PCB design refers to the production of circuit boards at the lowest possible cost by designing schematic drawings for circuit layout.
In the past, this was usually done with the help of expensive specialized tools, but now the increasing popularity of free, high-performance software tools and design models has greatly accelerated the design speed of circuit board designers.
Although engineers know that a perfect design is the best way to avoid problems, it is still a waste of time and money and a way to treat the symptoms rather than the causes.
For example, if a problem is found during electromagnetic compatibility (EMC) testing, it will cause significant cost and even require adjustment and rework of the original design, which will take months.
Layout is one of the first issues designers face.
This problem depends on the part of the drawing that some devices need to be set up together based on logical considerations.
It should be noted, however, that elements that are sensitive to temperature, such as sensors, should be set apart from elements that generate heat, including power converters.
For designs with multiple power Settings, 12-volt and 15-volt power converters can be located at different locations on the circuit board, as the heat and electronic noise they generate can affect the reliability and performance of other components and the circuit board.
These components also affect the electromagnetic performance of the circuit design, which is not only very important for the performance and energy consumption of the circuit board, but also has a great impact on the economy of the circuit board. Therefore, all circuit board equipment sold in Europe must obtain the CE mark to prove that it will not cause interference to other systems.
However, this is usually only in terms of power supply, and there are many devices that emit noise, such as DC-DC converters and high-speed data converters.
Due to defects in circuit board design, these noises can be captured by channel and radiated as small antennas, thus generating hybrid noise and abnormal frequency areas.
The problem of far field electromagnetic interference (EMI) can be solved by adding a filter to the noise point or by using a metal casing to shield the signal.
But the emphasis on devices that release electromagnetic interference (EMI) on the circuit board has led to cheaper enclosures for the circuit board, effectively reducing the cost of the entire system.
Electromagnetic interference (EMI) is indeed a factor that has to be paid attention to in the design of circuit boards.
Electromagnetic crosstalk can be coupled with the channel, which can disrupt the signal into noise and affect the overall performance of the circuit board.
If the coupling noise is too high, the signal may be completely overwritten, so more expensive signal amplifiers must be installed to restore normal.
However, this problem can be avoided if the circuit board layout is fully considered at the beginning of the design.
Because circuit boards are designed to vary from device to device, from place to place, from heat dissipation requirements, and from electromagnetic interference (EMI) conditions, the templates are useful.
Capacitance is also an important issue in circuit board design that cannot be ignored, because it will affect the speed of signal propagation and increase the consumption of power.
The channel can be coupled to a nearby line or run vertically through two circuit layers, inadvertently forming a capacitor.
These problems can be solved relatively easily by reducing the length of parallel lines and by adding kinks to one of them to cut off the coupling.
However, this also requires the engineering designer to fully consider the production design principles to ensure that the design is easy to manufacture while avoiding any noise radiation caused by excessive bending Angle of the circuit.
The lines can also be too close together, creating short circuits between them, especially at the bends where metal “whiskers” develop over time.
Design rule detection can often identify areas where the loop risk is higher than normal.
This problem is particularly prominent in the design of strata.
A metal circuit layer that may be coupled to all the circuits above and below it.
Although the metal layer does block noise, it also creates associated capacitance, which affects the speed of the line and increases the consumption of electricity.
In terms of the design of multi-layer circuit board, the design of through hole between different layers of circuit board is probably the most controversial issue, because the design of through hole will bring many problems to the manufacture of circuit board.
The through-hole between the PCB layers will affect the signal performance and reduce the reliability of the PCB design, so sufficient attention should be paid.
During the PCB design process, many different approaches can be taken to solve various problems. There are adjustment of the design scheme itself, such as adjusting the line layout to reduce noise; There is also a PCB layout approach.
The design elements can be installed automatically with the layout tool, but the ability to manually adjust the automatic layout will help improve the quality of the circuit board design. Through this measure, the design rule test will be assisted by technical documents to ensure that the PCB design can meet the requirements of the PCB manufacturer.
Separating the different layers of the circuit board reduces the associated capacitance, but this increases the number of layers of the circuit board, which increases costs and creates more through-hole problems.
Although orthogonal grid power supply system and ground circuit design may increase the physical size of circuit board, it can effectively play the role of grounding layer in double-layer circuit board, and reduce the capacity and complexity of circuit board manufacturing.
Many PCB design tools can help engineers solve many problems at the beginning of the design process, but engineers still need to be fully aware of the design requirements of printed circuit boards (PCB).
For example, if the editor of a printed circuit board (PCB) needs to know the number of layers of the circuit board at the beginning of the design, for example, a double-layer circuit board, it needs to have a grounding layer and a power layer, two independent layer composition.
Automatic component layout technology is very useful, which can help designers spend more time to design the layout area of the equipment. For example, power supply equipment can cause many problems if it is too close to sensitive signal lines or areas with high temperature.
In the same way, signal wiring can be done automatically without most of the problems, but analysis and manual handling of high-risk areas will help significantly improve the quality of printed circuit board (PCB) designs, increase revenue, and reduce overall costs.
Design rule detection is also a very powerful tool, which can detect the lines to ensure that the distance between the lines is not too close, resulting in a short return.
However, the overall design still has a high economic value.
The design and planning detection tool can also be used to detect and adjust the power layer and the ground layer to avoid large associated capacitance area.
The above tools will also be of great help to Gerber and Excellon in their wiring and PCB printing, as well as through hole drilling, etc. in order to produce the final product of the design.
In this way, the technical documentation is closely tied to the circuit board manufacturer.
Many problems need to be considered in PCB design process, and PCB design tools can effectively deal with most of them.
By adopting some best practice guidelines, engineers can effectively reduce costs, improve board reliability, and meet system specifications, thereby avoiding more problems with a lower cost of bending and sinking system certification