Solder Mask Application: This process involves strategically exposing through-holes while coating the rest of the PCB's circuits and copper areas. The primary goal is to avert short-circuits during the component mounting phase on the PCB. It also contributes to the reduction of tin solder usage.

Protective Layer Integration: This layer serves as a shield against moisture and various electrolytes that could potentially oxidize and harm the circuitry, compromising electrical properties. It additionally offers a defense against external physical damage, thus preserving the optimal isolation of the PCB.

Enhanced Isolation Measures: With the ongoing trend of PCBs becoming thinner and the widths and pitches of circuits increasingly narrowing, the significance of isolation between conductors has become more pronounced. Consequently, there's a growing emphasis on the isolation properties provided by the solder mask.