First, the advantages
- Flexible
A significant advantage of using flexible PCBs is that they can be more easily routed and assembled in three-dimensional space, and can be crimped or folded. As long as the radius of curvature within the allowable range, can withstand thousands or ten thousand times of usage without damage.
- Reduce the volume
In the assembly of components, compare with using wire and cable, the flexible PCB conductor cross-section is thin and flat which can reduce the size of the wire, and can be formed along the chassis, the equipment structure can be more compact, reasonable and smaller volume. Compared with the rigid PCB, it can save 60 to 90% space.
- Reduce weight
In the same volume, the flexible PCB, compared with the wire and cable, at the same current capacity, its weight can be reduced by about 70%, compared with the rigid PCB, it is aobut 90% weight reduction.
- The consistency of the assembly
Installed with a flexible PCB, eliminating the use of wire cable wiring error. As long as the processing drawings through the proofreading, all later produced around the circuit are the same. Connect the cable without mis-wiring.
- Increased reliability
When using a flexible circuit soldering, because in the X, Y, Z three wiring on the plane, reducing the switching interconnection, so that the whole system reliability increases, and the failure to check, to provide a convenient.
- Electrical parameter design controllability
According to the use of requirements, when engineer design the flex PCB, he/she can control the capacitor, inductance, characteristic impedance, delay and attenuation. Can be designed to have the characteristics of a transmission line. Because these parameters and wire width, thickness, spacing, insulation thickness, dielectric constant, loss tangent and so on, which in the use of wire and cable is difficult to do.
- End can be the overall soldering
The board circuit flexible printed, like a rigid PCB, has a terminal pad that eliminates wire stripping and tinning, thus saving cost. Terminal pad and element, device, plug connection, dip soldering or wave soldering can be used to replace each wire manual soldering.
- Material selection
Flexible PCB can be used according to different requirements, choose a different substrate materials to manufacture. For example, a polyester film may be used in connection applications requiring low cost. In applications requiring high performance, it is desirable to use a polyimide film.
- Low cost
With a flexible PCB assembly, the total cost can be reduced. This is because:
1) Due to the consistency of the various parameters of the flexible PCB wire; the implementation of the overall termination, eliminating the cable assembly with the installation of the error and often rework, and the replacement of flexible PCB more convenient.
2) the application of soft PCB design to simplify the structure, it can be directly attached to the component, reducing the clamp and its fasteners.
3) for the need to shield the wire, with a low price of soft PCB.
- Processing continuity
Continuous production of the flexible PCB can be achieved because the flexible clad sheet can be continuously supplied in a roll form. This also helps reduce costs.
Second, disadvantages
- One-time initial cost is high
Since flexible PCBs are designed and manufactured for specific applications, the initial cost of circuit design, wiring, and photomasking is high. Unless there is a special need to use soft PCB, usually a small amount of application, it is best not to use.
- Flexible PCB changes and repair more difficult
Once the flexible PCB is made, the change must start from the base map or the programmed light-painting program, so it is not easy to change. Its surface covered with a layer of protective film, repair before removal, repair and recovery, this is more difficult work.
- Dimensions are limited
As flexible PCB is not yet common, usually manufactured by batch process, so the size of the production equipment by the restrictions cannot be done very long, very wide.
- Improper operation, easy to damage
Even with improper operation of personnel easily lead to flex circuit damage, the soldering and rework need to be finished by trained personnel.