1. Color
Even for some people who do not know what PCBs are for, they generally know what PCBs look like. They at least seem to give a traditional style, that is, its green color. This green color is actually the color of the solder resist layer of glass paint translucent. Solder resist layer, despite the name is solder resist, but its main function is to protect the covered circuit from moisture, dust.
As for the solder resist layer why the choice of green, the main reason is considered green is the army protection standards, military equipment in the PCB first used a solder resist layer to protect the reliability of the circuit in the field, green is the natural protection color in the army. Others believe that the color of the epoxy resin used in the initial solder resist paint itself shows green, so it has been used to this day.
Now the color of the solder resist layer is already a variety of black, red, yellow and so on.
2. Who first invented the PCB
The earliest printed circuit boards need to be traced to the Austrian engineer Charles Ducas in 1920 proposed the use of ink conductive (printed brass wire on the backplane) concept. He used electroplating technology to produce a prototype PCB by generating wires directly on the surface of the insulator.
Initially the metal wires on the circuit board was brass, an alloy of copper and zinc. This disruptive invention eliminated the complex process of connecting electronic circuits and ensuring the reliability of circuit performance. This process did not begin to enter the practical application stage until the end of World War II.
3. Marking
In the green circuit board there are also a large number of white markings. For many years, people do not understand why these white printing markings are called "screen layer. They are mainly used to identify the information on the components of the board, as well as other content related to the board.
This information was first printed on the circuit board by screen printing, so called screen layers, and now use special inkjet printers to complete. This information can help circuit engineers to check whether there are faults in the circuit board.
4. Components
The function of a circuit board is accomplished by effectively connecting the components according to the schematic. Each component has its own unique function. Even two devices in close proximity to each other on the board can be very different. The types of devices basically include resistors, diodes, transistors, capacitors, relays, batteries, transformers, and many others (such as fuses, inductors, potentiometers, etc.).
5. Ubiquitous
It is no exaggeration to say that the PCB is ubiquitous. From computers to digital clocks, from microwave ovens to televisions and stereo systems. As long as the electronic items and equipment, more than 99% of the possibility of which contains PCB. so we may take for granted that without PCB may not be able to operate any electronic equipment.
6. NASA (National Aeronautics and Space Administration)
In the U.S. National Aeronautics and Space Administration (NASA) in many projects on the use of some stone-cold technology, including in the 1960s, NASA used PCBs on the Apollo 11 rocket, which is based on PCB electronic equipment light weight, low power consumption. That was mankind's greatest moment, the first time the astronauts were sent to the moon. This has the credit of the PCB.
7. Surface Mounted Soldering Technology (SMT)
Surface mount soldering technology makes the PCB into the modern. Compared to the previous jack mounting method, this surface mount soldering technology uses special glue to paste the device on the PCB first, and then the device is electrically connected to the board through a special reflow solder.
8. Rapid prototyping PCB
During local experiments on circuits, breadboards [2], cavity boards, and other general-purpose boards can be used for testing. With the increase in surface package components, there are new rapid PCB prototyping techniques, such as thermal transfer PCB, 3D printing of multilayer circuit boards.
9. Soft PCB
PCBs are not all flat and hard, there are many soft PCBs work in many tight electronic devices, they often constitute a lot of moving joints in the application circuit, or the composition of multi-layer three-dimensional circuit.
10. The world's largest PCB
The world's largest piece of PCB from the British company Johnson Electronics, this application in the unmanned solar aircraft flexible multilayer circuit board. It is about 28 meters long. Is made of flexible polyimide as the base of the circuit board has better heat dissipation, higher conductivity density. Such a long circuit board is made through a special production process for etching in sections.