Depaneling-Main depanel technologies
Main depanel technologies
A Depaneling router is a machine similar to wood router. It uses a router bit to mill the material of the PCB. The hardness of the PCB material wears down the bit, which must be replaced periodically.
Routing requires that single boards are connected using tabs in a panel. The bit mills the whole material of the tab. It produces much dust that has to be vacuumed. It is important for the vacuum system to be ESD-safe. Also the fixturing of the PCB must be tight - usually an aluminium jig or a vacuum holding system is used.
The two most important parameters of the routing process are: feed rate and rotational speed. They are chosen according to the bit type and diameter and should remain proportional (i.e. increasing feed rate should be done together with increasing the rotational speed).
Routers generate vibrations of the same frequency as their rotational speed (and higher harmonics), which might be important if there are vibration-sensitive components on the surface of the board. The strain level is lower than for other depaneling methods. Their advantage is that they are able to cut arcs and turn at sharp angles. Their disadvantage is lower capacity.
A saw is able to cut through panels at high feed rates. It can cut both V-grooved and not-V-grooved PCBs. It does not cut much material and therefore generates low amounts of dust.
The disadvantages are: ability to cut in straight lines only and higher stress than for routing.
Laser (as of March, 2010)
Laser cutting is now being offered as a sixth method by some equipment makers.
UV laser depaneling makes use of a 355 nm wavelength (ultraviolet), diode-pumped, Nd:YAG laser source. At this wavelength the laser is capable of cutting, drilling and structuring on rigid and flex circuit substrates. The laser beam, capable of cut widths under 25μm, is controlled by high-precision, galvo-scanning mirrors with repeat accuracy of +/- 4 μm.
A variety of substrate materials can be cut with a UV laser source including FR4 and similar resin-based substrates, polyimide, ceramics, PTFE, PET, Aluminum, Brass and Copper.
Advantages: accuracy, precision, low mechanical stress and flexible contour and cut capabilities.
Disadvantages: initial capital investment is often higher than traditional depaneling technologies, also the optimal board thickness is recommended to be no more than 1mm.
CO2 laser sources have also been used for depaneling, but are considered outdated as UV laser technology provides cleaner cuts, less-thermal stress and higher precision capabilities.