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.

Huawei P20
Huawei P20

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.

HTC U11
HTC U11

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.

Galaxy A9 Star2
Galaxy A9 Star2

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 Physical Vapor Deposition Technologies

Thin Film Deposition

Thin film deposition technology refers to the preparation of thin films on the surface of materials used in the fields of machinery, electronics, semiconductors, optics, aviation, transportation and etc., in order to impart certain properties (such as heat resistance, wear resistance, corrosion resistance, decoration, etc.) to these materials.

The two most common forms of thin film deposition techniques are physical vapor deposition (PVD) and chemical vapor deposition (PVD).

Physical Vapor Deposition —PVD

PVD is a process that achieves the transformation of the atoms from the source materials to the substrate to deposit a film by physical mechanisms such as thermal evaporation or sputtering.

PVD includes evaporation, sputtering and ion plating.

Evaporation

Evaporation is a common method of thin-film deposition. It is also called vacuum evaporation because the source material is evaporated in a vacuum. The vacuum allows the vapored particles to travel directly to the substrate, where they condense and deposit to form a thin film.

Evaporation (PVD)
Evaporation (PVD)

Sputtering

Sputtering is a physical vapor deposition (PVD) method of thin film deposition. It is a process whereby particles are ejected from a solid target material (sputtering target) due to the bombardment of the target by energetic particles.

Sputtering (PVD)
Sputtering (PVD)

Ion Plating

Ion plating is a physical vapor deposition (PVD) process which uses a concurrent or periodic bombardment of the substrate, and deposits film by atomic-sized energetic particles.

Ion Plating (PVD)
Ion Plating (PVD)

Characteristics of the main physical vapor deposition method

SAM Sputter Target Evaporation Sputtering Ion Plating
Particle energy eV 0.1-1 1-10 0.1-1
Deposition Rate um/min 0.1-70 0.01-50 0.1-50
Adhesion Poor Good Very Good
Density Low High Very High

Among the above three methods, although Ion plating’s film adhesion and density are better, due to technical limitations, the other two methods (evaporation and sputtering) are currently more widely used. In general, sputtering is the best PVD technology.

Stanford Advanced Materials (SAM) is one of the most specialized sputtering targets manufacturers, please visit https://www.sputtertargets.net/ for more information.

PVD vs. CVD: What’s the difference?

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. Then, using the example of cutting tools, let’s make a detailed comparison between these two methods.

Definition

Physical vapor deposition (PVD) uses low-voltage, high-current arc discharge technology under vacuum conditions to evaporate the target and ionize the vaporized material and the gas, and finally make the evaporated material and its reaction deposited on the workpiece.

Continue reading “PVD vs. CVD: What’s the difference?”