1. Laser Cleaning of Integrated Circuit Components The IC package is often packed in the IC package.
As IC integration increases, more and more pins are available, and the holes are getting smaller. The traditional method is difficult to remove the small hole mode flash. Excimer laser stripping can completely eliminate the small hole mode flash. The use of laser scintillation has unparalleled advantages over other methods. Obviously laser flashover will be the most suitable IC flashover technology. Laser scintillation generally uses a KrF excimer laser. The wavelength is 248 nm and the pulse width is 20 ns. Focusing with a plano-convex lens with a diameter of 50 nm and a focal length of 50 mm, the laser beam is incident perpendicularly in the air.
2. Integrated circuit component laser unmarking In the production of integrated circuits, the quality of package marks often occurs poorly or errors occur. Other users temporarily change the design and need to clear existing marks before re-marking.
Conventional cleaning methods have low speed, poor automation, and rough surface after processing, which limits their application in integrated circuits. The excimer laser has high efficiency in rejecting the mark and the mark quality is good. Laser de-bucking must properly control the stripping depth. Too deep affects the IC chip and reduces the ability to resist moisture attack. Too shallow, the mark cannot be completely removed. Save time with higher energy density and higher repetition rate. When the laser is backed off, the dust, grease and oxides on the surface are also removed to reveal a pure mold. After re-marking, the durability is better.
3. Cleaning of large astronomical telescopes
Due to the open-air use of large telescopes, the mirror surface is often contaminated by particles, which causes the specular reflectance to decrease, resulting in aggravation of image backing, which is a big problem encountered in astronomical observations. Large mirrors are difficult to clean using traditional methods. Good results were obtained with KrF excimer laser cleaning. The energy density threshold at which the laser beam is unable to produce specular damage increases as the wavelength increases. Starting from avoiding damage to the mirror, it is safer to choose longer wavelength cleaning. At the same time of laser cleaning, auxiliary gas or pumping should be blown in order to blow away or suck away particles falling from the irradiation area in time to prevent secondary pollution.
4. Cleaning of the magnetic head slider air bearing
In the manufacture of computer disk drives, in order to increase the storage density, the flying height of the magnetic head is continuously reduced by about 0.1 μm, and submicron particles may damage the sliding seat and the disk surface, causing the drive system to malfunction. Therefore, cleaning the slide air bearing is an indispensable process in the manufacturing process, and the conventional ultrasonic cleaning effect is very poor. New research proves that laser cleaning is a very effective method for cleaning the magnetic head slider air bearing. The magnetic head slider air bearing is made of aluminum oxide and titanium carbide. During the manufacturing process, the surface of the magnetic bearing is usually adhered to the zirconia particles, and the loose particles are first blown off by a strong air flow, and then laser cleaning is performed. The number of particles adhering to the surface was examined by optical microscopy before and after cleaning.
5. Laser cleaning of artwork
Laser cleaning of ancient art treasures is a fairly complex technique. At present, laser cleaning technology is mainly used for cleaning of cultural relics and large buildings, and chemical cleaning can damage its surface and endanger the environment.
In recent years, the use of laser cleaning technology has been successful in clearing the world-famous ancient architecture of Cologne Cathedral. After the laser cleaning of the stone carving collection, the same effect was obtained. The surface of the stone after laser cleaning was observed with an electron microscope. It was found that the structure of the stone after laser cleaning did not change, and the surface to be cleaned was smooth and flat without damage. The use of excimer lasers to clean Chinese ancient copper coins and metal compasses. The particle size of the surface contaminants can be cleaned from as small as a molecular group to as large as 80 μm, and the fine structure and color of the surface of the object remain intact without damage.