For both electronics enthusiasts and professionals, there is always the need for custom-sized PCBs. The required size of the PCB you need can vary across projects. While it might be possible, in certain cases, to order the right size from your provider or use an already available size for your project, you will definitely find yourself working on projects where you would need to cut PCB to size.
Here is a definitive guide about how to cut PCB for your projects.
Why we need to cut PCB?
There are several reasons why you might want to cut your PCB to the right size for your current project. Many projects require PCB sizes and dimensions that are not readily available. In these types of cases, cutting the size you need from a larger PCB might be the only option.
Moreover, a lot of professionals and enthusiasts prefer ordering larger PCBs and cutting custom sizes. This is a common practice as larger PCBs often cost less per unit of size. Therefore, this practice can help make projects more economical and cost-effective.
Cutting your own custom-sized PCBs can also help you save time. If you are in the middle of a time-critical project and have large PCBs lying around, cutting the size you need gives you access to the right board immediately. This way, you do not have to waste time waiting for custom-size boards to arrive from your supplier.
Processes for how to cut PCB
Before you can start cutting PCBs like a pro, it’s critical to learn about the process and the inherent best practices. This will allow you to make perfect cuts every time and end up with boards that are perfectly functional and without issues.
Let us go through the entire process, from preparation to finishing, that will allow you to cut PCBs to your preferred custom sizes perfectly, every time.
To start with, you need a clean work surface and proper safety gear. The importance of safety gear cannot be overstated. Whenever you are working with sharp tools, small pieces, and the possibility of chemical fumes, having the appropriate safety gear at your disposal if crucial. For cutting PCB, the proper safety gear would include heavy-duty gloves, safety glasses, a mask covering your face and mouth. If you have a fume hood, even better.
Next, you need to have your cutting tools at hand and accessible. Using a large desk mat can keep wooden surfaces protected. To cut the PCB, you might use a variety of cutting implements, ranging from small utility knives to large table saws or band saws. For each cutting tool, make sure that you follow all the relevant safety procedures. For larger saws, it’s a prudent idea to have a vacuum cleaner or suction device at hand to collect and remove debris. A straight edge and a sharpie are also nice to have.
Before cutting the PCB, you need to make sure that it is clean and free from dust. For this, you can use a clean cloth that is non-abrasive. Microfiber cloth works well for this. If the PCB has a lot of dust or dirt on it, it can be cleaned effectively using some isopropyl alcohol. You just have to wait till the alcohol dries off completely to start cutting.
Finally, make sure that your cutting tool is properly prepared. Securely place the PCB on to your work surface with the copper side facing upwards, and you are good to go.
When cutting your PCB, you need clean, straight lines. To make things easier, you can mark out the outline of the shape you want to cut with a sharpie and a straight edge. This can then serve as a guide for your cuts.
When doing the actual cutting, exercise utmost caution. Cutting tools can be dangerous in the wrong hands and proper care should always be maintained for better safety. Take your time and cut accurately as any error in cutting might render the PCB useless. Whether you use a small blade or utility knife, or a large saw, follow all relevant safety instructions.
When you are done cutting the PCB, it has sharp edges that need to be smoothed out. This can be achieved with sanding.
Wipe down the PCB and proceed to sand the edges smooth with high-quality sandpaper. While 200-grit sandpaper might be fine for most applications, you can choose a higher grit for smoother results. After sanding, clean off your PCB one final time with a damp cloth and it will be ready for use.
Tips for Smooth PCB Cutting
While the process outlined above might be simple to follow, there are many finer points that require your attention if you want the best results. Follow these tips for smooth PCB cutting, every time.
- Keep your tools sharp – With sharp cutting tools, you get cleaner, more accurate results. However, using a blunt tool can throw you off quite a bit, result in chips and uneven cuts, and might even render the board unusable. If the cutting tool you are using is not sharp enough, use the appropriate sharpening process and tools to make it razor-sharp for the best results.
- Do a test run – Practice makes perfect and this applies to cutting PCBs as well. The more practice you have, the better you will be at making accurate, smooth cuts. If you have scrap PCBs lying around, they can be perfect candidates for doing a few test runs. Follow the same process described above and see if your cuts meet your quality standards. Get some practice in on throwaway boards first, and then move on to the actual project.
- Use a magnifier – Being able to see where you are working can be crucial for accuracy while cutting PCBs. Using a magnifier can bring you a closer, zoomed-in view of where you are working. Depending on your requirements, this can be a simple magnifying glass or a specialized microscope.
- Sand multiple times – For a really smooth, fine edge on your PCB, you can borrow a woodworking technique and sand the edges multiple times. Start with 200-grit sand paper and go to a finer grit after every pass. You can finish sanding with 1500-grit or 2000-grit sandpaper for a truly remarkable finish. Your PCB will look like it has come out of a factory.
- Take your time – The most important tip when it comes to smooth PCB cutting is exercising patience. Rushing things will most likely get you in trouble. Inaccurate cuts, jagged edges, and chips are often the result of rushed cuts. For the best cuts, take it very slow and, if required, take breaks in the middle to relax your hands.
Once you know in detail about cutting PCB and understand these tips, you are sure to get excellent results every time.
For enthusiasts, knowing how to cut PCB is beneficial as it can help save on costs and time for major projects. With this guide, you should be able to learn how to cut PCB, what tools you need, and how to use them to achieve the best possible results.