For this reason, we have created this guide to help you understand and choose the most suitable type of via protection for your printed circuit board.
What is the purpose of via protection?
Protection against corrosion during the PCB metallization process and the assembly of printed circuit board components.
Electrical and mechanical insulation of the via interior.
Protection against solder mask penetration into the vias.
Protection against solder ball formation during wave or reflow soldering.
Protection against unwanted loss of solder paste and flux during soldering.
Protection against unwanted retention of air or other substances under the printed circuit board components.
Improvement of the thermal and/or electrical performance of the vias through the use of special filler resins containing metallic particles.
Improved vacuum performance by eliminating air leaks during assembly and ICT (In-Circuit Testing).
Creation of a solderable via surface (via in pad—only with Type VII sealing)—often used in HDI applications.
NCAB and Road Protection
Unlike IPC 4761, we always specify the fill level for the channels to our factories. Otherwise, the fill level would be undefined. The factories NCAB works with aim for a 100% fill level. A minimum fill level of 70% is required for Type V and VI protection standards, and 100% for Type VII. Channel filling must always be performed in a separate process and should not be combined with the regular welding mask application process.
