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64 The PCB Magazine • May 2016 It is the job of the PCB process engineer to ensure that a quality circuit is delivered. This process starts with sound mechanics of the im- aging system that include surface cleanliness and resist lamination parameters. Introduction You've heard the expression "garbage in, garbage out." This also applies to anything related the manufacturing of printed circuit boards. More specifically the subject of prima- ry imaging for pattern plating comes to mind. There are several key process steps that must be properly executed in order to insure that the electroplated copper trace conforms to dimen- sions that were intended. This also means that the plated trace is uniform in shape. Of course the electroplating process itself plays a signifi- cant role in the quest to obtain a uniform trace. The plated trace should be as free as possible from pitting, undercut, plated copper overhang (plating of metal up over the primary resist) and ragged edges. Again, this all starts with a prop- erly controlled imaging process. In a future col- umn this author will discuss electroplating of copper in more detail. Primary Imaging There are several process steps in imaging: • Resist lamination • Exposure • Development In the process of lamination, the dry film resist is applied onto a base material, typically a copper clad dielectric (for innerlayer imaging) or an outerlayer surface of the printed circuit by Michael Carano Rbp chemicAl technology Primary Imaging for Pattern Plating, Part 1 trouble in your tank 64 The PCB Magazine • May 2016