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90 The PCB Magazine • June 2016 THE 21ST CENTURY PCB FACTORY—DESIGNED TO ELIMINATE OFFSHORE COST ADVANTAGES focus is TDS (total dissolved solids) budgeting throughout the plant, along with analysis of specific critical contaminants. Water supply is only limited by the size of the pumps. For in- stance, in order to maximize absorption in the fume scrubber , 10 gallons/minute of DI water can be fed continuously into and out of the scrubber system reservoir. Additionally, rinses can be operated at 3−5 gallons/minute wheth- er they need it or not. With a closed loop sys- tem, there is no sacrificing rinse quality to save water. Lift stations integrated with conduc- tivity sensors can automatically identify an out-of-control waste stream as it happens, al- lowing for quick corrections by maintenance. Also, fresh rinse-water conductivity is always DI quality. New Equipment Technology In the past decade great developments have occurred in horizontal plating technologies along with direct imaging, inkjet, and CNC equipment. Only some of these have been real- ized in North American and European factories. Horizontal copper electroplating is an espe- cially rare technology in the U.S. market. The current state-of-the-art horizontal plater is capa- ble of conformal panel plating 30 microns (1.2 mils) of copper at 100% throwing power in just 18 minutes at 50 panels/hour, for most designs, at a fraction of the cost and thickness variation of standard vertical plating. These platers can also fill blind vias, through-holes and even trenches for embedded transmission lines, realizing 1- and 2-mil feature resolution. Yet, there are only two of these units in the USA—and hundreds in Asia. At Whelen Engineering, the total sur- face copper thickness variation achieved from this process is just 3%. Additionally, the ability to control the pulse profile (and hence surface roughness) on each individual insoluble anode segment has successfully eliminated the need for subtractive etching of the copper surface for resist adhesion. Direct imaging has been on the market for quite some time now, and is used as a mass pro- duction tool. At the 2015 productronica show in Munich, new LDI and MDI solutions, with lower operating costs than traditional UV la- ser systems, could be found everywhere. Also emerging now are inkjet processes, with some even containing integrated AOI solutions. Figure 13: Comparison of spent rinse-water conductivity. Figure 14: Horizontal conductive polymer metallization plus copper pulse electroplate.