How Printed Circuit Board works?

The composition of the circuit board

First of all, you need to know that the electronic circuit board can call the main board. The main board is generally names the PCB (Printed Circuit Board) board. The Chinese name is printed circuit board. It integrates various specifications of resistors, capacitors, inductors, diodes, etc.

The functional IC, under the joint action of these components, obtains the electronic motherboard of electronic products with various functions.


Circuit board design


The first is the design of the electronic motherboard.

The first step of this design is the drawing of the schematic diagram.

It is a diagram of the connection principle between various components on the circuit board. It can consider that the diagrams that can reflect the principle of the circuit are all schematic diagrams. And in the actual production process, the circuit principles of each module of the electronic motherboard can separate.

On the one hand because of the area limitation of the drawing. On the other hand because the communication between the modules is connected through the network signal. So as long as the network signal does not If it is wrong, there will be no confusion in the schematic diagram.


With the schematic diagram, you can know the working principle of each module in the circuit board. And the flow of signals or power, and have a glimpse of the core of the circuit board.

At the same time, when designing the schematic diagram, it is necessary to consider the selection of components. Including packaging format, withstand voltage, EMC (electromagnetic compatibility) and other factors. So the selection of components is also a very time-consuming and energy-consuming thing in schematic design. (After the selection is completed, a BOM table will generally be made).

After the schematic diagram, you need to find a way to turn all the components that appear in the schematic into a real PCB board.

Production of Printed circuit boards


Then you need to turn the various components in the schematic into the real life appearance.

At this time, you need to know the concept of packaging. The circuit pins on the silicon chip can connect to external connectors with wires to connect with other devices. Simply put. It is the existence of components, such as a 10Ω resistor, which can  package into pin type or SMD type.

Reflected on the component body is the specific shape, pin arrangement, and can reflect on the PCB board is the spacing, area, quantity and other parameters of the contact point of the pins and wires. It can  conclude that the PCB package is the product of the mapping of components to the PCB.

Then there is the drawing of the PCB board. First, draw an approximate mechanical frame, that is, the approximate shape and area of the circuit board. Then put the components into the mechanical frame. And generally the same functional modules can place in adjacent areas.

If there is a specific component library, you can directly select the corresponding component on the schematic diagram. And a corresponding component PCB packaging location will automatically generate on the PCB board.

However, in the PCB design, the number of layers of the PCB needs to considereat the beginning. If it is just a simple electronic circuit, generally only one or two layers, top and bottom, just needed. But if the circuit becomes complex and functions can increase, it is necessary to Increase the number of layers of the PCB. Including additional power planes, ground planes, solder mask layers, etc.


Specific steps


After the PCB layout of all components drawn.

The wiring can  performe, either automatically or manually. The wiring is actually what we call the wire, which corresponds to the wire on the schematic diagram. Of course, in the actual production process , the position of the wire should  adjuste according to the specific situation.

After wiring, you can see the preview of the PCB.

Of course, if the software supports it, you can also view the 3D renderings, which is how the final circuit board will look.


After all the above processes are completed.

The only thing left is to print the physical circuit board (PCB diagram) designed in the software to it. This process requires special PCB equipment or PCB factory to proof. According to your design drawings, the effect of proofing can show in the following figure.

electronic circuit board

Then the corresponding electronic components (resistors, capacitors, ICs, etc.). They  soldered to the PCB board with solder paste or solder to form the final electronic circuit board.