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30 PCB007 MAGAZINE I OCTOBER 2018 tion rinse systems for minimizing water and solution dragout. What makes the material handling so spe- cial is its capability from 0.025-mm inner lay- ers (rigid or flex) to finished panels of 6 mm or more. This includes an automated storage and retrieval system (AS/RS), or a refrigerated warehouse, that can pull a complete set of ma- terials for multilayer layup and place them in a sealed tray with its own RFID to control lami- nation. Precise Etching Control Another significant change is the switch from the alkaline copper ammonium sulfate etchant to acid cupric chloride. This is due to the cu- pric chloride having a controller that greatly improves the etch rate control and a new regen- eration and copper recovery unit that recondi- tions the etchant and electrowins the copper as a solid plate from Sigma Engineering in Swe- den. For more precise control of finished traces, GreenSource only etches from the bottom with a panel-flipper between the two etch modules. The etchers are significantly improved to al - low foil thicknesses from ½-oz. to 2-oz. copper without sacrificing throughput. This control is important for the copper thinning etching after lamination to control the surface build-up from HDI sequential laminations. Innovative Software What is not observable, but could be the most important innovation, is the dedication to continuous measurement of every panel. Since each piece of material is barcoded and every panel goes through AOI, the AOI from CIMS has the capability to make precision measurements and store these in a unique da- tabase supplied by XACT PCB of the UK. The software takes data from cameras, AOI, coordi- nate measuring machines (Impex ProX3), and X-ray to improve registration for imaging, lami- nation, and drilling. The X-ray drill data can be transformed into scaling, offset, and rotation data that can be used to convert the NC pro- gram to fit the measured panels. Table 6: The standard outer layer process comprises 60 steps; 11 steps more than the optimized GreenSource process flow. Table 5: The GreenSource outer layer manufacturing flow contains an optimized 39 process steps.