PCB Technical - The advantages and disadvantages of flexible circuit boards

Flexible circuit boards have many advantages such as space saving, weight reduction and high flexibility. The global demand for flexible circuit boards is increasing year by year. The unique characteristics of flexible circuit boards make it an alternative to rigid circuit boards and traditional wiring schemes in many occasions. At the same time, it also promotes the development of many new areas. The fastest growing part is the internal computer hard disk drive (HDD). In connection lines, the second fastest growing area is new integrated circuit packaging, and flexible circuit technology has great market potential in portable devices (such as mobile phones).

What are the types of flexible circuit boards

1. Single panel

The single-sided PI copper-clad material is used after the circuit is completed, and then covered with a protective film to form a flexible circuit board with only a single-layer conductor.

2. Ordinary double panel

After using the double-sided PI board with copper-clad material to complete the double-sided circuit, a protective film is added on both sides to become a circuit board with double-layer conductors.

3. Substrate to generate single panel

In the circuit manufacturing process using pure copper foil material, a protective film is added on each side of the circuit board to form a circuit board with only a single layer of conductors but exposed conductors on both sides of the circuit board.

4. The substrate generates double panels

Use two layers of single-sided PI copper-clad material in the middle to be laminated with adhesive glue that opens at a specific position to become a double-sided conductor circuit board with a two-layer separation structure in a local area to achieve a layered area. Circuit board with high flex performance

The advantages and disadvantages of flexible circuit boards

1. Advantages

(1) It can be freely bent, wound, and folded, can be arranged according to the space layout requirements, and can be moved and expanded in three-dimensional space, so as to achieve the integration of component assembly and wire connection;

(2) The use of FPC can greatly reduce the volume and weight of electronic products;

(3) FPC also has the advantages of good heat dissipation and solderability, easy assembly and connection, and low overall cost. The design of soft and hard combination also makes up for the slight deficiency of the flexible substrate in the component carrying capacity to a certain extent.

2. Disadvantages

(1) High one-time initial cost

Since the flexible PCB circuit board is designed and manufactured for special applications, the initial circuit design, wiring, and photographic plate require relatively high costs. Unless there is a special need to apply a flexible PCB, it is usually best not to use it for a small number of applications.

(2) It is difficult to change and repair the flexible PCB

Once the flexible PCB circuit board is made, it must be changed from the base map or the programmed light drawing program, so it is not easy to change. The surface is covered with a protective film, which must be removed before repair and restored after repair, which is a relatively difficult task.

(3) Size is restricted

When flexible PCB circuit boards are not yet popular, they are usually manufactured by batch process, so they cannot be made very long and wide due to the limitation of the size of production equipment.

(4) Improper operation is easy to damage

Improper operation of the assembly and connection personnel can easily cause damage to the flexible circuit, and its soldering and rework need to be operated by trained personnel.