Precision Processing of Mobile Phone Shell by Aluminum Die Casting
When these metals become fluids, they can be injected into the die-casting machine, and then die-cast into the prototype of the mobile phone metal shell. Although it seems relatively simple, it is necessary to prevent sand holes from appearing in shell processing even in such links. Once there are sand holes, in the subsequent processing and cutting, there will be small pits, so there is still need to improve the process and die knot. This trial and error improvement process wastes a lot of raw materials.
After the end of the previous die casting stage, these prototypes will accept the next option. Is it anodized like the iPhone to increase the metal texture, or is it directly painted? This seems like a difficult decision. But the reality has nothing to do with aesthetics: Die-cast housing is not conducive to doing anodized, and there are some considerations of product differentiation and so on.
After machine processing, the excess part is washed away, and the burr is worn away, and it can be seen that the metal casing of the mobile phone has been basically formed. As for the opening above, it is reserved for injection molding. The small holes on the back cover are CNC machined for injection molding and reinforcement. This logic is the same as the white strip on the back of the iPhone 6. To make the antenna signal go smoothly, the back cover can't use the whole piece of metal. So in the antenna part, we will always see traces of plastic. There is currently no way to overcome this, and this part of the plastic is not a spray point.
After the injection molding is completed, after re-grinding, the next step is the process of painting. The manufacturers will definitely not take the above-mentioned plain shell directly. The process of spraying paint is also a technology. The phone has a clear boundary between the plastic and metal parts of the back. If the painting process is not good enough, this dividing line will remain visible, and therefore do not see the visible boundaries of the Ministry of metal and plastic. Is an important indicator to judge whether the painting process is good or not.
After the painting is finished, the paint is baked. Generally speaking, the painting and baking paint are not done at one time, but in many cycles. And between the paint and spray paint, there will be another polishing, this group of mobile phone metal shell will eventually undergo five spraying, five painting and two polishing. Usually the first time is the primer, the last time the paint will be added pearl powder or aluminum powder to ensure the texture and look.
At this point, it is the part that mobile phone manufacturers like most, because this part has a very nice part, called diamond cutting. But before the diamond is cut, manufacturers need to make holes in cameras, volume keys, speakers and so on.
After each hole is opened, it is a very mysterious diamond cutting link. It is said that diamond cutting is not because the cut-out frame is crystal-clear like a diamond, but the tool that completes the cutting is a diamond. The edge of the cut case will have a very good high light feel. It’s not quite similar to the previous paint spray. Diamond cutting here can not be completed at one time, at least twice, three times is the conscience of the industry. After all, one more step, there will be more cost.
It should be pointed out that in order to ensure that the width and angle of the cutting are strictly consistent, it is necessary to use a kind of laser tool setting instrument to control the thickness of the knife edge and the width of the trimming edge. In simple terms, is to use a laser cutter to cut the first in place to walk around. The measured data is fed back to the CNC machine according to the shape of the measured object, and then the cutting can be started.