Piezoelectric quartz crystal resonators (commonly referred to as quartz crystals) are electronic components used for frequency selection and control. The manufacturing process begins with quartz crystal rods. These rods are cut at specific angles into square quartz wafers. These wafers undergo dozens of precision machining steps, including grinding, dicing, tumbling, etching, polishing, or photolithography (for photolithography-processed quartz wafers), to produce quartz wafers meeting various packaging and performance requirements. Metal electrodes such as gold or silver are vacuum-deposited onto the surface of the quartz wafers. After encapsulation, these become quartz crystal resonators. Alternatively, they are combined with related passive components like ICs, capacitors, and inductors, then encapsulated to form quartz crystal oscillators. As the core component of quartz crystals, quartz wafers exhibit characteristics such as small dimensions, brittle material properties, stringent tolerances for size, flatness, and parallelism, and high surface finish requirements. This results in significant challenges in both processing and quality control.