In this era where user experience is highly valued, more and more mobile phone, notebook, and wearable device manufacturers have begun to make efforts on the material of the casing. From the perspective of mobile phones alone, the material of mobile phone casings is gradually transitioning from engineering plastics to metals.
During the evolution of the material of the mobile phone shell, there have been many combinations: plastic and metal, glass and metal, all plastic, all glass, etc., but none of them have covered the limelight of all metal materials. From the actual touch experience, all-metal mobile phones do have an outstanding experience in many aspects, and they are better than other materials in terms of appearance and feel.
All manufacturers launch all-metal enclosure products
When it comes to full metal, CNC must be mentioned. At present, all metal shells of 3C products are basically processed by CNC numerical control machine tools (CNC). Due to its advantages of high efficiency, high precision, and stable processing quality, CNC has become an essential equipment for 3C shell manufacturers.
The all-metal integrated CNC machining process was first pioneered by Apple Inc.-the aluminum plate was die-cast from columnar solid aluminum, and was cut into a prototype of an integrated body after precision machining. As the body gradually formed, the shape of the keyboard on the body And various fine structures are milled. This process includes a total of nine CNC milling processes. After nine processes, a precision one-piece shell is obtained.
From programming to obtaining finished products, shell manufacturers need to go through multiple processes such as rough machining, semi-rough machining, semi-finishing, and finishing. Many times the whole process requires more than 10 stations to obtain finished products. To improve the yield, each process All need to be strictly controlled.
Meizu MX5 goes through 12 steps from right to left to get the finished product
A CNC machining preamble: modeling and programming
Before CNC machining starts, the first step is to model and program. The difficulty of 3D modeling is determined by the product structure. Modeling a product with a complex structure is difficult, and there are more and more complicated programming procedures. The programming includes the setting of the machining process, the selection of the tool, the setting of the rotation speed, the distance of each tool feed and so on. In addition, different products have different clamping methods, and fixtures must be designed before processing. Some products with complex structures require special fixtures.
The programming includes the entire product processing technology. Although the follow-up is done automatically by CNC, the early programming must be practiced by experienced personnel to avoid multiple trial and error and increase costs.
Two main processing technologies
The following video shows the main CNC machining processes required to make an all-metal phone case ↓↓
The high-speed drilling and tapping center is used to accurately mill the aluminum plate into a regular three-dimensional volume with a certain size, and prepare for the next process.
Rough milling: After positioning, the inner cavity structure, the positioning column combined with the fixture, and most of the redundant material outside are milled.
Milling the antenna slot: The signal problem of the all-metal casing is very difficult. You need to mill the antenna slot to leave a transmission path for the signal, and maintain the necessary connection points to ensure the strength and overall sense of the fuselage.
CNC finishing: precision milling of internal cavity, external structure, external surface, side, etc.
Polishing: High-speed precision CNC machine tools are used for polishing to eliminate knife marks and prepare for subsequent sandblasting.
Sandblasting: The metal surface is processed into a matte effect.
Anodizing:
Primary anode: coloring the phone, anodizing turns aluminum into gold. While improving the stability of the surface material
Secondary anode: A solid and dense oxide film is formed on the surface of the fuselage, which further enhances wear resistance.
The plastic shell is molded using an injection molding process, which can be mass-produced just by opening the mold, with a high yield. The CNC machining yield of the all-metal body is determined by the structural complexity and accuracy requirements of the casing. It is difficult to achieve the high yield of the plastic casing. In order to balance the high cost, most manufacturing companies will choose to purchase in the face of a price war. A large number of CNC equipment to reduce overall costs and achieve productivity requirements.