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A treatment that renders nonconductive
material receptive to electroless deposition. Non preferred
synonyms: Seeding,Catalyzing, and Sensitizing.
The conductive
foil and plating surrounding a hole.
An
accurately scaled (usually 1:1 ) pattern which isused
to produce the production master.
The ratio
of the circuit board thickness to the smallest hole
diameter.
Sheet material impregnated with
a resin cured to an intermediate stage (B- stage resin).
Prepreg is the preferred term.
Interconnection panels into or onto which printed circuits,
other panels, or integrated circuit packages can be
plugged or mounted.
The cylinder
formed by plating through a drilled hole.
The
substrate material upon which the conductive pattern
may be formed. The base material may be rigid or flexible.
A method
of testing printed circuit boards that employs a test
fixture mounting an array of contact pins configured
so as to engage plated-through holes on the board.
A mechanically
or laser drilled hole which only interconnects the second
or third layer to the surface layer of the board.
The
force per unit area required to separate two adjacent
layers of a board by a force perpendicular to the board
surface.
A mechanically
or laser drilled hole which interconnects internal layers
only.
The condition of a resin polymer when
it is in the solid state, with high molecular weight,
being insoluble and infusible.
The nominal distance between the centers of adjacent
features or traces on any layer of a printed circuit
board.
A corner which
has been rounded or angled to eliminate an otherwise
sharp edge.
A
relatively thin layer or sheet of metal foil which is
bonded to a laminate core to form the base material
for printed circuits.
A hole
in the conductive pattern larger than, but concentric
with, a hole in the printed board base material.
The fractional change in dimension of
a material for a unit change in temperature.
A hole
used for the attachment and electrical connection of
component terminations, including pins and wires, to
the printed circuit board.
That
side of the printed circuit board on which most of the
components will be mounted.
The configuration or design of the conductive material
on the base laminate. Includes conductors, lands, and
through connections.
The conductor width at the plane of the surface of the
base material. See also: Conductor Width.
The distance between the edge of a conductor and the
edge of a supported or unsupported hole.
The
observable width of the pertinent conductor at any point
chosen at random on the printed circuit board.
A cathode-quality
electrolytic copper used as a conductorfor printed circuits.
It is made in a number of weights (thicknesses); the
traditional weights are 1 and 2 ounces per square foot
(0.0014 and0.0028 inch thick).
The maximum current which can be carried continuously,
under specified conditions, by a conductor without causing
degradation of electrical or mechanical properties of
the printed circuit board.
A defined point, line, or plane
used to locate the pattern or layer for manufacturing,
inspection, or for both purposes.
Process
of removing a burr after board drilling. Deburring operations
fall into two categories: producing a clean, sharp edge
when removing heavy burr; and radiusing the edge of
the holes to prevent
build-up in plating.
An insulating
medium which occupies the region between two conductors.
Any method
of reducing feature locations on a flat plane to digital
representation in X-Y coordinates.
A measure of dimensional change caused by factors such
as temperature, humidity, chemical treatment, age, orstress;
usually expressed as units/unit.
A
hole in a printed circuit board where the means of determining
location is by coordinate values not necessarily coinciding
with the stated grid.
Coating
material in the form of laminated photosensitive film
specifically designed for use in the manufacture of
printed circuit boards and chemically machined parts.
They are resistant to various electroplating and etching
processes. Artwork or Photo-tool is used to expose the
circuit pattern onto the dry-film resist.
The deposition of conductive
material from an auto catalytic reduction of a metal
ion on certain catalytic surfaces.
The
electrodeposition of a metal coating on a conductive
object. The object to be plated is placed in an electrolyte
and connected to one terminal of a d-c voltage source.
The metal to be deposited is similarly immersed and
connected to the other terminal. Ions of the metal provide
transfer to metal as they make up the current flow between
the electrodes.
The ratio
of the depth of etch (conductor thickness) to the amount
of lateral etch (undercut).
The controlled
removal of all components of base materialby a chemical
process on the side wall of holes in order to expose
additional internal conductor areas.
The process
of removing unwanted metallic substance (bonded to a
base) via chemical, or chemical and electrolytic means.
A sample part or assembly manufactured
prior to the start of production for the purpose of
assuring that the manufacturer is capable of manufacturing
a product that will meet specified requirements.
A substance used
to promote or facilitate fusion, such as a material
used to remove oxides from surfaces to be joined by
soldering or welding.
A thin sheet
of metal, usually copper or aluminum, used as the conductor
for printed circuits. The thinner the foil, the lower
the required etch. time. Thinner foils also permit finer
definition and spacing. See Copper Foil.
A metallic
coating (usually tin or solder alloy) which has been
melted and solidified forming a metallurgical bond to
the base material.
A conductor layer, or portion of
a conductor layer, used as a common reference point
for circuit returns, shielding, or heat sinking.
A conductive pattern which is
contained entirely within a multilayer printed board.
A product made by bonding together two
or more layers of material.
The process
of preparing a laminate; or a multilayer PWB.
A portion of
a conductive pattern usually, but not exclusively, used
for the connection and/or attachment of components.
Also called Pad, Boss, Terminal area, Blivet, Tab, Spot,
or Donut.
The thickness of dielectric material between adjacent
layers of conductive circuitry in a multilayer printed
circuit board.
A format of
lettering or symbols on the printed board; e.g.,part
number, component locations, and patterns.
A material applied to enable selective etching,
plating, or the application of solder to a printed circuit
board.
The
preparation of a specimen for the microscopic examination
of the material to be examined, usually by cutting out
across-section, followed by encapsulation, polishing,
etching, staining,etc.
The minimum metal width, at the narrowest point, between
the circumference of the hole and the outer circumference
of the land. This measurement is made to the drilled
hole on internal layers of multilayer printed circuit
boards and to the edge of the plating on outside layers
of multilayer boards and double-sided boards.
The minimum allowable distance between adjacent
conductors that is sufficient to prevent dielectric
breakdown, corona or both, between the conductors at
any given voltage and altitude.
Printed circuit boards consisting of three
or more conducting circuit planes separated by insulating
material and bonded together with internal and external
connections to each level of the circuitry as required.
The portion of the conductive pattern on
printed circuits designated for the mounting or attachment
of components. Also called Land.
The base material
containing one or more circuit patterns that passes
successively through the production sequence and from
which printed circuit boards are extracted. See Backplanes
and Panels.
The
plating of the entire surface of a panel (including
holes).
Selective
plating of a conductive pattern (including holes).
A high
accuracy laser plotting system. It is used to produce
actual size master patterns for printed circuit artwork
directly on dimensionally-stable, high contrast silver
halide photographic film.
A hole with the plated copper on its sides to provide
electrical connections between conductive patterns at
the levels of a printed circuit board.
A
method of metal deposition employing a chemical reducing
agent present in the processing solution. The process
is further characterized by the catalytic nature of
the surface which enables the metal to be plated to
any thickness.
A method of metal deposition employing the work or cathode;
the anode the electrolyte, a solution containing dissolved
salts of the metal to be plated; and a source of direct
current. (See Electroplating)
Materials
which, when deposited on conductive areas, prevent the
plating of the covered areas. Resists are available
both as screened-on materials and as dry-film photopolymer
resists.
The mechanical
converting of X-Y positional information into a visual
pattern, such as artwork.
High
temperature thermoplastics used with glass to produce
printed circuit laminates for Multilayer and other circuit
applications requiring high temperature performance.
Sheet material
consisting of the base material impregnated with a synthetic
resin, such as epoxy or polyimide, partially cured to
the B-stage.
The melting of an electro-deposit followed
by solidification. The surface has the appearance and
physical characteristics of being hot-dipped.
The degree
of conformity of the position of a pattern, or a portion
there of, with its intended position or with that of
any other conductor layer of a board.
Coating material
used to mask or to protect selected areas of a pattern
from the action of an etchant, solder, or plating. Also
see: Dry-Film Resists, Plating Resists and Solder Resists.
A drawing which shows, by means
of graphic symbols, the electrical connections, components
and functions of an electronic circuit.
A
process for transferring an image to a surface by forcing
suitable media through a stencil screen with a squeegee.
Also called Silk Screening.
The
process of dipping printed circuit boards into molten
solder and leveling the surface with hot air.
Coatings
which mask and insulate portions of a circuit pattern
where solder is not desired.
A
method by which successive exposures of a single image
are made to produce a Multiple-lmage Production Master
Artwork.
A portion of a printed circuit board
or of a panel containing printed circuit coupons, used
to determine the acceptability of such boards using
destructive testing methods such as Microsectioning.
A metal
sheet less than 0.0007 inches (1/2 oz) thick or less.
The
general term for non-plated holes placed on a printed
circuit board or a panel used for registration and tooling
purposes during the manufacturing process, testing and
assembly.
Polymerizing, hardening,
or cross linking a low molecular weight resinous material
in a wet coating or ink, using ultravoilet light as
an energy source.
Equipment used for ultrasonic immersion cleaning employing
a transducer which converts electrical energy into mechanical
energy; an ultrasonic generator, and a tank to contain
the cleaning liquid. Both automated and conveyorized
ultrasonic cleaning systems exist.
The reduction
of conductor cross-section on a printed circuit board
caused by etchant removal of conductive metal under
the edge of the resist.
A plated-through hole used as a through
or inner-layer connection, but in which there is no
intention to insert a component lead.
A surface condition of base material
in which a weave pattern of glass cloth is apparent
although the unbroken fibers of the woven cloth are
completely covered with resin.
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