knowledge Archives - Page 9 of 12

Thinning and Coating Process of Mobile Phone Cover Glass

According to the needs of various terminal applications, glass cover panels require various optical glass processing processes such as cutting, edging, drilling, polishing, thinning, chemical strengthening, printing, laser engraving and coating. Today we will introduce the thinning and coating of mobile phone cover glass, which are the most important parts of the whole manufacturing process.

Cover glass thinning process

The glass mentioned in this article is not the 3mm, 5mm, 8mm or even 10mm glass for civil use, but the cover glass for electronic products such as smartphones and tablet computers. Among the glasses currently on the market, the thinnest is 0.15 mm. There is a special thinning process that reduces the thickness of the glass.

Since Steve Jobs started using Corning Gorilla Glass for his iPhones, there emerges a new component for electronic products—cover glass. At the same time, the pursuit of thinner and lighter in the industry is also urging glass manufacturers to make changes to make thinner cover glass.

Currently, the thinnest glass of gorilla can be made 0.4mm, and the Asahi Glass can make 0.2mm glass. In general, people’s expectations for cover glass are nothing more than two:

1. Reduce the space occupied by the glass.

2. Make the glass cover a certain flexibility.

Mobile phone cover glass thinning process

There are not many processes for glass cover thinning: pre-cleaning—etching and thinning—–secondary cleaning——-grinding (single or double sided)—–post-cleaning—–check the package

Pre-cleaning: Remove the stain on the surface of the glass cover. It is one of the key steps affecting the effect of thinning.

Etching and thinning: using acid and alkali to etch the glass cover achieve the purpose of thinning. The conditions and parameters (time, potash ratio, temperature, etc.) vary from manufacturer to manufacturer, which is the technical secret of the manufacturer.

Secondary cleaning: Clean the residue of the glass cover.

Grinding: To obtain a bright, flat surface. It is one of the key processes for appearance assurance and thickness tolerance control.

Post-cleaning: Clean the remaining grinding powder.

Check the packaging: The standard for the appearance of the glass is different depending on the requirements of the customer.

Mobile phone cover glass thinning treatment

1, multiple pieces of upright soak

2, waterfall flow processing

3, single piece vertical spray

Cover glass coating process

At present, vacuum magnetron sputtering coating technology is a widely used thin film deposition technology. The continuous development of sputtering technology and the exploration of new functional films have enabled the application of magnetron sputtering coating technology to be extended to many productions and scientific research fields.

magnetron sputtering system — magnetron-sputtering-system

magnetron sputtering coating applications

In the field of microelectronics, as a non-thermal coating technology, magnetron sputtering coating technology is mainly applied to materials that are not suitable for chemical vapor deposition or metal organic chemical vapor deposition. Moreover, using magnetron sputtering can obtain a large-area uniform film.

Magnetron sputtering technology is also used in optical films such as antireflection glass, low emissivity glass and transparent conductive glass. In the production of transparent conductive glass, the ITO conductive glass prepared by sputtering has an average transmittance of 90% or more in the visible light range.

In the modern machining industry, the use of magnetron sputtering technology to produce surface functional films, super hard films and self-lubricating films can effectively improve surface hardness, composite toughness, wear resistance and high temperature resistance and chemical stability, thus improve the service life of coated products.

In addition, magnetron sputtering coating technology also plays an important role in the research of high temperature superconducting thin films, ferroelectric thin films, giant magnetoresistive thin films, thin film luminescent materials, solar cells, and memory alloy thin films.

Magnetron sputtering coating advantages

Magnetron sputtering coating technology has become one of the main technologies of the industrial coating due to its remarkable advantages:

(1) Simple operation and easy control. In the coating process, if the sputtering conditions such as working pressure and electric power are relatively stable, the deposition rate is relatively stable.

(2) The deposition rate is high. When depositing most of the metal, especially the high melting point metal and oxide, such as tungsten, aluminum TiO2 and ZrO2 film, it has a high deposition rate.

(3) Low temperature of the substrate. Compared to two-pole sputtering or thermal evaporation, magnetron sputtering reduces the heating of the substrate, which is quite advantageous for achieving the sputter coating of the fabric.

(4) The sputtered film is strong. The sputtered film has excellent adhesion to the substrate and its mechanical strength is also improved.

(5) The sputtered film is dense and uniform. From the photomicrograph, the surface morphology of the sputtered film is fine and uniform.

(6)The sputtered films all have excellent properties. For example, sputtered metal films generally achieve good optical properties, electrical properties, and certain special properties.

(7) Easy to mass produce. The magnetron source can be expanded as required, so large-area coatings are achievable. In addition, sputtering can work continuously, and the coating process is easy to control automatically, so that the industrial assembly line can be realized.

(8) Environmentally friendly. Conventional wet plating produces waste liquid, waste residue, and exhaust gas, causing serious pollution to the environment. The magnetron sputtering coating method has high production efficiency while does not cause environmental pollution.

Please visit https://www.sputtertargets.net/ for more information.

How to make the phone case of gradient color like Huawei P20?

Gradient color is popular in 2018

It’s overwhelming how many smartphone models are currently available on the market today. However, as for the color of the phone, what get are the same old black, white, silver and gray, in glossy or matte.

Well, recently an exciting new trend has emerged. The Huawei P20 series let people see the optimal color design and professional photography. A few months ago, Huawei launched the P20 in Twilight, and the dual-tone gradient inspired by the Aurora Borealis made people feel excited.

Before that, HTC also introduced the two-tone gradient scheme. Although it does not offer the popular Twilight color scheme, it does bring us a few appealing options with its latest flagship device.

Samsung has also jumped on board the gradient crazy. The Korean tech giant has unveiled a new version of its Galaxy A9 Star in China which features a sleek purple gradient.

Well, these are just a few examples to show that gradient color is the fashion of the year 2018. Are you curious about how to achieve this kind of gradient color? Is it difficult?

Film coating-Physical vapor deposition

Actually, all the color of the shell is about film coating. A cellphone is made from a variety of metals, with the most common being aluminum alloys, lightweight materials commonly found in the phone case. And the film coating is to apply a colored film on the phone case.

Physical vapor deposition is the most widely used film coating technology. Under vacuum conditions, the surface of the material (usually referred to as the sputtering targets or evaporating pellets) is vaporized into gaseous atoms by physical methods, and is then deposited on the surface of the substrate to form a thin film. The main methods of physical vapor deposition include vacuum evaporation, sputtering coating, plasma coating, ion plating, and molecular beam epitaxy.

How to coat the gradient color

PVD can coat gold, brass, rose gold, silver white, black, smoky, copper, brown, purple, blue, burgundy, bronze and other colors on stainless steel, copper, zinc alloy and other metals. There are many choices and the price is affordable, compared to pure gold or other pure metals. (PVD Coating Materials.pdf) You can refer to our previous article for more information: Introduction to PVD Coatings.

By controlling the parameters of different targets and thickness of the deposited film, the film exhibits different colors (the gradation colors mentioned above) under the reflection, refraction and interference of light. Specifically, in the plating furnace space, bombard a specific sputtering target with ultra-high speed electrons; use a certain mask to cover a part of the ion cloud so that only the other part of the ion cloud can be attached to the substrate and forms a very thin layer of nano-plating; control the thickness of the coating to form a nanometer thickness difference; then spray the background color.

For more information, please visit https://www.sputtertargets.net/.

Introduction to PVD Coatings

What is PVD coating technology

PVD, or physical vapor deposition, is an advanced surface treatment technology widely used in the world. Under a vacuum condition, utilize the gas discharge to separate the gas or the evaporated substance, then accelerate the gas ion or the evaporated atoms to bombard the substrate and deposit a film. PVD film has fast deposition speed as well as strong adhesion, good diffraction, and wide application range.

PVD coating colors

PVD Coating Materials and Their Characteristics

Applications

PVD technology is widely used in the processing of door and window hardware, lamps, jewelry, handicrafts, and other decorative products.

PVD is now quite popular in the hardware field, and many of the world’s leading hardware manufacturers have begun to develop PVD products and mass production.

PVD for molds and precision parts

In recent years, PVD coating technology has been applied more and more in the work surface strengthening treatment of molds. Its outstanding advantages are that it can effectively improve the service life of the mold, and at the same time reduce the coating temperature to about 250 °C ~ 500 °C, which can reduce the deformation of the workpiece. The PVD composite coating has excellent performance and has potential applications that cannot be underestimated. One of the main applications of PVD technology in the mold industry is TiN coating.

PVD & CVD

There are currently two coating methods commonly used in production: physical vapor deposition (PVD) and chemical vapor deposition (CVD). The former has a deposition temperature of 500 ° C and a coating thickness of 2 to 5 μm; the latter has a deposition temperature of 900 ° C to 1100 ° C, a coating thickness of 5 to 10 μm, and the device is simple and the film is uniform.

Previously, most cemented carbides are coated by CVD. However, since the deposition temperature is high, the cemented carbide coated by the CVD method, a brittle decarburization layer (η phase) is easily formed between the coating layer and the substrate, resulting in brittle fracture of the blade. In the past decade or so, with the advancement of coating technology, the cemented carbide can also adopt the PVD method.

Development of cemented carbide coatings

Coating refers to the application of a thin layer of wear-resistant, refractory metal or non-metallic compound on the substrate of cemented carbide or high-speed steel by vacuum evaporation and sputtering.

A good coating material is required to have high hardness, good wear resistance, stable chemical properties, no chemical reaction with the workpiece material, heat and oxidation resistance, low friction factor, and strong adhesion to the substrate. However, a single coating material is difficult to meet the above requirements. Therefore, the development of cemented carbide coating materials has entered a new stage of thick film, composite film and multi-component coating.

The most mature and widely used cemented carbide coating material is TiN, but the bonding strength of TiN and the substrate is less than that of TiC. TiC coatings have high hardness and wear resistance, and good oxidation resistance, but they are brittle and not resistant to impact. Both of these kinds of coatings have advantages and disadvantages, and TiCN combines their merits.

Combine 1)the newly developed multi-component, ultra-thin TiCN, TiAlN coating, 2)TiC, TiN, Al2O3 coatings, and 3)a new anti-plastic deformation matrix can significantly improve the toughness, bond strength of the coating to the substrate, and wear resistance of the coating. At present, the technology of coating diamond film on the cemented carbide substrate is successfully realized, and the performance of the tool is comprehensively improved.

TiAlN, CrN, and TiAlCrN are also new materials for cemented carbide coatings developed in recent years. The chemical stability and oxidation resistance of TiAlN are good. Compared with TiN, the tool life can be improved by 3 to 4 times when processing high alloy steel, stainless steel, titanium alloy and nickel alloy with TiAlN.

CrN is a titanium-free coating with good chemical stability and no sticking. It is suitable for cutting titanium and titanium alloys, copper, aluminum and other soft materials.

TiAlCrN is a gradient structure coating, which not only has high toughness and hardness, but also has a small friction factor. It is suitable for milling cutters, hobs, taps and other tools, and its cutting performance is obviously better than TiN.

In addition to the above new coatings, there are some coatings with specific functions, such as MoS2, DLC lubricated coatings, which have a small friction factor (0.05) and are suitable for coating tools such as taps and drills to improve chip evacuation performance.

For more information, please visit https://www.sputtertargets.net/.

Year in Review: 2018 Top Posts Collection

Happy New Year in 2019! We are very happy with your company and encouragement that push us to insist on updating every week. On the occasion of the arrival of 2019, let us summarize the Top Posts in 2018 for you.

Metal History

“Metal History” is a popular column we have opened this year, aiming at introducing the discovery of different kinds of metals. Among them, the Top 3 posts in this column are as follows:

How was titanium discovered? | History of Titanium

Titanium is a metal element that is known as “space metal” because of its light weight, high strength and good corrosion resistance. The most common compound of titanium is titanium dioxide, and other compounds include titanium tetrachloride and titanium trichloride. Click the title of the article to know more.

Discovery and development of tungsten | History of Tungsten

The history of tungsten dates back to the 17th century. At that time, miners in the Erzgebirge Mountains of Saxony, Germany, noticed that some of the ore would interfere with the reduction of cassiterite and produce slag. The miners gave the mines some German nicknames: “wolfert” and “wolfrahm”. Click the title of the article to know more.

How was cerium discovered? | History of Cerium

Cerium is the most abundant rare earth elements. It is a silvery gray active metal, whose powder is easily oxidized in the air and soluble in acid. Cerium has been widely used in the automotive industry as a catalyst to reduce emission, and in glass industry as glass polishing materials. Cerium sputtering target is an important material in optical coating. Click the title of the article to know more. Click the title of the article to know more.

Metal Materials Application

Apart from history, we also introduce the multiple applications of these metal materials. Among them, the Top 3 posts in this column are as follows:

Molybdenum Target Mammography Detection

At present, molybdenum target mammography is considered the recommended breast screening examinations for women’s breast cancer, one of the major causes of deaths among women, affects about 12% of women around the world. Click the title of the article to know more.

Application of titanium and titanium alloys in medical field

Titanium is an ideal medical metal material and can be used as an implant for the human body. Titanium alloy has been widely used in the medical field and has become the material of choice for medical products. Click the title of the article to know more.

A short analysis of sputtering targets for semiconductor application

Semiconductors have high requirements for the quality and purity of the sputtering materials, which explains why the price of anelva targets is relatively high. Click the title of the article to know more.

Sputtering Targets

Sputtering Target is the consistent keyword of our website, and thus we have shared many useful information about some specific type of sputtering targets. Our intention is to help you better understand these materials—their properties, applications, developing prospect and so on. And the followings are the posts you really have to read. Among them, the Top 3 posts in this column are as follows:

PVD vs. CVD: What’s the difference?

In recent years, physical vapor deposition (PVD) and chemical vapor deposition (PVD) have wide applications in various industries to increase the hardness of tools and molds or apply beautiful colors to the products. Thus these two methods are considered as the most attractive surface coating technologies. Click the title of the article to know more.

What is the Indium Bonding for Sputtering Target?

The term “indium bonding” in thin film coating industry, simply speaking, refers to bond two (or more) sputtering targets with indium (In), or one (or more) with indium plate together. Click the title of the article to know more.

What is Target Poisoning in Sputtering Deposition?

At some stage in the sputtering deposition, positive ions are continuously amassed on the surface of the sputtering target. Due to the fact that those fantastic ions aren’t neutralized, the negative bias of the target surface gradually decreases, and progressively the normal operation can not be completed. This is the target poisoning phenomenon. Click the title of the article to know more.

Glad you are part of SAM’s 2018. Next year, please continue following us and we promise to give you more valuable information! Also, you can visit our official website https://www.sputtertargets.net/ for more information.

How was Silicon discovered? | History of Silicon

Silicon

Discovery of Silicon

In 1787, the French chemist Antoine-Laurent de Lavoisier first discovered the silicon present in rocks. In 1800, silicon was mistaken by Sir Humphry Davy as a compound. In 1811, French chemists Joseph Louis Gay-Lussac and Louis Jacques Thénard probably prepared impure amorphous Silicon by heating potassium with silicon tetrafluoride. They later named it silicon according to the Latin silex (meteorite).

Until 1823, silicon was first discovered in the form of a metal element by the Swedish chemist Jöns Jacob Berzelius. One year later, he extracted amorphous silicon in much the same way as Gay-Lussac, and then purified the elemental silicon by repeated cleaning; in the same year, he heated the silicon oxide powder and the mixture of iron and carbon at a high temperature and obtain the iron silicide.

In order to extract pure silicon, Berzelius dry-fired the silicon-fluorine-calcium compound, hydrolyzed the obtained solid, and manage to obtain the pure silicon. In 1824, in Stockholm, Berzelius obtained relatively pure silicon powder by heating potassium fluorosilicate and potassium. Therefore, it is agreed that the honor of discovering silicon belongs to Berzelius.

Properties of Silicon

Symbol:	Si
Atomic Number:	14
Atomic Weight:	28.09
Element Category:	metalloid
Color:	dark gray with a bluish tinge
Density:	2328.3 kg/m³
Hardness:	6.5
Proportion in Earth’s Crust:	25.7%
Other Names:	Silicium, Silicio

Application of Silicon

High-purity monocrystalline silicon is an important semiconductor material that can be used as a solar cell to convert radiant energy into electrical energy, which is a promising material in the development of energy.

Silicon can also be made into cermet composites, which are resistant to high temperatures, toughness, and can be cut. They not only inherit the respective advantages of metals and ceramics, but also make up for the inherent defects of both, and can be applied to weapons manufacturing and aerospace.

Pure silica can be used to draw high transparency glass fiber for optical fiber communication, which is the latest modern communication means.

Please visit https://www.sputtertargets.net/ for more information.

A Summary of the Titanium Alloy Properties

SAM®Titanium is a new type of metal. Its properties are related to the content of other impurities, such as carbon, nitrogen, hydrogen and oxygen. The purest titanium iodide has an impurity content of less than 0.1%, but it has low strength and high plasticity.

The general properties of 99.5% industrial pure titanium are as follow：

Stanford Advanced Materials
density ρ	4.5g/cm3
melting point	1725°C
thermal conductivity λ	15.24W/(mK)
tensile strength σb	539MPa
elongation δ	25%
section shrinkage ratio ψ	25%
elastic modulus E	1.078×105 MPa
hardness HB	195

(1) High specific strength

The density of titanium alloy is generally about 4.5g/cm3 (only 60% of steel), but the strength of pure titanium is close to that of normal steel. And some high-strength titanium alloys have higher strength than many alloy structural steels. Therefore, the specific strength (strength/density) of titanium alloy is much larger than that of other metal structural materials. It can be used to produce parts and components with high unit strength, good rigidity and lightweight. At present, titanium alloys are used for aircraft engine components, skeletons, skins, fasteners and landing gear.

(2) High-temperature strength

Titanium alloys can be used in higher temperature environments than aluminum alloys. Titanium alloys can retain the required strength and maintain long-term operation at the temperatures between 450 and 500 °C. While the specific strength of the aluminum alloy is significantly reduced when the temperature reaches 150 ° C.

(3) Good corrosion resistance

Titanium alloy can work in the moist atmosphere and seawater medium with good corrosion resistance, which is much better than stainless steel. It is especially resistant to pitting, acid etching and stress corrosion. In addition, titanium also has excellent corrosion resistance to alkali, chloride, chlorine organic substances, nitric acid, sulfuric acid, and the like. The fly in the ointment is that titanium has poor corrosion resistance to reducing oxygen and chromium salt media. For more information about the corrosion resistance of titanium, please read this passage Does titanium never corrode?

(4) Good low-temperature performance

Titanium alloys retain their mechanical properties at low and ultra-low temperatures. Titanium alloys with good low-temperature properties and extremely low interstitial elements. For instance, TA7 can retain a certain degree of plasticity at -253 °C. Therefore, the titanium alloy is also an important low-temperature structural material.

Please visit https://www.sputtertargets.net/ for more information.

Copper Sulfide Sputtering Targets Are The Best Sputtering Materials

Sputtering is a thin film deposition process in the modern technology world of CDs, semiconductors, disk drives and optical devices industries. Sputtering is the process at an atomic level, where the atoms are automatically sputtered out from the sputtering materials and then be deposited on another substrate, such as a solar panel, semiconductor wafer or optical device. It is an effect of the severe bombard of the high energy particles on the target.

In general, sputtering occurs only when kinetic energy is said to be bombarding particles at very high speeds, which is much higher than a normal thermal energy. At the atomic level, this makes thin film deposition more precise and accurate than that by melting the source material using conventional thermal energy.

Copper Sulfide is the best material for Sputtering Targets. It can be molded into the shape of Plates, Discs, Step Targets, Column Targets and Custom-made. Copper Sulfide is a combination of two materials—Copper and Sulphur. The chemical name of the product is CuS, which offers you the Copper Sulfide product with more than 99 percent purity.

Cyprus is the original source material for the chemical element Copper. The people of Middle East initially discovered it in 9000 BC. “Cu” is the canonical chemical symbol of copper.

Whereas Sulfur, otherwise known as sulphur, is first introduced in 2000 BC and discovered by Chinese and Indians. It is a chemical name originated from the Sanskrit word ‘sulvere’, and the Latin ‘sulfurium’. Both names are for sulfur.

Copper Sulfide metal discs and plates are highly adhesive and resistant against oxidation and corrosion. Using Copper Sulfide sputtering targets to deposit thin films will not produce highly reflective and extremely conductive films, but can also extensively increase the efficiency of the source energy.

So to achieve the desired noticeable result in a sputtering deposition, the built-up process used to fabricate the Sputtering Targets should be critical. A Copper Sulfide targeted material will give the best result. However, material like only an element, alloys, mixture of elements, or perhaps a compound can be used for the purposes.

For more information about sputtering targets, please visit http://www.sputtertargets.net/.

How to Prevent the Damage of ITO Exposure?

What is indium tin oxide

Indium Tin Oxide, or ITO, is a composition of indium, tin, and oxygen with different proportions. ITO is mainly used in the production of liquid crystal displays (LEDs), flat panel displays, plasma displays, touch displays, electronic paper applications, organic light-emitting diodes, and solar cells, and antistatic coatings as well as EMI shielding transparent conductive coating. The indium tin oxide film is typically deposited onto the surface physical vapor deposition, such as vacuum sputtering, or electron beam evaporation. Other uses for indium include: indium bonding, vehicle and aircraft bearings, cryogenic alloys and solders, and nuclear reactor control rods.

ITO dust hazard

In the ITO sputtering target manufacturing factory, although the surface grinding and cutting operations are carried out in a closed wet system, droplets and waste water containing indium tin oxide sprayed around the machine are evaporated to dryness, causing the indium tin oxide dust to be suspended in the air. And the inhalation of ITO dust by the human body can cause lung disease.

Protection and precautions

Smash, grind, cut and sputter targets and backplate bonding areas shall have adequate and appropriate exhaust equipment.
During work, workers are advised to wear appropriate dust masks to avoid inhalation of indium, indium tin oxide and indium compound particles and fumes.

Use appropriate eye and hand protection to prevent dust particles from splashing or touching.
Work clothes or dust-proof clothes should be used during work. Before going home, you should change clothes to avoid taking dust home, work clothes or dust-proof clothes in the factory.
Do not place drinking water and food at the work site to avoid contamination and avoid eating, and avoid eating or resting in the workplace.

The above points are strictly enforced at SAM’s factories, and we have never reported incidents of cancer caused by inhalation of harmful dust.

SAM is the world’s leading sputtering target manufacturer and we provide high-quality products and satisfying service. Please visit https://www.sputtertargets.net/ for more information.

What is the Indium Bonding for Sputtering Target?

The term “indium bonding” in the thin film coating industry, simply speaking, refers to bonding two (or more) sputtering targets with indium (In), or one (or more) indium plates together.

Indium

Indium can be uniquely used in lower temperature solders, is one of the softest materials. Indium is preferred for target bonding because of its excellent thermal conductivity of all available bonds. In addition, indium is the most efficient material at drawing heat away from the sputtering target. Most materials can be indium bonded and there are just a few exceptions.

Apart from indium bonding, indium is also popular for a variety of uses and purposes, such as creating alloys, photoconductors, and thermistors.

Indium bond

Sputtering targets can be cracked, warped, or damaged due to inadequate cooling, low hardness, or other reasons. From this point of view, although target bonding does generate a fee, it can well protect your target from damage. It is especially true for those less-strong target materials and precious metal materials.

Elastomer is an alternative bonding method that touts a higher temperature capability over the indium bond. Elastomer bonds are recommended when you are consistently melting indium bonds. We also recommend elastomer bonding for low melting point target materials, as well as, temperature-sensitive compounds and targets that have either low density or are especially fragile.

Indium bonding is preferred in applications where:

Cryogenic stability is needed

Sealing requires high levels of hermeticity

Maximum thermal transfer is required

Bonding to not-metallic surfaces

Flux cannot be used

Backing plates

OFHC Copper Backing Plate is another well-known backing plate. It is frequently used to bond ceramic targets because of its non-magnetism and low coefficient of thermal expansion. This metal has good electrical and thermal characteristics while also being easy to machine, easy to soften, and readily available at a low cost. Copper backing plates can be re-used, with care, 20 or more times.

A molybdenum plate is usually used to substitute copper plate if copper is not appropriate for the application. For instance, the coefficient of expansion for copper is mismatched with some ceramics. And for high-temperature bonding, copper may also oxidize badly or warp. In these conditions, molybdenum is a more suitable material.

SAM Sputter Target

If you are looking for an indium bonding manufacturer, SAM is undoubtedly your best choice. Stanford Advanced Materials is devoted to machining standard backing plates and working together with the Taiwan Bonding Company for providing bonding services. For questions about target bonding materials, methods, and services, please see our listing of frequently asked questions (FAQs).

Related blog: When do you need target bonding?

Deposition of silver on glass by e-beam evaporation

The case

I am attempting to use silver evaporation pellets to deposit one-micrometer thick silver layer on the glass substrate. I found that only electron beam evaporation is accessible within the facility. I tried Ag/Ti/glass but silver peels off the Titanium layer. Up to now, only Ag/Au/Ti/glass can partially work, and only 1/2 of my samples were fully coated with silver; the other half turned into blackish-rainbow color. I wonder what is wrong in the process? Should I should some intermediate layers?

Possible Cause and Solution

The thickness of the Titanium (Ti) layer may be too large. Generally speaking, 5 to 10 nm is enough in this case.

The process is not operated in a good vacuum condition, thus the titanium layer is oxidized. In electron beam evaporation, as well as other vacuum evaporation, the vacuum degree of the evaporator is extremely important, which will greatly influence the quality of the film obtained. Thus, please make sure the vacuum chamber is well sealed before evaporating.

It is hard to avoid that the evaporated silver (as well as gold) only loosely connected to the glass substrate. Cleaning the glass with acetone and then methanol could help. Or you can just replace the glass substrate by using another transparent substrate, such as Al2O3, SiO2, AlN and Diamond. The silver layer can better deposit on those substrates mentioned above.

Other Suggestions

Titanium is an excellent adhesion layer, but it is also true that it may lose some of its adhesiveness if the vacuum is not good enough. As for its alternatives, Chromium (Cr) and Aluminum (Al) are recommended to act as the adhesion promoter.

Rising the temperature up to 100℃ in the vacuum for a few minutes may also improve the adhesion of metals.

For the explanation of the terminologies of vacuum coating mentioned in this passage, please refer to Terminologies of Vacuum Evaporation.

For high purity silver evaporation materials, please visit Stanford Advanced Materials.

For more news and knowledge about vacuum coating, please see SAM News.

April 2024
M	T	W	T	F	S	S
« Mar
1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28
29	30