Issue link: https://iconnect007.uberflip.com/i/1526114
56 SMT007 MAGAZINE I SEPTEMBER 2024 replicate a common power delivery strategy of added copper fill regions on signal layers. Blocking for Manufacturing Factors, Fabrication, and Material Scope e test vehicle design consisted of replicat- ing the quadrant floorplan in a two-by-two grid to cover a full manufacturing panel as shown in Figure 6. Each quadrant was designed with a different copper balancing strategy under the component footprints. e copper patterns for an individual component footprint were iden- tical for components replicated within a single quadrant. e purpose of different copper bal- ance strategies within the same manufacturing panel was to block out manufacturing process and material lot factors. is approach allowed evaluation of design variations while maintain- ing the same press book location, same lami- nation press load, same thermal profiles, and same physical core and prepreg. Eight materi- als were included in the test, fabricated across eight supplier sites. Each fabricator selected the preferred core and prepreg combination to meet the target stackup. Copper distribution profile, materials chosen, and fabricators are shown in Figure 7. Analysis Methodology e warpage and coplanarity measurements were taken with shadow-moire technique at 1.7 µm resolution using 150 line per inch grat- ing. e tool model was an Akrometrix TTSM- J with the loading tray design adjusted for PCB Figure 7: Build matrix: copper distribution profiles, materials, and fabricator build lots. Figure 6: Full test vehicle panel and copper balance strategies by quadrant.