Flexible PCB FAQ
In the life of flexible pcb issues are concerned, besides the both ends of the flexible pcb to rigid pcb or the connector for connection problems, for the flexible pcb is the ultimate serious consequences – broken.
In order to prevent the flexible pcb is broken in use for some time, we should try to exclude flexible pcbin the folding process of the problems encountered. Described below is our common problems and common solutions:
1. FPC and housing has scratches.
allows the plant to do some transparent mold shell, installed over the whole observed after FPC hole in the state of motion to find the location of the interference with the housing flexible pcb, flexible pcb by changing the length to resolve the issue.
one of the oldest methods, that is, not flexible pcbsamples, we can put flexible pcb 2D drawing paper 1:1 print out (hard to try some of the paper), cut out the shape, carefully fitted to the phone, instead of flexible pcb discover and analyze and solve problems. Or do some manufacturers do not allow the alignment, only the rough shape of the flexible pcb samples, loaded to the phone analysis.
on the FPC can be in contact with the aperture where a layer of foam stickers, so that when the case does not directly turn in contact with the flexible pcb, thereby reducing damage to the FPC in order to increase its life. However, this method is a kind of stopgap feeling, it is best to find a cause from the design itself to be truly resolved.
In order to avoid scratching flexible pcb and the housing has, often foreign practice is to install an iron shaft housing, FPC is fixed to the Iron shaft, to avoid opening and closing the clamshell flexible pcb and the housing crash, friction.
Now a lot of rotating clamshell + phone first consideration in the selection of the FPC FPC around the shaft, or simply using coaxial cable coaxial cable instead of FPC, FPC and easy to avoid distortion or breakage problems.
2. FPC in the folding process of abnormal sound.
FPC in the shaft hole length exceeds the diameter (the lid, there is no interference), but open to a certain angle, FPC will be a twisting process, it will run into the hole wall, we abnormal sound can be heard. FPC common solutions to reduce the length to ensure that the folding does not scratch and can work with the inner wall;
FPC itself is multi-layered, and the inner wall of the hole in the lid when it has interference, so when the flip is always abnormal sound can be heard. We can enable manufacturers tied with tape or glue the layers together seemingly layer, but not in the best part about the folding stick together, keep multilayer structure. flexible pcb same length can be reduced.
Above for flexible pcb and housing has scratches and the flexible pcb discussion abnormal sound, there are many times exist simultaneously, the solution also co-exist.
The above analysis only for the analysis of the most common problems and solutions, in future work may encounter more problems and solutions, and then gradually improve the data.