NASA STD 8739.3 Definitions Flashcards
Article
A unit of hardware or any portion thereof required by this contract
Assembly
A functional subdivision of a component, consisting of parts or sub assemblies that perform functions necessary for the operation of the component as a whole. Examples: Regulator assembly, power amplifier assembly, gyro assembly, etc…
Axial Lead
Lead wire extending from a component or module body along its longitudinal axis.
Bifurcated (Split) Terminal
A terminal with a slot or split opening in which conductors are placed before soldering
Birdcage
A defect in stranded wire where the strands in the stripped portion between the covering of an insulated conductor and a soldered connection (or end tinned lead) have separated from the normal lay of the strands
Blister
Raised area on the surface of the laminate caused by the pressure of volatile substances entrapped within the laminate
Blow hole
a cavity in the solder surface whose opening has an irregular and jagged form, without a smooth surface
Bridging
a buildup of solder between components, conductors, and/or base substrate forming and undesired conductive path
Circumferential Seperation
A crack or void in the plating extending around the entire circumference of a PTF, or in the solder fillet around the conductor, in the solder fillet around an eyelet, or at the interface between a solder fillet and a land.
Cold Flow
Movement of insulation (e.g. Teflon) caused by pressure
Cold Solder Connection
A solder connection exhibiting poor wetting and a grayish, porous appearance due to insufficient heat, inadequate cleaning before soldering, or excessive impurities in the solder.
Component
A functional subdivision of a system, generally a self contained combination of assemblies performing a function necessary for the system;s operation. Examples: power supply, transmitter, gyro package, etc..
Conduction Soldering
Method of soldering which employs a soldering iron for transfer of heat to the soldering area
Conductor
A lead, solid or stranded, or printed wiring path serving as an electrical connection
Conformal Coating
A thin electrically non-conductive protective coating that conforms to the configuration of the covered assembly.
Connection
An electrical termination that was soldered. A solder joint.
Construction Analysis
The process of destructively disassembling, testing, and inspecting a device for the purpose of determining conformance with applicable design, process, and workmanship requirements. This process is also known as Destructive Physical Analysis (DPA)
Contaminant
An impurity or foreign substance present in a material that affects one or more properties of the material. A contaminant may be either ionic or non ionic. An ionic, or polar compound, forms free ions when dissolved in water, making the water a more conductive path. A non-ionic substance does not form free ions, nor increase the water’s conductivity. Ionic contaminants are usually processing residue such as flux activators, finger prints, and etching or plating salts.
Crazing
An internal condition occurring in the laminate base material in which the glass fibers are separated from the resin
Cup Terminal
A hollow, cylindrical terminal to accommodate one or more conductors.
Delamination
A separation between plies within a base material or any planar separation within a multilayer PWB
Deviation
A specific authorization, granted before the fact, to depart from a particular requirement of specifications or related documents
Dewetting
The condition in a soldered area in which the liquid solder has not adhered intimately,
but has receded, characterized by an abrupt boundary between solder and conductor, or solder
and terminal/termination area leaving irregularly shaped mounds of solder separated by areas
covered with a thin solder film.
Disturbed Solder Joint
Unsatisfactory connection resulting from relative motion between the
conductor and termination during solidification of the solder.
Dross
Oxide and other contaminants that form on the surface of molten solder.
Egress
An opening that provides a pathway from the interior of an enclosed space.
Encapsulating Compound
An electrically nonconductive compound used to completely enclose
and fill in voids between electrical components or parts.
Excessive Solder Joint
Unsatisfactory solder connection wherein the solder obscures the
configuration of the connection.
Eyelet
A hollow tube inserted in a terminal or PWB to provide mechanical support for
component leads or for electrical connection.
Flatpack
A part with two straight rows of leads (normally on 0.050 inch centers) that are parallel
to the part body.
Fillet
A smooth concave buildup of material between two surfaces; e.g., a fillet of solder between
a conductor and a solder pad or terminal.
Flux
A chemically-active compound which, when heated, removes minor surface oxidation,
minimizes oxidation of the basis metal, and promotes the formation of an intermetallic layer
between solder and basis metal.
Fractured Solder Joint
A joint showing evidence of cracking, resulting from movement
between the conductor and termination, after solidification of the solder.
Haloing
Mechanically-induced fracturing or delaminating on or below the surface of the base
PWB material; it is usually exhibited by a light area around holes, other machined areas, or both.
Hook Terminal
A terminal formed in a hook shape.
Insufficient Solder Connection
A solder connection characterized by incomplete coverage of
one or more of the metal surfaces being joined or by incomplete solder fillets.
Interfacial Connection
A conductor that connects conductive patterns between opposite sides
of a PWB.
Interlayer Connection
An electrical connection between conductive patterns in different layers
of a PWB.
Joint
A solder joint; a termination.
Lifted Land
A land that has lifted or separated from the base material, whether or not any resin
is lifted with the land
Mission Essential Support Equipment
Equipment used in a closed loop with the system, where
failure of this equipment would degrade the mission or imperil personnel. This category includes
items of ground support equipment whose functions are necessary to support the count down
phase and those items of ground support equipment used in pre-count down phases whose
problems can create a safety hazard, cause damage to flight hardware, or inability to detect a
problem on the flight hardware.
Measling
Discrete white spots below the surface of the base material, usually caused by
moisture, pressure, and/or thermally induced stress.
Nick
A cut or notch on a conductor.
Nonwetting
A condition whereby a surface has contacted molten solder, but the solder has not
adhered to all of the surface; basis metal remains exposed.
Offgassing
The release of volatile parts from a substance when placed in a vacuum environment
that may affect crew members.
Outgassing
The release of volatile parts from a substance when placed in a vacuum environment.
Overheated Joint
An unsatisfactory solder joint, characterized by rough solder surface; dull,
chalky, grainy, porous or pitted.
Pad
A portion of a conductive pattern used as a soldering area. Also called a land.
Part
An element of a component, assembly, or subassembly that is not normally subject to
further subdivision or disassembly without destruction of designed use.
Part Lead
The solid conductor attached to a part
Pierced (Perforated) Terminal
A terminal containing a hole through which conductors are
placed before soldering
Pinhole
A solder connection with a small hole penetrating from the surface of the solder to a
void of indeterminate size within the solder connection.
Pit
A relatively small recess in the solder surface, the bottom of which is visible from all angles of
vision.
Plated-Through-Hole
A plated-through hole is one formed by a deposition of metal on the
inside surface of a through-hole. Also known as a supported hole. The configuration is used to
provide additional mechanical strength to the soldered termination or to provide an electrical
interconnection on a multilayer PWB.
Porous Solder Joint
A joint having a grainy or gritty surface.
Potting Compound
An electrically nonconductive compound used to partially encapsulate or for
a filler between parts, conductors, or assemblies.
Printed Wiring Assembly. (PWA)
The PWA consists of the PWB, components, and associated
hardware and materials.
Printed Wiring Board
. A pattern of conductors printed (screened) onto the surface of an
insulating base to provide interconnection for parts.
Radial Lead.
Lead wire extending from a component or module body along its latitudinal axis.
Radial Split.
A crack or other separation in the flange of an eyelet or other circular connector,
which extends outward from the center. Such cracking is usually the result of swaging or other
setting process as the item is embraced in a printed wiring board.
Repair
Operations performed on a nonconforming article to place it in usable condition. Repair
is distinguished from rework in that alternate processes rather than reprocessing are employed.
Resistance Soldering
Method of soldering by passing a current between two electrodes through
the area to be soldered
Rework
The reprocessing of articles or material that will make it conform to drawings,
specifications, and contract.
Rosin Solder Joint.
Unsatisfactory connection that has entrapped rosin flux. This entrapment is
usually due to insufficient heat or insufficient time at soldering temperature, or both, not enabling
the rosin to rise to the surface of the solder. This results in insufficient bonding and/or high
electrical resistance
Solder
A nonferrous, fusible metallic alloy used to join metallic surfaces
Solderability.
The property of a surface that allows it to be wetted by a molten solder
Solder Connection
An electrical/mechanical connection that employs solder for the joining of
two or more metal surfaces.
Solder Mask
Coating material used to mask or protect selected areas of a pattern from the
action of an etchant, solder, or plating.
Solder Pad
Termination area on a printed wiring conductor
Solder Spatter
Extraneous irregular-shape solder fragments.
Solder Spike
A cone shaped peak or sharp point of solder usually formed by the premature
cooling and solidification of solder on removal of the heat source.
Soldering
The process of joining clean metallic surfaces through the use of solder without direct
fusion of the base metals.
Staking Compound
An electrically nonconductive adhesive material used for additional support
after a component has been attached by mechanical or soldering process.
Straight Pin Terminal
A round post-type smooth terminal, with no grooves.
Straight-Through Termination.
A conductor termination extending through a PWB without
subsequent forming of the lead.
Stress Relief.
The formed portion of a conductor that provides sufficient length to minimize
stress between terminations
Stud Termination
An unbendable conductor termination extending through a PWB
Supplier
In-house NASA, NASA contractors, and subtier contractors
Surface Mounting
The electrical connection of components to the surface of a conductive
pattern that does not utilize part holes.
Supportive Hole
A hole in a printed board that has its inside surface plated or otherwise
reinforced.
Terminal
A tie point device used for making electrical connection.
Termination
The point at which electrical conductors are joined.
Termination Area.
A conductive surface on a PWB used for making electrical connections (also
referred to as a solder pad).
Thermal Shunt
A device with good heat dissipation characteristics used to conduct heat away
from an article being soldered.
Tinning
The coating of a surface with a uniform layer of solder
Tubelet
A tubular metal part. Its ends may or may not be flared.
Turret Terminal
A round post-type grooved stud around which conductors are fastened before
soldering.
Unsupported Hole.
A hole containing no plating or other type of conductive reinforcement
Via
A PTH used as an interlayer connection, but in which there is no intention to insert a
component or other reinforcing material.
Void
A space enclosed on all sides by the solder
Wave Soldering
A process wherein PWAs are brought in contact with the surface of
continuously flowing and circulating solder.
Wetting
Flow and adhesion of a liquid to a solid surface, characterized by smooth, even edges,
and a low dihedral angle.
Wicking
A flow of molten solder, flux, or cleaning solution by capillary action.
