1. Overview of PVD coating materials
PVD coating materials are mainly used to prepare various thin-film materials with specific functions. The application fields include flat panel displays, semiconductors, solar cells, opto-magnetic recording media, optical components, energy-saving glass, LEDs, tool modification, decorative items, etc.

(1) Overview of thin film material preparation technology

Thin-film materials are grown on substrate materials (such as glass, optical glass, etc.) and are usually formed by coatings of metals, non-metals, alloys, or composite materials. It has high permeability, absorption, cut-off, light separation, reflection, filtration, interference, protection, waterproof and antifouling, antistatic, electrical conductivity, magnetic permeability, insulation, and wear resistance. It has the functions of high temperature resistance, corrosion resistance, oxidation resistance, radiation protection, decoration and reorganization, etc., which can improve product quality, environmental protection, energy saving and prolong product service life.
Improve the original performance, etc. At present, the preparation techniques of thin films mainly include physical vapor deposition (PVD) and chemical vapor deposition (CVD).
The thin film material grows on the substrate material (such as screen display glass, optical glass, etc.), and is generally formed by coating materials such as metals, non-metals, alloys or compounds. , interference, protection, waterproof and anti-fouling, anti-static, conductive, magnetic permeability, insulation, wear resistance, high temperature resistance, corrosion resistance, oxidation resistance, radiation protection, decoration and composite functions, and can improve product quality, environmental protection, energy saving , Extend product life
Improve the original performance, etc. At present, thin-film material preparation technologies mainly include physical vapor deposition (PVD) technology and chemical vapor deposition (CVD) technology.

①CVD technology

CVD technology is a technology that relies on chemical reaction at high temperature to introduce the vapor containing gaseous reactants or liquid reactants and other gases required for the reaction into the reaction chamber, and chemical reactions occur on the surface of the substrate to form thin film materials.

②PVD technology

PVD technology is one of the main technologies for the preparation of thin film materials, which refers to the use of physical methods under vacuum conditions to gasify the surface of a certain substance into gaseous atoms, molecules or partial ionization into ions, and through low-pressure gas (or plasma) process, in The technology of depositing thin film materials with certain special functions on the surface of substrate materials. Under PVD technology, the substances used to prepare thin film materials are collectively referred to as PVD coating materials. After years of development, PVD technology has become the current mainstream coating method, mainly including sputtering coating and vacuum evaporation coating.
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A. Vacuum evaporation coating for optical coating materials
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Vacuum evaporation coating refers to a deposition technology in which a certain substance is deposited on the surface of the substrate material by heating and evaporating a certain substance by using the thermal energy of the film heating device (called the evaporation source) under vacuum conditions. The material to be evaporated is the raw material of the thin film material deposited by the vacuum evaporation coating method, which is called evaporation material.
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The vacuum evaporation coating system generally consists of three parts: a vacuum chamber, an evaporation source or an evaporation heating device, a substrate placement and a heating device for the substrate. In order to evaporate the material to be deposited in a vacuum, a container is required to support or contain the evaporative material, while the heat of evaporation needs to be provided to bring the evaporative material to a temperature high enough to generate the desired vapor pressure. The basic principles of vacuum evaporation coating are as follows:
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The vacuum evaporation coating technology has the characteristics of simplicity and convenience, convenient operation, and fast film formation speed. It is a widely used coating technology, mainly used in the coating of small-sized substrate materials.
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B. Sputtering coating of optical coating materials
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Sputtering coating refers to the use of ions generated by an ion source, which are accelerated and aggregated in a vacuum to form a high-speed ion beam, which bombards the solid surface. Technology on the surface of substrate materials. The bombarded solid is the raw material for depositing thin-film materials by sputtering, which is called the sputtering target.
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Generally speaking, the sputtering target is mainly composed of target blank, back plate (or back tube) and other parts, among which, the target blank is the target material bombarded by high-speed ion beam, which belongs to the core part of the sputtering target. During the coating process, after the target blank is hit by ions, its surface atoms are scattered by sputtering and deposited on the substrate to form a thin film material; since the sputtering target needs to be installed in a special equipment to complete the sputtering process, the interior of the equipment is high. In the working environment of high voltage and high vacuum, the material of most target blanks is soft or highly brittle, which is not suitable for direct installation in the equipment. Therefore, it needs to be bound with the back plate (or back tube). It plays the role of fixing the sputtering target, and has good electrical and thermal conductivity.
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The basic principles of sputtering coating of optical coating materials are as follows:
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The sputtering coating process has good repeatability and controllable film thickness, and a thin film with uniform thickness can be obtained on a large-area substrate material. It has become one of the main technologies for preparing thin-film materials. Various types of sputtering thin-film materials have been widely used. Therefore, the demand for sputtering targets, a functional material with high added value, is increasing year by year, and sputtering targets have also been It has become the most widely used PVD coating material in the current market.