Historical Development of vacuum coating technology
In the film prepared in vacuo, crystalline coating system comprising a metal, semiconductor, insulator and other elemental or compound film. Although the chemical vapor deposition also uses vacuum, low pressure or vacuum plasma and other means, but generally refers to a physical vacuum deposition method for depositing a thin film. Vacuum coating has three forms, namely vapor deposition, sputtering and ion plating.
Vacuum coating technology is now beginning in the 1930s, forties and fifties began industrial applications, industrial mass production began in the 1980s, has made a wide range of applications in the electronics, aerospace, packaging, decoration, gilt printing and other industries. Vacuum coating means in a vacuum environment, a metal or metal compound vapor is deposited onto the surface of the material in the form of (usually non-metallic material), is a physical vapor deposition process. Because often the metal film coating, it is also called vacuum metallization.
Generalized vacuum coating further comprises a metal or non-metallic materials and other non-metallic surface of the vacuum vapor deposition polymer functional film. In all plating material to the plastic is most common, followed by, for paper coating. Relative to metals, ceramics, wood and other materials, plastics have sufficient sources of performance is easy to control, easy processing and other advantages, so a wide variety of plastic or other polymer materials as structural engineering decorative materials, widely used in automobiles, household appliances, household packaging, decorative and other industrial fields. However, the presence of surface hardness of plastic materials are mostly not high enough to look gorgeous, abrasion and low defects, such as the plastic surface layer deposited thin metal film can be given away plastic bright metallic appearance, suitable metal source also can greatly increase the wear resistance of the material surface, greatly expanded the scope and application of decorative plastic.
Vacuum coating machine theory and analysis of the various components
Vacuum coating machine is currently the most widely produced vacuum vacuum equipment, usually with a vacuum chamber, vacuum unit, electrical control cabinet of three parts, exhaust system uses a "diffusion pump + roots pump mechanical pump + + + Cold trap polycold "components. The company specializes in vacuum coating equipment development and production has experienced technical team and quality service team for you to solve any problems in the use of equipment encountered. The following detailed description of each part of the composition and working principle of vacuum coating machines.
First, the main vacuum - a vacuum chamber according to the size of the processed product requirements vary, are not the same vacuum chamber, currently the most widely used of diameter 1.3M, 0.9M, 1.5M, 1.8M, etc., the cavity made of stainless steel "target = _blank> stainless steel, requires no rust, solid, etc., to connect the various parts of the vacuum chamber has a valve, used to connect each suction pump.
Two auxiliary pumping system: an important part of the exhaust system for vacuum coating machine system, mainly by mechanical pump, booster pump (pump introduces the Roots), three major oil diffusion pump. The exhaust system uses a "diffusion pump + mechanical pump + roots pump Cold trap + polycold" components. Exhaust process: first a mechanical pump vacuum chamber evacuated to less than about 2.0 * 10-2PA low vacuum, vacuum diffusion pump provides premise successor, then when the diffusion pump vacuum chamber, but also with the mechanical pump oil diffusion composition tandem pump, in such a manner pumping action.
Mechanical pump: also called foreline pump, mechanical pump is the most widely used as a roughing pump, which is to remain sealed and oil mechanical methods rely constantly changing volume of the pump suction cavity, so that the container is drawn expanding the gas within the volume to obtain a vacuum.
1. Mechanical pumps Category: Mechanical pumps There are many commonly used slide vacuum valve (this mainly applies to large-scale equipment), reciprocating piston, fixed and rotary vane chip (this is currently the most widely used, this article describes) four types.
2. The mechanical pump is to work from the atmosphere, its main parameters are the ultimate vacuum, pumping speed, this is the design and selection of an important basis for the mechanical pump. Single-stage pump may be pumped from the atmosphere, the container 1.0 * 10-1PA ultimate vacuum, the two-stage mechanical pump containers may be pumped from the atmosphere 6.7 * 10-2 Pa, or even higher. Pumping rate, refers to the rotary vane pump operation at rated rpm, the volume of gas that can be discharged per unit time, you can use the following formula to calculate: Sth = 2nVs = 2nfsL fs temporal end, said suction chamber cross-sectional area, L is empty cavity length, coefficient represents twice per rotor revolution exhaust process, Vs indicates when the rotor is in the horizontal position, the end of inspiration, the maximum volume of the cavity space and time, the rotational speed is n. Mechanical pump exhaust also has the effect of motor speed and the tightness of the belt relationships relatively loose belt when the motor, the motor speed is very slow when the effect of the mechanical pump exhaust will deteriorate, so regular maintenance point inspection, mechanical pump oil seal also needs often point inspection, the oil is too small, amounting to less than a sealing effect, it will leak in the pump, oil too, the suction hole clogged the intake and exhaust can not, in general, in The oil level can be online under 0.5 cm.
3. Mechanical pumps are often used for pumping dry air, but not too high oxygen content extraction, explosive and corrosive gases, the mechanical pump is typically used for pumping permanent gas, but not water vapor good results, so it is not pumping water vapor. Rotary vane pumps play a major role in the parts are stator, rotor, shrapnel, etc., but the inside of the rotor and the stator in different stator mandrel, as two of the inscribed circle, the rotor slot is equipped with two shrapnel, shrapnel middle two spring-loaded, to ensure that the shrapnel firmly attached to the inner wall of the stator.
