Contact Us

CNC Processing Technology of Metal Shell of Mobile Phone

Date: Aug 13 2021 | By:LC Rapid
Tag:CNC Machining,

In this era when user experience is highly valued, more and more manufacturers of mobile phones, laptop, 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.

In this article, we will introduce the processing process of the metal frame of the mobile phone. Overview: At present, the metal shell manufacturing process of 3C products can be roughly divided into three types. One is full CNC machining, another is die-casting, and finally the combination of CNC machining and die-casting.

At present, all metal shells of 3C products are basically processed by CNC machine tools. CNC has become an indispensable equipment for 3C shell manufacturers due to its high efficiency, high precision, and stable processing quality.

All-metal integrated CNC machining process: The aluminum plate is die-casted from columnar solid aluminum. After precision machining, it is cut into the prototype of the integrated body. As the body gradually takes shape, the shape of the keyboard and various fine structures on the body are milled. 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 obtain the finished product. In many cases, the whole process requires more than 10 processes to obtain the finished product. If you want to improve the yield rate, each process must be strictly controlled.


Ⅰ. CNC machining, die-casting molding process and combination of CNC and die-casting

1. CNC machining process

As the name implies, the complete CNC machining starts with a piece of aluminum alloy plate (or other metal material plate), and then it is directly processed into the required mobile phone back cover shape using a precision processing abs cnc machining, including various steps, grooves, and screw holes and other structures on inner frame.

2. Die-casting molding process

The process of full die-casting is very similar to the process of manufacturing plastic products. Both are processed by precision molds, but the material is made of molten metal instead of plastic.

3. Combination process of CNC and die-casting

The combination of CNC and die-casting process means die-casting first, and then CNC finishing.

Ⅱ. Pre-order work of 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 subsequent CNC processing is completed automatically, the pre-programming must be operated by experienced personnel to avoid multiple trial and error and increase the cost.

Ⅲ. The main CNC processing technology

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 process.

Rough milling: After positioning, roughly mill out of the inner cavity structure, and for the positioning column combined with the fixture, mill 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.

The precision CNC machining: Finishing milling of inner cavity, outer structure, outer surface, side edge, etc.

Polishing: Use high-speed precision CNC machining tools for polishing to eliminate knife marks and prepare for subsequent sandblasting.

Sandblasting: The metal surface is processed into a frosted effect.


1. Primary anode: color the mobile phone, and anodize the aluminum to gold. At the same time improve the stability of the surface material.

2. 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 cnc production service can be achieved only by opening the mold, with a high yield rate. 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, when facing price wars, most manufacturers will choose to purchase a large number of CNC processing equipment to reduce the overall cost and meet the requirements of productivity.

LC RAPID was established in 2008 and has grown rapidly driven by our manufacturing expertise and unremitting commitment to help customers meet their project engineering needs. We also help customers manufacture parts and products in on-demand manufacturing.

LC RAPID's project engineering team is always responsible for ensuring that parts are completed on time and correctly. We make it easier for our customers, from start-ups to Fortune 100 companies, to manufacture on-demand by providing the most effective way to purchase high-quality customized parts and products. We are committed to providing our customers with an innovative way to easily work with our manufacturing facilities. If necessary, please consult.

Request A Quote
Get your prototyping and production projects started today
Contact us now to request started today
YinCheng Road, XiaBian Community, ChangAn Town, DongGuan City, GuangDong Province, China.
sales@lcrapid.com +86-18898486814