There is no doubt that the printed circuit board (PCB) is a landmark tool in human technology. why? That’s because it’s hidden in every electronic device today. Just like other great inventions in history, PCB has gradually matured with the advancement of the wheel of history. It has a history of 130 years of development. It is the most beautiful landscape in the wheel of the industrial revolution.
PCB has become a means of optimizing the production process of electronic devices. Those electronic devices that used to be hand-made have to be replaced by PCB because more functions will be integrated on the circuit board.
Comparing Circuit Boards in 1968 Calculators to Modern Computer Motherboards
PCB board color
Even for some people who don’t know what a PCB is, they generally know what a PCB looks like. They at least look like they have a traditional style, and that is its green color. This green is actually the color that the solder mask glass paint transmits light. Although the name of the solder mask is solder mask, its main function is to protect the covered circuit from moisture and dust.
As for why the solder mask layer is green, the main reason is that green is the military protection standard. The PCB in the military equipment was the first to use the solder mask layer to protect the reliability of the circuit in the field, and green is the natural protective color in the military. Some people think that the color of the epoxy resin used in the original solder mask paint itself is green, so it has been used to this day.
Now the color of the solder mask layer is various, including black, red, yellow and so on. After all, green is not an industry standard.
Who invented the PCB
If you ask who invented printing, the honor is Bi Sheng during the Northern Song Dynasty in China. But the earliest printed circuit boards need to be traced back to the concept of using ink to conduct electricity (printing brass wires on the bottom plate) by Austrian engineer Charles Ducas in 1920. He used electroplating technology to directly generate wires on the surface of the insulator to make a prototype of the PCB.
Originally the metal wires on circuit boards were brass, an alloy of copper and zinc. This disruptive invention eliminates the complex wiring process of electronic circuits and ensures the reliability of circuit performance. This process did not begin to enter the practical application stage until the end of World War II.
Printed Circuit Board Patents and Charles Ducas
White marker
There are also plenty of white markings on the green circuit board. For many years, people wondered why these white printed marks were called “screen layers”. They are mainly used to identify the information of the components on the circuit board, as well as other related content of the circuit board.
This information was first printed on the circuit board by screen printing, so it was called the screen layer, and now it is done using a special inkjet printer. This information can help circuit engineers to check for faults in the board.
Components
The function of the circuit board is mainly accomplished by effectively connecting the components according to the schematic diagram. Each component has its own unique function. Even two devices that are closely adjacent on a circuit 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.).
PCBs are everywhere
It is no exaggeration to say that PCBs are everywhere. From computers to digital clocks, from microwave ovens to televisions and stereo systems. As long as it is electronic items and equipment, there is a more than 99% chance that it contains a PCB. So we might take it for granted that no electronic device could function without a PCB.
NASA
Some groundbreaking technologies have been used in many NASA projects. In the 1960s, NASA used PCBs on the Apollo 11 rocket. This is because PCB-based electronics The device is light in weight and consumes little power. That was humanity’s greatest moment, sending astronauts to the moon for the first time. One of them is the credit of the PCB.
Surface Mount Soldering Technology
Surface mount soldering technology has modernized PCBs. Compared with the previous jack mounting method, this surface mount soldering technology first uses special glue to paste the device on the PCB, and then electrically connects the device to the circuit board through special reflow soldering.
Rapid Prototyping PCB
In the process of local experiments on the circuit, the test can be carried out with the help of breadboards, perforated boards, and other general-purpose circuit boards. With the increase of surface packaging components, there are also new rapid PCB prototyping technologies, such as thermal transfer PCB, 3D printing multi-layer circuit boards, etc.
3D Printed Circuit Boards
Flexible PCB
PCBs are not all straight and hard, and many soft PCBs work in many compact electronic devices, and they often form application circuits in many movable joints, or form multi-layer three-dimensional circuits.
Transparent and Soft PCB
The largest PCB in the world
The world’s largest PCB comes from a flexible multi-layer circuit board used in an unmanned solar aircraft by Johnson Electronics in the UK. It is about 28 meters long. The circuit board made of soft polyimide as the base has better heat dissipation and higher conductivity density. Such a long circuit board is made by etching in sections through a special production process.
Longest Flexible Circuit Board
