The story behind the nova 2 magic mirror version: Huawei invented a new metal craft for it

Huawei nova 2Plus is a mobile phone for young people released in May. At the end of May, this mobile phone was chosen on the couch and invited the spokesperson Zhang Yixing. After more than two months, Huawei added a new color to the phone, which is a mirror-like version. It is officially called "Magic Mirror Edition".

Huawei is not the first manufacturer to make a mirror phone. Recently, Sony and Xiaomi have successively released similar products, but the polished metal back of nova 2Plus is not the same as their craft. Sina Digital recently visited Huawei's Beijing Research and Development Institute to learn the story behind the nova 2Plus mirror process.

1 Why do you have a mirror version?

The design of the nova 2Plus Mirror is inspired by a well-known sculpture “Cloud Gate” in Qianxi Park, Chicago. It is inspired by mercury and created this integrated metal full-mirror sculpture, compared to traditional sculpture. Very eye-catching and unforgettable.

"Cloud Gate" in Chicago

In Huawei's view, mobile phone products with the same metal structure are the best choice to express this inspiration.

According to Huawei's product positioning, nova users are concentrated between the ages of 18-29. At the press conference in May, the two phones announced five colors: black, gold, pink, blue and green. Huawei believes that young people's mobile phones should have a more cool color, so the mirror version is a good choice.

2 technical problems

It is not an easy process to move this mercury-like sculpture effect to a mobile phone.

Almost everyone likes the smooth texture of metal. However, in the daily consumer products of mobile phones, the actual problems such as wear resistance, scratch resistance and heat dissipation performance are faced.

Aluminum alloy processing is already a very mature process in the electronics industry, but aluminum alloy polishing can not achieve the mirror brightness, even if it can be achieved, it will be smooth because of the soft texture; metal harder stainless steel is a good choice, but It is also problematic and heavy.

Stainless steel polishing is not difficult (the iPod is typical). For the mobile phone, which is always in your hand, how to keep the stainless steel mirror texture and lighter body is a balance between technology and practicality.

3 Huawei's solution

First of all, the implementation of two similar effects of the mirror panel mobile phone in the industry:

Bright silver Sony XZP uses the technology of film film. Film film is a film formed by coating a plastic transparent film with an emulsion. A film film can be applied to the glass panel to make a mirror effect. The process of Xiaomi 6 is more difficult. The back is curved glass and film. The process is difficult to flatten, so it uses PVD plating, which attaches hundreds of millions of nano-sized indium metal particles to the glass surface in a vacuum environment, and then forms a unique mirror effect.

Wang Qiang of the Huawei Research Institute of Japan, as a representative, answered the way Huawei adopted: metal composite + CMP (chemical mechanical) polishing process.

Our common metal tubes are actually most composite process products.

In the industry, bimetallic composites are not a fresh process. The traditional bimetals are mainly composed of three types: cold rolled composite, hot rolled composite and explosive composite. Most of them combine between two metals by high pressure or high temperature. This metal compounding does not smelt or bond the two technologies together. Rather, it forms an effective bond by interdiffusion between metal atoms. However, this conventional process has obvious disadvantages, that is, in a high temperature and high pressure environment, a relatively strong internal stress of the material is generated. This can result in a significant deformation of a metal sheet during subsequent processing.

Huawei's Japanese R&D team has developed a new surface active process that uses sub-ions to soften the adhesion of metal surfaces, softening substances and other species in a vacuum environment, allowing the metal to recombine under normal temperature and low pressure conditions. A process with minimal internal stress.

From the parameter point of view, the traditional composite process requires 1.5 mm of raw materials to get the last 1 mm of composite material (can be simply understood as pressing two metal plates together), but the new process developed by Huawei's Japanese R&D team only needs 1.02. -1.05 mm is fine. This means that there is substantially no change in the two metal composites before and after, so that the internal stress can be made very small and can be carried out under normal temperature conditions.

Wang Qiang said: This process is developed by Huawei and is very leading technology.

4 Next polishing

After solving the metal compounding process, the next problem is polishing.

The traditional polishing process is not complicated, it is the physical removal of the uneven surface of the metal surface, or a brighter surface. However, for the requirement of "can be a mirror", physical polishing is not fine enough, so Huawei introduced CMP (Chemical Mechanical Polishing).

This polishing is a kind of mechanical polishing with the help of chemical corrosion. The Japanese team firstly formulated the polishing liquid to make it slightly chemically corrode the surface of the product during the grinding process. Then the corrosion progressed along with the work and mucous membranes. The high-speed relative motion between the consumables allows the corroded compound to be easily ground and then a new mucus solution to be ground, which is a dynamic cycle. The main point is to achieve a good balance between chemical corrosion and mechanical grinding.

The blending of the slurry, the grinding speed, the angle, and the balance of all these factors is a long and long process. After the surface polishing, the gloss of the product can be increased by 100 times, and finally the mirror effect is achieved.

The final nova 2Plus mirror version brightness to 1300Lux

The second step after that is to add a coating to the product to further enhance the hardness and scratch resistance of the nova 2Plus mirror. Huawei conducted a scratch-resistant test. The process is similar to that of a steel ball used in a household: use a thinner steel ball, plus a 1 kg load, to move on the surface of the product and record whether there are obvious scratches. From the test results, the scratch resistance of the mirror version is better than PVD (vacuum coating).

5 results of 100,000 pieces of raw materials

Throughout the process, Huawei's Japanese R&D team invested 100,000 raw materials before and after, and experienced 127 processing steps before gradually moving to mass production.

When Wang Qiang told us about this process, what was placed in front of him was the change process of 10 pieces of metal prototype materials, which were the result of 100,000 pieces of raw materials.

10 pieces of representative

The development process of the entire project of the Mirror Edition, from materials and processing technology, Huawei has faced many new challenges. In the end, Huawei used the Mirror version of the technology on the nova 2 mobile phone instead of the higher end product.

According to Huawei's statement, in addition to the combination of time and technology maturity, they hope that the mirror version can represent the young and fashionable nova brand, and use it to express Huawei's courage to innovate and be independent.