PCB knowledge, how much do you know
Oct 31, 2022
It has high reliability, high density, design, assembly test and maintainability. It is one of the important electronic industry components and is required for almost every electronic device. It is widely used in consumer, communications, automotive, industrial control, medical, aerospace, military and other products. PCB board plays an indispensable and important role.
1. How are PCB boards discovered and widely used?
Here we have to mention Paul Eisler, the creator of PCB.
In 1936, he first used printed circuit boards in radios. In 1943, Americans mostly used this technology in military radios, and in 1948, the United States officially recognized this invention for commercial use. Printed circuit boards have only been widely used since the mid-1950s.
2. Common colors of PCB
Common PCB colors are red, yellow, green, blue, and black, but green is the most used.
Since about the middle and late last century, the industry has begun to pay attention to the color of PCB boards; many high-end board types of first-tier manufacturers have also adopted green PCB board color design, so people slowly think that the color of PCB is green. is high end.
Secondly, the production and maintenance personnel need to watch the components on the PCB board for a long time when they are working. Compared with other colors, green is much more comfortable for the eyes.
After the green PCB board is welded by SMT, when it is tested and verified by AOI, the positioning of the optical instrument will be more accurate and better identified; and the production cost of the green PCB board will be lower.
The principle of blue and black is that they are doped with cobalt and carbon lamp elements, respectively, and have certain electrical conductivity. In the case of power-on, short-circuit problems are likely to occur, and green PCBs are relatively environmentally friendly. In high temperature environments When used, generally no toxic gas is released.
There are also a small number of manufacturers in the market who use black PCB boards. On the one hand, it looks high-end. On the other hand, it is not easy to see the wiring on the black board, which brings certain difficulties to copying the board.
3. PCB board design
To manufacture a PCB, the layout design of the PCB must first be carried out.
The basic process of PCB design is: preliminary preparation → PCB structure design → PCB layout design → PCB constraint setting and wiring design → wiring optimization and silk screen placement → network DRC inspection and structure inspection → PCB board making.
With the continuous miniaturization, precision and high speed of electronic products, PCB design not only needs to complete the circuit connection of various components, but also considers various challenges brought by high speed and high density.
4. PCB Screen Printing
Screen printing is a layer of ink traces (mostly white) to mark the position, symbols, etc. of the various components of the PCB on the board. The screen-printed side is also known as the icon side; it is often used as part of a PCB design.
5. Are there wires on the PCB?
In fact, PCBs are connected without wires.
Most electrical devices and technologies require wires to be connected, there are no wires in a PCB, but copper traces are used to carry current throughout the device and connect all components.
