IPC-T-50F_.pdf.pdf - 第35页

Forward Crosstalk 21.1406 Noise induced into a quiet line, as seen at the end of the quiet line that is the farthest from the signal source, because the quiet line has been placed next to an active line. (See also ‘ ‘Bac…

Float 44.0531

A warp or ﬁll yarn that does not interlace with the next

designated yarn, but passes over or under two or more

adjacent yarns.

Floating Bushing 37.0533

A connector mounting device that allows for connector

body movement in order to facilitate its alignment with a

mating part or mating assembly.

Floating-Annulus Tape-Automated Bonding 74.0532

A carrier tape format that uses a free-ﬂoating annulus ring

to separate suspended leads.

Flocculant 76.0534

A substance that induces ﬂocculation.

Flocculation 76.0535

The combination or aggregation of suspended solid par-

ticles in such a way that they form small clumps or tufts

that resemble wool.

Flow Soldering 75.0536

see ‘‘Wave Soldering.’’

Flush Conductor 22.0537

A conductor whose outer surface is in the same plane as is

the surface of the insulating material adjacent to the con-

ductor.

Flux 75.0538

A chemically- and physically active compound that, when

heated, promotes the wetting of a base metal surface by

molten solder by removing minor surface oxidation and

other surface ﬁlms and by protecting the surfaces from

reoxidation during a soldering operation.

Flux Activation Temperature 75.0540

The temperature at which ﬂux becomes active enough to

remove oxides from the metals being joined.

Flux Activity 75.0541

The degree or efficiency with which a ﬂux promotes wet-

ting of a surface with molten solder. (See also ‘‘Solder-

Spread Test,’’ ‘‘Wetting Balance.’’)

Flux Characterization 76.0542

A series of tests that determines the basic corrosive and

conductive properties of ﬂuxes and ﬂux residues.

Flux Residue 76.0543

A ﬂux-related contaminant that is present on or near the

surface of a solder connection.

Flux-Cored Solder 46.0539

A wire or ribbon of solder that contains one or more con-

tinuous ﬂux-ﬁlled cavities along its length.

Flux-Spatter Test 76.1402

A semiquantitive test that characterizes the ability of ﬂux

and ﬂux residues, upon rapid heating of the ﬂux, to remain

in one area rather than form a dispersion of ﬁne droplets.

Fluxing 75.1745

The efficiency with which a ﬂux promotes wetting of a

surface with molten solder.

Foil Burr 51.0544

A rough edge or area that remains on the surface of a foil

after it has been cut, pierced, or drilled.

Foil Lamination 55.0545

A process for making multilayer printed boards with sur-

face layer(s) of metal foil bonded in a single operation.

(See also ‘‘Cap Lamination.’’)

Foil Profile 45.0546

The roughness of a foil surface that results from the manu-

facture of the foil and/or from a bond-enhancement treat-

ment.

Foot Length 74.0547

The longer dimension of the bonding surface of a wedge-

type bonding tool.

Footprint 22.0548

see ‘‘Land Pattern.’’

Forced Gas Convention Soldering 75.1746

Reﬂow soldering using forced hot air or nitrogen gas as the

primary source of heat.

Forced-Field Analysis 93.1403

A technique that is used to help solve a problem by identi-

fying those forces that are preventing improvement

(restraints) and those forces that affect improvement

(drives).

Foreign Material (Soldering) 75.1404

A lumpy, irregular coating that has covered, or partially

covered, particles of material that are located on, but are

different than, the material or coating of the items to be

soldered.

Fork Contact 37.1405

A type of female connector contact that consists of ﬂat

spring metal that has been formed into a two tine ‘‘fork-

like’’ shape so that it mates with a spade contact.

Form 22.0549

The shape of a feature.

IPC-T-50F June 1996

Forward Crosstalk 21.1406

Noise induced into a quiet line, as seen at the end of the

quiet line that is the farthest from the signal source,

because the quiet line has been placed next to an active

line. (See also ‘‘Backward Crosstalk.’’)

Fractional-Factorial Experiment 91.0550

An experiment whereby only a portion of the complete

factorial is run.

Frame Pitch 74.0551

The distance from the centerline of one tape-automated

bonding frame to the centerline on the next frame site on a

reel of carrier tape.

From-To List 21.0553

Written instructions in the form of a list that indicates the

locations of wiring terminations.

Fully Additive Process 53.1407

An additive process wherein the entire thickness of

electrically- isolated conductors is obtained by the use of

electroless deposition. (See also: ‘‘Semi-Additive Pro-

cess.’’)

Fully-Electroless Process 53.0554

see ‘‘Fully-Additive Process.’’

Functional Tester 92.0556

Equipment that analyzes the unit under test as a complete

functional entity by applying inputs and sensing outputs.

Functionality, Resin or Curing Agent 41.0555

The number of reactive groups per molecule.

Fused Coating 56.0557

A metallic coating, usually a tin or solder alloy, that has

been melted and solidiﬁed to form a metallurgical bond to

a basis metal.

Fusing 56.1676

Melting of a metallic coating (usually electrodeposted tin

or tin-lead) on a conductive pattern, followed by solidiﬁca-

tion

Fusing Fluid 56.0467

The heat-transfer medium used to attain a fused coating.

Fusing Flux 56.1408

An activated organic ﬂuid that is used in the fusing of a

tin-lead plating on a basis metal. (The application of these

predominantly water- soluble ﬂuids is usually followed by

the use of a fusing oil.)

Fusing Oil 56.1409

An thermally-stable, nonactivated, ﬂuid that is used in the

fusing of tin lead plating on a basis metal. (The application

of these predominantly water-soluble ﬂuids is usually pre-

ceded by the use of a fusing ﬂux.)

Galvanic Corrosion 76.1410

Corrosion associated with the current of a galvanic cell

consisting of two dissimilar conductors in an electrolyte or

two similar conductors in dissimilar electrolytes.

Galvanic Deposition 53.0560

see ‘‘Electrodeposition.’’

Galvanic Displacement 53.0561

see ‘‘Immersion Plating.’’

Gang Bonding 74.0562

The making of several terminations simultaneously. (See

also ‘‘Single- Point Bonding.’’)

Gas Blanket 75.0564

A ﬂowing inert gas atmosphere used to keep metallization

from oxidizing.

Gas-Tight Area 97.0563

The common area between mated-metal surfaces from

which gas vapors and impurities are excluded.

Gauge Precision 22.0559

The absolute precision achieved in measuring feature size

or feature location.

Gaussian Distribution 94.1807

See ‘‘Normal Distribution’’

Gel Time 55.0566

The time in seconds required for prepreg to change its

physical state from that of a solid material to a liquid, and

then back to a solid material.

Gelation Particle 44.0565

Microparticles of precured, usually transluscent, resin in a

laminate system.

Generative Process Planning 91.0567

A computer-based method whereby new process plans are

created that are based on part or product information and

manufacturing capabilities.

Generic Specification (GS) 26.1782

A document that describes as many general requirements as

possible, pertaining to a set, family or group of products,

materials, or service.

June 1996 IPC-T-50F

Geometric Tolerance 22.0568

A tolerance that is used to control form, proﬁle, orientation,

location and runout.

Gerber Data 25.1411

A type of data that consists of aperture selection and opera-

tion commands and dimensions in X- and Y-coordinates.

(The data is generally used to direct a photoplotter in gen-

erating photoplotted artwork.)

Glass Binder 44.0569

Glass powder added to a thick-ﬁlm resistive or conductive

ink in order to bind together the metallic particles after ﬁr-

ing

Glass Transition Temperature 55.1412

The temperature at which an amorphous polymer, or the

amorphous regions in a partially-crystalline polymer,

changes from being in a hard and relatively-brittle condi-

tion to being in a viscious or rubbery condition.

Go/No-Go Test 92.0570

A testing process that yields only a pass or a fail condition.

Golden Assembly 92.0571

see ‘‘Know Good Assembly

Golden Board 92.0572

see ‘‘Known Good Board’’

Gouge 92.0573

A form of wear that consists of a wide groove deformation,

accompanied by material removal, that penetrates a consid-

erable distance below a surface.

Graded Wedge 54.0574

see ‘‘Etching Indicator.’’

Grading Frame 44.0575

Equipment used to continuously inspect fabric by the use

of backlighting.

Green Strength 56.0577

The strength of substance, joint, or assembly before it has

been cured (set).

Greige 44.0578

Fabric in a loom state that has no ﬁnish.

Grey-Scale Processing 92.0576

The utilizing of more than one level of signal strength,

intensity or amplitude to perform an inspection operation.

Grid 22.1812

An orthogonal network of two sets of parrallel equidistant

lines that is used for locating points on a printed board.

Gross Leak 95.0580

A leak in a sealed package that is greater than 0.00001

cubic centimeters per second at one atmosphere of differ-

ential air pressure.

Ground 20.0581

A common reference point for electrical circuit returns,

shielding, or heat sinking.

Ground Plane 20.1413

A conductor layer, or portion thereof, that serves as a com-

mon reference for electrical circuit returns, shielding, or

heat sinking. (See also ‘‘Signal Plane’’ and ‘‘Voltage

Plane.’’)

Ground Plane Clearance 22.1414

Removed portions of a ground plane that isolate it from a

hole in the base material to which the plane is attached.

(See Figure G-1.) (See also ‘‘Signal Plane’’ and ‘‘Voltage

Plane.’’)

Guarding 92.0582

The in-circuit testing process of ensuring that a shunt path

does not interfere with the testing of a device.

Guide Pin 37.0583

A connector interfacing device that allows for connector

body movement in order to facilitate contact alignment

prior to contact engagement.

Gull Wing Leads 36.1747

An SMT lead form. Leads extending horizontally from the

component body centerline, bent downward immediately

past the body and then bent outward just below the bottom

of the body, thus forming the shape of a gull’s wing.

IPC-I-001031

Figure G–1 Ground (or voltage) plane clearance

Through Hole

Ground-Plane

Clearance

Nonfunctional

Land

Conductive

Pattern