IPC-T-50F_.pdf.pdf - 第74页
Torsional Strength 74.1095 The torque required to separate adhesive-bonded (and cured) materials and/or components. (See also ‘ ‘Lap Shear Strength’ ’ and ‘ ‘Shear Strength.’ ’) Touch-Up 92.1097 The identification and eli…
Thick Film 45.1545
A film, greater than 0.1 mm (0.004-inch) thick, deposited
by screen printing and subsequently fired at high tempera-
tures in order to fuse it into its final functional form.
Thick-Film Circuit 83.1073
A microcircuit in which passive components of a ceramic-
metal composition are formed on base material by screen-
ing and firing.
Thick-Film Hybrid Circuit 83.1074
A hybrid circuit with thick-film components and intercon-
nections.
Thick-Film Network 83.1075
A hybrid circuit comprised only of thick-film components
and interconnections.
Thin Film 45.1079
A film, less than 0.1-mm (0.004-inch) thick, deposited by
accretion process, such as vacuum or pyrolytic deposition.
Thin-Film Hybrid Circuit 83.1076
A hybrid circuit with thin-film components and intercon-
nections. (See also ‘‘Hybrid Circuit.’’)
Thin-Film Integrated Circuit 83.1077
A hybrid integrated circuit comprised only of thin-film
components and interconnections. (See also ‘‘Hybrid Inte-
grated Circuit.’’)
Thin-Film Network 83.1078
A hybrid circuit comprised only of thin-film components
and interconnections.
Thin Foil 45.1080
A metal sheet that is less than 0.02mm (0.0007 inch) thick.
Thinner (Liquid) 76.1081
A nonactivated solvent or solvent system that is used to
replace evaporated solvent and to reduce the solids content
of another substance.
Thixotropic Ratio 49.1082
An indication of thixotropy in the form of the ratio of vis-
cosities measured at two different shear rates.
Thixotropy 49.1083
A property of a substance, e.g., an adhesive system, that
allows it to get thinner upon agitation and thicker upon
subsequent rest.
Three-Layer Carrier Tape 36.1546
The carrier for conductors used in tape-automated bonding
that consists of a dielectric layer, an adhesive, and a etched
metal-foil conductor layer. (See also ‘‘Multilayer Carrier
Tape,’’ ‘‘Single-Layer Carrier Tape,’’ and ‘‘Two-Layer Car-
rier Tape.’’)
Threshold 21.1084
The magnitude of intensity that delineates that a signal is
representative of a changed state.
Through Connection 22.1086
see ‘‘Interlayer Connection.’’
Through Migration 90.1087
see ‘‘Dendritic Migration.’’
Through-Hole Mounting 72.1085
The electrical connection of components to a conductive
pattern by the use of component holes.
Tie Bar 53.1088
see ‘‘Plating Bar.’’
Tinning 71.1089
The application of molten solder to a basis metal in order
to increase its solderability.
Titrometry 92.1090
see ‘‘Volumetric Analysis.’’
Tolerance 26.1091
The total amount by which a specific dimension is permit-
ted to vary.
Toleranced Dimension 26.1092
A dimension with a tolerance.
Tombstoned Component 73.1093
A defect condition whereby a leadless device has only one
of its metallized terminations soldered to a land and has the
other metallized termination elevated above and not sol-
dered to its land.
Tooling Feature 22.1547
A physical feature that is used exclusively to position a
printed board or panel during a fabrication, assembly or
testing process. (See also ‘‘Locating Edge,’’ ‘‘Locating
Edge Marker,’’ ‘‘Locating Notch,’’ ‘‘Locating Slot,’’ and
‘‘Tooling Hole.’’)
Tooling Hole 22.1094
A tooling feature in the form of a hole in a printed board
or fabrication panel.
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Torsional Strength 74.1095
The torque required to separate adhesive-bonded (and
cured) materials and/or components. (See also ‘‘Lap Shear
Strength’’ and ‘‘Shear Strength.’’)
Touch-Up 92.1097
The identification and elimination of defects in a product.
Trace 22.1098
see ‘‘Conductor.’’
Track 22.1099
see ‘‘Conductor.’’
Transfer Soldering 75.1101
The use of a soldering iron to transfer a measured amount
of solder, in the form of a ball, chip, or disc, to a solder
connection.
Transfer-Bump Tape Automated Bonding 74.1100
Tape automated bonding that uses discrete bumps between
the die lands and carrier tape to facilitate inner-lead bond-
ing.
Transmission Cable 21.1102
Two or more transmission lines in the form of an
interconnection-wiring cable.
Transmission Line 21.1103
A signal-carrying circuit with controlled conductor and
dielectric material physical relationship such that its elec-
trical characteristics are suitable for the transmission of
high-frequency or narrow pulse electrical signals. (See also
‘‘Balanced Transmission Line,’’ ‘‘Microstrip’’ ‘‘Stripline,’’
and ‘‘Unbalanced Transmission Line.’’)
Transmittance 24.1104
The ratio of the amount of light that is transmitted through
an object or material to the quantity of light that is incident
upon it.
Treatment Transfer 92.1548
The transfer of copper-foil treatment to a base material as
indicated by the presence of black, brown or red streaks
after the copper has been removed by etching.
Treeing 53.1549
A dendritic-type of plating growth that extends onto the
surface that is adjacent to edge of a conductive pattern.
(This is normally caused by excessive plating current.)
Tri-State 21.1105
A high-impedance state of an electronic device that effec-
tively disconnects the device output from all other cir-
cuitry.
Trim Lines (Pattern) 22.1106
Lines that define the borders of a pattern. (See also ‘‘Cor-
ner Marks.’’)
Trim Lines (Printed Board) 22.1550
Lines that delineate the border of a printed board. (See also
‘‘Corner Marks.’’)
Trimming 77.1108
The cutting of a film component by a laser beam or abra-
sive jet in order to modify its value.
Trimming Notch 77.1109
see ‘‘Kerf.’’
True Position 22.1110
The theoretically-exact location for a feature or hole that is
established by basic dimensions.
True Position Tolerance 22.1111
The total permissible deviation from a true position.
Trumeter 44.1112
A device used to accurately measure yardage passing a
specific point of reference.
Truth-Table Testing 21.1551
The application of electrical signals in accordance with a
prescribed logic matrix pattern that indicates the outputs
that should result from a given pattern of inputs.
Tuberculation 76.1113
The formation of localized corrosion products that are scat-
tered over a surface in the form of knob-like mounds.
Turnkey System 11.1114
A self-contained hardware and software system that per-
form a specific task.
Turret Solder Terminal 37.1552
A round post-type stud (stand-off) solder terminal with a
groove or grooves around which one or more wires are
wrapped prior to soldering. (See Figure T-1.)
IPC-I-001034
Figure T–1 Turret solder terminal
TOP SHOULDER
UPPER POST SELECTION
LOWER POST SELECTION
BASE
SINGLE TURRET DOUBLE TURRET
IPC-T-50F June 1996
70
Twist 60.1553
The deformation of a rectangular sheet, panel or printed
board, that occurs parallel to a diagonal across its surface,
such that one of the corners of the sheet is not in the plane
that contains the other three corners.
Two-Layer Carrier Tape 36.1554
The carrier for conductors used in tape-automated bonding
that consists of a dielectric layer with a layer of plated/
etched conductors. (See also ‘‘Multilayer Carrier Tape,’’
‘‘Single-Layer Carrier Tape,’’ and ‘‘Three-Layer Carrier
Tape.’’)
Two-Piece Contact 37.1115
A type of discrete connector contact that mates with
another discrete formed-metal connector contact. (See also
‘‘Edge-Board Contact.’’)
Two-Sided Board 60.1116
see ‘‘Double-Sided Board.’’
Type I Error 91.1117
The rejection of a hypothesis that is true.
Type II Error 94.1118
The accepting of a hypothesis that is false.
U
Ultrasonic Bonding 74.1119
A termination process that uses ultrasonic-frequency vibra-
tion energy and pressure to make the joint.
Ultrasonic Cleaning 76.1120
Immersion cleaning that is done by passing high-frequency
sound waves through a cleaning medium to cause micro-
agitation.
Ultrasonic Soldering 75.1121
Fluxless soldering wherein molten solder is vibrated at
ultrasonic frequencies while making the joint.
Unbalanced Transmission Line 21.1556
A transmission line that has distributed inductance, capaci-
tance, resistance, and conductance elements that are not
equally distributed between its conductors.
Uncased Device 35.1122
A component without a package.
Unconditional Test 92.1123
A test without limitations or restrictions on test mode, test
time, etc.
Undercut, After Fabrication 92.1124
The distance, measured parallel to the surface of a printed
board, from the outer edge of a conductor (excluding over-
plating and coatings) to the maximum point of the indenta-
tion on the same edge of
Undercut, In Process 92.1125
The distance, measured parallel to the surface of a printed
board, from the outer edge of a conductor (including etch
resist) to the maximum point of the indentation on the
same edge of the conductor. (See also ‘‘Undercut, After
Fabrication.’’)
Underwriters Symbol 94.1126
A logotype that denotes that a product has been recognized
(accepted) by Underwriters Laboratories, Inc. (UL).
Unfil 44.1127
A device attached to the loom which automatically winds
yarn onto quills from yarn packages and maintains a sup-
ply of quills for the shuttle.
Unload Time 92.1128
The time required to remove a unit from the evaluation
equipment, to collect the evaluation data, and to make the
system ready for the next unit.
Unsupported Hole 22.1129
A hole in a printed board that does not contain plating or
other type of conductive reinforcement.
Upload (Test) 92.1130
The ability of an analyzer to accept test program data from
a host computer.
Usable Resolution 52.1131
The smallest image and separation that can be produced,
and subsequently processed, in a given emulsion or thick-
ness of photoresist.
User Inspection Lot (Material) 91.1132
All of the material of the same type and, as far as practical,
of the same type designation that is produced from the
same equivalent batches or lots of constituent material
under essentially the same conditions and that is offered for
inspection at one time.
V
Vacuum Evaporation 53.1133
The deposition of a metal film onto a base material by
evaporation techniques.
Vacuum Head 73.1775
A handling instrument with a small vacuum cup which is
used to pick up clip devices and other surface mounting
devices.
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