scholarly journals OCCURRENCE OF DEFECTS THE PRODUCTION OF MASKS

2021 ◽  
Vol 6 ◽  
pp. 176-182
Author(s):  
Anastasiya V. Iisenko ◽  
Dmitry M. Nikulin

The article discusses the main stages of the route for the production of masks, during which defects are formed. The main defects and possible reasons for their appearance are given. A method of correcting defects in the form of punctures and undergrowth by the laser method is considered. The disadvantages of the laser method in correcting the elements of the topological pattern of masks are presented.

2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


2013 ◽  
Vol 86 (5) ◽  
pp. 1020-1026
Author(s):  
V. K. Goncharov ◽  
G. A. Gusakov ◽  
M. V. Puzyrev
Keyword(s):  

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.


Author(s):  
Laurentiu Rusen ◽  
Valentina Dinca ◽  
Cosmin Mustaciosu ◽  
Madalina Icriverzi ◽  
Livia Elena Sima ◽  
...  

2010 ◽  
Vol 24 (03) ◽  
pp. 257-269 ◽  
Author(s):  
MENGYAN SHEN

Pulsed laser-assisted etching is a simple but effective method for fabricating small regular structures directly onto a surface. We have successfully fabricated submicro- or nano-meter sized spikes on a solid surface immersed in liquids with femtosecond laser pulse irradiations. This method is applicable to different metals such as stainless steel, copper, titanium, cobalt, as well as different semiconductors, such as Si and GaAs. The femtosecond laser method is much faster than other methods. We can control the experimental conditions to design and fabricate nanostructures in different materials and on the surfaces with different morphologies. Here, we discuss the nanostructures formation with femtosecond pulse laser irradiations, and introduce our results of the nanostructure for applications in sensing, biology and artificial photosynthesis. The femtosecond laser irradiation technique can efficiently integrate metal, semiconductor and polymer nanostructures in various small devices to leverage the expertise in other research fields and applications.


2018 ◽  
Vol 45 (3) ◽  
pp. 145-154 ◽  
Author(s):  
Ahmed I. Marwan ◽  
Uladzimir Shabeka ◽  
Julie A. Reisz ◽  
Connie Zheng ◽  
Natalie J. Serkova ◽  
...  

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