FPC (Flexible Printed Circuit) is a flexible PCB, which is made of flexible insulating substrates. It has the characteristics of high wiring density, free bending and folding, three-dimensional three-dimensional assembly, thin thickness, and light weight. With the development of electronic products in the direction of light, thin, short and small, FPC has been widely used in aerospace, automobile, medical and other fields.
Advantages and disadvantages of FPC
FPC is a printed circuit made of a flexible insulating substrate, which has advantages that PCB does not have:
(1) It can be freely bent, wound, and folded, and can be arranged arbitrarily according to the requirements of the spatial layout, and can be moved and stretched arbitrarily in the 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, which is suitable for the development of electronic products in the direction of high density, miniaturization and high reliability. Therefore, FPC has been widely used in aerospace, military, mobile communications, laptop computers, computer peripherals, PDA, digital cameras and other fields or products;
(3)FPC also has the advantages of good heat dissipation and solderability, easy assembly and connection, and low overall cost.
(1) High one-time initial cost: Since flexible PCBs are designed and manufactured for special applications, the cost of initial circuit design, wiring and photographic plates is relatively high. Unless there is a special need to apply a flexible PCB, it is usually best not to use it in a small amount of applications;
(2) It is difficult to change and repair the flexible PCB: once the flexible PCB is made, it must be changed from the base map or the compiled light drawing program, so it is not easy to change. Its surface is covered with a layer of protective film, which must be removed before repairing and restored after repairing, which is a relatively difficult task;
(3) The size is limited: flexible PCBs are usually manufactured by batch process when they are not yet popular, so limited by the size of production equipment, they cannot be made very long and wide;
(4)Improper operation is easy to damage: improper operation of the installation and connection personnel can easily cause damage to the flexible circuit, and its soldering and rework need to be operated by trained personnel.
Application of FPC in the new energy market
The performance of FPC itself is highly compatible with new energy vehicles. FPC has the characteristics of light weight, simple structure, and easy line connection. It is a good line carrier for connecting automotive electronic components. It has obvious advantages in safety, assembly efficiency, battery life, and reduced self-weight. The FPC connection solution has become the absolute main solution in the power battery of passenger cars.
With the increasing intelligence of automobiles, the demand for electronic components in lighting systems, display systems, power systems, battery management systems, and sensors has increased, and the number of circuit carriers required to connect electronic components has increased accordingly. As a traditional circuit carrier, the automotive wiring harness is relatively bulky and has complicated connection methods, which cannot conform to the development trend of the continuous increase in the number of electronic components in new energy vehicles.
However, automotive FPCs are widely used in new energy vehicles due to their advantages such as light weight, simple structure, and convenient line connection.
With the rapid development of new energy vehicles, the market demand for automotive FPCs has surged. According to data from EV Sales, global new energy vehicle sales have increased from 770,000 in 2016 to 6.75 million in 2021. According to Matt Bohlsen’s latest forecast, global new energy vehicle sales are expected to reach 10.4 million in 2022. The explosive growth of new energy vehicles has driven the rapid development of power batteries in the field of new energy. FPC is an important accessory for new energy power batteries.
Compared with traditional wire harnesses, FPC can realize modularization and automatic production, which can improve production efficiency through automated production, and rely on the remarkable characteristics of FPC itself to achieve lightweight batteries and higher safety performance. It is the general trend for FPC to replace traditional wire harnesses.
According to the statistics, the automotive FPC market reached 5.3 billion RMB in 2018, a year-on-year increase of 8.4%. The main growth drivers of the market come from the improvement of the degree of automotive electronics and the increase in the penetration rate of new energy vehicles. From 2016 to 2022, the annual growth rate of FPC for automobiles will remain between 6% and 9% for a long time. By 2022, the FPC market for automobiles will grow to 7 billion RMB.
At present, the FPC solution has become the most important choice for most of the new models of new energy vehicles. FPC is integrated to CCS (Cells Contact System, integrated busbar, wiring harness board integration). CCS products are composed of FPC, plastic structural parts, copper and aluminum bars, etc. The copper and aluminum bars connect multiple batteries in series and parallel through laser welding. FPC is connected with copper and aluminum bars and plastic structural parts to form electrical connection and signal detection structural components.