Guide to high speed PCB

What is high speed PCB?

High speed PCB is one of the most commonly used type of printed circuit boards (PCBs). High speed PCBs are used in applications that require high-speed signals. They are designed to operate at frequencies above 10 GHz, which makes them ideal for applications such as telecommunications, military radar systems and aerospace systems. 

A good example of high speed PCBs is the implementation of the latest WiFi standards for smart phones and laptops along with other wireless devices such as Bluetooth speakers or headsets etc.

The key difference between high speed PCBs and regular printed circuit boards lies in the material from which they are manufactured. The ordinary FR-4 glass fiber sheet cannot meet the requirements of making high speed PCBs. It must be made of high-frequency material, such as Rogers PCB, Taconic PCB, Argon PCB, etc.

FR-4 glass fiber sheet

The advantages of high speed PCB

The advantages of using high speed PCBs are the following:
● A high speed PCB could be very useful if you need to transmit high frequency signals.
● High speed PCBs are used in products like video streaming devices, cell phones, and routers.
● Cost effective for high volume production.
● Designed to reduce signal integrity concerns.
● High speed PCB can lead to lower maintenance, higher reliability, and greater customer satisfaction.
● They can be used in many high temperature environments, such as those found in military and aerospace applications.

How to design the high speed PCB?

When designing high speed PCB, you have to consider a lot of aspects. Some of the considerations are:

★Ground Plane

A ground plane is the largest copper area on your board. It connects to your ground on the opposite side of the PCB, which is why it’s called a “plane”. It’s used to reduce EMI and RFI, as well as reduce noise coupling between layers.

★ Signal routing

Signal routing is a very important step in PCB design. The main objective of signal routing is to keep the signal as short as possible so that it does not interfere with other signals.

★ Placing components

When placing components, you should do the following:

●Do not place components too close to each other. This reduces the chance of them interfering with each other or their surrounding circuitry.

●Do not place components on the same side of your board as they will interfere with each other and cause noise in your system. This can be solved by using vias through layers, but if using wire-wrapped traces then try not to put anything under these wires when soldering them into place; this will help reduce any interference issues.

The stackup and impedance of high speed PCB

Knowing the stackup and impedance will help you design high speed PCB.
The stackup refers to the PCB layer. Copper layers should be inserted in both sides of the board in even numbers (2, 4, 6, 8, 12, etc.). It serves to maintain symmetry throughout the stack-up.
Layer arrangements:
4 and 6-layer stackups:

Impedance is the opposition to the flow of current and is commonly measured in ohms (Ω). Impedance can be affected by:

● The number of layers in your PCB and their thickness (the thicker they are, the higher their resistance).

● The type and arrangement of components on your high speed PCB.

The high speed PCB routing

The high speed PCB routing

The high speed PCB routing is a tedious and time-consuming process that requires special consideration. It is the process of laying out the electrical pathways on a PCB.

The high speed PCB routing process differs from normal PCB routing in several ways. It has to be done very quickly and smoothly because there are many small parts that need to be connected together at once. 

You will have to take into account how these small parts will be placed on the board so that they do not interfere with each other or cause any other problem during manufacture or assembly. If you want your design fast enough then it has to be designed with multiple layers of copper interconnected between layers.Once you have completed this step, you can move onto other tasks such as soldering or assembly.

Tools for the design and layout of high speed PCB

The first thing that you should do is to prepare the schematic diagram of your circuit. You can use Eagle or any other CAD software for this purpose. If possible, try to draw it with as much accuracy as possible so that it can be easily replicated on the PCB later on.

♥ IF-THEN rules for design

IF-THEN rules are used to define the behavior of a high speed PCB. In electronic design, they are especially useful because they can be easily implemented in hardware by using logic gates (such as AND, OR and NOT). The simplest IF-THEN rule looks something like this:If you know that the voltage V1 is greater than V2, then you must change the output signal so that it becomes less negative.

♥ Power distribution network

The power distribution network (PDN) is used to supply power to the components on your high speed PCB. It should be designed in such a way that it can supply power to all parts of the board.

♥ Role of vias in high speed PCB

Role of vias in high speed PCB
Vias are used for the connection between two different layers. They are also used to connect sections of a high speed PCB and can be made from either copper or tungsten, though copper is more commonly used. In high speed PCB, vias should be as small as possible so they don’t cause any problems with electrical performance or thermal resistance.

Beside these, there are other basic high speed PCB tools available. They include hand-drawn schematics, point to point routing, as well as simulation software.

Conclusion

High speed PCB is an emerging product in the vast field of electronics. They are becoming more and more popular. They have many advantages over traditional PCBs, such as lower operating temperature, lower impedance and faster signal transmission.

However, the designing process of high speed PCB is not so easy because there are so many aspects to consider during designing a high speed PCB.