In today's electronics-driven world, the reliability of devices like smartphones, GPS systems, and medical devices hinges on the cleanliness of their printed circuit board assemblies (PCBAs). Contaminants on PCBAs can lead to malfunctions or even catastrophic failures, making PCB cleaning a crucial aspect of manufacturing. This article explores two prominent cleaning methods: in-line aqueous cleaning and vapor degreasing. While both are effective, vapor degreasing stands out for its superior cleaning and environmental benefits. By understanding the importance of PCB cleaning and selecting the right method, manufacturers can ensure the integrity and performance of their electronic products in a competitive market.