Laser cleaning development history
In the early days of lasers, many researchers were exploring what lasers could do for us. As one of the first people to actively promote laser technology, Nobel Prize winner in physics, Dr. Arthur Schawlow, proposed the concept of laser cleaning very early, and in 1968, he invented a prototype laser cleaning machine with ruby laser. In order to remove the wrongly printed characters in the printing process, and applied for an invention patent.
In 1972, Professor John Asmus of the University of California was invited to Venice, Italy, to discuss with local experts how to use laser holographic imaging technology to record the historical relics suffered by floods. When they observed the interaction between the focused ruby laser and the stone statue, they found that the contamination accumulated on the surface of the stone statue was removed, but the stone itself was not significantly damaged. After returning to the United States, Asmus did a lot of research work on this basis, and tried the effect of different lasers in the cleaning of cultural relics. These work laid the foundation for pulsed ruby laser and pulsed Nd:YAG laser for laser cleaning.
In the 1980s, with the rapid development of the semiconductor industry, new requirements were placed on cleaning technology. Traditional cleaning methods have encountered difficulties in cleaning the tiny particle contaminants on the surface of wafers or other microelectronic devices. Laser cleaning can just solve such problems, and related application research has been carried out rapidly. IBM, Bell Labs and other well-known institutions are involved. IBM’s W. Zapka and others first applied for a patent on laser cleaning in 1987, and then A.C. Tam et al. successfully applied laser cleaning technology to remove microparticles on the surface of masks. Professor Susan Allen of Florida State University and Bell Labs have also developed a method of “steam cleaning”, that is, a mixed liquid film of alcohol and water is coated on the surface of the material to be cleaned, and then laser irradiation is used to achieve cleaning, which can greatly improve the efficiency of cleaning. The efficiency of laser cleaning. It is these works that realize the application of early laser cleaning technology in the industrial field.
Since the 1990s, more research and applications have been carried out in Europe and the United States, and industrial application scenarios have continued to expand. After entering the 21st century, my country has also started a lot of research on laser cleaning technology, but the large-scale application and promotion have only begun in the past five years or so. At present, laser cleaning technology has gradually been well-known and accepted by users in a large number of industries, and has broad development prospects. Its main application fields and application scenarios are shown in the figure below, and it is still expanding.