Utilizing ultra-short lasers, 21 Century Co., Ltd. has introduced ablation-type nano-polishing equipment that is distinguished from conventional melting-type laser polishing equipment. 21st Century Co., Ltd. is a company that orders and manufactures ultra-precision laser processing, carbide cutting tools, MCT tooling, ultra-precise molds, automated precision parts, and measuring gauges.
It is difficult to apply the laser polishing technology using the conventional melting/resolidification method to the production of ultra-precision vacuum plates for the production of electronic components which are sensitive to changes in surface hardness, and for the production of high density integration and miniaturized electronic components, vacuum plates also require high precision and a high level of surface roughness, so physical polishing is limited in terms of meeting these requirements. To overcome such difficulties, 21 Century Co., Ltd. has developed nano-polishing equipment using a femtosecond laser that has little thermal effect.
Rather than improving the surface roughness through surface melting/resolidification using conventional nanosecond laser technology, by replacing with ultra-short lasers and cutting the material surface precisely (ablation), a very low surface roughness RY value can be obtained compared to conventional physical polishing. Not only that, but the technology causes very little change in the physical properties of the surface as it ablates the material surface rather than inducing melting which changes the surface hardness.
The equipment is equipped with a displacement sensor and an optical camera, and dedicated software has been developed so that the operator does not to deal with complicated settings, so after initial setting, it is possible to measure material height and perform flatness calibration, edge measurement, and polishing in one go, and it is more accessible compared to conventional precision polishing technology that requires a high level of proficiency.
In particular, the dedicated software includes an automated optical inspection (AOI) function, so if a hole is damaged during mold processing with many micro-holes, it is possible to measure and inspect it on the spot.
Regarding the stage, an anti-vibration stage (vibration-proof table) has been applied to perform ultra-precision machining at mass production sites with a lot of vibration. It is completely shielded against fumes and dust generated during processing, and the internal circulation system is configured to effectively discharge such impurities to the outside.
Finally, the equipment is designed to enable ‘on-the-fly’ processing in which the stage moves and the laser scanner operates at the same time by linking the stage and scanner for increased productivity. In general, in processing requiring high precision, processing is mainly performed using only a scanner; however, in order to secure a higher level of productivity, processing is performed while the stage and the scanner are linked and activated at the same time.
An official at 21 Century Co., Ltd. said, “Nano-polishing technology using the equipment is a core technology that surpasses the limitations of existing processing technology due to the high integration of semiconductors and electronic components by actually applying femtosecond lasers, which were mainly in the research stage, to industrial sites.” He closed by saying, “The technologies derived from this technology will be leading technologies in the precision processing field in the future.”