Month: March 2023

Understanding the Mechanisms of Vacuum Evaporation Coating

Vacuum evaporation coating is a common method used to deposit thin films onto a substrate. This technique is widely used in a variety of industries, such as electronics, optics, and aerospace, due to its ability to create precise and uniform coatings with a high level of purity. There are several mechanisms used to achieve vacuum evaporation coating, each with its own advantages and limitations.

RESISTANCE EVAPORATION

One common method is resistance evaporation, which uses a resistance evaporation source made of tungsten, molybdenum, or tantalum to evaporate low melting point materials such as gold, silver, zinc sulfide, magnesium fluoride, chromium oxide, and others. However, this method may not meet the needs of vapor deposition of certain metals and non-metals.

ELECTRON BEAM EVAPORATION

Electron beam evaporation is another technique used for vacuum evaporation coating. It involves heating the evaporating material with an electron beam, which can provide a much larger energy density than the resistance heat source. This allows for the heating of refractory metals and non-metallic materials such as tungsten, molybdenum, niobium, SiO2, AI2O3, and others. Additionally, the material to be vapor-deposited is placed in a water-cooled crucible, which helps to avoid evaporation of the container material and reaction between the container material and the membrane material, thus improving the purity of the membrane.

Various Types of Evaporation Pellets Materials

HIGH-FREQUENCY INDUCTION HEATING EVAPORATION

High-frequency induction heating evaporation is another method used for vacuum evaporation coating. The metal is heated to the evaporation temperature using the principle of induction heating. The crucible containing the evaporation material is placed in the center of the spiral coil, and a high-frequency current is passed through the coil to heat the metal evaporation material until evaporation. This method has a large evaporation rate, uniform and stable evaporation source temperature, easy temperature control, and requires less purity of the evaporation materials.

ARC HEATING EVAPORATION

Arc heating evaporation uses the arc discharge heating method, which is similar to the electron beam heating method. This method is particularly suitable for evaporation of refractory metals and graphite that have a high melting point and a certain conductivity. It also has the advantage of being relatively inexpensive compared to the electron beam heating apparatus.

CONCLUSION

In conclusion, vacuum evaporation coating is a versatile and widely used technique for depositing thin films onto a substrate. There are several methods used to achieve this, each with its own advantages and limitations. By understanding the different mechanisms of vacuum evaporation coating, researchers and industry professionals can choose the appropriate method to achieve the desired coating properties for their specific applications.

If you want to learn more about sputtering targets, such as metals, alloys, oxides, and ceramic materials, you can visit the website of Stanford Advanced Materials (SAM) Corporation at https://www.sputtertargets.net/. SAM is a global supplier of various sputtering targets and regularly updates their knowledge and interesting stories related to sputtering targets on their website.

Requirements of The Width of ITO Glass: Thinner Is Better?

In recent years, the requirements for processing technology in various industries have been continuously improved. Taking ITO materials as an example, the line width and interval of processing ITO conductive patterns have higher requirements. And often there is such a question, can the ITO laser etching machine be able to achieve a line width below 20 microns? Can the processing interval be 20 microns? The answer is yes. So what is the smallest line width of the ITO laser etching machine? Let SAM Sputter Target answer it for you.

Further Reading: An Introduction to ITO – Indium Tin Oxide

The thickness of the ITO line width is determined by the laser and the optics and relates to the spot size of the focus and the thermal influence of the source on the material. Shorter wavelength results in lower energy, narrower pulse width, higher magnification of the beam expander, smaller negative of the field lens, and smaller spot size, so it could produce a line with thinner width. Of course, several of the above-mentioned parameters have a relative limit value. For example, if the magnification of the beam expander is too high, the energy density will be poor, which is not suitable for processing. Therefore, we need to take a range of values in order to apply them to the processing needs.

Related: Indium Tin Oxide Sputtering Target

In addition, even with the same laser etch machine, the line widths made by different materials are different. For example, the etch line width of a nickel alloy material is thicker than that of an ITO material, depending on the absorption of the laser wavelength by the material itself. This article analyzes based on ITO conductive glass.

The general requirement for ITO glass in the touch screen industry is less than 20 microns, which uses a narrow pulse-width infrared nanosecond laser. Different industries have different requirements for ITO line width. In some industries, the resistance of ITO line width has relatively high requirements, while in some industries, it is required to ensure that it is cut and insulated.

In the current laser market, the minimum line width of ITO conductive glass is 5 micrometers, and different line widths can be selectively selected according to different light sources. For example, the minimum line width of an ultraviolet nanosecond laser can be 15 micrometers. Of course, there are also EUV lithography machines that can achieve nanometer levels by means of extreme ultraviolet lasers. The requirements for line width are mainly determined by different product requirements.