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How to Make Metal Back Panel for Cell Phone —CNC Machining for Cell Phone Metal Back Panel

How to make Metal Back Panel for Cell Phone —CNC Machining for Cell Phone Metal Back Panel

Time to read: 3min


Nowadays, many cell phone, notebook and wearable device manufacturers are starting to make efforts on the casing material. Just from the cell phone field, cell phone shell material is also gradually from engineering plastic to metal transition.


Cell phone shell material evolution during the emergence of many kinds of combinations: plastic and metal, glass and metal, all plastic, all glass, etc., but ultimately did not overshadow the wind of all-metal material. From the actual touch experience, all-metal cell phones do have outstanding experience in many aspects, whether the appearance or feel are better than other materials.

Metal casing product electronics manufacturers have introduced

Metal casing product electronics manufacturers have introduced


CNC machining process is almost the optimal choice for all-metal manufacturing. Currently, all-metal housings for 3C products are basically CNC machined. CNC machining has become the most common machining process for 3C housing manufacturers due to its high efficiency, high precision, and stable machining quality. Click on ProleanHub CNC machining service to get detailed information.


The all-metal unibody CNC machining process was first introduced by Apple – the aluminum plate was die-cast from a solid column of aluminum, which was first cut into the prototype of the unibody by precision machining, and as the body gradually took shape, the keyboard shape and various subtle structures on the body were milled out.



Housing manufacturers need to go through multiple processes from programming to finished products such as rough machining, semi-rough machining, semi-finishing, finishing, etc. Many times, the whole process requires more than 10 processes to obtain the finished product, and to improve the yield rate, each process needs to be strictly controlled.

The finished product is obtained through 12 processes from right to left

The finished product is obtained through 12 processes from right to left


1. CNC machining pre-process work: modeling and programming


The difficulty of 3D modeling is determined by the structure of the product, which is more difficult to model and more complicated to program. The programming package includes the process setting, tool selection, speed setting, tool feed distance, the distance of tool movement, etc. In addition, different products have different clamping methods, so it is necessary to design a good fixture before machining, and some products with complex structure need to make special fixtures.


Programming includes the entire product machining process. Although the follow-up is done by CNC automation, but the pre-programming must be practically experienced personnel to operate, to avoid multiple trial and error to increase costs.


2 The Main Processing Process

The following video shows the main CNC machining processes required to make an all-metal phone case



1) Using a high-speed drilling and tapping center, the aluminum plate is precisely milled into a regular three-dimensional volume of a certain size, ready for the next process.

Processing Process 1


2)Rough milling: After positioning, rough milling out the inner cavity structure, the positioning column combined with the fixture, and milling away most of the redundant material outside.

 Processing Process 2


3) Milling antenna slot: the signal problem of all-metal shell is tricky, need to mill out the antenna slot to leave the transmission path for the signal, keep the necessary connection points to ensure the strength and overall sense of the body.

Processing Process 3


4)CNC finishing: Finishing milling of inner cavity, external structure, outer surface, side edges, etc.

Processing Process 4

Processing Process 5

Processing Process 6

5) Polishing: Use high-speed precision CNC machine tools for polishing, eliminating knife patterns and preparing for subsequent sandblasting.

6)Sandblasting: The metal surface is treated into a sandblasting effect.


Primary anodizing: coloring the phone, anodizing the aluminum into gold. Also improve the stability of the surface material

Secondary anodizing: the surface of the body to form a solid and dense oxide film, wear resistance is further enhanced.

 Processing Process 7

Processing Process 8

 logo PL

Plastic shell molding using injection molding process, only need to open the mold can be mass production, the yield is very high. The CNC processing yield of the full metal body is determined by the structural complexity and precision requirements of the shell together, it is difficult to achieve the same high yield of plastic shell, in order to balance the high cost, most manufacturing companies in the face of the price war will choose to purchase a large number of CNC equipment to reduce the overall cost and achieve the productivity requirements.

Post time: May-11-2022

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