PCB (printed circuit board) depaneling, also called singulation, is the procedure 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 Router 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 any other waste.
Demand Driven by Size
As technology continues to evolve, the gadgets we use become more advanced and often decrease in size. This reduced size requires smaller PCBs. With no set standard for PCBs, every board is ideal for a particular item. Therefore, the process for depaneling separate boards from the multi-image board is exclusive. Production factors like stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are usually manufactured in large panels containing multiple boards at the same time, but may also be produced as single units if necessary. The depaneling of PCBs process could be fully automatic, manual, or semi-automatic. There are numerous methods used, including laser PCB depaneling, within the electronics industry. Let’s examine the things they are:
The punching method is the procedure of singular PCB Router being punched from the panel by using a unique fixture. The punching fixture has sharp blades on one part and supports on the other. A different die is needed 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 across the cut line on both sides to lessen overall board thickness. PCBs are subsequently broken out of the panel. Each side in the panel are scored to your depth of about 30 percent in the board’s thickness. Once boards have already been populated, they may be manually broken from the panel. You will find a strain put on the boards that may damage some of the components or crack the solder joints, in particular those close to the fringe of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” technique is a manual substitute for breaking the web after V-scoring to cut the other web. Accuracy is crucial, as the V-score and cutter wheels must be carefully aligned. There is a slight amount of stress on board which may affect some components.
Laser depaneling can be performed on boards requiring high tolerances. Depaneling occurs without physical contact, without mechanical stress, and is adaptable to reduce requirements via 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 individual circuits linked to the panel frame by narrow tabs which can be subsequently broken or snapped to singulate the circuits. Routing can take up hbrerp panel area because of wide kerf width of a 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 can be lower 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 though with noticeable heat effect on the fringe of the cut for many 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 significantly 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 across 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 integral role down the road in the PCB manufacturing industry. As demand for Laser Depaneling continue to parallel technology trends, such as wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and minimize costs for manufacturer will also continue to rise.
Inside our Applications Development Lab, we work together with each client to ascertain the ideal laser and optics configuration to get a manufacturing process.
Within this three-part series on PCB depaneling, upcoming posts will talk about the huge benefits and challenges of PCB depaneling, together with the evolution of PCB depaneling with laser systems.