PCB (printed circuit board) depaneling, also referred to as singulation, is the procedure of removing numerous smaller, individual PCB Depaneling from a larger multi-PCB panel produced during production. The depaneling process was created to be able to increase throughput of PCB manufacturing lines 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 be a little more advanced and often decline in size. This reduced size requires smaller PCBs. With no set standard for PCBs, every board is designed for a certain item. Therefore, the procedure for depaneling separate boards coming 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 usually created in large panels containing multiple boards at any given time, but may also be produced as single units if need be. The depaneling of PCBs process could be fully automatic, manual, or semi-automatic. There are several methods used, including laser PCB depaneling, inside the electronics industry. Let’s examine what they are:
The punching method is the process of singular PCBs being punched from the panel with the use of a special fixture. The punching fixture has sharp blades on one part and supports on the other. An alternative die is necessary for every board and dies must frequently get replaced to keep up sharpness. Even though the production rates are high, the custom-designed fixtures and blades require a reoccurring cost.
Boards are scored along the cut line for both sides to reduce overall board thickness. PCBs are subsequently broken out of the panel. Both sides of the panel are scored to some depth of about 30 percent from the board’s thickness. Once boards have been populated, they can be manually broken out from the panel. There exists a strain put on the boards that will damage a few of the components or crack the solder joints, in particular those close to 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 cut the rest of the web. Accuracy is critical, since the V-score and cutter wheels must be carefully aligned. You will find a slight amount of stress on board 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 it is adaptable to cut requirements via 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 Laser PCB Cutting Machine are routed leaving the individual circuits connected to the panel frame by narrow tabs which are subsequently broken or snapped to singulate the circuits. Routing may take up significant panel area due to wide kerf width of the physical bit.
Laser routing offers 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 lower 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 though with noticeable heat effect on the edge of the cut for many 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 significantly vboqdt compared to CO2 laser as well as the cost/watt of UV lasers is higher than that of CO2
In general, businesses that are understanding of char and fine debris along the cut line will employ the UV laser while users who clean the circuits after singulation may benefit from the greater speed of the CO2 laser.
Laser systems for depaneling play an essential role down the road from the PCB manufacturing industry. As need for Manual PCB Depaneling continue to parallel technology trends, including wearables and Internet of Things (IoT) devices, the requirement for systems that increase production line speed and reduce costs for manufacturer will even carry on and rise.
Inside our Applications Development Lab, we work together with each client to determine 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.