Assembly, Printed Board – An assembly of several printed circuit assemblies or printed wiring assemblies, or both.Assembly, Printed Circuit (wiring) – A printed circuit orprinted wiring board on which separately manufacturedcomponents and parts have been added.Assembly, Single-Sided – Packaging and interconnectingstructure with components mounted only on the primaryside.*Base Material – The insulating material upon which aconductive pattern may be formed. (The base material maybe rigid or flexible, or both. It may be a dielectric or insulatedmetal sheet.)*Basic Dimension – A numerical value used to describethe theoretical exact location of a feature or hole. (It is thebasis from which permissible variations are established bytolerance on other dimensions in notes or by feature controlsymbols.)*Blind Via – A via extending only to one surface of aprinted board.*Buried Via – A via that does not extend to the surface ofa printed board.*Castellation – A recessed metalized feature on the edge ofa leadless chip carrier that is used to interconnect conductingsurface or planes within or on the chip carrier.*Chip Carrier – A low-profile, usually square, surfacemountcomponent semiconductor package whose die cavityor die mounting area is a large fraction of the package sizeand whose external connections are usually on all foursides of the package. (It may be leaded or leadless.)*Chip-On-Board (COB) – A printed board assembly technologythat places unpackaged semiconductor dice andinterconnects them by wire bonding or similar attachmenttechniques. Silicon area density is usually less than that ofthe printed board.*Coefficient of Thermal Expansion (CTE) – The lineardimensional change of a material per unit change in temperature.(See also ‘‘Thermal Expansion Mismatch.’’)*Component – An individual part or combination of partsthat, when together, perform a design function(s). (See also‘‘Discrete Component.’’)*Component Mounting Site – The location on a PackageInterconnect (P&I) structure that consists of a land patternand conductor fan-out to additional lands for testing or viasthat are associated with the mounting of a single component.*Conductive Pattern – The configuration or design of theconductive material on a base material. (This includes conductors,lands, vias, heatsinks and passive componentswhen these are an integral part of the printed board manufacturingprocess.)*Conductor – A single conductive path in a conductivepattern.