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MARCH 2020 I PCB007 MAGAZINE 47 apart or adding additional steps to the process, thus giving the material time to cool down. These mitigation techniques need to be con- sidered in the context of the effect they have on overall throughput. Rising Production Costs Another challenge facing PCB manufactur- ers is the increasing costs associated with the addition of new production facilities and the expansion of existing facilities. The costs to accommodate the new capital equipment re- quired to support an increase in production ca- pacity have risen sharply in the past few years. Factors, such as increasingly stringent environ- mental regulation, make expansion more cost- ly and time-consuming. While this has been the case in the U.S. and Europe for some time, it has only been recently that the cost of land and labor in what were traditionally consid- ered lower-cost countries (such as China) in- creased. These trends cause many PCB manufactur- ers to focus on optimizing existing facilities rather than adding new ones. This makes it imperative that they minimize their factory footprint while still maintaining or increasing production throughput, placing a premium on extracting higher productivity from their exist- ing systems. Laser Technology Evolution The first commercially-available UV lasers were lamp-pumped and characterized by a rel- atively low 1–5-kHz repetition rate and low 1–3 W average power. Although that performance profile met the need for the applications at the time, the reliability and lifespan of these lasers were notoriously low. These lasers would not be suitable to address the processing challeng- es presented by today's FPCB materials, 24/7 production environments, and high manufac- turing volumes. Today, advancements in laser technology have made available new state-of-the-art, di- ode-pumped solid-state (DPSS) and fiber-based UV lasers that operate at well over 100-kHz rep- etition rate and tens of watts of average power, often lasting tens of thousands of hours. These new high-performance lasers provide the basis for effective, high-volume production of flex circuits. However, they must be matched with similarly high-performance beam delivery and control capabilities to achieve the high produc- tivity, yield, quality, and flexibility necessary to process the broad range of materials and ap- plications that are typically used in consumer electronics. Laser Systems Rise to Today's Challenges and Technologies Harnessing new laser technology for specific applications requires more than just the right laser. It also requires the right set of beam de- livery and control technology to optimize the characteristics of the laser and its effect on the material. Not only have today's processing challenges increased, but so have the challeng- es associated with the much-higher repetition rates and higher average power available on today's state-of-the-art lasers. Optimizing for a Wider Range of Materials and Higher-power Lasers Laser processing both thick and thin material constructions with a range of thermal proper- ties and capture layer thicknesses at high yields is already a challenge. Doing so while integrat- ing a high repetition rate, high-average-power lasers able to maximize productivity makes the challenges even more difficult. The ideal laser system offers improved methods of reducing the heat accumulation and laser energy vari- ability presented to the workpiece (Figure 1). Coupling high-rep-rate laser technology with faster beam steering capabilities, such as ESI's AcceleDrill™ technology, allows for better ther- mal management and minimizes the negative Figure 1: Larger bite size equates to lower localized heating.