PCB News - Talking about the advantages and disadvantages of soft and hard board FPCB

Talking about the advantages and disadvantages of soft and hard board FPCB

The disadvantages of rigid-flex board

If you simply compare the "soft-hard board" with the "soft board + circuit board + connector", the biggest disadvantage is that the price of the "soft-hard board" is more expensive, and it may be more than the original simple soft board. The price of "hard board" is nearly doubled, but if the price of the connector or the cost of HotBar is deducted, the price may tend to be the same, and the detailed cost may have to be calculated to have a clearer outline. Another shortcoming is that it may need to use a carrier to support the part of the soft board for both the production and the furnace, which invisibly increases the assembly cost of the SMT.

The advantages of rigid-flex board

In addition to the price, there are many advantages to using a rigid-flex board, as listed below:

1. It can effectively save the space on the circuit board and eliminate the use of connectors or HotBar processes

Because the FPCB soft and hard board has been combined, the space that originally needed to use the connector or the HotBar process can be saved. For some circuit boards with high-density requirements, one less connector is needed. Space is like picking up a treasure.

In this way, it also saves the cost of parts using the connector or the cost of the HotBar process. In addition, the space between the two boards can be made tighter by eliminating the need for connectors.

2. The signal transmission distance is shortened and the speed is increased, which can effectively improve the reliability

The traditional signal transmission through the connector is "circuit board-connector-flexible board-connector-circuit board", while the signal transmission of the flexible and hard composite board is reduced to "circuit board-flexible board-circuit board", signal transmission The distance between different media is shortened, and the problem of signal transmission attenuation between different media is also reduced. Generally, the circuit on the circuit board is made of copper, while the contact terminal of the connector is gold-plated, and the solder pin is fully tin-plated. In addition, solder paste is required to be soldered on the circuit board, and the signal transmission between different media will inevitably be attenuated. If you switch to a flexible and hard board, these media will become less and the signal transmission ability can be relatively improved., For some products that require higher signal accuracy, it helps to improve their reliability.

3. Simplify product assembly and save assembly man-hours

The use of soft and hard boards can reduce the man-hours for SMT parts, because the number of connectors is reduced. It also reduces the man-hours for assembly of the whole machine, because the assembly action of inserting the soft board into the connector is omitted, or the manufacturing process of HotBar is omitted. It also reduces the cost of parts management and inventory, because the BOM is reduced, so the management becomes less.