Flexible PCB is the option when you chose the flex PCB, Packaging, Reliability, Capabilities, and Cost Savings. In simple words, a flexible printed circuit can be defined as a pattern of conductive traces bonded on a flexible substrate. Compatible with assembly process, Co planarity – Flat and uniform Good solder ability, an extended shelf life lowest overall cost easily rework able highest yield in the production, Complying with all ROHS requirement Testability, Increase in design freedom .Installation flexibility. Increased reliability and durability. Improved heat dissipation. Improved airflow Manufacturing criteria.
The structures in this thesis are all fabricated in flexible plastic foils. Flexible foils are thin and light, and they can be bent into three-dimensional shapes. This makes them good candidates for applications where weight and volume must be restricted, as in a hearing aid or heart pacemaker, and where the circuitry must withstand bending, such as in a foldable mobile phone. So, as with miniaturization, by choosing a flexible substrate in favor of a rigid one, new applications and functions become possible imp source.
Fabricating Flex PCBs
Flex PCB fabrication technology encompasses a multitude of different manufacturing techniques. The choice of process does not necessarily always depend on the quality or the size of the structures you can build with it. Neither does it necessarily depend only on the price. A flex PCB manufacturer 14 will also often choose a fabrication process depending on the availability of the process as much as on quality and price. Does the manufacturer have the necessary equipment to implement a new technique, or is an often expensive investment in new machines or know-how necessary? Another important question is: is the fabrication technique reliable Moreover, the choice of manufacturing technique will depend on issues such as meeting legislation on e.g. the use and disposal of environmentally hazardous substances. The starting point of every flex PCB fabrication processes is the plastic foil. Polyimide flex PCB foils are available both as bare plastic foils and as metal coated foils with metal on one or both sides of the foil.
The printed-circuit board assembly industry can be divided into two major groups of players: captive plants, producing for downstream plants or divisions of the same firm; and independent plants or contract manufacturers, which sell their assembly services to different firms. Our study considers only captive plants.
The printed circuit board assembly industry exhibits several characteristics that make a study of this type difficult. First, most of the plants in the industry are highly automated, which implies that the human-related factors of flexibility implementation will tend to be less relevant here than in a more labour-intensive industry. Second, the production process is quite standardized. Most plants purchase their PCBA assembly equipment from a few major vendors, so there is less variation in the production process in this industry than in other assembly industries. Third, printed wiring assembly is an intermediate industry which supplies assembled boards to be used in final applications. This implies that customers are manufacturing firms, rather than the actual end users. Finally, as we said above, our study only considers captive plants. This has two implications for us. On the one hand, plants in our sample tend to be more insulated from market pressures than plants competing in the open market. Thus, they may be slower and less responsive in implementing different flexibility types than plants in the open market might be. On the other hand, the fact that all our plants belong to large corporations makes it difficult to control for corporate-wide resources and policies that might be influencing a plant’s behavior.
In reality, production technology turned out to be significantly related to mix and new-product flexibility, but with a pattern opposite to what we expected given the capabilities of the technology. The automotive sector makes extensive use of wiring in harness for a variety of on-
Vehicle control applications.
Telecommunications
As mobile phone screens and LCDs have become more complex, showing an ever greater amount of information, the increasing demands for more inputs and outputs has led to the application of flex integrated circuits to link screens to their driver chips and power supply.
Aviation: The FPC applications within the aviation sector are almost exclusively based on polyimide film with copper conductors. The aviation sector and in particular the defence sector were pioneers in the development of flex-rigid boards, which offer the advantages of both rigid and flexible circuits.
Disadvantage
• Cost is higher then rigid PCBs
• risk of damage during handling or use
• difficult assembly process
• Repair and rework is difficult
• worse panel utilization resulting in increased cost
