When sourcing wireless charging receivers, the most critical factor is Qi Standard Compatibility (typically version 1.2.4 or 1.3). You must verify the Output Current and Voltage (e.g., 5V/1A or 9V/1.1A) to ensure it matches the charging speed requirements of the target devices. Additionally, pay attention to the Conversion Efficiency rate, which should ideally be above 75% to minimize heat generation and energy loss. For internal DIY modules, check the Coil Type (copper vs. alloy) and the Thickness of the PCBA, as ultra-thin designs are essential for seamless integration into mobile phone cases or small electronics.