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Glossary
padstack A numbered list of padstack or via
stack descriptions. Each description contains a
pad or via definition, including layer, style, drill
diameter, size, offset, and solder mask guard
width.
post processing A term used to describe the
processes performed after the board has been
routed in order to produce manufacturing
information (silkscreens, reports, drill tapes,
assembly drawings, and so on).
pan With an object selected, to have the
screen automatically scroll to display successive
sections of the board when you move the mouse
to the screen edge.
power plane A copper layer usually
dedicated to a single signal that is considered to
be a power supply. The ground plane is a power
plane that supplies the ground potential.
PCB
property A characteristic of an object that can
be edited. A property consists of a name and a
value. Examples of property names are part
value and color. Their respective property values
can be something such as capacitor and red.
Acronym for printed circuit board.
PGA Acronym for Pin Grid Array. A chip
package with a high density of pins that is used
for large amounts of I/O.
pin The portion of a component to which an
electrical connection can be made.
pin swap The exchange of identical function
pins in order to decrease route lengths.
pin-to-pin spacing The physical spacing
between pins on a device.
placement The position of components on a
board. The process of selecting where
components will reside on a board.
plane layer A layer of copper that may have
pads and holes that connect to it or pass through
it. Typically used for the power and ground
layers, CAD tools output a Gerber file for a
plane layer in a negative form, meaning that the
areas without copper are identified. Regular
copper layers are output in positive form,
meaning that the areas with copper are identified.
plated through-hole A through-hole that
establishes an electrical connection between
layers of a board by way of a metal deposition
on the inner surface that defines the hole.
polar placement The process of placing
components using polar coordinates referenced
from a user-defined pole. Typically, this is used
for test fixtures.
query When you select an object on the
screen, Layout displays the object properties for
viewing or editing. You can use Layout’s query
tool to inquire about object properties.
radial lead A lead extending out the bottom
of a component, rather than from the end. See
also axial lead.
ratsnest line A connection between two pads
that reflects an electrical connection in the
netlist. A ratsnest is an unrouted connection, and
serves as a reminder that the pads must be
connected. Once a ratsnest is routed, it becomes
a track. See also connection, routing, track.
reference designator A character string
denoting the type of component and a number
that is specific to that component.
registration The alignment of a pad on one
side of the board (or layers of a multilayer
board) to its pad on the opposite side.
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