PCB (printed circuit board) depaneling, also referred to as singulation, is the process of removing numerous smaller, individual PCBs from the larger multi-PCB panel produced during manufacturing. The depaneling process was developed in order to increase throughput of PCB Depanel as circuit board sizes reduced. At CMS Laser, our depaneling process has the main benefit of speed, pin-point accuracy, no tooling cost or wear, no part induced stress, without any cutting oils or any other waste.
Demand Driven by Size
As technology consistently evolve, the gadgets we use become more advanced and frequently decrease in size. This reduced size requires smaller PCBs. Without set standard for PCBs, every board is designed for a particular item. Therefore, the procedure for depaneling separate boards from the multi-image board is unique. Production factors such as stress, precision and cleanliness are paramount to keeping board defects as low as possible.
PCBs are generally manufactured in large panels containing multiple boards at a time, but can also be produced as single units if needed. The depaneling of PCBs process can be fully automatic, manual, or semi-automatic. There are numerous methods used, including laser PCB depaneling, within the electronics industry. Let’s examine whatever they are:
The punching method is the procedure of singular PCB Router being punched from the panel with the use of a special fixture. The punching fixture has sharp blades on a single part and supports on the other. Another die is required for each board and dies must frequently be replaced to keep sharpness. Although the production rate is high, the custom-designed fixtures and blades demand a reoccurring cost.
Boards are scored along the cut line on both sides to reduce overall board thickness. PCBs are subsequently broken out from the panel. Either side from the panel are scored to a depth of around 30 percent from the board’s thickness. Once boards happen to be populated, they can be manually broken from the panel. There is a strain put on the boards that may damage a number of the components or crack the solder joints, especially those close to the fringe of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” method is a manual option to breaking the internet after V-scoring to cut the remaining web. Accuracy is essential, because the V-score and cutter wheels should be carefully aligned. There is a slight amount of stress aboard that could affect some components.
Laser depaneling can be carried out on boards requiring high tolerances. Depaneling occurs without physical contact, with no mechanical stress, and it is adaptable to slice requirements through a computer controlled process. Laser depaneling is acceptable for installation in surface mount technology (SMT) lines or with board unloaders/loaders for standalone operation.
Most PCBs are routed leaving the person circuits connected to the panel frame by narrow tabs that are subsequently broken or snapped to singulate the circuits. Routing will take up hbrerp panel area due to wide kerf width of the physical bit.
Laser routing offers a complete software-controlled process without reliance upon any mechanical dies or blades. Laser routing can cut any shape path including curves and sharp corners. The cut kerf width could be less than 20 microns, providing exceptional accuracy.
Laser routing can be carried out using either:
High-power CO2 laser (~10µm wavelength)
The CO2 laser can thermally cut through FR4, glass fibers along with other rigid and flex circuit substrates at comparatively high-speed though with noticeable heat effect on the side of the cut for the majority of substrates.
Solid-state UV laser (355nm wavelength).
The UV laser, with a considerably smaller focused spot size, ablates the panel material with considerably less heat along with a narrower kerf width. However, due to lower power levels, the cutting speed is much slower compared to the CO2 laser and the cost/watt of UV lasers is higher than that of CO2
In general, companies that are sensitive to char and fine debris over the cut line will employ the UV laser while users who clean the circuits after singulation can be helped by the higher speed from the CO2 laser.
Laser systems for depaneling play an important role later on in the PCB manufacturing industry. As demand for Laser Depaneling carry on and parallel technology trends, like wearables and Internet of Things (IoT) devices, the requirement for systems that increase production line speed and reduce costs for manufacturer will also carry on and rise.
In our Applications Development Lab, we assist each client to discover the ideal laser and optics configuration to get a manufacturing process.
Within this three-part series on PCB depaneling, upcoming posts will discuss the advantages and challenges of PCB depaneling, along with the evolution of PCB depaneling with laser systems.