In this era when user experience is highly valued, more and more manufacturers of mobile phones, notebooks, and wearable devices are beginning to exert efforts on shell materials. From the mobile phone field alone, the material of mobile phone shells is gradually transitioning from engineering plastics to metal.
During the evolution of mobile phone shell materials, there have been many combinations: plastic and metal, glass and metal, all plastic, all glass, etc., but in the end none of them overwhelmed the limelight of all metal materials.
From the actual touch experience, the all-metal mobile phone does have an outstanding experience in many aspects, and it is better than other materials in terms of appearance and feel.
When mentioning all metal, CNC must be mentioned. At present, all metal shells of 3C products are basically processed by CNC machine tools (Computer numerical control machine tools, CNC). CNC has become an indispensable equipment for 3C shell manufacturers due to its high efficiency, high precision, and stable processing quality.
The working principle of CNC machine tools, in simple terms, is to use drawing software such as UG to build a 3D model, and then use programming software to write procedures based on the 3D model, and finally import these 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.
Pre-order work for CNC machining:
Modeling and programming
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 processing 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.
The main CNC process required to manufacture all-metal mobile phone casings
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.
Rough milling: After positioning, rough milling out of the inner cavity structure, the positioning column combined with the fixture, and milling out most of the external redundant materials.
Antenna slot milling: The signal problem of the all-metal housing is very difficult. It is necessary 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 body.
CNC finishing: finishing milling of inner cavity, outer structure, outer surface, side edge, etc.
Polishing: Use high-speed precision CNC machine tools for polishing to eliminate knife marks and prepare for subsequent sandblasting.
Sandblasting: processing the metal surface into a frosted effect.
Primary anode: color the mobile phone, and anodize the aluminum to gold. At the same time 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 process, 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. It is difficult to achieve the high yield rate of the plastic shell. In order to balance the high cost, most manufacturers will choose to purchase when facing price wars. A large number of CNC equipment to reduce the overall cost and meet the requirements of productivity.