IPC-T-50F_.pdf.pdf - 第37页
H Halide Content 76.0584 The ratio of the mass of free halides to the mass of solids in a flux, expressed in mass percent of free chloride ion. Haloing 51.1415 Mechanically-induced fracturing or delamination, on or below …
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
Ground-Plane
Clearance
Through Hole
Conductive
Pattern
IPC-T-50F June 1996
32
H
Halide Content 76.0584
The ratio of the mass of free halides to the mass of solids
in a flux, expressed in mass percent of free chloride ion.
Haloing 51.1415
Mechanically-induced fracturing or delamination, on or
below the surface of a base material, that is usually exhib-
ited by a light area around holes or other machined fea-
tures.
Hand Soldering 75.0585
Soldering using a soldering iron or other hand-held,
operator- controllable apparatus.
Hard Wiring 75.0587
Electrical wiring that is inseparable from an assembly with-
out the use of special tools and processes.
Hardeners 56.0586
see ‘‘Curing Agent.’’
Haywire 37.0588
A discrete electrical connection that is added to a printed
board in order to modify the basic conductive pattern
formed on the board. (See also ‘‘Jumper Wire.’’)
Header (Connector) 37.0589
A pin field that is positioned in a 3- or 4-sided plastic
housing that mounts directly onto a printed board.
Header (Module) 36.0590
The base of an electronic component package that contains
leads.
Heat Cleaning 44.0591
A process in which organic yarn binder (size) is removed
from a fabric. (See also ‘‘Sizing.’’)
Heat Column 75.0592
The heating element in a eutectic die bonder or wire
bonder that is used to bring the base material up to its
bonding temperature.
Heat of Fusion 56.0593
The quantity of heat required to convert a unit weight of
solid material to its liquid state.
Heatsink 30.0594
A mechanical device that is made of a high thermal-
conductivity and low specific-heat material that dissipates
heat generated by a component or assembly.
Heatsink Plane 22.0595
A continuous sheet of metal on or in a printed board that
functions to dissipate heat away from heat generating com-
ponents.
Heatsink Tool 75.1416
A heatsink that is temporarily attached to a heat-sensitive
component in order to minimize the transfer of heat from
the component lead to the component body during a solder-
ing operation.
Heavy Mark (Fabric) 44.0596
A filling defect that extends across the width of a fabric
containing in excess of two picks per inch from nominal.
Heel, Bonding 74.0598
The part of a lead adjacent to a termination that has been
deformed by the edge of the bonding tool.
Heel Break 97.0599
The rupture of a lead at the heel of a bond.
Heel Crack 97.0600
A crack across the width of a lead at the heel of a bond.
Heel (Drill) 51.0597
The trailing edge of a drill land
Helix Angle 51.0601
The angle of the spiral generated by the flute of a drill with
respect to the axis of the drill.
Hermaphroditic Contact 37.0602
A type of connector contact that mates with a contact that
is identical to itself.
Heterocyclic 76.0603
A cyclic or ring structure, often in the shape of a pentagon,
in which one or more of the atoms in the ring is an element
other than carbon.
Hierarchical Database 11.0604
A database that is arranged in a tree-like structure of logic.
High-Impedance State 21.0605
see ‘‘Tri-State.’’
High-Voltage Wire 37.0606
Insulated wire, with an insulation thickness that is deter-
mined by corona-related factors, that is used for voltag es
over 240 Vac RMS or over 340 Vdc.
Hipot Test 92.0607
A method in which the unit under test is subjected to a high
alternating current (ac) voltage.
Histogram 91.0608
A graph that depicts values that were obtained by dividing
the range of a data set into equal intervals and that plots the
number of data points in each interval.
June 1996 IPC-T-50F
33
Hole Breakout 60.1699
A condition in which a hole is not completely surrounded
by the land. (See Figure H-1.)
Hole Density 22.0610
The quantity of holes in a unit area of printed board.
Hole Location 22.0611
The dimensional position of the center of a hole.
Hole Pattern 22.1621
The arrangement of all the holes in a printed board or pro-
duction board.
Hole Pull Strength 53.0613
The load or pull force along the axis of a plated-through
hole that will rupture the hole.
Hole Void 53.0614
A void in the metallic deposit of a plated-through hole that
exposes the base material.
Homocyclic 76.0615
A ring compound containing only one kind of atom in its
ring structure.
Homologous Series 76.0616
A series of organic compounds in which each successive
member has one more CH
2
group in its molecule than the
preceding member.
Homopolymer 76.0617
A polymer derived from a single monomer with the aid of
initiators that act in the manner of catalysts.
Hook 51.0618
The rake condition in the flute face of a drill. (See Figure
H-2.)
Hook Solder Terminal 37.0619
A solder terminal with a curved feature around which one
or more wires are wrapped prior to soldering. (See Figure
H-3.)
Horn 74.0620
A cone-shaped object that transmits ultrasonic energy from
a transducer to a bonding tool.
Hot Plate Reflow Soldering 75.1748
Reflow soldering using direct contact or close proximity to
a hot plate as the primary source of heat.
Hybrid Circuit 83.1417
An insulating base material with various combinations of
interconnected film conductors, film components, semicon-
ductor dice, passive components and bonding wire that
form an electronic circuit.
Hybrid Integrated Circuit 83.1418
An insulating base material with various combinations of
interconnected film conductors, film components, semicon-
ductor dice, passive components and bonding wire that per-
form the same function as a monolithic semiconductor inte-
grated circuit.
Hybrid Microcircuit 83.1419
An insulating base material with various combinations of
interconnected film conductors, film components, semicon-
ductor dice, passive components and bonding wire that
form an electronic microcircuit.
Hydrocarbon Tolerance 76.0621
see ‘‘Dilution Ratio.’’
Hydrolytic Stability 76.0622
The degree of resistance of a polymer to permanent prop-
erty changes from hydrolytical effects.
IPC-I-001031
Figure H–1 Hole breakout
IPC-I-000000
Figure H–2 Hook
IPC-0-000000
Figure H–3 Hook solder terminal
IPC-T-50F June 1996
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