There are many kinds of circuit boards on the market, and the professional terms are different, among which the fpc board is very widely used, but many people do not know much about the fpc board, so what does the fpc board mean?
1, fpc board is also called “flexible circuit board”, is one of the PCB printed circuit board, is a kind of the use of insulating material as a substrate, such as: polyimide or polyester film, and then through a special process made of printed circuit board. The wiring density of this circuit board is generally relatively high, but the weight will be relatively light, the thickness will be relatively thin, and has good flexibility performance, as well as good bending performance.
2, fpc board and PCB board is a big difference. The substrate of the fpc board is generally PI, so it can be arbitrarily bent, flexed, etc., while the substrate of the PCB board is generally FR4, so it can not be arbitrarily bent and flexed. Therefore, the use and application fields of fpc board and PCB board are also very different.
3, because the fpc board can be bent and flexed, the fpc board is widely used in the position that needs to be repeatedly flexed or the connection between small parts. The PCB board is relatively rigid, so it is widely used in some places where it does not need to be bent and the strength is relatively hard.
4, fpc board has the advantages of small size, light weight, so it can effectively reduce the size of electronic products is very small, so it is widely used in the mobile phone industry, computer industry, TV industry, digital camera industry and other relatively small, relatively sophisticated electronic products industry.
5, the fpc board can not only be freely bent, but also can be arbitrarily wound or folded together, and can also be freely arranged according to the needs of the space layout. In the three-dimensional space, the fpc board can also be arbitrarily moved or telescoped, so that the purpose of integration can be achieved between the wire and the component assembly.
What are PCB dry films?
1, single-sided PCB
The base plate is made of paper phenol copper laminated board (paper phenol as the base, coated with copper foil) and paper Epoxy copper laminated board. Most of them are used in domestic electricity products such as radios, AV appliances, heaters, refrigerators, washing machines, and commercial machines such as printers, vending machines, circuit machines, and electronic components.
2, double-sided PCB
The base materials are Glass-Epoxy copper laminated board, GlassComposite copper laminated board, and paper Epoxy copper laminated board. Most of them are used in personal computers, electronic Musical Instruments, multi-function telephones, automotive electronic machines, electronic peripherals, electronic toys, etc. As for Glass benzene resin copper laminated laminates, Glass polymer copper laminated laminates are mostly used in communication machines, satellite broadcasting machines, and mobile communication machines due to their excellent high-frequency characteristics, and of course, the cost is also high.
3, 3-4 layers of PCB
The base material is mainly Glass-Epoxy or benzene resin. Mainly used in personal computers, Me (medical electronics, medical electronics) machines, measuring machines, semiconductor testing machines, NC (NumericControl, numerical control) machines, electronic switches, communication machines, memory circuit boards, IC cards, etc., there are also glass synthetic copper laminated board as multi-layer PCB materials, Mainly focus on its excellent processing characteristics.
4,6-8 layers of PCB
The base material is still based on GLASS-epoxy or Glass benzene resin. Used in electronic switches, semiconductor testing machines, medium-sized personal computers, EWS (EngineeringWorkStation), NC and other machines.
5, more than 10 layers of PCB
The substrate is mainly made of Glass benzene resin, or GLASS-epoxy as a multi-layer PCB substrate material. The application of this kind of PCB is more special, most of them are large computers, high-speed computers, communication machines, etc., mainly because it has high frequency characteristics and excellent high temperature characteristics.
6, other PCB substrate material
Other PCB substrate materials are aluminum substrate, iron substrate and so on. The circuit is formed on the substrate, most of which is used in the turnaround (small motor) car. In addition, there are flexible PCB (FlexiblPrintCircuitBoard), the circuit is formed on the polymer, polyester and other main materials, can be used as a single layer, double layer, to multi-layer board can be. This flexible circuit board is mainly used in the movable parts of cameras, OA machines, etc., and the connection between the hard PCB or the effective connection combination between the hard PCB and the soft PCB, as for the connection combination method due to high elasticity, its shape is diversified.
Multi-layer board and medium and high TG plate
First, multi-layer PCB circuit boards are generally used in what areas?
Multilayer PCB circuit boards are generally used in communication equipment, medical equipment, industrial control, security, automotive electronics, aviation, computer peripheral fields; As the “core main force” in these fields, with the continuous increase of product functions, more and more dense lines, the corresponding market requirements of the quality of the board is also getting higher and higher, and the customer demand for medium and high TG circuit boards is constantly increasing.
Second, the particularity of multi-layer PCB circuit boards
Ordinary PCB board will have deformation and other problems at high temperatures, while the mechanical and electrical characteristics may also decline sharply, reducing the service life of the product. The field of application of multi-layer PCB board is generally located in the high-end technology industry, which directly requires that the board has high stability, high chemical resistance, and can withstand high temperature, high humidity and so on.
Therefore, the production of multi-layer PCB boards uses at least TG150 plates, in order to ensure that the circuit board is reduced by external factors in the process of application and extends the service life of the product.
Third, high TG plate type stability and high reliability
What is TG value?
TG value: TG is the highest temperature at which the sheet remains rigid, and TG value refers to the temperature at which the amorphous polymer (also including the amorphous part of the crystalline polymer) transitions from the glassy state to the high elastic state (rubber state).
The TG value is the critical temperature at which the substrate melts from solid to rubbery liquid.
The level of TG value is directly related to the stability and reliability of PCB products, and the higher the TG value of the board, the stronger the stability and reliability.
High TG sheet has the following advantages:
1) High heat resistance, which can reduce the floating of PCB pads during infrared hot melt, welding and thermal shock.
2) Low thermal expansion coefficient (low CTE) can reduce warping caused by temperature factors, and reduce the copper fracture at the corner of the hole caused by thermal expansion, especially in PCB boards with eight or more layers, the performance of plated through holes is better than that of PCB boards with general TG values.
3) Has excellent chemical resistance, so that the PCB board can be soaked in the wet treatment process and many chemical solutions, its performance is still intact.