PCB board quality and PCB board type introduction
PCB is introduced
Printed Circuit Board is an important electronic part, support body of electronic components and carrier for electrical connection of electronic components. Because it is made by electronic printing, it is called “printed circuit board“.
Classification of PCB
There are three main types of PCB boards:
1. The single-layer board
Single-layer Boards: on the most basic PCB, parts are centered on one side and wires on the other.
The PCB is called single-layer because the conductor appears on only one side. Because single panels have many strict restrictions on the design of circuits (because there is only one side, the wiring cannot cross and must go around a separate path), only early circuits used such boards.
2. Double-layer board
Double-layer Boards: this type of board has wiring on both sides, but to use a double-layer lead, you must have a proper electrical connection between the two sides.
The “bridge” between these circuits is called a guide hole (via). A guide hole is a small, metal-filled hole in a PCB that can be connected to a wire on both sides.
Because the area of the double-lauer board is twice as large as that of the single-layer board, the double-layer board solves the problem of interlaced wiring in the single-layer board (it can pass through the hole to the other side) and is more suitable for use in more complicated circuits than the single-layer board.
3. Multi-layer board
Multi-layer Boards: to increase the area available for wiring, more single or double layer boards are used. With a double lining, two one-way for outer layer or two double lining, two blocks of single outer layer of the printed circuit board, through the positioning system and alternate insulation adhesive materials and conductive graphics interconnection according to design requirement of printed circuit board becomes four, six layer printed circuit board, also known as multilayer printed circuit board.
The number of layers on the board does not mean that there are several independent wiring layers. In special cases, empty layers will be added to control the thickness of the board. Usually, the number of layers is even, and it contains the two outermost layers. Most motherboards have 4 to 8 layers of structure, but technically it is possible to have nearly 100 layers of PCB.
Most large supercomputers use fairly multi-layered mainframe boards, but because such computers can be replaced by clusters of many ordinary computers, the use of super-multilayered boards has become obsolete.Because each layer in the PCB is closely combined, it is not easy to see the actual number, but if you carefully look at the motherboard, you can still see.
Flexible Printed Circuit Board
PCB role
Electronic equipment using printed board, because of the same type of printed board consistency, so as to avoid manual wiring error, and electronic components can be automatically inserted or pasted, automatic solder, automatic detection, to ensure the quality of electronic equipment, improve labor productivity, reduce the cost, and facilitate maintenance.
PCB features (advantages)
PCB can be more and more widely used because it has many unique advantages, including the following.
1. Densified
For decades, PCB high density can be developed with the improvement of integrated circuit integration and installation technology.
2. High reliability
Through a series of inspection, test and aging test, the PCB can be guaranteed to work reliably for a long time (life, generally 20 years).
3. Designability
PCB performance (electrical, physical, chemical, mechanical, etc.) requirements, can be through design standardization, standardization, etc. to achieve the PCB design, short time, high efficiency.
4. Productive
Adopt modern management, can carry on standardization, scale (quantity), automation production, guarantee product quality consistency.
5. Testability
Established a relatively complete test method, test standards, various test equipment and instruments to detect and identify the PCB product qualification and service life.
6. Assemblability
PCB products not only facilitate the standardization of the assembly of various components, but also can be automated, large-scale mass production. At the same time, PCB and various components assembly components can also be assembled into larger parts, systems, until the machine.
7. Maintainability
Because PCB products and various component assembly components are designed and manufactured in a standardized way, these components are also standardized.Therefore, once the system fails, it can be replaced quickly, conveniently and flexibly, and the system can be recovered quickly. Of course, there are many more examples. Such as the system miniaturization, lightweight, high-speed signal transmission and so on.
PCB industry trends
PCB industry is developing rapidly
Since the reform and opening up, China’s preferential policies in labor resources, market, investment and other aspects have attracted the large-scale transfer of European and American manufacturing industries. A large number of electronic products and manufacturers have set up factories in China, which has led to the development of related industries including PCB. According to CPCA statistics of China, in 2006, the actual production of PCB in China reached 130 million square meters and the output value reached 12.1 billion us dollars, accounting for 24.90% of the total output value of PCB in the world, surpassing Japan to become the world’s first. From 2000 to 2006, the annual growth rate of China’s PCB market reached 20%, far exceeding the global average. The global financial crisis in 2008 caused a huge impact on the PCB industry, but it did not cause a catastrophic blow to China’s PCB industry. Under the stimulus of national economic policies, China’s PCB industry showed a comprehensive recovery in 2010, and the output value of China’s PCB reached 199.71 billion us dollars in 2010. Prismark predicts China will maintain a compound annual growth rate of 8.10% between 2010 and 2015, higher than the global average of 5.40%.
Regional distribution is uneven
PCB industry in China is mainly distributed in south China and east China, which together account for 90% of the whole country, and the industry aggregation effect is obvious. This phenomenon is mainly related to the fact that the main production bases of China’s electronics industry are concentrated in the pearl river delta and the Yangtze river delta.
PCB downstream application distribution
The distribution of downstream applications in China’s PCB industry is shown in the figure below.Consumer electronics accounted for the highest share, 39 percent. Computers followed at 22%. 14% for communications;Industrial control/medical devices 14%. Automotive electronics accounted for 6%. Defense and aerospace accounted for 5%.
Outdated technology
Although China is now the world’s first in terms of industrial scale, the overall technical level of PCB industry is still behind the world’s advanced level. In terms of product structure, multilayer boards account for most of the output value, but most of them are medium and low-end products below 8 layers. HDI, flexible boards and other products have a certain scale, but there is a gap with Japan and other foreign advanced products in terms of technical content.
What are the types of PCB board materials?
94v-0 and 94v-2 belong to a class of flame retardant materials, of which 94v-0 belongs to the highest flame retardant material.
PCB board is generally divided into several colors, green is the most common, and black, red, blue, yellow color and quality is irrelevant, just a personalized performance.
PCB board mainly considers the material and thickness, and rarely considers the color.What you said should be the color of solder ink!
Solder ink colors are white, yellow, black, red, blue, and a transparent ink, most often green ink.According to the accuracy of the board to use resistance welding ink is different.
According to the material, it can be divided into organic materials and inorganic materials
A. organic materials
Phenolic resin, fiberglass /Epoxy, Polyimide, BT/Epoxy and others are all listed in the list.
B. inorganic materials
Aluminum, copper-invar-copper, ceramic, etc.
Yongmingsheng is a professional PCB manufacturing factory. We are from China. You are welcome to contact us