Physical vapor deposition

Physical terms

Collection

zero Useful+1

zero

Physical Vapor Deposition (PVD) technology refers to the application of Physical methods Vaporize the surface of the material source (solid or liquid) into gaseous atoms or molecules, or partially ionize into ions, and pass Low pressure gas (or Plasma ）Physical vapor deposition is the main technology for depositing thin films with special functions on the substrate surface surface treatment One of the technologies.

PVD (physical vapor deposition) coating technology is mainly divided into three categories: vacuum Evaporation coating , vacuum sputter coating and vacuum ion coating. The main methods of physical vapor deposition are: Vacuum evaporation Sputtering coating, arc plasma coating Ion plating and molecular beam epitaxy Etc. Corresponding vacuum Coating Equipment Including vacuum evaporation Coater Vacuum sputtering coater and vacuum ion coater.

With the improvement of deposition methods and technologies, Physical vapor deposition technology Not only can it be deposited Metallic film 、 Alloy film It can also deposit compounds, ceramics, semiconductors, polymer films, etc.

Physical vapor deposition (PVD) technology has been applied since the beginning of the 20th century, but it has rapidly developed into a new technology with broad application prospects in the past 30 years, and is developing towards environmental protection and cleaning. In the watch industry, especially in the surface treatment of high-grade watch metal appearance parts, it has become more and more widely used.

Chinese name: Physical vapor deposition
Foreign name: Physical Vapour Deposition(PVD)

Discipline: Physics 、 Materials Science
main features: Environment improvement, no pollution, less consumables

catalog

Fundamentals

Announce

edit

Physical vapor deposition technology The basic principle can be divided into three process steps:

(1) Gasification of the plating material: Even if the plating material is evaporated, sublimated or sputtered, it is also through the gasification source of the plating material.

(2) Migration of atoms, molecules or ions of the plating material: atoms, molecules or ions supplied by the gasification source generate various reactions after collision.

(3) The atoms, molecules or ions of the plating material are deposited on the substrate.

Basic characteristics

Announce

edit

Physical vapor deposition technology Process Simple, environmentally friendly, pollution-free, less consumable, uniform and dense film forming Binding force Strong. This technology is widely used in Aerospace , electronics, optics, machinery, construction, light industry metallurgy , materials and other fields, can be prepared with wear-resistant, corrosion resistant, decorative, conductive, insulating Photoconductive 、 piezoelectricity , magnetic, lubricating, superconducting, etc film ^[1] 。

With high technology and Emerging industry With the development of physical vapor deposition technology, many new advanced highlights have emerged, such as Multi arc ion plating And Magnetron sputtering Compatible technology, large rectangular long arc target and sputtering target, unbalanced magnetron sputtering target, twin target technology, ribbon foam multi arc deposition winding coating technology, strip fiber fabric winding coating technology, etc., used coating complete equipment fully automatic , large chemical industry Scale development.

Vacuum evaporation

Announce

edit

principle

Vacuum evaporation Under vacuum condition Target material The technology of heating and evaporation to vaporize a large number of atoms and molecules and leave the liquid plating material or the solid plating material surface (or sublimation), and finally deposit them on the substrate surface. In the whole process, gaseous atoms and molecules China Council After few collisions Direct migration And depositing on the surface of the substrate to form a film. Methods of evaporation include Resistance heating , high-frequency induction heating, electron beam 、 laser Bundle ion beam High energy bombardment of plating materials, etc.

Vacuum evaporation is the earliest technology used in PVD.

Evapotranspiration source

Heat the plating material to Evaporation temperature This heating device is called evaporation source. The most common evaporation sources are resistance evaporation sources and Electron beam evaporation source ， Special purpose The evaporation sources of are high-frequency induction heating Arc heating 、 Radiant heating 、 Laser heating Evaporation source, etc.

Basic process

Fundamentals of vacuum evaporation Process As follows:

one
Pretreatment: including cleaning and pretreatment of plated parts. The specific cleaning methods include detergent cleaning, chemical solvent cleaning, ultrasonic cleaning and ion bombardment cleaning. Specific pre-treatment includes electrostatic removal and priming.
two
Furnace loading: including vacuum chamber cleaning and plating hanger cleaning, evaporation source installation, commissioning, plating jacket.
three
Vacuum pumping: Generally, the first rough pumping is above 6.6Pa, and the front stage maintenance vacuum pump of the diffusion pump is opened earlier to heat the diffusion pump. After sufficient preheating, open the high valve and pump to 6 × 10 with diffusion pump -3 Pa background vacuum.
four
Baking: bake and heat the plated parts to the required temperature.
five
Ion bombardment: vacuum degree is generally 10 Pa~10 -1 Pa， The ion bombardment voltage is 200V~1kV, and the separation time is 5min~30min,
six
Pre melting: adjust the current to make the plating material pre melting and degassing for 1min~2min.
seven
Evaporative deposition: adjust the evaporation current as required until the required deposition time is over.
eight
Cooling: the plated parts are cooled to a certain temperature in the vacuum chamber.
nine
Furnace discharge: close the vacuum chamber and vacuumize to 1 × 10 after taking out the pieces -1 Pa， Only when the diffusion pump cools to the allowable temperature can the maintenance pump and cooling water be shut down.
ten
Post treatment: apply finish paint, etc.

sputtering deposition

Announce

edit

Sputtered coating refers to the use of functional particles (such as argon Ion bombardment target Material surface The process of making atoms on the target surface obtain enough energy to escape is called sputtering. Filling under vacuum argon (Ar), and in the high voltage Lower argon glow discharge , which can ionize argon (Ar) atoms into argon ions (Ar + )。 Argon ion Electric field force Accelerate bombardment of cathode made of plating material under the action of Target material The target will be sputtered and deposited on the surface of the workpiece^[4] 。

The sputtering target is deposited on the surface of the substrate, which is called sputtering coating. The incident ions in the sputtered coating are generally obtained by glow discharge -2 Pa~10Pa, so the sputtered particles are easy to mix with Vacuum chamber Collision of gas molecules in, resulting in Direction of movement Randomization makes the deposited film easy to be uniform. Developed scale Magnetron sputtering coating ， Deposition rate Higher, process Repeatability Good, easy to automate, suitable for large Architectural decoration Coating and functional coating of industrial materials, such as TGN-JR multi arc or Magnetron sputtering In coiled material Foam plastic And the production and preparation of nickel nickel and silver silver plating on the surface of fiber fabrics.

Sputtered coatings can be divided into DC sputtering 、 RF sputtering and Magnetron sputtering Corresponding glow discharge Voltage source And control field are respectively high voltage DC , RF（ RF ) alternating current And magnetic control (M) field^[2] 。

Plasma coating

Announce

edit

In physical vapor deposition cold cathode Arc evaporation The solid plating material is used as the cathode, and water cooling is used to form many bright spots on the surface of the cold cathode, that is, cathode arc spots. The arc spot is the root of the arc near the cathode. Under vacuum condition, use the arc striking pin to strike the arc between the vacuum gold wall (anode) and the plating material (cathode Arc discharge A number of cathode arc spots are rapidly moving on the cathode surface, which constantly and rapidly evaporate or even "allotrious" plating material, making it ionize into an arc with the plating material as the main component Plasma And can rapidly deposit the plating material on the substrate.

In minimal space current density Extremely high, extremely small arc spot size, estimated to be about 1 μ m~100 μ m, current density up to 10 five A/ cm 2~10 seven A/cm2。 Each arc spot exists for a very short time, and the plating material at the correction point of the ionized cathode is evaporated explosively metal ion New arc spots will also be generated on the cathode surface, and many arc spots will be generated and disappear continuously, so Weigh many Arc evaporation. The earliest designed plasma accelerator type multi arc evaporation ionization source is to configure a magnetic field behind the cathode, so that the ions after evaporation can obtain the Hall acceleration effect, which is conducive to increasing the energy bombardment volume of ions. With this arc evaporation ionization source, the ionization rate is high, so it is also called arc plasma coating. Because plasma coating often produces multiple arc spots, it is also called multi arc evaporation ionization process.

Ion plating

Announce

edit

Ion plating The basic principle is to use some Plasma Ionization technology can partially ionize the atoms of the plating material into ions, and generate many high-energy neutral atoms at the same time bias 。 In this way, under the action of deep negative bias, ions are deposited on the surface of the substrate to form a film.

The ion plating film is prepared by inert gas Glow discharge to make plating material (such as metal titanium ）Vaporization, evaporation and ionization. The ions are accelerated by the electric field and bombard the workpiece surface with high energy carbon dioxide , nitrogen and other reactive gases, TiC and TiN can be obtained on the surface of the workpiece overburden The hardness is up to 2000HV.

Ion plating technology It was first established in 1963 by D M. Mattox proposed. In 1972, Bunshah&Juntz introduced reactive evaporation Ion plating (AREIP), this method can deposit TiN, TiC, etc Superhard membrane 。 Moley&Smith developed hollow hot cathode ion plating in 1972 and developed hollow hot cathode ion plating in 1973 RF ion plating (RFIP)。 In the 1980s Magnetron sputtering ion plating (MSIP) and Multi arc ion plating (MAIP)。

Ion plating is the most widely used coating process in physical vapor deposition.

characteristic

The basic feature of ion plating is to adopt some methods (such as Electron beam evaporation Magnetron sputtering, or multi arc evaporation ionization, etc.) Neutral particle When ionizing into ions and electrons, a negative bias voltage must be applied on the substrate, so that ion pair The substrate produces bombardment, and the ions are deposited on the substrate after the negative bias voltage is properly reduced, which is suitable for high speed steel Tools, hot forging dies and other materials surface treatment Process.

The advantages of ion plating are as follows:

① film And matrix Binding force Strong, low reaction temperature.

② The film is uniform and dense.

③ Under the action of negative bias, the winding plating performance is good.

④ No pollution.

⑤ Multiple Base material All are suitable for ion plating.

Reactive ion plating

If using Electron beam evaporation source Evaporation, at crucible Add 20V~100V positive bias voltage on the top. Lead in the vacuum chamber Reactivity Gases, such as nitrogen, oxygen acetylene 、 methane Equivalent reactive gas replacement argon , or add argon on this basis. electron beam High energy electrons in the medium can reach thousands to tens of thousands Electron volt The energy of can not only make the plating material melt and evaporate, but also can stimulate Secondary electron 。 The secondary electrons accelerate under the action of the upper positive bias voltage, collide with the neutral particles evaporated from the plating material, ionize into ions, and ionize on the surface of the workpiece to obtain oxide (e.g. TeO2, SiO2, Al2 O3 、 ZnO , SnO2, Cr2O3, ZrO2, InO2, etc.). It is characterized by high deposition rate and low process temperature.

Multi arc ion plating

Multi arc ion plating is also called Arc ion plating Because there are multiple arc spots on the cathode, it is called "multi arc".

The main characteristics of multi arc ion plating are as follows^[3] ：

① Cathode arc evaporation ionization source can directly generate plasma from solid cathode without producing molten pool, so it can be arranged in any direction, or multiple evaporation ionization sources can be used.

② The ionization rate of the plating material is high, generally up to 60%~90%, significantly improving the adhesion with the substrate to improve the performance of the film.

③ High deposition rate, improving the efficiency of coating.

④ The equipment structure is simple, and the arc power supply works at low voltage large current The working condition is relatively safe.

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

Jinggong Network Anbei No. 1100000200001