CNC (Numerical Control Machine Tool) Processing Technology
All metal shells of 3C products are basically processed by computer numerical control machine tools (CNC). CNC has become a necessary equipment for 3C shell manufacturers due to its high efficiency, high precision, and stable processing quality.
1. The working principle of CNC machine tools
First use drawing software such as UG to build the 3D model, and then use the programming software to write the process according to the 3D model, and finally import the data into the machine tool, install the workpiece, and start it.
The all-metal integrated CNC machining process was first pioneered by Apple. The aluminum plate is die-casted from a columnar solid aluminum material. After precision machining, it is cut into the prototype of the integrated body. As the body gradually takes shape, the shape of the keyboard on the body And various fine structures are milled out.
This process includes a total of nine CNC milling processes. After nine processes, a precise one-piece shell is obtained.
Shell manufacturers need to go through multiple processes such as roughing, semi-roughing, semi-finishing, and finishing from programming to obtaining the finished product. In many cases, the whole process requires more than 10 stations to obtain the finished product. If you want to improve the yield rate, each process All need to be strictly controlled.
2. Pre-order work for CNC machining
Before CNC machining starts, modeling and programming are first required.
The difficulty of 3D modeling is determined by the product structure. Product modeling with complex structure is more difficult, and programming procedures are more and more complicated. The programming includes the working procedure setting, tool selection, speed setting, the distance of each feed of the tool and so on.
In addition, the clamping methods of different products are different, the fixtures must be designed before processing, and some products with complex structures require special fixtures.
Programming includes the processing technology of the entire product. Although the follow-up is completed automatically by CNC, the pre-programming must be operated by experienced personnel to avoid multiple trial and error and increase the cost.
1) DDG
Use the 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 CNC machining.
2) Rough milling
After positioning, the inner cavity structure, the positioning column combined with the fixture are rough milled, and most of the external redundant materials are milled.
3) Milling antenna slot
The signal problem of the all-metal casing is very difficult. It is necessary to mill out the antenna slot to leave a transmission path for the signal, and maintain the necessary connection points to ensure the strength and integrity of the body.
4) CNC finishing
Fine milling of internal cavity, external structure, external surface, side edges, etc.
5) Polishing
Use high-speed precision CNC machine tools for polishing to eliminate knife marks and prepare for subsequent sandblasting.
6) Sandblasting
Treat the metal surface to a frosted effect.
7) Anode treatment
Primary anode: color the mobile phone, anodize the aluminum to gold, and improve the stability of the surface material;
Secondary anode: A strong and dense oxide film is formed on the surface of the fuselage, and the wear resistance is further enhanced.
Plastic shell molding uses injection molding technology, and mass production can be achieved only by opening the mold, and the yield rate is very high. The CNC machining yield rate of the all-metal body is determined by the structural complexity and precision requirements of the shell, and it is difficult to achieve the high yield rate of the plastic shell.
