PCB (printed circuit board) depaneling, also referred to as singulation, is the process of removing numerous smaller, individual PCBs from the larger multi-PCB panel produced during manufacturing. The depaneling process was made in order to increase throughput of PCB Depanel 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, without any cutting oils or any other waste.
Demand Driven by Size
As technology consistently evolve, the gadgets we use become a little more advanced and frequently decrease in size. This reduced size requires smaller PCBs. With no set standard for PCBs, every board is ideal for a specific item. Therefore, the process for depaneling separate boards coming from a multi-image board is different. Production factors including stress, precision and cleanliness are paramount to keeping board defects to a minimum.
PCBs are generally produced in large panels containing multiple boards at the same time, but can also be produced as single units if needed. The depaneling of PCBs process could be fully automatic, manual, or semi-automatic. There are numerous methods used, including laser PCB depaneling, within the electronics industry. Let’s examine the things they are:
The punching method is the procedure of singular Inline PCB Router being punched out of the panel by using an exclusive fixture. The punching fixture has sharp blades on one part and supports on the other. Another die is required for each and every board and dies must frequently be 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 over the cut line on sides to reduce overall board thickness. PCBs are subsequently broken out of the panel. Either side in the panel are scored to some depth of around 30 percent from the board’s thickness. Once boards have already been populated, they can be manually broken out of the panel. There exists a strain put on the boards that may damage a number of the components or crack the solder joints, especially those close to the edge of the board.
Wheel Cutting/ Pizza Cutter:
The “pizza cutter” method is a manual substitute for breaking the internet after V-scoring to cut the rest of the web. Accuracy is essential, because the V-score and cutter wheels must be carefully aligned. There is a slight degree of stress aboard which may affect some components.
Laser depaneling can be performed 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 PCBs are routed leaving the person circuits attached to the panel frame by narrow tabs which are subsequently broken or snapped to singulate the circuits. Routing will take up hbrerp panel area as a result of wide kerf width of the physical bit.
Laser routing provides 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 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 as well as 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, having a considerably smaller focused spot size, ablates the panel material with significantly less heat as well as a narrower kerf width. However, because of lower power levels, the cutting speed is significantly slower compared to CO2 laser and the cost/watt of UV lasers is higher compared to CO2
Generally speaking, businesses that are responsive to 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 greater speed of the CO2 laser.
Laser systems for depaneling play an integral role down the road from the PCB manufacturing industry. As demand for Laser Depaneling still parallel technology trends, including wearables and Internet of Things (IoT) devices, the need for systems that increase production line speed and lower costs for manufacturer may also carry on and rise.
In our Applications Development Lab, we work with each client to determine 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.