Terms and Glossary

A STEP (ISO 10303) part that specifies how to represent and exchange product data for a particular application domain. AP 210 is the application protocol for electronic assembly and interconnect design.

The formal data modeling language used to define information models in the STEP family of standards. EXPRESS defines entities, types, rules, and constraints.

Standard for the Exchange of Product Model Data — a comprehensive set of ISO standards for representing and exchanging product data throughout its lifecycle.

ISO Technical Committee 184, Subcommittee 4 — the body responsible for developing and maintaining STEP (ISO 10303) and related industrial data standards.

National Institute of Standards and Technology — a U.S. federal agency that has contributed significantly to STEP development and AP 210 research.

An industry-government consortium that advances the development and implementation of STEP standards, including AP 210.

The abstract definition of information requirements for an application protocol, expressed in EXPRESS. Defines what data needs to be represented.

The concrete implementation model that maps ARM requirements to the STEP integrated resources. Defines how data is actually structured in a STEP file.

A fundamental data structure in EXPRESS, analogous to a class in object-oriented programming. Entities have attributes, may have constraints, and can participate in inheritance hierarchies.

A collection of ENTITY, TYPE, FUNCTION, and RULE definitions in EXPRESS. The AP 210 schema defines all entities used for electronic design data.

A version of the EXPRESS schema that includes all referenced entities inline, rather than referencing external schemas. The ARM extended longform is the primary AP 210 schema file.

A complete assembly consisting of a printed circuit board with components mounted on it. The primary artifact described by AP 210.

The interconnect substrate — a board with conductive traces that electrically connect components. AP 210 models the PCB as an interconnect substrate with layers.

The set of pads on a PCB that correspond to the leads of a component. Defines how a component is physically attached to the board.

An individual pad in a footprint where a component lead is soldered.

A plated-through hole that connects traces on different layers of a PCB. Types include through-hole, blind, and buried vias.

A single conductive or non-conductive layer in a PCB stackup. AP 210 uses stratum technology to model multi-layer substrates.

A component package type where connections are made through an array of solder balls on the bottom of the package.

A component package with leads extending from all four sides.

A package type approximately the same size as the integrated circuit die it contains.

The STEP standard defining the text-based file format for exchanging STEP data. AP 210 data is exchanged using Part 21 files.

A specific occurrence of an entity in a STEP file, identified by a numeric reference (e.g., #42).

The numeric identifier for an entity instance in a STEP Part 21 file (e.g., #42 = PRODUCT(…​)).

The physical medium that provides electrical connections between components. In practice, a PCB.

The hierarchical organization of a product into assemblies, sub-assemblies, and components. AP 210 supports both physical and functional decomposition.

The logical and physical representation of how components are electrically connected, including nets, interconnections, and interfacial connections.

Constraints on the design that encode manufacturing capabilities, electrical requirements, or physical limitations.

Breaking down a product by its functional purpose rather than physical structure (e.g., a Wheatstone Bridge circuit viewed as a measurement function rather than as four resistors).

Java STEP Data Access Interface — a Java framework for working with STEP data, used in the NIST AP 210 reference implementation.