PCB (printed circuit board) depaneling, also called 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 benefit of speed, pin-point accuracy, no tooling cost or wear, no part induced stress, without any cutting oils or 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. With no 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 unique. Production factors including stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are usually produced in large panels containing multiple boards at the same time, but can be produced as single units if needed. The depaneling of PCBs process may be fully automatic, manual, or semi-automatic. There are many methods used, including laser PCB depaneling, in the electronics industry. Let’s examine what they are:
The punching method is the procedure of singular PCB Depaneling Router being punched from the panel through the use of a special fixture. The punching fixture has sharp blades on one part and supports on the other. Another die is necessary for every board and dies must frequently be replaced to keep sharpness. Even though the production rate is high, the custom-designed fixtures and blades require a reoccurring cost.
Boards are scored across the cut line for both sides to lessen overall board thickness. PCBs are subsequently broken out from the panel. Both sides from the panel are scored to your depth of about 30 percent from the board’s thickness. Once boards have been populated, they could be manually broken from the panel. There is a strain put on the boards that will damage some of the components or crack the solder joints, particularly those near to the edge of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” technique is a manual option to breaking the internet after V-scoring to reduce the remaining web. Accuracy is critical, as 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, 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 connected to the panel frame by narrow tabs that are subsequently broken or snapped to singulate the circuits. Routing may take up hbrerp panel area because of wide kerf width of a physical bit.
Laser routing supplies 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 may 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 and other rigid and flex circuit substrates at comparatively high speed however with noticeable heat effect on the edge of the cut for most substrates.
Solid-state UV laser (355nm wavelength).
The UV laser, using a considerably smaller focused spot size, ablates the panel material with significantly less heat and a narrower kerf width. However, because of lower power levels, the cutting speed is significantly slower than the CO2 laser and also the cost/watt of UV lasers is higher compared to CO2
Generally speaking, firms 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 benefit from the greater speed of the CO2 laser.
Laser systems for depaneling play an integral role later on from the PCB manufacturing industry. As need for Laser Depaneling continue to parallel technology trends, including wearables and Internet of Things (IoT) devices, the necessity for systems that increase production line speed and lower costs for manufacturer may also carry on and rise.
Within our Applications Development Lab, we work together with each client to determine the ideal laser and optics configuration to get a manufacturing process.
Within this three-part series on PCB depaneling, upcoming posts will discuss the huge benefits and challenges of PCB depaneling, together with the evolution of PCB depaneling with laser systems.