Here’s Everything You Need to Know About Fiducial PCB


If you’re a complete beginner, chances are you don’t know what fiducial PCBs are. It’s OK, we’ve all been there. But if you want to be an expert at PCB manufacturing and learn how they can help you stand out from the competition, then this is where you should start.

Here's Everything You Need to Know About Fiducial PCB

Fiducial PCB

In this blog post, you’ll learn what fiducial markers are, how they work and why you might use them. Fiducial markers or fiducials are used throughout the printed circuit board (PCB) industry. There are a few different kinds of fiducials that can be used for PCB marking and manufacturing. Some are more common than others.

What are Fiducials


What are Fiducials?

Fiducials are markers placed on the PCB to help determine the distance between two points. They are used by manufacturers and engineers to ensure that the correct components are being used in each product.

They’re tiny things that help you find your place and make sure you’re doing things right, whether it’s on a circuit board or at a party. Fiducials are basically like the stars in the sky: they’re always there and they never change. If you know where they are, you can navigate the world around them.

If you want to create a circuit board for a new model of car, you might need to measure the distance between two terminals on your battery. You could use a ruler or some other tool, but that would be extremely time-consuming and inaccurate. Instead, you can use fiducials to help get your measurements more accurate.

How do Fiducials Work in a PCB

Fiducials in a PCB

How do Fiducials Work in a PCB?

Fiducials are the little black dots you see printed on a PCB. They’re usually small, round, and offer a quick way to align your PCB with another board or component. Fiducials can also be used to measure distances between components and ensure that everything is placed correctly on your board.

When a fiducial is placed on a PCB, it’s usually a metal mark that has been etched into the copper layer of the board. The metal is usually a gold or silver substance, but it could be any other conductive metal. Fiducials work by allowing you to easily locate and identify specific points on your board without having to trace them out manually.

Why Do You Need Fiducial PCBs

Fiducial PCBs

Why Do You Need Fiducial PCBs?

Fiducial PCBs are placed on the PCB during the manufacturing process. They serve to ensure that both the PCB and its components are properly aligned. Without fiducials, you could not be sure that your PCB is properly aligned—and you certainly wouldn’t know where any of the components are located. That’s why they’re so important!

Without fiducials, it would be difficult to figure out where things should go.That’s not just a problem for the manufacturer: if there aren’t enough fiducials for an entire design, then someone else might accidentally put their part in the wrong place—and that could cause serious problems later on down the line.

How to Add Fiducial in a PCB?

When you’re adding fiducial markers to your PCB, it’s important to know these steps to ensure that you’ve placed them properly.

What kind of Fiducial Mark to Use

You should know what kind of fiducial marker to use. You can choose from several different types, including global fiducial markers and local fiducial markers. Global fiducial markers are used for general-purpose alignment. Local fiducial markers are used for alignment with a specific component or assembly. The most common type of global fiducial marker is a round pad or ball. Local fiducial markers are used for component alignment and include hole patterns and rectangular pads.

Where to Place the Fiducial Marks

The placement of the fiducial marks should be in a location that is easily identifiable on the board and will not interfere with any other component or trace. The best way to do this is by using a CAD program that has an option for placing fiducial marks on a PCB.

The location of these marks depends on the type of board being manufactured. For example, if you’re manufacturing a PCB for an integrated circuit (IC), the fiducial marks would be located at specific points around the perimeter of the IC.

What’s the Size and Shape of the Fiducial Marks

You have to specify the size of your fiducial mark. This is important because if you don’t tell us the size we will have no idea how big or small it should be.

The shape also matters a lot as well. You need to specify whether it should be square, rectangular etc. If you don’t tell us about this, then we will just assume that it can be any shape.

How Many Fiducial Marks Do You Need

You will need to know how many fiducial marks you need. If you are using a laser system, the number of fiducial marks will depend on the size of your PCB and the machine that you are using. If you are using an optical system or a camera-based system, then there is no limit on how many fiducial marks can be used.

Global and Local Fiducial Markers

Global and Local Fiducial Markers

2 Types of Fiducial PCB Markers

In printed circuit board manufacturing, there are two main types of fiducial markers: global fiducials, and local fiducials. Both types can be used for PCB manufacturing, but it’s best to use each type for the job it’s intended for.

Global Fiducial Markers

These markers are the more common type of marker. They’re used to mark out a position that is unique on a board, such as where an IC or other part will be placed. Global fiducials are typically in the form of dots or circles, and they can vary in size (though they should be large enough to not look like noise).

Global fiducials are used in conjunction with a measurement system that uses an absolute coordinate system. These markers are placed on the board to provide reference points for the machine vision system to track. These markers can be placed at regular intervals or in specific patterns based on the requirements of your application.

Local Fiducial Markers

These markers are similar to global fiducials in that they’re used to mark out a unique position on a board, but they’re smaller and less noticeable than global fiducials. They’re typically used for aligning components during assembly, so there’s no need for them to stand out as much as global fiducials do.

Local fiducials are used by systems that use relative coordinates and require more accuracy than global markers can provide. They provide a reference point for the vision system so that it can accurately locate features on the board, such as holes or other features that will help improve its ability to detect objects on the PCB surface.

Types of Fiducial PCB Markers

Factors For Fiducial PCB

Factors to Remember in Designing Fiducial PCB

The creation of Fiducial PCB is an interesting procedure that requires a lot of patience. For this reason, if you don’t have the patience, it will be much better for you to purchase them instead. This will save you from a lot of frustration when making your own. Of course, doing it yourself will be more satisfying and will also help you better understand how things work. Here are factors to remember in designing fiducial PCB:


You want to make sure that the shape of your PCB is exactly what you want it to be. If it’s too big or too small, you may find yourself wasting materials or making parts that don’t fit together properly.

The shape of a fiducial mark can affect its visibility from a distance. A circular or square-shaped fiducial mark has more surface area than other shapes and therefore allows more light to reflect off of it and make it more visible from further away than other shapes do.


Consider the size of your PCB. Depending on the size, it might not fit into the enclosure you want it to go into. It may not be able to hold the components you need it to hold.

If you make them too large, they can be difficult for the machine to handle. If you make them too small, there’s a chance that the machine will miss them altogether. The size of the fiducial mark must be large enough to be easily spotted. But, not so large that it interferes with other components on the board.


You need to think about what material your fiducial PCB will be made out of. This is because different materials have different properties and characteristics.

For example, FR-4 has excellent mechanical strength and high thermal conductivity but a low dielectric constant. So if you’re using an FR-4 PCB board, you can expect your fiducials to be more durable and last longer than those printed on other types of circuit boards.


When designing and manufacturing Fiducial PCB, you need to consider clearance. Clearance is the amount of space between one Fiducial and another. It can be related to the size of the Fiducial. It also depends on how many Fiducials are in a given area.

Clearance is important because it affects how accurately your Fiducial will be able to locate its position on the board. If there is too little clearance between two adjacent Fiducials, they may interfere with each other during assembly or operation.

If there is too much clearance between them, they will not be able to find their correct position on the board. The best way to ensure that your fiducials all have adequate clearance is through proper planning and layout before production begins.

Common Issues when Designing Fiducial PCB

Issues of Fiducial PCB

Common Issues when Designing Fiducial PCB

Fiducial PCBs are a great way to get your circuit boards and components to work together. But, they can be tricky to design. Here are the top 3 issues you’ll want to avoid when designing your PCB:

Position Deviation

This is a common issue when designing fiducial PCBs. This is the result of misaligned components and can lead to poor-quality products. This happens when the actual position of your component doesn’t match up with the intended spot on your PCB design.

To avoid this issue, it’s important to select components that are compatible with your PCB manufacturer’s process and also position them carefully in the design.

Direct Light Can Cause Bumps

Fiducial PCBs are designed to be used in a lot of applications, but when they’re used with direct light, it can cause bumps to appear on the PCB. This is because the light source can heat up the PCB and damage it.

To prevent this from happening, use an indirect light source instead of direct light. You can also use special materials that don’t absorb the heat from the light.

No Soldermask should cover the Fiducial

No Soldermask cover the Fiducial

No Soldermask should cover the Fiducial on a PCB

When designing a PCB, it’s important to remember that no soldermask should cover the fiducials. The reason for this is that the solder mask needs to be removed before applying the solder paste. If there is a soldermask covering the fiducials, then they might not be visible when you’re done with your manufacturing process!


Fiducial markers are designed to break through the surface of the printed circuit board and to sit just slightly off or outside of it. For engineers and technicians, these serve as a visual representation of where they need to drill holes in the printed circuit board in order to attach them. For other non-technical people, fiducial markers are more ambiguous. They serve as a visual reminder of the purpose behind the circuits and wires connected to them. Either way, the use of fiducial markers is significant for any printed circuit board and for the end user who depends on its functionality.

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