Cutting PCB Boards: A Comprehensive Guide

When it comes to manufacturing any electronic item, you need PCBs. In short, Printed Circuit Boards (PCBs) are the foundation of modern electronics. But there comes a time when you need to cut PCBs. This can be for many reasons,, including custom design, prototyping, or repair.

To cut PCBs, you need precision, allowing you to avoid damaging the circuits or components. There are various methods and tools that you can use for cutting PCBs to bring them into alignment with your needs.

From Score-and-Snap to PCB Shears (Guillotine), and many methods you can use to cut PCBs. This blog will navigate you through the best techniques and tools to as well as the right process for accurate PCB cutting with precision. Let’s explore!

Why You Need to Cut PCBs

Custom sizing: A standard PCB is less likely to fit into specific enclosures or designs. Cutting a PCB board is a way to adjust it to the required size, ensuring everything fits accurately. Panelization: Manufacturers often manufacture multiple boards on a single large panel. When it comes to separating each board, depanelizing or cutting them apart comes into play. Panelization is essential for mass production or handling several circuits. Repairs: Sometimes, a PCB board might have damaged sections, and to remove them, you need to cut the PCB. You can cut the damaged section and keep the remaining part safe, circumventing the need to replace the entire board, saving a significant amount of cost.

Tools for Cutting PCB Boards

Be it resizing, depanelizing, or repairing, cutting a PCB is often the key to resolving the issue. For this to happen, you need to have the right tools. Here are the right tools with which you can perform clean PCB cutting to get the desired performance and functionality.

Manual Tools

Manual tools are considered to be right for small projects or quick adjustments. These tools are convenient to use and often cost-effective. The following are some kinds of manual tools you need to know:

Utility knives: Ideal for scoring and snapping thinner boards. Utility knives are simple and get the job done for basic cuts. Heavy-duty shears: When it comes to working with thicker boards, you need something more substantial. Heavy-duty shears act like scissors that help get the work done, however, they are built to handle more rigid materials. Precision cutters: If you need to make intricate and delicate cuts, precision cutters are your go-to tools. They help you perform more detailed work, especially on delicate circuits.

Automated Tools

Automated tools deliver more accuracy for larger projects or complex designs, while streamlining the PCB cutting process. Here are some types of automated PCB cutting tools that are crucial for professional projects:

CNC machines: These machines provide high-precision cutting and are great for complex designs, with the ability to handle larger projects. You just need to set the design, and the CNC machine performs the rest. Laser cutters: These cutters are excellent alternatives when speed and accuracy are your priorities, specifically for complex designs like high-frequency PCBs. They are fast, precise, and the right tools for professional use when you need sharp, clean edges. Dremel tools: These tools are a versatile, handheld option for PCB cutting. These tools are perfect for DIY projects and small-scale works that need control but don’t require the precision of a CNC machine. where you need control but don't need the precision of a laser cutter and a CNC machine.

Cutting Methods for PCB Boards

The following are the PCB cutting methods you should know for excellent PCB cutting:

Score-and-Snap Method

This method of PCB cutting gets done using tools like a Utility knife and a metal ruler. They help score deeply along the cut line, making use of a knife and ruler. They flip and score the opposite side and snap the board along the scored line, ensuring a convenient PCB cutting. The score and snap method is best for thin PCBs, needing quick cuts.

PCB Shears (Guillotine)

This is one of the PCB Cutting methods with specialized PCB cutting shears. It works by placing the PCB inside the blade and pulling the lever for a clean, straight, smooth cut. This method is best for professional labs, mass production, and straight cuts without dust.

Rotary Tools (Dremel)

This method of PCB cutting gets done using a Dremel with a cutting wheel attachment. It works by marking the cut line and carefully guiding the cutting wheel along the line. The very method is best for cutting PCBs in irregular shapes and small, detailed cuts.

Hand Saws

This PCB cutting method is conducted by using a fine-toothed hacksaw or jeweler’s saw. It secures the board in a vise saw slowly along the marked line, ensuring a smooth cutting of the PCB. This way of PCB cutting is best for small jobs and cutting thicker boards.

Table Saw / Circular Saw

This method of PCB cutting is done using a table saw with a fine-toothed blade. It’s done by setting the blade height low and pushing the PCB steadily across. It helps a smooth cutting of PCB boards. It’s right for large quantities, consistent cuts (advanced users only).

CNC Milling

For this method, you need to use a CNC milling machine with fine bits. It gets done by loading PCB design into the CNC software, and the CNC machine mills (cuts) along the programmed path, efficiently removing material precisely. This way is right for complex routing, precision cuts, small production runs, and creating odd-shaped boards.

Laser Cutting

This PCB cutting method is done using tools like a CO₂ laser cutter (industrial-grade). First off, you need to program the design, and the laser precisely cuts through the PCB material. It’s an excellent way of PCB cutting, especially for high-end production and detailed custom shapes.

Saving

This method of PCB cutting is done using a table saw, circular saw, or band saw with a fine-toothed blade. First off, you need to secure the PCB board on a stable surface, and then push the PCB steadily through the spinning blade to achieve a straight cut. The saving method of PCB cutting is best for cutting many boards quickly, straight cuts, and heavy/thick PCB panels.

V–Cutting

This PCB cutting method takes place using tools like a V-scoring machine or a specialized PCB V-cutter. The machine makes shallow V-shaped grooves on both sides of the PCB along cut lines. After assembly, you just need to simply snap the board apart at the score lines. V-cutting is the best option for mass production, pre-separated panels (especially in SMT assembly), clean straight lines without needing complete cuts.

PCB Cutting Methods, and Their Pros and Cons

Here's a clean and simple comparison table summarizing the PCB cutting methods, along with their pros and cons:

Method	Best For	Pros	Cons
Score and Snap	Thin boards, quick jobs	Simple, cheap, no power tools needed	Not very precise, tough on thick boards
PCB Shears (Guillotine)	Straight, clean cuts, production work	Fast, professional finish, no dust	Expensive, limited to straight cuts
Rotary Tool (Dremel)	Complex shapes, detailed cuts	Flexible, cuts curves	Creates dust, requires a steady hand
Hand Saw (Hacksaw/Jeweler’s Saw)	Small DIY projects	Affordable, good control	Slow, rough edges without finishing
Table Saw / Circular Saw	Bulk cutting, straight lines	Very fast, consistent	Overkill for small jobs, safety risks
Laser Cutter	High-precision custom cuts	Super clean, can cut complex shapes	Very expensive, not DIY-friendly

Pro Tips for Clean PCB Cuts

Mark clearly: Make use of a fine-tip permanent marker or masking tape to guide your cuts clearly. Go slow: Don’t rush, as it can crack or delaminate the PCB. Deburr edges: Use sandpaper, a file, or a deburring tool to smooth rough edges when the cutting is finished. Mind the components: If the board is populated (components already soldered), consider protecting them or cutting carefully around them.

PCB Cutting Process: Step-by-Step Instructions

When it comes to PCB cutting, you need the right tools and proper preparation. Once cut, appropriate PCB assembly is essential to ensure seamless functionality. Here's a step-by-step PCB cutting process you should know to guide you through each step:

Preparation

Dust or debris may affect the cut; hence, make sure you’ve cleaned the board before starting the PCB cutting. Use a cloth or compressed air, enabling you to remove any dirt easily. Next up, properly mark the cut lines. For this, use a marker and ruler to draw straight lines where you want to cut, helping precise cut.

Setting Up Tools

Choose your PCB cutting tool as per your board's material and thickness. If you’ve thin boards, you should choose a utility knife or precision cutter. In case the board is thicker, heavy-duty shears or a saw should be the way to go. For more complex designs, a laser cutter or a CNC machine will give you the best results.

Cutting

Now, get started on PCB cutting. If you’re using manual tools, like a knife or shears, choose to apply steady pressure and follow the cut lines. In case you're using automated tools, for example, a CNC or laser cutter, let the machine handle the cutting process while you monitor the progress.

Post-Cut Finishing

After cutting, there may be some rough edges. Use sandpaper or a fine file, enabling you to smooth the edges. It’ll help you make the board look clean and prevent issues when getting placed on an enclosure.

Common Mistakes to Avoid

Using the wrong tool: Thick boards require sturdier tools; thin ones are likely to snap easily. Skipping safety: Fiberglass dust is hazardous; hence, mask up before you step up to use power tools. Poor securing: A moving board might lead to jagged cuts or injuries; hence, ensure they’re secured properly. Before starting: Use gloves when handling sharp-edged boards. Wear safety glasses to protect your eyes from flying debris. Work in a ventilated area to prevent inhaling fiberglass dust. Consider securing your PCB firmly to avoid slips.

Wrapping Up!

When you’ve chosen the right tool and know the method, PCB cutting is no longer a tiny affair. Through this blog, you have come to know all that you need, including tools, methods, a step-by-step process, and the mistakes to avoid. This information will guide you through a smart PCB cutting. If you need further assistance, get in touch with a PCB manufacturing company for appropriate solutions.