Depaneling is a process used by PCB manufacturers to unpackage shipments of circuit boards without damaging them. Manufacturers can save a lot of time and money in the long run if this process is done effectively. Depaneling can be a complicated process sometimes, as there are many different types of circuit boards and methods of depaneling. This can lead to unnecessary stress which will make the whole process a lot less fun than it needs to be. Here are some of the different types of depaneling and how to avoid stress during each one.
For PCBs bought in array form, depaneling is a required part of the process. During this portion of the process, you should look to cut material costs by fitting as many boards as you can onto a standard panel, which will reduce waste as well. On the labor cost side of things, you should keep in mind that while punchers and cutters are manual operations, they are often time faster than lasers. If you need edge sanding on your PCBs, that will cost you extra time and money as well.
There are four main categories to keep in mind before setting up a PCB depaneling program.
- Labor Cost
- Material Cost
- Tooling Cost
Each will differ depending on the specifications of the PCB and the equipment your have at your disposal.
For example, If you need to acquire extra tools for your puncher to fit with the PCB design you have, this should be taken into account. Laser systems used for cutting can usually be programmed with minimal effort, but the cutters might still require tooling for this method as well. If you need to place your components close to the edge of your boards or you have a fixed limit on board dimensions, you should consider going with a laser cutting process.
For PCB designers, it’s important to know which tool will be used for depaneling, so they can design the board in a way that components will not be damaged in the depaneling process. This is particularly the case for surface mount components which need to be kept a safe distance away from the edge. In some cases, it’s best to make the board bigger than it might need to be, just to be safe in case the knowledge of what depaneling tool will be used for is not available.
For regular rectangular boards, the components are soldered and placed, and then special tools are used to separate the PCBs with as little bending stress as possible. For thin PCBs, use a guillotine type cutter, and for thicker boards, a “pizza cutter” is required.
For curved boards, break-out tabs are commonly used when you have to separate with a punch or hook tool. This will leave something known as “mouse bites” in the area where the tabs were. If your product needs to be a perfect tight fit or needs smooth edges, you will need to take extra time and money to buff these mouse bites off. Mechanical routers can also be used to depanel PCBs that are cured which causes less bending stress, but more overall vibration stress on the PCBs. Routers create a lot of dust too so make sure you have a system in place to remove it before choosing this method.
While some of these methods aim to reduce bending stress as much as possible, they do not get rid of it completely. The PCBs are still susceptible to cracking unless you use a UV laser cutter. The UV laser cutter is the only depaneling method that eliminates bending stress completely. It can make very precise narrow cuts in any shape or contour you may need. It also allows the components to be situated closer to the edge of the board which helps you get the most bang for your buck.
Laser cutting is becoming a more attractive option today as smaller PCBs are requiring tighter tolerances for board size and only laser cutting can accommodate this. Laser cutting might not be suitable for thicker PCBs however, because it would need to make an inefficient amount of passes over the same area just to finally cut through the board. This would be a waste of time as well.
There are many ways to depanel your PCBs, and they all have benefits and drawbacks. After reading this article, you should be able to decide which method works best for you and your bottom line. Whether you are looking for a simple manual puncher process or a more complicated and expensive laser cutting method, you should take into account the capabilities and limitations of each method before making your decision.