Aligned block copolymer (BCP) nanopatterns are crucial for advanced nanotechnology applications, including lithography, nanofabrication, and data storage. For these technologies, having precise and defect-free patterns is essential. However, achieving defect-free patterns remains a significant challenge due to imperfections in the self-assembly process or external conditions. In our study, we applied shear stress to BCP films to align the patterns and immersed them in various solvents to enhance pattern quality and reduce defects. Characterization using scanning electron microscopy (SEM) and image analysis showed significant improvements in pattern uniformity and a substantial reduction in defect density compared to traditional methods. The results demonstrate that this simple, scalable, and adaptable strategy enhances the quality and performance of BCP nanopatterns. This strategy expands their potential in various applications, supporting the development of next-generation devices.