​ What is FPC soft board and soft - hard combined board

Believe that people working in the electronics industry, for the circuit board is still very familiar, whether you are engaged in software or hardware are inseparable from the circuit board, but most people usually may only contact with the ordinary circuit board, have not seen or even heard of FPC soft board and soft and hard combined board, the following to introduce what is FPC soft board and soft and hard combined board, What are the differences between them and ordinary circuit boards, where to pay attention to PCB design and so on.

FPC soft board and soft and hard combined board is also a kind of circuit board, only in special circumstances will be used, before introducing FPC soft board and soft and hard combined board, we first understand what is the circuit board?

Circuit board according to the name can be divided into: ceramic circuit board, alumina ceramic circuit board, aluminum nitride ceramic circuit board, circuit board, PCB board, aluminum substrate, high frequency board, thick copper plate, impedance board, PCB, ultra-thin circuit board, ultra-thin circuit board, printed circuit board, etc., can be found in any electronic equipment, for the electronic devices in the circuit to play a fixed and connected role.

Next, let's introduce what is FPC soft board.

FPC circuit board is also called flexible circuit board Flexible circuit board is made of polyimide or polyester film as a substrate with a high degree of reliability, excellent flexibility of the printed circuit board. With high wiring density, light weight, thin thickness, good bending characteristics, mainly used for connecting with other circuit boards. FPC soft board can save the internal space of electronic products to a certain extent, so that the product assembly processing is more flexible. For example, LCD/OLED, AMOLED screen display panel in smart phones is connected through FPC soft board, which is widely used in laptop, digital camera, medical, automotive, aerospace and other fields.

After we have a clear understanding of the soft board, it is very easy to understand the soft and hard combined board. As the name suggests, the soft and hard combined board refers to the flexible circuit board and hard circuit board, which are combined together according to the relevant process requirements after pressing and other processes, to form the circuit board with FPC characteristics and PCB  board characteristics.

Therefore, it can be used in some products with special requirements. There are both flexible areas and rigid areas. It is of great help to save the internal space of products, reduce the volume of finished products and improve the performance of products. So its price is relatively expensive, the production cycle is also relatively long.

After we understand what is FPC soft board and soft and hard combined board, then in the actual design we need to pay attention to what?

What to pay attention to in layout is:

1, the device needs to be placed in the hard area, the flexible area is only used for connection, so as to improve the life of the board and ensure the reliability of the board. If the device is placed in the flexible area, it is easy to cause the welding pad cracking or character shedding.

2, when the device is placed in the hard area and soft area to maintain at least 1mm spacing.

When wiring needs attention:

1, the soft area graphic distance from the plate edge at least 10mil, can not punch holes, holes and soft and hard joint distance at least 2mm.

2,  Soft boardarea line should be smooth, the corner needs to use arc line connection, at the same time, the line and the arc should be vertical, pad need to add tear processing, avoid tearing

3. At the edge of the bending area, copper foil needs to be used to reinforce the connection at the bending place.

4, in order to achieve better flexibility, the bending area should avoid the change of the width of the line, as well as the uneven density of the line.

5, table bottom wiring as far as possible to stagger, avoid the bottom line of the table coincide together.