Powering the Future: Why True Ceramic Circuits Are Not Just ‘Better PCBs’
Global Sourcing Spotlight: The Global Quality Gap—Why Consistency Wins the Contract
Knocking Down the Bone Pile: Precision Milling of Underfilled SMT Components
Additional EDX probing was done on cut walls of boards with different thicknesses and with differences in laser system setups. From those, ones were selected for an 800 µm board (33 mil) cut with setup conditions as in Table 1 and comparing those to a cut made in a similar board which was depaneled with a router.
A finely focused beam was used to be able to measure the chemical components on the epoxy and also on the glass fibers. In the tests, probes 3 and 4 are done with different cooling (or rest) times between passes thereby allowing the surface to remain cooler.
Table 1. Comparison between cut walls of boards with setup conditions and boards depaneled with a router.
Figure 16: Inspecting epoxy areas.
Figure 17: EDX analysis epoxy area.
Figure 18: Inspecting surface of glass fibers.
Figure 19: EDX analysis on glass area.
Figure 17 shows that with shorter cooling times a slightly higher amount of carbon and oxygen are present.
For probes 5 and 6 the cutting speed was changed significantly, which means that with the slower speed a complete cut is obtained with fewer repetitions. With the higher cutting speed more carbon and less oxygen remains present.
All the tests were compared to a routed side wall where in each case more carbon was present there while the amount of oxygen did not vary significantly.
The chemical element that would raise most concern is carbon, yet in all these laser cut cases, the presence of this element is lower or at most similar to that in the routed board.
Conclusions
Using a laser for depaneling can have significant economic advantages because more boards can be placed on the same panel. But also one can expect better long-term reliability as the board’s edges are not exposed to bending strain when breaking the last connecting points to the panel.
In addition, the board edges are not seeing high levels of compression when they are being cut. The panels retain their original rigidity during assembly which may make it possible to work without pallets.
Page 5 of 6
