At present, the full metal shell of 3C products is basically CNC processed. The full metal integrated CNC processing technology was first pioneered by Apple. The aluminum plate is die-cast from solid aluminum in a cylindrical shape. After precision processing, it is first cut into the prototype of an integrated fuselage. As the fuselage gradually takes shape, the keyboard shape and various subtle structures on the fuselage are milled out. This process includes a total of nine CNC milling processes, and after nine processes, a precise integrated molded shell is obtained.
From programming to obtaining finished products, shell manufacturers need to go through rough processing, semi-rough processing, semi-finishing, and finishing. In many cases, the whole process requires more than 10 processes to obtain the finished product. In order to improve the yield rate, each process needs to be strictly controlled.
1. Pre-processing work: modeling and programming
Before CNC processing begins, modeling and programming are required first. The difficulty of 3D modeling is determined by the product structure. Modeling of products with complex structures is more difficult, and the programming processes required are more and more complex. Programming includes the process setting, tool selection, speed setting, the distance of each tool feed, etc. In addition, different products have different clamping methods. Before processing, the fixture must be designed. Some products with complex structures require special fixtures.
2. Main processing technology
- Use a high-speed drilling and tapping center to accurately mill the aluminum sheet into a regular three-dimensional volume of a certain size, ready for the next process.
- Rough milling: After positioning, the inner cavity structure, the positioning column combined with the fixture, and most of the redundant materials on the outside are milled out.
- Milling antenna slots: The signal problem of the all-metal shell is very tricky. The antenna slot needs to be milled out to leave a transmission path for the signal, and the necessary connection points are maintained to ensure the strength and overall sense of the fuselage.
- CNC finishing: Fine milling of the inner cavity, external structure, outer surface, side, etc.
- Polishing: Use high-speed precision CNC machine tools for polishing to eliminate knife marks and prepare for subsequent sandblasting.
- Sandblasting: Treat the metal surface to a frosted effect.
- Anodic treatment: primary anodizing, coloring the phone, anodizing turns aluminum into gold and improves the stability of the surface material; secondary anodizing, a strong and dense oxide film is formed on the surface of the phone, further enhancing the wear resistance.
