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.