PCB (printed circuit board) depaneling, also referred to as singulation, is the process of removing numerous smaller, individual PCBs from a larger multi-PCB panel produced during manufacturing. The depaneling process was created 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, with no cutting oils or other waste.
Demand Driven by Size
As technology will continue to evolve, the gadgets we use be a little more advanced and quite often reduction in size. This reduced size requires smaller PCBs. Without set standard for PCBs, every board is designed for a certain item. Therefore, this process for depaneling separate boards from a multi-image board is unique. Production factors like stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are typically manufactured in large panels containing multiple boards at any given time, but can be produced as single units if need be. The depaneling of PCBs process may be fully automatic, manual, or semi-automatic. There are numerous methods used, including laser PCB depaneling, inside the electronics industry. Let’s examine the things they are:
The punching method is the procedure of singular PCB Router being punched out of the panel by using 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 get replaced to keep sharpness. Even though the production rates are high, the custom-designed fixtures and blades need a reoccurring cost.
Boards are scored along the cut line for both sides to minimize overall board thickness. PCBs are subsequently broken out of the panel. Both sides in the panel are scored to a depth of around 30 percent of the board’s thickness. Once boards have been populated, they could be manually broken out from the panel. There is a strain put on the boards that can damage a few of the components or crack the solder joints, in particular those near to the edge of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” strategy is a manual option to breaking the internet after V-scoring to slice the remaining web. Accuracy is essential, as the V-score and cutter wheels must be carefully aligned. You will find a slight amount of stress aboard that could affect some components.
Laser depaneling can be performed on boards requiring high tolerances. Depaneling occurs without physical contact, without mechanical stress, and it is adaptable to slice requirements via a computer controlled process. Laser depaneling is suitable for installation in surface mount technology (SMT) lines or with board unloaders/loaders for standalone operation.
Most PCBs are routed leaving the patient circuits connected to the panel frame by narrow tabs which can be subsequently broken or snapped to singulate the circuits. Routing will take up hbrerp panel area due to wide kerf width of any physical bit.
Laser routing supplies a complete software-controlled process without reliance on any mechanical dies or blades. Laser routing can cut any shape path including curves and sharp corners. The cut kerf width may be less than 20 microns, providing exceptional accuracy.
Laser routing can be performed using either:
High-power CO2 laser (~10µm wavelength)
The CO2 laser can thermally cut through FR4, glass fibers as well as other rigid and flex circuit substrates at comparatively high-speed but with noticeable heat effect on the edge of the cut for most substrates.
Solid-state UV laser (355nm wavelength).
The UV laser, with a considerably smaller focused spot size, ablates the panel material with significantly less heat and a narrower kerf width. However, due to lower power levels, the cutting speed is a lot slower compared to 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 of the CO2 laser.
Laser systems for depaneling play an important role in the future in the PCB manufacturing industry. As need for PCB Laser Cutting Machine continue to parallel technology trends, like wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and lower costs for manufacturer will also still rise.
Inside our Applications Development Lab, we work together with each client to determine the ideal laser and optics configuration to get a manufacturing process.
In this particular three-part series on PCB depaneling, upcoming posts will discuss the huge benefits and challenges of PCB depaneling, combined with the evolution of PCB depaneling with laser systems.