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APRIL 2019 I PCB007 MAGAZINE 81 Table 4. This table is based on various commer- cially available copper electrolytes used in the latest generation horizontal plating equipment. Current research and development efforts re- garding copper through-hole filling cover the following topics: • Faster processing time (cost driven) • Plating less copper on the surface (cost driven) • Increasing the uniformity (technology driven) • Better filling performance, low dimple (technology driven) • Keeping the void-free level (quality driven) • Selecting parameters to plate higher aspect ratios Other New Electroplating Copper Technologies As the technology of filling microvias and through-holes is already established and in pro- duction, the electronics market requires newer features, such as pillar plating realized on IC substrates or smaller RDL (redistribution layer) structures, to enable panel level packaging (PLP) on the IC substrate level. That develop- ment has already progressed quite far. A newer equipment approach with recently developed copper electrolytes does enable these technolo - gies. The first copper plating equipment of this new generation offers the following: 1. Plating of a target copper thickness of 6 µm on a 600x600-mm panel with a copper thick- ness distribution of less than 5% (Figure 9) Figure 9: Achieved copper thickness distribution on a 600x600-mm panel. Figure 8 (a–c): Copper filling of a through-hole with patented "Bridge-Plating." Table 4: Copper-filled through-holes (dimensions that can be filled today).