In addition to the connection between the two ends of the FPC and the PCB board or connector, the ultimate serious consequence for the FPC is – breakage.
In order to prevent the FPC from breaking after a period of use, it is necessary to try to eliminate the problems encountered by the FPC in the folding process.
The following are some of our common problems and common solutions:1. The FPC has scratches with the housing.
(1) You can ask the mold factory to make some transparent shells, observe the movement state of the FPC in the vias after installing the whole machine, find the interference position between the FPC and the shell, and change the FPC
In addition to the connection between the two ends of the FPC and the PCB board or connector, the ultimate serious consequence for the FPC is – breakage. In order to prevent the FPC from breaking after a period of use, it is necessary to try to eliminate the problems encountered by the FPC in the folding process.
The following are some of our common problems and common solutions:1. The FPC has scratches with the housing.
(1) You can ask the mold factory to make some transparent shells, observe the movement state of the FPC in the vias after installing the whole machine, find the interference position between the FPC and the shell, and solve the problem by changing the length of the FPC.
(2) One of the oldest methods is that when there is no FPC sample, we can print the FPC 2D drawings 1:1 on paper (the paper should be as hard as possible), cut out the appearance, and carefully put it into the mobile phone, instead of FPC to find and analyze and solve the problem. Or let the manufacturer make some FPC blank samples with no wiring and only shape, and install them in the mobile phone for analysis.
(3) A layer of foam can be pasted on the place where the FPC is in contact with the aperture, so that the shell will not be in direct contact with the FPC when it rotates, so as to reduce the damage to the FPC and increase its life. However, this method has a feeling that it treats the symptoms but not the root cause, and it is best to find the cause from the design itself to achieve a real solution.
(4) In order to avoid scratches between the FPC and the shell, a common practice in foreign countries is to install an iron shaft in the shell, and the FPC is fixed to the iron shaft to avoid the collision and friction between the FPC and the shell when opening and closing the flip cover.
(5) Nowadays, many flip + rotating mobile phones, when choosing FPC,
first consider winding the FPC on the shaft (method 4 above), or simply use coaxial cable instead of FPC, so as to avoid the occurrence of problems such as easy twisting and breaking of FPC.
2. There is abnormal sound in the FPC during the folding process.
(1) The length of the FPC in the shaft hole exceeds the hole diameter (when the cover is closed, there is no interference), but when it is turned over to a certain angle, the FPC will have a twisting process, it will touch the inner wall of the hole, and we can hear the abnormal sound. The common solution is to reduce the length of the FPC to ensure that it does not scratch the inner wall and can work normally when folding;
(2) The FPC itself is multi-layered, and the inner wall of the hole has been interfered with when the lid is closed, so the abnormal sound can always be heard when the lid is flipped. We can ask the manufacturer to tie the multiple layers tightly with tape or glue them together to look like one layer, but it is better not to stick them together in the winding part and retain the multi-layer structure. At the same time, it is also possible
