Via Tenting, Filling and Via-in-Pad: What to Request

“Cover all vias” is not a complete manufacturing instruction. A solder-mask cover, a filled hole and a copper-capped surface describe different results. When a via sits in a component's solderable pad, the required surface condition matters to both fabrication and assembly.

Name the intended structure

Tenting generally refers to covering a via opening with solder mask. Filling introduces material into the hole; capping describes an additional surface treatment. These terms are not interchangeable. Eurocircuits' via-covering discussion illustrates the distinction and explains its own available process. Confirm DIYIPCB's proposed construction for the particular design rather than assuming a mask checkbox selects every operation.

Create a small annotated cross-section or a reference drawing that shows the desired outcome. State which via group needs treatment and whether the requirement applies on one side or both. This removes ambiguity when only some vias are located inside solder pads.

Review vias that intersect solderable pads

For an exposed-pad IC or a dense package, begin with the component manufacturer's land-pattern and assembly guidance. Discuss the via pattern together with stencil apertures and the assembler's process. An open hole in a solderable area can provide a path for solder movement; a covered opening should not be assumed equivalent to a planar, filled and capped pad.

Do not solve the issue by deleting thermal or electrical connections without reviewing their function. Likewise, moving a via out of a pad may change routing or heat flow. Treat the choice as a design and process decision, not only a price option.

Prepare a targeted request

• Identify affected reference designators and pad locations.
• Provide via diameter, pad geometry and the relevant layer structure.
• Describe the required top and bottom surface condition.
• Ask which process, inspection and drawing notes are needed.
• Request any associated cost or lead-time impact before approval.

Check the accepted fabrication notes

For example, if only the vias under U3 require filling and capping, name that region rather than applying an unclear whole-board note. Review the manufacturer's proposed interpretation against the assembly requirements. Keep the accepted treatment with the board revision so a reorder preserves the same construction even if a different person prepares the next quotation.

Technical reference: Eurocircuits: via-covering process distinctions. Supplier-specific process limits in the reference are not DIYIPCB manufacturing commitments.