how are pcbs made
The base material or substrate is usually glass fiber. Historically, the most common symbol for this glass fiber is "FR4". Fiberglass is stacked on top of each other and fixed with resin, and made into a unit strong enough to hold the board. There are also flexible PCBs built on flexible high-temperature plastics.
Cheaper PCBs should be made with other materials. Epoxy resins or phenolic resins lack the durability of FR4, but are much cheaper. These types of substrates can also be found in low-end consumer electronics products.
The PCB can be single-sided (one copper layer), double-sided (one substrate layer with two copper layers on both sides), or multiple layers (outer and inner copper layers, alternating with substrate layers).
The next layer is thin copper foil. It is laminated to the circuit board by heating and adhesive. Generally, on a double-sided PCB, copper is applied to both sides of the substrate. In cheaper electronic devices, the PCB may have copper on only one side. When we say double-sided or double-layer board, we are referring to the number of copper layers in the lasagna.
This lasagna can be as few as 1 layer or as many as 16 or more layers.
The layer on top of the copper foil is called the solder mask. This layer provides a typical green color for PCBs. It is applied to the copper layer to insulate the copper traces. It eliminates the possibility of accidental contact with other metals, solder or conductive drill bits. This layer helps users solder to precise locations and prevents solder jumpers.
Apply a white wire mesh layer on top of the solder mask. This silk screen adds letters, numbers and symbols to the PCB. This makes it easier to assemble and instruct humans to better understand the circuit board. We often use screen labels to indicate the function of each pin or LED.
Cheaper PCBs should be made with other materials. Epoxy resins or phenolic resins lack the durability of FR4, but are much cheaper. These types of substrates can also be found in low-end consumer electronics products.
The PCB can be single-sided (one copper layer), double-sided (one substrate layer with two copper layers on both sides), or multiple layers (outer and inner copper layers, alternating with substrate layers).
The next layer is thin copper foil. It is laminated to the circuit board by heating and adhesive. Generally, on a double-sided PCB, copper is applied to both sides of the substrate. In cheaper electronic devices, the PCB may have copper on only one side. When we say double-sided or double-layer board, we are referring to the number of copper layers in the lasagna.
This lasagna can be as few as 1 layer or as many as 16 or more layers.
The layer on top of the copper foil is called the solder mask. This layer provides a typical green color for PCBs. It is applied to the copper layer to insulate the copper traces. It eliminates the possibility of accidental contact with other metals, solder or conductive drill bits. This layer helps users solder to precise locations and prevents solder jumpers.
Apply a white wire mesh layer on top of the solder mask. This silk screen adds letters, numbers and symbols to the PCB. This makes it easier to assemble and instruct humans to better understand the circuit board. We often use screen labels to indicate the function of each pin or LED.
If you have PCB to produce, please send Gerber to sales@pcbsky.com.cn .Thank you.
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