Micro-via drilling with UV DPSS has aided the march toward smaller, denser wiring patterns in pcb manufacturing. To further this end, pcb board the precision machining capabilities of UV lasers are also being leveraged for the wire patterning itself. Current techniques include laser-direct imaging (LDI)4, in which relatively low-power, low-pulse-energy lasers expose the wiring pattern onto a resist material for subsequent chemical etching pcb board. There are now increasing efforts at applying the highest-power UV lasers for laser direct patterning (LDP) in next-generation HDI manufacturing.5 In LDP [also referred to as laser direct ablation (LDA)], there is no supplemental etch process; PCB manufacturing rather pcb board, higher-intensity laser pulses are used to actually ablate grooves in the resin material to the proper depth and width for subsequent copper deposition. LDP processing can easily generate wiring street widths and spacings of 20 μm or less (see Fig. 3)—a number likely to shrink in the future pcb board.
The features were direct-ablated with a scanned, tightly focused Gaussian beam, resulting in processing speeds in the meters-per-second regime pcb board. For this approach, a laser with high output power at high PRFs is a good solution, pcb board such as the Pulseo 355-Turbo laser system, which offers high power and pulse energy stability at PRFs in the 250–500 kHz regime. Depending on the beam delivery system configuration—and considering the potential for parallel split-beam processing PCB manufacturing, etc.—the 20 W output power enables processing of 20-μm-dimension LDP features at speeds beyond 5 m/s. pcb board For the smaller feature sizes of the future, significantly higher speeds are possible since more condensed beams can be used, pcb board so less energy is required to achieve the same energy density PCB manufacturing.
