IPC-T-50F_.pdf.pdf - 第26页
Detail Specification 26.1740 A detailed written description of a part or a process. Detailed Specification (DS) 26.1781 A document that describes the exact requirements for a specific product, material, or service. Detect…
Datum Feature 22.0345
An actual feature of a part that is used to establish a datum.
Datum Reference 22.0346
A defined point, line or plane that is used to locate a pat-
tern or layer for manufacturing purposes, inspection pur-
poses, or both.
Decoupling 21.1375
The absorbing of noise pulses in power supply lines, that
was generated by switching logic, so as to prevent the lines
from disturbing other logic in the same power-supply cir-
cuit.
Defect 90.0348
Any nonconformance to specified requirements by a unit or
product.
Defect Identification 90.0349
The provision for recording the location of a detected
anomaly.
Definition 52.1701
Degree of conformity of the pattern edges with the produc-
tion master.
Definition (Phototool) 24.0350
The clarity of detail in an optically-produced image.
Degradation 90.0351
A decrease in the performance characteristics or service life
of a product.
Degrees of Freedom (df) 94.0352
The number of comparisons that are available in order to
learn about an event.
Delamination 55.1376
A separation between plies within a base material, between
a base material and a conductive foil, or any other planar
separation with a printed board. (See also ‘‘Blister.’’)
Delivered Panel (DP) 50.1788
A production or prototype panel, or portion of either,
intended to contain one or more printed boards in a specific
arrangement or cluster, in order to facilitate economic
assembly and testing in the next level of manufacturing.
Dendritic Growth 90.0353
Metallic filaments that grow between conductors in the
presence of condensed moisture and an electric bias. (See
also ‘‘Whiskers.’’)
Dendritic Migration 90.0354
Migration that proceeds through an insulator in a ‘‘treeing’’
fashion.
Denier 44.0355
The weight, in grams, of 9000 meters of fiber, filament or
yarn..
Densitometer 24.0356
An instrument that is used to measure the amount of light
that has been absorbed by a photographic film.
Density (Phototool) 24.0357
The logarithm of the value of opacity.
Dent 45.0358
A smooth depression in conductive foil that does not sig-
nificantly reduce the foil’s thickness.
Dentrices 90.0359
see ‘‘Dendritic Migration’’
Dependent of Feature Size 22.0360
The concept that permits tolerances of form or position to
vary in proportion to, and dependent on, a feature’s size.
Depth of Field (Optical) 24.0361
The maximum vertical height of an object facing a lens
over which an image is in focus.
Design Automation 20.1377
The use of computer systems, programs, and procedures in
the design process wherein, the computer is responsible for
the decision-making activity and data manipulation func-
tion.
Design Spacing of Conductors 22.0364
The spacing between conductors as delineated or otherwise
noted on the master drawing. (See also ‘‘Conductor Base
Spacing.’’)
Design Width of Conductors 22.0365
The width of conductors as delineated or otherwise noted
on the master drawing. (See also ‘‘Conductor Base Spac-
ing’’ and ‘‘Conductor Spacing.’’)
Design Rule 22.0363
Guidelines that determine automatic conductor routing
behavior with respect to specified design parameters.
Design-Rule Checking 22.0362
The use of a computer-aided design program to perform
continuity verification of all conductor routing in accor-
dance with appropriate design rules.
Desmear 57.0366
The removal of friction-melted resin and drilling debris
from a hole wall.
June 1996 IPC-T-50F
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Detail Specification 26.1740
A detailed written description of a part or a process.
Detailed Specification (DS) 26.1781
A document that describes the exact requirements for a
specific product, material, or service.
Detection 91.0367
A strategy that attempts to identify and separate acceptable
and unacceptable outputs from a process.
Developing (Phototool) 24.0368
The chemical treatment of radiation-modified photosensi-
tive material in order to produce an image.
Device 30.0369
An individual electrical circuit element that cannot be fur-
ther reduced without destroying its stated function.
Dewetting 97.0370
A condition that results when molten solder coats a surface
and then recedes to leave irregularly-shaped mounds of
solder that are separated by areas that are covered with a
thin film of solder and with the basis metal not exposed.
(See Figure D-1.)
Diazo Material 24.0371
A nonsilver, room-light hardening, ultraviolet-sensitive
coating material.
Dibasic Acid 76.0372
An acid containing two atoms of acidic hydrogen in a mol-
ecule.
Dice 35.0373
Two or more die.
Dicyandiamide 41.0374
A solid curing agent for epoxy resins.
Die 35.0375
The uncased and normally leadless form of an electronic
component that is either active or passive, discrete or inte-
grated. (See also ‘‘Dice.’’)
Die Bonding 74.0376
The attachment of a die to base material.
Dielectric 40.0377
A material with a high resistance to the flow of direct cur-
rent, and which is capable of being polarized by an electri-
cal field.
Dielectric Constant 21.1379
The ratio of the capacitance of a configuration of electrodes
with a specific material as the dielectric between them to
the capacitance of the same electrode configuration with a
vacuum or air as the dielectric.
Dielectric Breakdown 21.1378
The complete failure of a dielectric material that is charac-
terized by a disruptive electrical discharge through the
material that is due to deterioration of material or due to an
excessive sudden increase in applied voltage.
Dielectric Fluid 21.0378
A fluid that has excellent dielectric strength, excellent vol-
ume resistivity, a low dielectric constant, and a low dissi-
pation factor.
Dielectric Strength 21.1380
The maximum voltage that a dielectric can withstand under
specified conditions without resulting in a voltage break-
down, usually expressed as volts per unit dimension.
Diffusion Bond 74.0379
A bond formed in the absence of any liquid phase at any
time prior to or during the joining process.
Digital Circuit 21.0380
An electrical circuit that provides two (binary) or three dis-
tinct relationships (states) between its input and output.
Digitizing (CAD) 25.0381
The converting of feature locations on a flat plane to its
digital representation in X-Y coordinates.
Dilution Ratio 76.1221
The maximum number of unit volumes of hydrocarbons
that can be added per unit volume of active solvent in order
to cause the first trace of gelation to occur when the con-
centration of nitrocellulose in the solution is 8-grams per
100-milliliters.
Dimensional Stability 21.1381
A measure of the dimensional change of material that is
caused by factors such as temperature changes, humidity
changes, chemical treatment (aging), and stress exposure.
IPC-I-001029
Figure D–1 Dewetting
DEWETTING
SOLDER
BASE METAL
BASE MATERIAL
IPC-T-50F June 1996
22
Dimensioned Hole 22.0382
A hole in a printed board whose location is determined by
physical dimensions or coordinate values that do not nec-
essarily coincide with the stated grid.
Dimorphism 40.0383
The existence of a substance in two different crystalline
forms.
Dip Soldering 75.1382
The making of soldered terminations simultaneously by
bringing the solder side of a printed board with through-
hole mounted components into contact with the surface of
a static pool of molten solder. (See also ‘‘Drag Soldering.’’)
Diphase Cleaning 76.0384
Cleaning by means of solutions that contain a solvent layer
and an aqueous layer.
Dipole 21.0385
An assemblage of atoms or subatomic particles, separated
by a finite distance, that have equal electric charges of
opposite sign.
Dipole Moment 21.1383
Molecules in which the atoms, their electrons, and their
nuclei, that are so arranged that one part of the molecule
has a positive electrical charge while the other part is nega-
tively charged.
Direct Dimensioning 22.0388
The maximum variation between two features that is con-
trolled by the tolerance on the dimension between the fea-
tures.
Direct Cleaning 76.0386
see ‘‘Cathodic Cleaning’’
Direct Current (DC) 21.1796
A current produced by a voltage source that does not vary
with time and is normally provided by power supplies,
transformers or batteries to power electronic circuits.
Direct Current Cleaning 76.0387
see ‘‘Cathodic Cleaning’’
Discrepant Material 92.0389
Material that does not conform to specification.
Discrete Component 30.0392
A separate part of a printed board assembly that performs
a circuit function, e.g., a resistor, a capacitor, a transistor,
etc.
Discrete Wiring Board 64.0390
A base material upon which discrete wiring techniques are
used to obtain electrical interconnections.
Discrete Wiring Board Assembly 64.0391
An assembly that uses a discrete wiring board for compo-
nent mounting and interconnecting purposes.
Dispersant (Organosol) 41.0393
A liquid component that has a solvating or peptizing action
on a resin so as to aid in dispersing and spreading it.
Disperse Phase (Suspension) 41.0394
The particles of solid material dispersed in a liquid
medium.
Dispersing Agent 41.0395
A surface-active agent added to a suspending medium to
promote uniform separation of extremely-fine solid par-
ticles.
Dissipation Factor 21.0396
A value that represents the tendency of insulating or dielec-
tric materials to absorb some of the energy in an
alternating-current signal.
Dissolution of Metallization 36.1741
The process of dissolving metal, usually by introduction of
chemicals. (See also ‘‘Leaching, Metallization’’).
Distributed Numerical Control (DNC) 25.0398
A network that links computer programs or computer-aided
systems to numerically-controlled machine tools.
Disturbed Solder Connection 97.1384
A solder connection that is characterized by the appearance
that there was motion between the metals being joined
when the solder was solidifying.
Don’t Care Area 22.0399
see ‘‘Exclusion Area’’
Doping 35.0400
The addition of an impurity to alter the conductivity of a
semiconductor die.
Double-Sided Assembly 80.0401
A packaging and interconnecting structure with compo-
nents mounted on both the primary and secondary sides.
(See also ‘‘Single-Sided Assembly’’)
Double-Sided Printed Board 60.0402
A printed board with a conductive pattern on both of its
sides.
Download, Computer 11.1385
The transfer of computer programs or data from a com-
puter to a lower- level computer. Expert System - Software
that applies human-like reasoning to solve a problem by
the use of rules and heuristics.
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