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 made so that you can increase throughput of PCB Depanel as circuit board sizes reduced. At CMS Laser, our depaneling process has the advantage 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 often decline in size. This reduced size requires smaller PCBs. Without set standard for PCBs, every board is designed for a specific item. Therefore, this process for depaneling separate boards from a multi-image board is different. Production factors such as stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are generally produced in large panels containing multiple boards at any given time, but can also be produced as single units if need be. The depaneling of PCBs process can be fully automatic, manual, or semi-automatic. There are numerous methods used, including laser PCB depaneling, in the electronics industry. Let’s examine the things they are:
The punching method is the method of singular Inline 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 necessary for each board and dies must frequently get replaced to keep sharpness. Even though production rate is high, the custom-designed fixtures and blades demand a reoccurring cost.
Boards are scored across the cut line on both sides to minimize overall board thickness. PCBs are subsequently broken out from the panel. Both sides of the panel are scored to a depth of approximately 30 percent from the board’s thickness. Once boards have been populated, they could be manually broken out of the panel. There exists a strain put on the boards that may damage some of the components or crack the solder joints, particularly those near to the side of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” method is a manual alternative to breaking the web after V-scoring to slice the remaining 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 carried out on boards requiring high tolerances. Depaneling occurs without physical contact, without any mechanical stress, and is adaptable to reduce requirements through 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 attached to the panel frame by narrow tabs that are subsequently broken or snapped to singulate the circuits. Routing can take up hbrerp panel area as a result of wide kerf width of a physical bit.
Laser routing offers 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 under 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 fringe of the cut for the majority of substrates.
Solid-state UV laser (355nm wavelength).
The UV laser, using a considerably smaller focused spot size, ablates the panel material with considerably less heat as well as a narrower kerf width. However, as a result of lower power levels, the cutting speed is much slower than the CO2 laser and also the cost/watt of UV lasers is higher than that of CO2
Generally speaking, businesses that are understanding of char and fine debris over the cut line will employ the UV laser while users who clean the circuits after singulation can benefit from the higher speed of the CO2 laser.
Laser systems for depaneling play an essential role later on from the PCB manufacturing industry. As interest in PCB Laser Cutting Machine continue to parallel technology trends, including wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and lower costs for manufacturer will even carry on and rise.
Within our Applications Development Lab, we assist each client to discover the ideal laser and optics configuration for a manufacturing process.
Within this three-part series on PCB depaneling, upcoming posts will discuss the advantages and challenges of PCB depaneling, together with the evolution of PCB depaneling with laser systems.