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68 PCB007 MAGAZINE I OCTOBER 2020 achieve this in a single step is the MacuSpec THF 100 process, which can be installed in VCP plating lines or conventional hoist tanks with direct solution impingement and pulse rectification. Large Area Plating Cells: Uniform High-Speed Copper Plating for Panel-Level Packaging Large-area or panel-lev- el format is driven by a quest for lower packaging costs. Large panel formats of 510 mm x 515 mm up to 600 mm x 600 mm and even larger sizes typical of display manufacturers present unique technical challenges for plating and tooling but offer new op- tions for hybrid packaging and designs required with heterogeneous integration. Single-panel plating cells have been developed to control the current density over the large panel area, similar to a fountain plat- ing tool for wafers. For or- ganic and glass substrates, specific plating chemis- tries have been developed for use in SEMSYSCO HSP tools. Large-scale RDL and copper pillar features can be obtained with the right match of plat- ing additives and plating tool. These systems can control the Z-axis height within tight toler- ances within the unit and across the panel and are successfully operating in mass production today. MacDermid Alpha and SEMSYSCO have partnered to develop an HSP tool that can han- dle 600 mm x 600 mm panels located in the MacDermid Alpha GDAC in Zhongli, Taiwan. This tool is utilized in conjunction with cus- tomers to test process chemistries on various panel designs and applications. Figure 15 shows an example of a large area format on a Gen5 glass substrate, 1100 mm x 1300 mm in size. These substrates are plated at 3.5 ASD for 23 minutes for a target feature height of 17 µm. Results were an average of 17.1 µm with a range of 15.9 to 18 µm. The process chemistry was Systek BMP-LP for pillar plating, and Systek UVF 100 for RDL plating, while the plating tool was a SEMSYSCO HSP. Figure 15: Panel-level equipment testing. Large-area Gen5 glass substrate (top left); large-area within-panel copper plating height distribution for panel-level plating equipment (top right); substrate-side copper pillar plating for advanced packaging (middle left); within-unit distribution photography of test panel for pillar plating chemistry (middle right); and panel-level scale RDL plating example, showing homogenous deposit on lines and pads, even height distribution between lines, and pads and flat shape profile on pad (bottom).