What Is a Printed Circuit Board?

Printed circuit boards, also known as printed circuit boards, are providers of electrical connections to electronic components.

Printed circuit board

Printed circuit boards, also known as printed circuit boards, are providers of electrical connections to electronic components.

Printed circuit boards are often referred to as "PCBs" and cannot be referred to as "PCB boards."

Its development has a history of more than 100 years; its design is mainly layout design; the main advantages of using circuit boards are greatly reducing errors in wiring and assembly, and improving automation and production labor rates.

Can be divided according to the number of circuit board layers

With the rapid development of electronic technology, printed circuit boards are widely used in various fields, and almost all electronic equipment includes corresponding printed circuit boards. In order to ensure the normal operation of electronic equipment, reduce mutual electromagnetic interference, and reduce the adverse effects of electromagnetic pollution on humans and the ecological environment, electromagnetic compatibility design cannot be ignored. This article introduces design methods and techniques for printed circuit boards.

In the design of printed circuit boards, component layout and wiring of circuit connections are two key links. ^[1]

Printed circuit board manufacturing technology is a very complex and highly comprehensive processing technology. Especially in the wet processing process, a large amount of water is used, so a variety of heavy metal wastewater and organic wastewater are discharged, the components are complex, and the treatment is difficult. Calculated according to the utilization rate of printed circuit board copper foil is 30% to 40%, then the copper content in waste liquid and wastewater is quite considerable. Calculated based on 10,000 square meters of double-sided panels (the thickness of copper foil on each side is 35 microns), the copper content in waste liquid and wastewater will be about 4,500 kg, and there will be many other heavy and precious metals. If these metals in the waste liquid and wastewater are discharged without treatment, it will cause waste and pollute the environment. Therefore, the wastewater treatment and the recovery of copper and other metals in the printed board production process are very meaningful, and are an indispensable part in the production of printed boards.

As we all know, the waste water in the printed circuit board production process is a large amount of copper, and a very small amount of lead, tin, gold, silver, fluorine, ammonia, organic matter and organic complexes.

As for the process of producing copper wastewater, there are: sinking copper, all-plate electroplating copper, pattern electroplating copper, etching, and various pre-processing steps for printed boards (chemical pre-treatment, brush-plate pre-treatment, volcanic ash grinding board pre-treatment, etc.).
The copper-containing wastewater generated by the above steps can be roughly divided into complex wastewater and non-complex wastewater according to their components. In order to achieve the national wastewater discharge standards, the maximum allowable concentration of copper and its compounds is 1mg / l (calculated as copper), different wastewater treatment methods must be adopted for different copper-containing wastewater.