PCB Board History
The development history of PCB board can be traced back to the early 20th century. In 1936, the Austrian Paul Eisler first applied PCB board in the radio; in 1943, the United States widely used PCB board in the military radio; in 1948, the United States officially recognized that the invention could be used for commercial purposes. Thus since the mid-1950s, PCB began to be widely used, and then entered into the phase of rapid development.
As PCB boards become more complex, some designers are confused about the definition and use of each layer when designing PCBs. To avoid unnecessary misunderstanding, EPCB will briefly introduce each layer of a PCB board.
It is generally used to place information about PCB board and assembly methods, such as PCB dimension, vias, assembly instructions, etc.
Internal plane only can be found in the multilayer board. Generally, the total PCB board layer is made up of the signal layer and inner layer. Like signal layer, inner layers to signal layers or inner layers can connected by through holes, blind holes and buried holes.
Top Signal Layer: It mainly used to place components. Both double-layer and multi-layer board arrange wires on it.
Bottom Signal Layer: Also known as welding layer, it is mainly for wiring and welding. Both double-layer and multi-layer board place components on it.
Mid Signal Layer: The maximum is 30 layers where signal lines are arranged, except supply wire and ground wire. Each layer can be connected by through holes, blind holes and buried holes.