PCB (printed circuit board) depaneling, also called singulation, is the method of removing a lot of smaller, individual PCB Depaneling from a larger multi-PCB panel produced during manufacturing. The depaneling process was created in order to increase throughput of PCB manufacturing lines as circuit board sizes reduced. At CMS Laser, our depaneling process has the main benefit of speed, pin-point accuracy, no tooling cost or wear, no part induced stress, with no cutting oils or any other waste.
Demand Driven by Size
As technology will continue to evolve, the gadgets we use become more advanced and often decrease in size. This reduced size requires smaller PCBs. Without any set standard for PCBs, every board is ideal for a particular item. Therefore, the process for depaneling separate boards from the multi-image board is exclusive. Production factors like stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are typically created in large panels containing multiple boards at any given time, but can also be produced as single units if needed. The depaneling of PCBs process may 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 PCBs being punched out from the panel with the use of a unique fixture. The punching fixture has sharp blades on one part and supports on the other. A different die is necessary for each and every board and dies must frequently get replaced to maintain sharpness. Even though the production rates are high, the custom-designed fixtures and blades require a reoccurring cost.
Boards are scored over the cut line for both sides to reduce overall board thickness. PCBs are subsequently broken out of the panel. Each side from the panel are scored to your depth of about 30 percent in the board’s thickness. Once boards have been populated, they could be manually broken from the panel. There exists a strain put on the boards that will damage a few of the components or crack the solder joints, especially those close to the fringe of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” strategy is a manual alternative to breaking the net after V-scoring to cut the remaining web. Accuracy is critical, since the V-score and cutter wheels must be carefully aligned. You will find a slight degree of stress aboard that could affect some components.
Laser depaneling can be performed on boards requiring high tolerances. Depaneling occurs without physical contact, without any mechanical stress, and is adaptable to reduce requirements by way of 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 attached to the panel frame by narrow tabs which can be subsequently broken or snapped to singulate the circuits. Routing will take up significant panel area because of 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 can be lower than 20 microns, providing exceptional accuracy.
Laser routing can be performed using either:
High-power CO2 laser (~10µm wavelength)
The CO2 laser can thermally cut through FR4, glass fibers as well as other rigid and flex circuit substrates at comparatively high-speed though with noticeable heat effect on the side 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 considerably 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 and also the cost/watt of UV lasers is higher compared to CO2
In general, companies that are sensitive to 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 larger speed in the CO2 laser.
Laser systems for depaneling play an important role in the future from the PCB manufacturing industry. As need for Manual PCB Depaneling carry on and parallel technology trends, such as wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and lower costs for manufacturer will also carry on and rise.
Within our Applications Development Lab, we work together with each client to discover the ideal laser and optics configuration for a manufacturing process.
In this three-part series on PCB depaneling, upcoming posts will talk about the benefits and challenges of PCB depaneling, along with the evolution of PCB depaneling with laser systems.