PCB Drilling: The Most Common Types and How To Successfully Drill PCB

PCB drilling is a process of creating rectangular holes in printed circuit boards (PCBs) to accommodate various components. It can be a tedious process to design and layout the PCBs, but once you get it right, it’s easy to repeat the process again and again.

Drilling PCBs involves making precise, straight holes in the board with exact specifications. It is a critical step in the manufacturing process of electronics components used for making PCBs. If your company manufactures PCBs as part of their electronics assembly line, then drilling is almost always necessary from start to finish.

In this article, you will learn about the most common types of PCB drillers and how to drill a PCB successfully, so that component placement is accurate and repeatable.

What is PCB Drilling?

Drilling a PCB is a process of creating rectangular holes in printed circuit boards (PCBs) to accommodate various components. It can be a tedious process to design and layout the PCBs, but once you get it right, it's easy to repeat the process again and again. Once your PCB design is complete, you will need to create your PCB. You can either have your PCB manufactured by your PCB manufacturer or PCB manufacturing services done by an outside company.

There are many service providers who offer PCB fabrication or PCB manufacturing services. Once your PCB is ready, it will then be routed. Routing PCBs involves creating a pattern on the PCB that allows electronic components to be placed in specific locations on the board. The routing process is critical because it determines how the circuit will work. The routing will allow the electrical components to communicate and work together if the routing is done correctly.

Why is drilling a PCB necessary?

PCB drilling is part of the schematic design process. It is essential to drill the PCB to create a series of holes in the board to fit transistors, resistors, capacitors, diodes, and other electronic components. The holes in PCBs are essential to the function of electronic devices and are often used to connect the components to the board. The device might not work properly if the holes are not in the correct place on the PCB. Therefore, drilling a PCB is a critical step in the PCB manufacturing process.

Electronic components are made in a clean environment to ensure they are free of dirt and other contaminants. Once the components are manufactured and tested, they are wrapped in a protective coating and placed in a PCB. The PCB connects electronic devices such as computers, smartphones, and other electronic devices.

6 things you must know before drilling your PCB

There are many things you have to consider before starting this process.

• First and foremost, you should have a basic understanding of PCB design and layout. To properly drill a PCB, you will have to know the board's layout and the components' exact placement.
• Secondly, you should have the right tools for the job. A PCB drill has several parts, including a drilling bit, a chuck, and a handle. The bit is what makes the hole in the board, and the chuck holds the bit in place as it makes the hole. You will also need a bit holder to hold the bits while they cool down.
• Next, you need to understand the PCB design and layout well. This will help you make all the suitable modifications to the design to create the right space for the components.

Types of PCB Drillers

• Sharp Drilling Machine:

The sharp drilling machine is designed for professional use. It is best for drilling holes in heavy materials like copper clad, copper foil, and aluminum.

• Tabletop Drilling Machine:

The tabletop drilling machine is best for drilling through PCBs made from light materials like FR-4, FR-PTFE, Polyimide, etc.

• Rotary Drilling Machine:

The rotary drilling machine is used for drilling through thick materials like glass-fiber reinforced plastic (glass-fiber is used in aviation and aerospace applications), light wood, and so on.

Steps to Successfully Drill a PCB

This process is an extension of routing where the drilling machine is used to create precise, straight holes in the PCB. It is worth mentioning that drilling should never be used to cut holes in PCBs. There are five steps involved in drilling a PCB. Here they are:

• Choosing the right drilling machine:

This is the most crucial step in PCB drilling. Make sure you select the right drilling machine for the job. The most critical aspect to consider is the size of the workpiece you are drilling. This will determine the required headstock length, bit size, and spindle speed of the drilling machine. If the length of the PCB is smaller than the drilling machine spindle, then there are several drilling machines for both manual and automated drilling.

• Preparing the workpiece:

The drilling process can damage the PCB if the workpiece is not appropriately prepared. If you are drilling through a PCB made out of light materials, you must first mill the workpiece to get rid of any imperfections.

On the other hand, you can use sandpaper to get rid of any high-gloss contaminants on the surface of the PCB.

• Setting the spindle speed and bit size:

You need to set the spindle speed and bit size based on the thickness of the material the PCB is made of. Generally, drilling through thick materials like aluminum, thick wood, or glass-fiber reinforced plastic (GF-FR-PC) requires higher spindle speeds and bigger bit sizes. On the other hand, drilling through light materials like FR-4, FR-PTFE, Polyimide, and so on is done with smaller spindle speeds and smaller bit sizes.

• Drilling the PCB:

Once all the above steps are done, you can start drilling the PCB.

Pros of PCB drilling

• Low cost- Most PCB manufacturers offer PCBs at a low cost. If a PCB is damaged and you need to change the design, then a new PCB will cost you less than $100. This makes drilling a necessity.

• Low risk- The risk involved in drilling PCBs is low because it involves a relatively slow process. Unlike other high-risk manufacturing processes, the worst that can happen is a few broken circuits.

• Quick changeover- During an emergency when PCBs are short, drilling can be done quickly to replace the damaged or old PCBs.

• Functional- A PCB that has been drilled has a better chance of being used after an emergency situation.
• Recycled materials- Drilling uses scrap materials that are usually thrown away. This means a large quantity of non-renewable materials is being used, which benefits the environment.

Precautions while drilling PCBs

When drilling a PCB, it is essential to consider a few precautions to ensure that you do not damage the PCB or injure yourself.

• Firstly, wear proper safety equipment such as safety glasses, a dust mask, and a pair of gloves to prevent any materials from splashing.
• You should also use an anti-static mat to reduce the buildup of static electricity on the PCB. A static charge can cause the glue to adhere to the PCB or components to move out of place, putting the board and device at risk.
• When drilling a PCB, it is essential to start slowly. The drill should move at a consistent speed, and the rotation should be smooth and consistent.
• You should also be aware of the direction of travel of the drill as well as the distance traveled. If the drill breaks through the PCB or moves too quickly or slowly, you may end up damaging components or the board.

Tips and tricks while drilling a PCB

Here are a few tips and tricks to help you through drilling a PCB.

• Use a PCB drill bit that is the right size for your board. If you are drilling a board with components that are smaller or larger than the bit size, the drilling will be inaccurate and result in a too small or large hole.
• Always drill from the center of the board. This will make sure that you are drilling to the correct place.
• If you are drilling a board with several layers, you have to consider this. Start drilling from the center of the board and drill through each layer as you go.

FAQs (Frequently Asked Questions)

What size of holes do I need to drill in a PCB?

The size of the hole depends on the component that you are drilling. You can use the size chart to select the right drill bit size.

What is PCB drilling temperature?

Drilling temperature is the temperature of the drilling machine spindle while drilling the PCB.

How long does it take to drill a PCB?

The time required to drill a PCB depends on the material being drilled and the type of drill machine being used. The time required may vary from 5 to 15 minutes.

Do I need special tools to drill PCBs?

Yes, you will require special tools like a drill bit, spindle, and so on to drill PCBs. You can get these tools from your PCB manufacturer or any hardware store.

What is a drill press, and how do I use one?

A drill press is designed to drill through heavy materials like granite, concrete, etc. It is usually faster and more efficient than a tabletop drilling machine.

Conclusion:

Drilling a PCB can be tricky, especially if you have never done it before. However, with some practice, you can successfully drill a PCB. You should ensure that you are drilling the board from the center and that the holes are of the correct size. With the things mentioned above in mind, you should be able to safely and successfully drill a PCB.