ACM Research Inc. is developing wet-processing equipment for wafer-level packaging (WLP) and panel-level packaging (PLP), where substrate flatness, residue removal and process uniformity are becoming more demanding as package structures grow more complex. Speaking to EE Times Asia at SEMICON West 2026 in San Francisco, Sally Ann Henry, chief technologist at ACM Research, identified panel warpage and the lack of standard substrate dimensions as key challenges for equipment suppliers. The company is addressing these requirements with equipment for cleaning, electroplating and other wet-processing steps. ACM Research was founded in Fremont, California, in 1998 by Dr. David Wang. After establishing a subsidiary in Shanghai, the company expanded its technology development and manufacturing capabilities. It went public on Nasdaq in 2017. Jim Straus, Vice President of Sales for North America, Europe, and Southeast Asia, said ACM Research had maintained compound annual growth of about 50% over the past eight or nine years. Although much of its business remains in Asia, the company is expanding its R&D and manufacturing operations in South Korea and the United States. Jim Straus, Vice President of Sales for North America, Europe, and Southeast Asia, ACM Research In Oregon, ACM Research is preparing a 40,000-square-foot facility with a demo lab, and R&D and manufacturing capabilities. The company planned an opening ceremony for November 2026, with operations expected to be running by the first or second quarter of 2027. Panel processing presents new equipment demands The shift towards heterogenous architectures amid the exponential growth of artificial intelligence (AI) and high-performance computing (HPC) applications is driving the need for advanced packaging, which increasingly combines chiplets, high-bandwidth memory (HBM), processors and sensors on a common substrate. Wet-processing equipment must support the formation and cleaning of the copper interconnects that connect these components, while maintaining uniformity across the substrate. Henry said ACM Research’s technology covers a range of processes, including coating, developing, cleaning, metal etching and electroplating. For WLP and the transition to PLP, cleanliness and process non-uniformity are among the main concerns. Panel formats under development include 310x310mm, 510x515mm and 600x600mm substrates. Unlike conventional 300mm wafers, these larger panels can experience greater warpage, complicating chemical delivery and removal during wet processing. “You need to have different robots in your equipment to handle it. You need to make sure that warpage is not there, and it is as flat as it can be,” Henry said. Substrate flatness affects how uniformly chemicals reach and leave the surface. If a panel is not sufficiently flat, different areas can receive different amounts of chemical exposure, potentially producing uneven etching or damaging underlying layers. Equipment suppliers must also contend with the absence of a common panel format. Manufacturers are evaluating different dimensions, making it difficult to develop a single platform that accommodates all requirements. Suppliers may need to adapt equipment designs and substrate-handling systems for multiple formats, according to Henry. Cleaning and plating for dense interconnects Smaller redistribution layers (RDLs) and through-silicon vias (TSVs) place tighter demands on cleaning and deposition processes, according to Henry. Residues and other defects can interfere with interconnect formation, while non-uniform copper plating can affect electrical connections across the package. Henry said manufacturers need clean surfaces and uniform films across the substrate, whether processing a wafer or a panel. Chemical selection depends on the materials involved and the specific process step. ACM Research develops some of its own chemistries, while customers may also require particular formulations. Cleaning is especially impor