As an important electronic component, printed circuit board is the support body of electronic components. Because of its important role in the field of electronic components, it is called "electronic carrier" by many people.
Today, printed circuits are used in communication products, computers, and almost all other electronic products. The development and perfection of printed circuit technology created conditions for the invention of integrated circuit, which changed the face of the world. With the development of science and technology, printed circuit boards are widely used in military, communications, medical, electric power, automobile, industrial control, smart phones, wearable and other high-tech fields.
The invention of printed circuits
The printed circuit was invented by Austrian electrical engineer Paul Eisler in the mid-1930s. Eisler studied electrical engineering at the Vienna Institute of Engineering and, after graduating in 1930, studied printing technology. In his research on electronic circuit boards, he often went to the library to consult books on printing technology.
After careful consideration, he came up with the idea that if you printed the circuit of an electronic device on a circuit board at a time, as you would print a book or a newspaper, you wouldn't have to make the circuit board piece by piece by hand, and you wouldn't have to weld the circuit line by person, which would greatly improve the efficiency and reliability of electronic products.
In the printing industry, photo platemaking is often used to produce pictures on paper. That is, by taking photos, the picture of the bottom plate, etched on the copper plate or zinc plate, with this copper plate or zinc plate, you can print a lot of pictures.
Eisler experimented with making circuit boards in a similar way to the printing industry. He drew an electronic circuit diagram, then etched the circuit diagram onto an insulating board covered with copper foil, so that the unwanted copper was etched away, leaving only the conductive circuit. In this way, the electronic components are connected to each other through circuits formed by copper foil on the board. This kind of printed circuit can not only improve the reliability of electronic products, but also greatly improve the production efficiency, which has great value and potential for the development of new electronic products.
The printed circuit technology makes the mass production of electronic equipment simple and easy, and lays the foundation for the mechanization and automatic production of electronic products. Since the 1950s, great progress has been made in various electronic products, including communication equipment, with the use of printed circuit technology.
With the continuous improvement of the manufacturing level of printed circuit, the printed circuit produced can reach a high precision, so as to push the manufacture of circuit board to a new stage. When making plates in the printing industry, a large picture can be reduced to a certain size by shooting.
In the manufacture of printed circuits, it is also possible to reduce the electronic circuit diagram to make a small area, complex circuit and high reliability of the electronic circuit board. This kind of printed circuit board is very suitable for communication equipment and computer with complex circuit and high reliability requirement. The development of printed circuit technology laid the necessary technical foundation for the subsequent invention of integrated circuit.
From the invention of the circuit board, its history of more than 60 years. History shows: no circuit board, no electronic circuit, flight, transportation, atomic energy, computer, aerospace, communication, home appliances... None of this will work.
The reason is easy to understand. Chip, IC, integrated circuit is the food of electronic information industry, semiconductor technology reflects a country's level of industrial modernization, guide the development of electronic information industry. And semiconductor (integrated circuit, IC) electrical interconnection and assembly must rely on circuit boards.
Types of printed circuit boards
Printed circuit boards used in actual electronic products vary widely and are classified according to different standard printed circuit boards.
Classification by distribution of printed circuits
According to the printed circuit distribution can be divided into single panel, double panel, multilayer plate 3
The single panel is on the insulating substrate of a thickness of o. 2 -- 5mm, with only one surface coated with copper foil, and the printed circuit is formed on the substrate by printing and etching methods. Single panel manufacturing is simple, easy to assemble, suitable for a play circuit requirements, such as radio, television, etc.; Not suitable for situations requiring high assembly density or complex circuits.
Dual panels are printed circuits on both sides of an insulated substrate with a thickness of.2 -- 5mm. It is suitable for general requirements of electronic products, such as electronic computers, electronic instruments and meters. Because the wiring density of double panel printed circuit is higher than that of single panel, the volume of equipment can be reduced.