Huawei P30 Series Sky Gradient Technology Revealed

- Apr 28, 2019-

Huawei P30 series "sky" gradient technology revealed


As a high-end fashion flagship under the brand of huawei, P series has been devoting great efforts to ID design, and has verified the unique fashion sense of P series again and again.


Huawei P30 series follows the gradual structural color design of P20 series, and challenges the brand-new expression of structural gradient color again.


Among them, the successful development of the hot "sky state" pioneered the vacuum optical sputtering process and the latest inkjet micron inkjet printing process, two key technologies.


I. technological process of 3D glass


As indicated above, the three processes involved in the key process of gradient are as follows:


II. OC0 technology was applied for the first time, and the strength of cover plate was increased by more than 30%

Why spray a layer of silicone before coating?

Because the coating process is single-sided cavity coating, the film is shown as the surface tension, before the white glass reinforced by the balance of compressive stress is destroyed, the other two sides of the glass force is not balanced, this will lead to four bar bending and ball impact test strength sharply decreased. The figure below shows the force analysis diagram.
The role of the coating: enhance the strength of glass, offset the coating produced by the internal stress, enhance the strength of glass cover.

What are the technical difficulties of the silicone coating?

The difficulty of the silicone coating is that the film thickness should be strictly controlled within 1-2um, transparent and invisible, smooth and bright, no rainbow on the light reflection.

In order to solve this problem, the glass manufacturer, after nearly three months of technical breakthrough, adopted the self-developed OC0 technology to increase the strength of the cover glass by more than 30%, making the front and rear glass cover of P30 series mobile phones more lasting. This is the first application of OC0 technology in domestic mobile phones, as well as the first application of OC0 technology in 3D glass, which has pioneered the industry.


Diagram of force analysis of coated glass

III. Principle and process of gradient coating

1. Coating principle:

Physical Vapor Deposition (PVD) technology represents the process of vaporizing a solid or liquid surface into a gaseous atom, molecule or part of an ion and depositing a film with a special function on the substrate surface by a low-pressure gas (or plasma) process under a vacuum condition using a Physical method.

The main methods of physical vapor deposition are vacuum evaporation, sputtering, plasma and ion deposition. The following is a comparison of advantages and disadvantages of several coating methods, it can be concluded that the sputtering coating is better than other coating methods.


Figure PVD coating mode contrast

The aurora process of huawei P30 series is realized by sputtering coating, but the process and target material have been innovatively improved. In the plating furnace space, special target materials are bombarded with super-high speed electrons, and some ion clouds are covered by a certain kind of cover, only the other part of ion clouds are attached to the glass surface, forming a very thin nano coating. By controlling the thickness of the coating, forming nanometer thickness difference, and then spray on the background color, the aurora color is full of mystery


Figure magnetron sputtering coating principle

2. technological process

Pretreatment of plating furnace loading vacuuming target and ion cleaning coating cooling out post-treatment

When making the gradient coating, a baffle (MASK) will be added between the target and the workpiece. The thickness of the film deposited in the corresponding position of the large area of the MASK will be less, while that in the small area of the MASK will be more. The following figure


A MASK was added between the target and the workpiece

The film forming Angle of a, b and c is Angle a >, b > and c. The distance between the film forming area and the evaporation source da<db<dc finally leads to the significant difference in the thickness of a, b and c. The thickness of the film forming area of the three points is different. The following figure


Due to different distances and thicknesses of film forming areas, different colors (gradient) appear in the figure.

IKS PVD,rainbow PVD coating,


IV. Inkjet micron inkjet printing process:

White after coating the lumenal through spraying color ink-jet printing process, the process principle and there are differences between the conventional spraying process, the main difference is that the number of spray gun, micron grade ink-jet printing has W on the number of spray gun, by adjusting the air pressure gun, thin thick ink, ink evaporation into small particles, uniform coating lumenal surface again. It is two besmear commonly two bake, bake time is 45 minutes commonly, bake temperature is 160-180 degrees.


Painting process flow

V. Summary

From the process point of view, due to the color span, sky sky coating film thickness compared to last year's aurora color has a significant increase, it was difficult to achieve mass production. Glass manufacturers through the research for more than three months of by magnetron sputtering deposition, adjusting process parameters at different target in different section, change the thickness of the coating and layers, and the variety of the light reflected by customizing texture bright light, to create a new generation of coating color structure, combined with the pioneering inkjet micron grade ink-jet printing technology, presents a sky of such natural and unique aesthetic feeling.