Terminology

Conventions, abbreviations and acronyms are used in descriptions of the analyses.

Term

Explanation

NFP

Non-functional pad.

NPTH

Non-plated through hole.

PTH

Plated through hole (component hole).

Via

Via drill.

Text

A feature of type text or a line, arc, or pad tagged with the feature attribute Copper Text.

Circuit

A line, arc or surface used to facilitate the flow of electricity.

r0

Null feature ID. In many analysis categories there are two associated features, such as two pads in the pad to pad spacing category. Sometimes, when a drill annular ring is measured, there are two features, namely the pad and the drill. But there may be cases where there is an annular ring measurement between a drill and a drawn surface. In that case there is no pad to refer to; the ID will be an r0 null feature.

RM

Reliability Margin. The RM is defined in the ERF variables list at the end of each Action chapter.

DRA

Design Registration Allowance. The DRA for a category is the margin between the minimum measurement in the category and the RM. The DRA for a board is the minimum of all DRAs for categories for which a DRA is defined.

Plated Hole

This term is used to refer to PTHs and vias only.