How to Design the Best PCB | 2021
Fri, Dec 27, 2019
If there is one thing about the modern world of electronics that is widespread, it would be PCBs
PCBs, an acronym for ‘Printed Circuit Boards’, is today found wherever there is a need for electrical connections, making them an integral part of the modern technological world.
To begin with, PCB technology was an innovation that came about several decades ago.
Developed to replace inefficient wires, they quickly became highly sought after for a host of benefits, including but not limited to structural strength, efficiency, lower energy needs, etc.
Today, the usage of PCBs has only continued, and given the current trends, very likely to continue well into the near future.
When it comes to the design aspect of the PCBs, there is a lot that can be said. One of the most important, and also interesting, would be the many steps used by professionals to make these technological marvels.
Given in the list below, are ten key tactics used by the pros for manufacturing printed circuit boards.
1.) Management of Resistance
The design of PCBs needs to take into consideration the amount of thickness, length, and width to control the PCB trace resistance.
For those wondering what resistance is, it is a term used to define the property of a metal, where there is a certain ‘resistance’ to the flow of electricity through a wire or other such object made from it.
One of the ways in which the trace is made is through the measuring of the amount of copper used, typically in ounces.
In simple terms, the variability of the thickness of the trace can provide for a range of different resistances, in turn allowing for a range of possibilities to be achieved during the design phase of the PCB circuit.
2.) The Management of Heat
An important issue with almost any electronic in the world is heating.
Electricity has the property of heat generation, which can be a good or bad thing, depending on how you look at it. In the case of bathroom components such as geysers or boilers, it can be great. But in the case of electronics such as computer components or PCBs in general, it can be a real nightmare. This is because excess heat can damage the components and in some cases even prove to be a fire hazard.
One of the most common ways in which the heat has been traditionally dealt with is with the help of a heatsink. In general, a heat sink can be thought of as a metal plate, which has a large surface area to allow for the heat to flow through it and into the air around it. The heat sink often comes together with a cooling fan, as in the case of the cooling system on top of a computer processor.
In many cases, the PCB mounted heatsinks tend to connect to heat sources, as well as vast areas of the board itself, so as to allow for the maximum dispersal of heat from the system.
3.) Using Smaller Loops
A loop can be understood as a circuit that goes in a ‘loop’ manner from one part of the circuit board to another.
It is very easy to observe in a typical board, where the circuit starts off as a straight line from one end to another, after which it turns at a certain angle, and then once more until the direction of the circuit is changed entirely.
This is done for a variety of reasons such as creating enough space for components, providing for the necessary resistance, and so on. Smaller loops are preferred because they have lower inductance and resistance in comparison to larger ones. In addition to this, there is also a marked reduction in high-frequency voltage spikes during usage.
4.) Decoupling the Placement of Capacitors
A good idea for the placement of capacitors would be to have them as close as possible to the power and ground pins of the PCB.
The reason for this is that it helps to prevent issues associated with inductance and radiation.
5.) The Management of Via Size & Number
Vias have a certain inductance and resistance to them, which play a key role in the design and function of PCBs.
When routing a trace from one part of the PCB to another and there exists the need for a low inductance or resistance, it would e a good idea for one to use multiple vias.
Likewise, the usage of large vias is a good strategy in cases where there is a need for lower resistance. This is particularly good when it comes to the use of grounding filter capacitors and other high current nodes.
6.) The Placement of Heat-Sensitive Components
There are several components on a PCB that are heat sensitive.
Even in cases where they are ‘shielded’ from the heat through physical barriers, there is still a certain potential for heat damage.
The components which come under this category include, among others, MOSFETs, diodes, bridge rectifiers, inductors, and resistors. All of these components tend to have a very low degree of heat tolerance and can be negatively affected when exposed to the same.
These components must therefore be placed as far away from sources of heat as possible. The use of heatsinks is another good way to protect these delicate components from heat-related damage.
7.) Preventing Damage during the Drilling of Holes
The average PCB comes with a range of holes, which serve a variety of purposes.
These holes are typically drilled using mechanical means, and the process itself is a standard industry practice. The holes in turn, after being drilled, become the base for vias, and other circuitry.
The major concern is not so much the hole, but rather the board’s integrity. Drilling a hole through the board can result in damage, especially through spinning, in cases where the board isn’t secured. It should therefore be ensured that the board is properly secured before any drilling is begun.
Likewise, the same holds true for the drilling process itself, where the correct drilling location is confirmed, so as to avoid damaging any nearby circuitry or design.
8.) Leave Room between Copper Traces & Fills
This is important because the lack of space can result in a short circuit or other shock hazards.
Always ensure that a certain amount of space exists between the copper traces at all times.
9.) Keep Noise & Analog Traces Away from Each Other
This is an important thing to remember, as the two tend to get in the way of each other, resulting in a ‘doubling’ of the signal on the traces.
The consequence of this can range from interference to short-circuits, both of which are bad for the PCB.
10.) A Second Opinion Is a Good Thing
As much as you may be confident with your design, it is a good idea to get a second opinion.
A neutral third-party review of the design can go a long way in giving you another perspective of things, and help you make any necessary changes.
This will help in everything from the overall design improvement to raising efficiency and so on.
In summary, there are indeed many ways in which the manufacturing of PCBs can be done.
At the same time, however, some strategies and tips are much better in comparison to others, for a wide range of factors.
The points mentioned above, as well as others like them, are a great way to know about the many unique ways that experts go about with the design process, ultimately making the technology efficient, safe, and reliable for everyone.