Semiconductor field
Semiconductor wafers and optical substrate cleaning semiconductor wafers and optical substrates in the processing of the same process, that is, the raw material in the form of cutting, grinding and other forms of processing for the desired shape. This process introduces particulate contaminants, which are difficult to remove and cause serious problems of recurring contamination. Contaminants on the surface of semiconductor wafers affect the quality of printed circuit boards, which in turn shortens the life of semiconductor chips. Contaminants on the surface of optical substrates affect the quality of the optics and coatings, and can lead to energy inhomogeneity and shortened service life. Since laser dry cleaning is prone to substrate surface damage, this cleaning method is less used in the cleaning of semiconductor wafers and optical substrates, and laser wet cleaning and laser plasma shock wave cleaning have more successful applications in this field. Xu Chuanyi et al. studied the deposition of micron-level special magnetic paint as a dielectric film on the surface of ultra-smooth optical substrate, followed by the use of pulsed laser cleaning, the cleaning effect is better, although its impurity particles per unit area of the particulate matter increased, but the size of the impurity particles and the coverage of the area have decreased significantly, the method can be effective in cleaning the micron-level contaminant particles on the surface of the ultra-smooth optical substrate. Ping Zhang studied the laser plasma cleaning technology in the working distance and laser energy on the cleaning effect of pollutant particles of different particle sizes, the test results show that for the conductive glass substrate on the polystyrene particles, the energy of the 240 mJ laser's optimal working distance of 1.90 mm, with the increase in laser energy to clean up the effect of the increase is obvious, and large particles of pollutants are easier to clean up.
Metal material field
Metal material surface cleaning metal material surface cleaning compared to semiconductor wafers and optical substrate cleaning, cleaning pollutants belong to the macro category. Pollutants on the surface of metal materials are mainly oxidized layer (corrosion layer), paint, coatings, other attachments, etc., according to the type of pollutants can be divided into organic pollutants (such as paint, coatings) and inorganic pollutants (such as corrosion layer). Metal material surface contaminants cleaning mainly to meet the subsequent processing or use requirements, such as titanium alloy parts welding before the need to remove the surface of the material about 10μm thick oxide layer, aircraft overhaul need to remove the original paint coating on the surface of the skin in order to facilitate the re-spraying, rubber tire molds need to be cleaned up regularly to ensure that the surface of the rubber particles to ensure that the surface cleanliness to ensure that the production of the quality of the tires and the life of the molds. The damage threshold of metal materials is higher than the threshold of laser cleaning of surface contaminants, by selecting the appropriate power laser can achieve better cleaning results, in some areas have been mature applications. Wang Lihua et al. studied the application of laser cleaning technology in the treatment of aluminum alloy and titanium alloy surface oxidation, the results show that the use of energy density of 5.1 J/cm2 laser can be used to clean up the surface of the oxide layer of the A5083-111H aluminum alloy at the same time to maintain the good quality of the substrate, the use of an average power of 100 W pulsed laser scanning mode can be effective in cleaning the surface of the oxidized layer of titanium alloy and improve the surface hardness of the material. The average power of 100 W pulsed laser can effectively clean the oxide layer on the surface of titanium alloy and improve the surface hardness of the material by scanning. Domestic Ruike Laser, Da Nu Laser, Shenzhen Chuangxin and other companies developed laser cleaning equipment has been widely used in tires and other rubber molds, metal corrosion layer, parts and components surface oil cleaning.
The field of cultural relics
Cultural relics and paper surface cleaning metal artifacts and stone artifacts, etc. Due to the long history of its surface will appear such as grime, ink and other pollutants, these pollutants need to be cleaned up in order to restore cultural relics. Painting and calligraphy and other paper in the improper storage of its surface will grow mold and the formation of plaque, these plaques seriously affect the original appearance of the paper, especially for the cultural or historical value of the paper, will affect its appreciation and protection. Zhao Ying et al. studied the feasibility of ultraviolet laser cleaning of mold plaques on rice paper, the test results show that the use of laser scanning with an energy density of 3.2 J/mm2 for one time can remove thin plaques, scanning for two times can be clean plaques, but if the use of the laser energy is too high, it will be damaged in the removal of plaques at the same time as the rice paper. Zhang Xiaotong et al. successfully restored a gilt bronze artifact using laser vertical irradiation liquid film method. Zhang Licheng et al. used laser cleaning technology in the restoration of a Han Dynasty painted female terracotta figurine. Yuan et al. studied the effect of laser cleaning technology applied in the cleaning of stone cultural relics, comparing the damage of the sandstone body before and after cleaning and the effect of ink cleaning, smoke pollution cleaning and paint pollution cleaning respectively.
