What should be ensured regarding bubbles and voids in conformal coating?

The correct answer highlights the importance of ensuring that bubbles and voids in conformal coating do not bridge non-common conductors. This is critical because bridging can create unintended electrical pathways, potentially leading to short circuits or malfunctioning in electronic assemblies. Non-common conductors refer to those raised above the ground plane, which could become conductive due to the presence of moisture or contaminants trapped within bubbles or voids.

Preventing these bubbles and voids from bridging non-common conductors maintains the integrity of the coating, ensures moisture protection, and supports the overall functionality and reliability of the electronic devices. A well-coated assembly should effectively insulate and protect against environmental factors, and the presence of voids that lead to bridging jeopardizes this protection.

Additional choices suggest either that bubbles and voids are permissible in general or that they require immediate reapplication of the coating, both of which do not align with the standards set forth in J-STD-001 regarding uniformity and reliability of conformal coatings. Thus, avoiding bridging is paramount for maintaining device performance and safety.