无掩模光刻在 FO WLP 双图像曝光中的实践探索

Core Viewpoint - The article discusses the advancements and challenges in Fan-Out Wafer-Level Packaging (FOWLP) technology, emphasizing the need for new materials and processes to enhance chip integration and performance [1][2][3]. Group 1: FOWLP Development - FOWLP aims to address the limitation of insufficient external contacts on chips by cutting wafers into pieces and reassembling them into a new wafer, increasing the chip's surface area for more external contacts [1]. - The manufacturing of FOWLP faces challenges such as the need for new high-temperature dielectrics that can cure at significantly lower temperatures, around 200°C, compatible with epoxy molding materials used in FOWLP [1][2]. Group 2: Process Challenges - Key challenges include eliminating unnecessary warping of the reconstructed wafer due to mismatched thermal expansion coefficients between the silicon epoxy layer and the polymer RDL layer [2]. - Designers must choose between "face-up" and "face-down" configurations to manage high profiles and non-planarity between chips and molds [2]. - Reliable connections for copper RDL lines are critical, as damaged lines can lead to electrical failures between chips and PCBs [2]. Group 3: Advanced Packaging Techniques - The application of stepper lithography in next-generation advanced packaging faces limitations, particularly in accurately reconstructing wafers from different manufacturers [3]. - The use of maskless exposure lithography technology is proposed as a solution to overcome the challenges posed by traditional stepper lithography, allowing for high-resolution patterns essential for advanced devices [3][4]. Group 4: MLE Technology - MLE technology has been demonstrated to achieve resolutions as low as 1.5 µm and high aspect ratios up to 1:7, successfully applied in standard copper plating processes [5]. - The dual-embedding process using MLE technology aims to reduce the number of lithography steps by 50%, showcasing its economic feasibility in advanced packaging applications [5][6]. Group 5: Industry Event - The 2025 TrendBank (Fifth) Lithography Materials Industry Conference will be held from July 8-10 in Hefei, focusing on new applications, trends, and in-depth discussions on the lithography materials supply chain [8].