PCB (printed circuit board) depaneling, also known as singulation, is the process of removing numerous smaller, individual PCB Depaneling from a larger multi-PCB panel produced during production. The depaneling process was made so that you can increase throughput of PCB manufacturing lines 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 consistently 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 ideal for a certain item. Therefore, this process for depaneling separate boards from the multi-image board is unique. Production factors such as stress, precision and cleanliness are paramount to keeping board defects as low as possible.
PCBs are typically produced in large panels containing multiple boards at a time, but can be produced as single units if need be. The depaneling of PCBs process can be fully automatic, manual, or semi-automatic. There are several methods used, including laser PCB depaneling, within the electronics industry. Let’s examine what they are:
The punching method is the method of singular PCBs 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 every board and dies must frequently get replaced to keep up sharpness. Even though the production rate is high, the custom-designed fixtures and blades require 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 of the panel are scored to a depth of approximately 30 percent in the board’s thickness. Once boards have been populated, they could be manually broken out of the panel. There is a strain put on the boards that may damage some of the components or crack the solder joints, especially those near the side of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” strategy is a manual substitute for breaking the web after V-scoring to reduce the other web. Accuracy is critical, since the V-score and cutter wheels must be carefully aligned. You will find 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, without mechanical stress, and is also 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 Laser PCB Cutting Machine are routed leaving the patient circuits connected to the panel frame by narrow tabs which are subsequently broken or snapped to singulate the circuits. Routing will take up significant 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 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 however with noticeable heat effect on the edge 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 significantly less heat as well as a narrower kerf width. However, as a result of lower power levels, the cutting speed is much vboqdt compared to the CO2 laser as well as the cost/watt of UV lasers is higher compared to CO2
Generally speaking, businesses that are understanding of 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 larger speed of the CO2 laser.
Laser systems for depaneling play an essential role down the road of the PCB manufacturing industry. As need for Manual PCB 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 will even still rise.
Within our Applications Development Lab, we work together with each client to ascertain 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.