” However, it is not just that the world is getting smaller, practically everything we use is getting smaller. Manufacturing technology has advanced to higher levels of precision to satisfy the increasing demand to reduce the size of parts and products in the electronics, computer, and biomedical industrial sectors. New processing concepts, procedures, and machines are thus needed to fulfill the increasingly stringent requirements and expectations.
In the traditional mechanical/manufacturing engineering communities it implies material removal processes at a certain scale (not clearly defined), while for others including those who were the principal force behind the development of micro-electro-mechanical-systems (MEMS) technologies, this term encompasses the universe of silicon processing techniques for MEMS devices that were adopted or suitably modified from lithography-based techniques that are prevalent in integrated circuit manufacture.
At this time, unfortunately, a convergence in terminology has not been forthcoming and, hence, a definition of the term Micro-Machining to be implied in the context of this assessment is in order.
In principle, one may take two viewpoints:
- The first viewpoint may define Micro-Machining as the collection of all cutting operations that are performed on micro/meso-scale components and products that fall into the 100 µm to 10,000 µm size range as shown in the figure below. The Micro-Machining regime is characterized by the requirement of producing high accuracy complex geometric features in a wide variety of materials in the above-defined size range. These requirements impose the use of considerably downsized tooling (micro-tools, e.g., end mills in the 50 to 500-micron diameter range), small unreformed chip thicknesses and feed rates (submicron to a few microns), and speed settings (50K to 200K RPM might not be uncommon) that would be considered technologically infeasible at the conventional macro-scale. As a consequence, the principal distinction between Macro- and Micro-Machining operations emerges and manifests itself as the dominance of plowing and rubbing phenomena at the cutting edge over shearing and the necessity to take micro-structural effects into consideration.
The second viewpoint approaches the definition of the Micro-Machining regime from the standpoint of the magnitude of the undeformed chip thickness being removed in the cutting process. It is difficult to define a clear-cut value of the undeformed chip thickness that would differentiate the macro-, micro/meso- and nano-scale cutting regimes since other factors such as grain-structure, cutting edge radius, etc., also come into play.
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