PCB (printed circuit board) depaneling, also known 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 to be able 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, and 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 reduction in size. This reduced size requires smaller PCBs. Without set standard for PCBs, every board is designed for a certain item. Therefore, the process for depaneling separate boards from the multi-image board is different. Production factors including 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 be produced as single units if needed. The depaneling of PCBs process could be fully automatic, manual, or semi-automatic. There are several methods used, including laser PCB depaneling, in the electronics industry. Let’s examine what they are:
The punching method is the method of singular PCB Depaneling Router being punched out of the panel with the use of an exclusive fixture. The punching fixture has sharp blades on one part and supports on the other. An alternative die is required for each and every board and dies must frequently be replaced to keep up sharpness. Although the production rate is high, the custom-designed fixtures and blades demand a reoccurring cost.
Boards are scored across the cut line on sides to reduce overall board thickness. PCBs are subsequently broken from the panel. Both sides from the panel are scored to your depth of around 30 percent of the board’s thickness. Once boards happen to be populated, they could be manually broken from the panel. You will find a strain put on the boards that will damage a number 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” method is a manual substitute for breaking the web after V-scoring to slice the other web. Accuracy is critical, as the V-score and cutter wheels should be carefully aligned. There is a slight amount of stress aboard which 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 is adaptable to slice requirements by way of 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 person circuits connected to the panel frame by narrow tabs which are subsequently broken or snapped to singulate the circuits. Routing may take up hbrerp panel area due to wide kerf width of any physical bit.
Laser routing provides 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 lower than 20 microns, providing exceptional accuracy.
Laser routing can be executed 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 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 along with a narrower kerf width. However, as a result of lower power levels, the cutting speed is significantly slower compared to the CO2 laser and also the cost/watt of UV lasers is higher compared to CO2
Generally speaking, businesses that are responsive 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 larger speed of the CO2 laser.
Laser systems for depaneling play an essential role in the future of the PCB manufacturing industry. As demand for PCB Laser Cutting Machine still parallel technology trends, such as wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and reduce costs for manufacturer may also continue to rise.
Inside our Applications Development Lab, we work together with each client to ascertain the ideal laser and optics configuration for any manufacturing process.
In this three-part series on PCB depaneling, upcoming posts will talk about the advantages and challenges of PCB depaneling, together with the evolution of PCB depaneling with laser systems.