annularring

Annular ring is a term most commonly used in printed circuit board (PCB) engineering to describe the copper ring that surrounds a drilled hole, such as a via or through-hole component pad. The annular ring, or annulus, provides the electrical connection between layers and adds mechanical support for the hole.

Note: The one-word form annularring is not standard; it may appear as a typographical error or dataset artifact.

In fabrication, the annular ring is defined by the drill size, the copper thickness, and the plating process, and is specified by design rules. The width of the annular ring determines the amount of copper around the drilled hole, affecting solderability, current capacity, and reliability. If the annular ring is too small, vias can fail to plate or open; if too large, they can cause spacing issues and short circuits in dense boards. Variations in drilling tolerance and plating quality can also alter the effective annular ring after manufacture.

Applications and considerations: annular ring width is a key parameter in PCB design and fabrication flows, influencing manufacturability, testability, and thermal performance. Designers adjust via sizes and annular rings to balance electrical performance with board density and reliability.

See also: annulus (mathematics), via, pad, PCB design, plating. If you meant a different context for annular ring, such as geological or biological ring structures, please note that annular ring has other uses and definitions outside PCB technology.