What are the formation mechanisms of vacuum evaporation coating?

The formation mechanism of vacuum evaporation coating is as follows:

1.Evaporation condensation mechanism: the material is directly evaporated into gas after heating, and then the gas enters the vacuum chamber and then condenses on the substrate.

2.Ion beam-assisted evaporation: Ion beam-assisted technology is added when evaporating materials, which can increase the effect of electrons, so that the materials that are not easy to evaporate can be transformed into an ionic state with high evaporation, and the compactness and adhesion of the film layer are improved.

3.Electron bombardment evaporation: Electron beam bombardment evaporation technology is used to evaporate the material, when the material is heated to the evaporation temperature, a large number of high-speed electrons are ejected on the surface of the material, and the interaction between the electrons and the material throws out part or the whole of the surface of the material to form a thin film.

4.Magnetically controlled sputtering: the metal material is placed in a magnetic field, a voltage is applied and heated in a vacuum environment, the metal material is bombarded by gas ions and decomposed into particles, and deposited on the substrate under the action of the magnetic field.

The above are a few common ways in the formation mechanism of vacuum evaporation coatings.

1.Resistance evaporation plating: Resistance evaporation sources are used to evaporate materials with low melting points, such as gold, silver, zinc sulfide, magnesium fluoride, chromium trioxide, etc. The resistor evaporation source is generally made of tungsten, molybdenum and tantalum.

2.Electron beam evaporation plating: It is an important heating method in vacuum evaporation technology to vaporize and evaporate the film material by electron beam heating, and then condense on the surface of the substrate to form a film.

There are many types of such devices. With the wide application of thin film technology, not only the types of membranes are required, but also the quality requirements of membranes are more stringent. Resistance evaporation plating can no longer meet the needs of evaporation of some metals and non-metals.

The electron beam heat source can obtain a much greater energy density than the resistance heat source, which can reach 104-109 W cm2, so that the film can be heated to 3000-6000C. This provides a good heat source for the evaporation of refractory metal and non-metallic materials such as tungsten, molybdenum, germanium, SiO2, AI2O3, etc. And because the evaporated material is placed in a water-cooled crucible, the evaporation of the container material and the reaction between the container material and the membrane material can be avoided, which is extremely important to improve the purity of the membrane.

In addition, heat can be applied directly to the surface of the film, resulting in high thermal efficiency and low heat conduction and radiation loss.

3.High-frequency induction heating evaporation plating: The principle of induction heating is used to heat the metal to the evaporation temperature.

The crucible filled with the coating material is placed in the ** (non-contact) of the spiral coil, and a high-frequency current is passed through the ** circle, which can make the metal coating material generate an electric current to heat itself up until it evaporates.

The characteristics of the induction heating evaporation source: 1) the evaporation rate is large 2) the temperature of the evaporation source is uniform and stable, and it is not easy to produce aluminum droplet splashing phenomenon 3) the evaporation source is charged at one time, without the wire feeding mechanism, the temperature control is relatively easy, and the operation is simple 4) the purity requirements of the membrane are slightly wider.

4.Arc heating evaporation plating: A heating method similar to the electron beam heating method is the arc discharge heating method.

It also has the characteristics of avoiding the pollution of resistance heating materials or crucible materials, and the heating temperature is high, especially suitable for the evaporation of refractory metals and graphite with high melting point and certain conductivity. At the same time, the equipment used in this method is simpler than that of electron beam heating devices, making it a relatively inexpensive evaporation device.

Evaporation Evaporation coating is to evaporate thin film materials into atoms or molecules by means of electric current heating, electron beam bombardment heating and laser heating in a vacuum, and then they move in a linear motion with a large free path to collide with the substrate.

Sputtering coating is to bombard the target with charged ions, so that some atoms on the surface of the target escape, and the escaped atoms are deposited on the solid surface near the target to form a thin film. Evaporative coating is to heat the substance to reach the melting point, and then to the boiling point, and evaporate it onto the substrate. 1. Sputtering technology is different from vacuum evaporation technology.

Sputtering refers to the phenomenon in which charged particles bombard the surface (target) of a solid state, causing solid atoms or molecules to eject from the surface. Most of the ejected particles are in an atomic state, and the high-nucleated finch is often called a sputtering atom. The sputtering particles used to bombard the target can be electrons, ions or neutral particles, because ions are easy to accelerate under the electric field to obtain the required kinetic energy, so ions are mostly used as early bombardment particles.

2. The sputtering process is based on glow discharge, that is, the sputtering ions are all in the gas discharge. Different sputtering techniques use different glow discharges of silver. DC diode sputtering utilizes DC glow discharge; Three-pole sputtering is a glow discharge that uses the support of a hot cathode; RF sputtering is the use of radio frequency glow discharge; Magnetron sputtering is the use of glow discharge under the control of a ring magnetic field.

3. Sputtering coating has many advantages compared with vacuum evaporation coating. For example, any substance can be sputtered, especially elements and compounds with high melting point and low vapor pressure; Good adhesion between the sputtered film and the substrate; High film density; The film thickness is controllable and the repeatability is good. The disadvantage is that the equipment is more complex and requires a high-voltage device.

1. Evaporation coating: Evaporation of a substance by heating to make it deposit on the solid surface, which is called evaporation coating. This method was first developed by MFaraday proposed in 1857 that the Coellidad has become one of the commonly used coating techniques in modern times.

2. Compared with other vacuum coating methods, evaporation coating has a higher deposition rate, and can be used to coat compound films that are not easy to decompose due to elemental substance. In order to deposit high-purity single crystal layers, molecular beam epitaxy can be used.

Evaporative coating is a commonly used thin film preparation technique that uses an evaporation source to heat a material to evaporation temperature, and then carefully evaporates the material through the chain to be deposited on the surface of the substrate to form a thin film. Here are a few common types of evaporation sources:

Electron beam evaporation source: An electron beam is used to heat the material to an evaporation temperature and then evaporate it on the substrate. The electron beam evaporation source has the advantages of high temperature and high speed, and is suitable for the evaporation of multi-tremor materials.

Resistance Heating Evaporation Source: The solder mask wire in the evaporation source is heated by applying electricity to evaporate the material onto the substrate. Thermal resistance evaporation source sheds are suitable for a wide range of materials and are relatively simple to operate.

Sputtering evaporation source: A combination of sputtering and evaporation. The material is evaporated onto the substrate by means of ion bombardment.

Sputtering evaporation sources are suitable for a wide range of materials and enable higher film uniformity and complex shapes.

Gas Transport Evaporation Source: By placing the material in a high-temperature evaporation vessel, a gas carrier is used to evaporate and deposit the material on the substrate. Gas transfer evaporation sources are suitable for applications with high melting points or high material requirements.

The choice of these evaporation sources depends on factors such as the required film material, film property requirements, equipment and process parameters. Different evaporation sources may have different advantages and disadvantages in terms of material selection, evaporation rate, uniformity, etc.

In the coating industry, evaporation can be used to deposition thin films. With this thin film deposition method, the source material used for deposition is evaporated in a vacuum, and the vapor particles can move freely to the surface of the substrate. Upon reaching the substrate substrate, the evaporated material settles and condenses back into a solid state, forming a thin film on the substrate.

Types of different sources of evaporation.

The materials used to make evaporation sources typically have high melting points and low vapor pressures.

Lamp potato silk. The filament is made of tungsten, molybdenum, tantalum and other metals with high melting points, and the evaporated substances are generally hung or placed on the filament, and a large current is passed through the filament containing the evaporation material in a vacuum, and these materials will be heated and collapsed to their melting point and finally evaporate. Hand in hand circle.

Crucible. Crucibles for evaporative film deposition are made of high-temperature resistant materials such as tungsten, molybdenum, tantalum, and high-temperature resistant alumina, graphite, or boron nitride. Usually, manufacturers need to choose different crucibles depending on the material to be evaporated.

Evaporation boats. The evaporation boat is the best source of thermal evaporation for vacuum evaporation of aluminum materials. Usually the boat-shaped evaporation source is made of tungsten material, and now the evaporation boat is also made of conductive high-performance ceramic composites, the main raw materials used are boron nitride and titanium diboride, the evaporation surface can be grooved or laser surface etching, its performance is reliable, the evaporation rate is accurate and the service life is long.

What is the difference between vacuum evaporation and vacuum sputtering, ion plating.

Hello, I have inquired for you 1. Vacuum evaporation vacuum evaporation, referred to as evaporation, refers to the evaporation and vaporization of the coating material (or film material) through a certain heating and evaporation method under vacuum conditions, and the particles are scattered to the surface of the substrate to form a thin film. Advantages: The process is simple, the purity is high, and it is easy to form the required pattern through the maskingDisadvantagesWhen evaporating compounds, it is difficult to control the component ratio due to the thermal decomposition phenomenon, and it is difficult for low vapor pressure substances to form films2, sputtering coating Sputtering coating refers to the process of discharging the material (target) by applying high pressure in a space filled with inert gas (such as argon), electrocuting the alumina into atoms, colliding with the target, causing the target atoms to fall off, and adhesion to the substrate to form a thin film. Advantages: good sputtering adhesion performance, easy to maintain the composition ratio of compounds and alloys, disadvantages need sputtering targets, target materials need to be refined, and the utilization rate is low, and it is not convenient to use mask deposition 3, ion plating ion plating is a process in a vacuum environment that uses high-pressure gas discharge to evaporate the plating material and ionize it, and is deposited on the surface of the product to form a coating.

After the ion plating process is adopted, the quality of the plating is very good, the coating structure is dense, there will be no pinholes, bubbles and other conventional coatings, the thickness of the product surface is uniform, and even the irregular product surface with grooves or water chestnuts can be ion-coated. Advantages: good ion adhesion performance, compounds, alloys, and non-metals can be film-forming, and the disadvantages are that the device and operation are more complicated, and it is not convenient to use mask deposition, I hope it can help you.