Introduction:
The assembly of flexible PCB is basically same with the rigid-PCB assembly, and in actual manufacturing process, the operator will take different processes according to the different requirements of the process. Its common single-side mount flexible PCB assembly process as shown in the figure 1.
Characteristics of Flex-PCB Assembly:
Flex-PCB Attached to Rigid-PCB:
Flexible PCB is easy to be deformed due to its light and thin characteristics, so it cannot be assembled directly on the SMT production line like rigid PCB. That is to say, in order to assembly flexible PCB, the flexible PCB must be fixed on the substrate of rigid PCB, so that it can be disguised as rigid PCB for assembly. The flatness, positioning accuracy and consistency of the substrate are the key factors to achieve product quality control, and also the key points of flexible PCB assembly.
Low density:
At present, the price of flexible PCB is relatively higher than that of rigid PCB. From the perspective of product cost, most flexible PCBs are only used for the connection between different functional modules. The number of components to be assembled on flexible PCBs is small and the distribution density is low, generally less than 50 components or even two connectors.
Panel：
Flexible PCB is mainly used in mobile phones, digital cameras and other light, small, thin electronic products. The area of its single-side flex-PCB is not large, what’s more, the number of single-side flex-PCB components is small, so in order to improve the assembly efficiency, most factories will choose to use panels. After assembly, these flex-PCBs which have different functions will be separated by v-cutting or v-scoring.
High Requirements of Product Quality:
Due to the frequent application of flexible PCB in such environment that requires repeated bending and precision control, the components assembled on it must be able to meet the requirements of its operating environment, so the quality requirements of flexible PCB in assembly such as cleanliness, anti-static measures and reliability of soldering are generally much higher than the general rigid PCB. Besides, at present, with the implementation of lead-free technology, the challenges of flexible circuit board assembly are increasing.
High Assembly Cost:
Compared with rigid PCB assembly, flexible PCB assembly has a lot of characteristics, such as more investment in specific fixture, long production cycle, relatively lower equipment utilization rate, more accessories and operators, higher requirements of production environment and product quality. This makes the total cost of flexible PCB assembly is high, especially the initial investment cost is higher.
Conclusion:
With the development of electronic products, the use of flexible PCB is expanding, and the assembly process of flexible PCB will be improved. The manufacturing and assembly costs will continue to reduce, which will promote the further expansion of the use of flexible PCB, so that the application of flexible PCB into a virtuous cycle.
