Issue link: https://resources.pcb.cadence.com/i/1310860
www.cadence.com 2 Allegro PCB Designer Manufacturing Option report in hand, PCB fabricators can make recommendations for design changes that result in significant cost and time savings while maintaining design intent. Design Analyzer bridges the gap between engineer and PCB fabricator by extracting key information about the PCB and presenting it in an easy-to-read format. Hierarchical Rule-Set-Driven Analysis Manage the myriad of checks and the analysis process by creating rules sets. Checks are organized into layer types and sub-categories to simplify the selection of checks to perform and the setting of corresponding parameters. Define the type and order of a group of checks (rule set) to be performed. Analysis can include netlist or layer comparison, design rule verification, fabrication, and assembly checks on the entire design, a specific layer, or a region of the design. This dramatically reduces set up and execution of the analysis. Analysis rule sets can be saved and recalled for use on any design. Rule sets can be defined for a specific PCB technology, vendor capability, or unique design requirement. For many designs, different regions or layers of a PCB have unique constraints and subsequently require custom analysis. Use unique rule hierarchy to tailor an analysis to bare board construction, board density, or component technology. PCB Fabrication Analysis Fabrication analysis will detect specific design content that might have an adverse effect on PCB fabrication. Features such as less-than-minimal spacing, acid traps, minimal annular rings, minimum features sizes, and copper and mask slivers are just a few examples of the fabrication analysis available. Drill- related analysis includes minimal distances between drills, pads without drills, mill path errors, coincident or overlapping drills, and others. Figure 2. Acid trap violation PCB Assembly Analysis Assembly analysis will detect specific PCB content that might have an adverse effect on PCB assembly. Solder and paste mask features—such as less-than- minimal mask spacing, missing masks, extra mask, minimal mask annular rings, and mask-size-to-pad-size ratios—are examples of mask analysis available. Silkscreen-related analysis includes ink over pads, ink over mask exposures, and other checks. Less-than-minimal part spacing, pad spacing between adjacent parts, and minimal spacing between component pads and adjacent vias, drills, and copper objects are examples of component-related analysis. Figure 3. Silkscreen-to-solder-mask spacing violation Error Charting Large-scale analysis can often result in a large number of reported failures. Viewing the results of large-scale analysis in chart form allows you to get to the root of the failure and quickly ascertain a remedy. Charting allows you to review specifics of the failures to identify trends or unexpected results. DFM Checker's charting feature reports the exact nature of the error and the PCB features related to that error. The charting function groups common errors so they can be quickly identified and resolved. Crossprobing with Allegro PCB Editor The Manufacturing Option's DFM Checker module is tightly integrated with Allegro PCB Editor to walk through errors. Select errors within DFM Checker and it zooms into the error location within Allegro PCB Editor. This expedites the process of finding and correcting errors in the source PCB design. DFM Checker adds DRC markers in Allegro Constraint Manager with details of the violation. Figure 1. Use of hierarchical rule sets helps identify defects, avoiding costly bare board scrap