Printed Circuit Design & Fab - April 2008 - (Page 35) IMAGING be able to incorporate are shown in FIGURE 3. These targets include, through holes, matrix of through holes, innerlayer fiducials skived /under resin, matrix of microvia holes, mixed microvia / through holes, surface pads, ring/dotted ring – all covered or not covered by resist. Some LDI systems use a UV marker to create targets on one side of an inner layer (FIGURE 4), thereby avoiding the need for drilling through holes, which is an additional undesirable process step. As one side of the innerlayer is being printed, two UV marks are printed on the underside as well. When the layer is turned over, those two UV marks are then used to achieve accurate (or “the most accurate”) side-to-side registration. parameters are stored in the system, many statistical charts can be easily and quickly extracted. These include panels imaged over a specific period of time, panels per shift, potential vs. actual panels per day, printed panels per energy setting (mJ/cm²), system utilization (hours/day), average batch size, panel size distribution, and much more. All of this information can be accessed and customized for each PCB fabricator’s needs. This is an example of the power of digital printing. The two examples, FIGURE 5 and FIGURE 6, show scaling data with respect to a particular batch. Summary In the last few years we have witnessed the introduction of many new LDI capabilities and uses. It is our prediction that LDI technology will continue to proliferate. In addition to higher LDI speeds and increased accuracy, there has also been an improvement in the cost of ownership. New LDI capabilities are being developed, such as real time analysis, advanced alert mechanism, on-line inspection and enhanced real time feedback. The trend is a focus on improvements to productivity. It is up to the many users of LDI to share their experiences with suppliers and engage them in the development of future solutions. PCD&F GUY ALON is the director of PCB marketing for Orbotech Inc; Guya@orbotech.com. Ralph Birnbaum, PhD is the LDI marketing manager of the PCB Division in Orbotech Ltd; Ralph-b@ Orbotech.com. Process Feedback An important aspect of every digital printing process is the availability of instant feedback for the user. The quick manner in which data is converted to imaged pattern must be accompanied by safeguards in the form of alerts. For example, if the panel is badly distorted and the dynamic scaling option suggests a value beyond the set limits, an alert should appear. Another confidence building feature is the registration feedback, essentially showing the operator the expected front-to-back registration for the imaged panel. In addition to instant feedback, data can be generated from the LDI system’s vast database of imaging history for review by supervisors and managers. Since every image’s Find the cure. High Variety of Pitches, Signal Routing, Stack Heights and Terminations www.samtec.com/signal_integrity http://www.samtec.com/signal_integrity http://www.samtec.com/signal_integrity
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.