Flexible circuit board is also a kind of circuit board, common flexible circuit board anti fracture effect is not ideal, flexible circuit board in the impact or external force pressure is likely to lead to flexible circuit board fracture, so as to make a flexible circuit board damage, and flexible circuit board heat resistance effect is not ideal, it is easy to cause fire, so that flexible circuit board is practical The performance and service life are greatly reduced, which brings great inconvenience to users. The following is referred to as FPC to analyze the causes of its fracture.

Firstly, it may because the FPC is too short. Secondly, the material is too hard, it may be better to replace it with a softer one. Another point is that FPC fracture is an initial problem. There are several problems brought about by FPC: fracture causes LCD not to display and flip abnormal sound; for fracture, most of the design length is too short, and the hole gap structure design at the FPC is not reasonable. The abnormal sound of flip is often caused by the contact and scratch between FPC and shell wall. In short, FPC should be designed after repeated attempts It is better to use transparent shell, or cut the shell, observe more, and then make design improvement. Some manufacturers do not have problems when they start proofing. If there are problems in mass production, we must see whether it is the problem of materials.

For example, when the fracture is the electromagnetic shielding layer on the outer layer of FPC, and this layer is folded from the back of the product in the swing area, it can be judged that this layer is made separately and then adhered to the FPC product. The reason is that the shielding layer is solid copper with high hardness, which increases the possibility of fracture during rolling. Moreover, the shielding layer is attached to the FPC, which is not a close whole with the FPC product. During the rolling process, the shielding layer will deviate from the original bending direction, which may lead to stress concentration and fracture. In view of this situation, we can wrap tape around the fracture and bind it to FPC to increase its tightness with FPC. At the same time, the copper surface of shielding layer is changed into grid to reduce the hardness. In the long run, the use of printed or coated conductor for the shielding layer of FPC swing area, or bonding with conductive cloth specially used for FPC electromagnetic shielding, will completely avoid the problem of shielding fracture, and the cost will not increase.

In fact, an anti tearing line can be designed for FPC to prevent moisture and dust. Changing the copper layer of FPC into copper mesh can increase the deflection of FPC. FPC shielding now a lot of useful aluminum foil, flip will be better. The most important thing in FPC design is to reduce the stress concentration. The fillet must be as large as possible. Many cases are broken in the inner fillet of FPC. Increasing the fillet will improve greatly. There should be no obvious stress at both ends of the shaft. The connector should not be too close to the leading out part of the rotating shaft, otherwise the adhesive layer at both ends of FPC will produce great torque. FPC also has its own torsion. If the axial length of the shaft is longer, the torsion will be weakened, but if the axial length is too long, there will be obvious layer to layer slapping sound.

The supplier of FPC is also a very important link. There are electrolytic copper and calendered copper on FPC copper wire. The service life of electrolytic copper is relatively low, which may affect the test. It is very important to simulate the length of FPC. It is better to analyze the failure parts in one step. In fact, FPC life is also related to the casing structure. Due to the frequent need for movement and the limited space in the casing, FPC will inevitably contact with the hard casing. Quality and price are inseparable. However, the value of FPC is relatively low, but the original devices on board are not cheap. In addition, if the FPC is damaged during the warranty period, the warranty cost is much higher than the FPC value.