High power PCB design has gained popularity in the recent past. Previously, the design was limited to military equipment.
In this section, let us look at the definition of the PCB.
We will also look at some of its features, pros and cons, and application.
High power PCBs are printed circuit boards made of heavy copper. This enables them to handle higher rates of current compared to other boards.
They are also able to resist high temperatures for extended periods. As such, they provide strong connection points.
High power PCB designs are fabricated for specific devices.
These devices require higher amounts of current flows and are often subjected to varying temperatures.
For them to perform effectively and efficiently, high power PCB design incorporates the following features:
The copper layer in high power PCB design is thicker and heavier compared to those found in other PCBs. This gives it the ability to conduct higher currents.
This ability to conduct higher currents is coupled with the ability to dissipate heat. This helps in ensuring that no short circuits occur during operations by devices made from the board.
For these reasons, high power PCB is able to resist and adapt to fluctuating temperatures that the device is used in.
Due to their ability to conduct high rates of currents and to accommodate fluctuating temperatures, high power PCBs has many applications. Let us have a go through some of these applications.
Solar power distribution boards heavily rely on high power PCBs for efficiency.
Since solar power distribution boards transmit both higher currents and voltage, they rely on high-power boards. This enables them to transmit currents effectively.
In the military, most applications need high currents and also get subjected to fluctuating temperatures. As such, it is imperative to make them using PCBs that can handle these features. These qualities can only be found in high power PCBs.
Military applications such as communication devices, satellites and radar, therefore, rely on high power PCBs for efficiency.
They are also used in armored military vehicles and fighter jets used in military operations.
In the recent past, industries have heavily relied on high power PCBs. This is because within the sectors, there is heavy reliance on high currents and voltage.
The power distribution transformers within the industry also use high power PCBs. This enables them to transmit currents effectively for the performance of the industrial machines.
Airplanes and spacecraft are subjected to fluctuating temperatures and rely on high currents and voltage to perform effectively and safely. Failure to make considerations when identifying the most suitable board can result in fatalities.
Take, for instance, the current flow during the launching of a spacecraft. This cannot be handled with any other PCB owing to the high currents involved.
Communication devices in the industry also rely on high power PCBs since they get exposed to diverse environments. This is the same case with the radar used by the control tower.
Satellites are exposed to fluctuating temperatures. To effectively perform their functions, they also need high current flows.
Other PCBs cannot sustain these factors. High power PCBs are thus used in the industry.
There are quite a number of high power printed circuit boards available in the market today. Let’s look at some of the most common classification criteria.
These are high power printed circuit boards which allow for mounting of components on both sides. They are the entry level into more complex applications made using high power PCBs.
Using vias, they alternate routing traces between the top and the bottom layers. This makes them more efficient and dependable compared to single-sided high power printed circuits.
Rigid-Flex high power printed circuits are made up of both rigid and flexible circuit substrates.
More often than not, rigid-flex high power boards are composed of multiple layers of flexible substrates. These flexible substrates are then attached to either one or more rigid boards.
This attachment is done either internally or externally. The intended application for high power rigid-flex board is crucial in determining how the attachment is done.
Also, the flexible components are designed to be always flexible.
This flexibility is useful in corners and areas that need extra space. Rigid substrates are helpful in areas that require additional support.
With these capabilities, there is a surety that these high power rigid-flex boards can be curved during the manufacturing and installation processes.
Rigid-flex technology gives high power PCBs the ability to fit into smaller applications. This results in enhanced performance and convenience.
Multilayer high power circuit boards have at least three conductive layers. Cross circuit board plated through hole is the most commonly used electrical connection strategy in these boards.
Depending on the purpose the board is being manufactured for, the conductive layers can be as many as twelve. However, there are some companies that are now fabricating PCBs with up to 100 layers.
This gives room for the manufacture of some of the most complex high power PCB applications.
The heavy copper endowed in the high power PCB gives it the ability to endure thermal strains that it is subjected to.
Devices made of high power PCBs are hence in a position to resist thermal fluctuations, making them reliable.
This explains their preference in the manufacture of military applications.
Heavy copper also gives high power PCBs the ability to conduct high currents without much strain. High currents on PCBs with lighter copper are susceptible to failure and malfunctioning.
Devices such as power transformers are exposed to very high currents. Without high power PCBs, they are likely to fail or cause disasters.
Heavy copper used in the manufacture of high power PCBs gives it mechanical strength. This is very important in supporting the components that are mounted on the board.
The connector sites are more strengthened in high power PCBs. This extends to the through holes which are also made stronger by the copper.
High power PCB design also helps in the reduction of the product size. This is achieved through incorporation of multiple copper weights onto the same layer of the circuitry.
This explains its preference in military applications as most products have to be portable.
With heavy copper plated vias, high current transfer through the board is made possible. This helps in the transfer of heat to the external heat sinks.
It makes high power PCBs the most effective board for applications that require high currents to function effectively.
The heat sinks in the high power PCB design can also be directly plated on the board. This explains the reliance on high power PCB design in industrial applications.
High power PCB design is expensive to fabricate. This is because they demand heavier and thicker copper, which is very expensive, to be able to operate effectively.
The processes involved in high power PCB design can be time-consuming. The additional features that are imperative for the effective functioning of the PCB consume time. This is unlike other simpler PCBs.
In this section, we first look into circuit board layout considerations before proceeding to discuss the design tips. We then discuss the steps involved in designing high power PCBs.
The first consideration that should be made during the design process is the board layout.
Establishment of the power path is the most important rule for the high power circuits.
This will be of essence in coming up with the location and amount of power that should flow through the circuit. It further informs the position of the IC and the amount of heat dissipation that is required for the board.
There are a many of factors that inform the layout for a specified design. These are:
In the past, analog and mixed-signal circuit boards were used. They included high-power and analog blocks.
In other instances, they included sensitive digital analog blocks which had low power.
In the first step for the layout, you should design and place power blocks.
Ensure that you keep the connections within the individual power blocks. This applies to both short and wide blocks.
As you do this, make sure that you deter unwarranted ground loops and generation of noise. Generally, make the following considerations:
Apart from the mentioned layout considerations, it would also be essential to avoid lumping together different power components on board.
For the board to achieve thermal balance, ensure that you distribute these heat components evenly across the board.
This will also effectively protect the board from warping. Thus, you can be assured of reduced heat on the board and protection of sensitive circuitry.
The signals will also enjoy equal protection during operation.
Whenever there is power flow within a circuit, it is obvious that all the components will generate heat.
When heat is generated in the passive components and the ICs, the heat will most likely be dissipated. This heat is dissipated to cooler ambient air that surrounds the device.
This dissipation is made possible by the device’s lead frame or through the package. Most IC packages are thus designed not to leave a lot of room through which external heat sinks can occur.
Also, this calls for a method through which heat can be extracted from the device. Exposed pad is one such method. For the thermal performance to be optimal, use a die inside the package.
This die should have an EP directly connected to it. These ICs can then be mounted correctly on the board. In so doing, heat transfer from the package to the board will be optimized.
In most instances, components found within the power path will always produce enormous amounts of heat. Thus, it is important to come up with strategies through which the generated heat can be dissipated to the ambient environment.
To achieve this, you have the option of adding an external heat sink onto the board. This will enable your board to expel the heat from the device and to dissipate it into the ambient air.
These heat sinks should be made from materials with high thermal conductivity capabilities. Such materials include metals such as aluminum and copper.
It is advisable to put these heat dissipaters along the airflow path. This will lead to a faster dissipation rate.
The positioning of the IC should be in a manner that the heat sinks are fixed in a desirable location. You can then make heat transfer optimal from the IC to the heat sink by using thermal epoxy.
This will be essential in easing heat transfer between your devices. Ensure that you create enough room on the board.
However, this is never appropriate for smaller devices or even compact applications.
Take care when routing high power paths that exist between the I
