IPC-T-50F_.pdf.pdf - 第24页
Cumulative Tolerance 22.1373 The summation of the tolerances that are permitted between funtionally- related features. (See also ‘ ‘Baseline Dimensioning,’ ’ ‘ ‘Basic Dimension,’ ’ ‘ ‘Chain Dimension- ing’ ’ and ‘ ‘Direc…
Cover Lay (Flexible Circuit) 42.0304
The layer of insulating material that is applied covering
totally or partially over a conductive pattern on the outer
surfaces of a printed board.
Cover Layer 42.0305
see ‘‘Cover Lay.’’
Cpk Index (Cpk) 91.0307
A measure of the relationship between the scaled distance
between the process mean value and the closest specifica-
tion limit.
Crack, Foil 90.0308
A break or separation that extends partially or completely
through a layer of metallic foil.
Crack, Plating 90.0309
A break or separation that extends partially or completely
through a metallic coating(s), its overplate, or both.
Cracking 90.0310
A condition that makes breaks or separations in coatings
that extend through to an underlying surface.
Cratering 74.0311
A defect in which a portion of a die under is torn loose by
an excessive amount of ultrasonic wire-bonding energy.
Crazing (Base Material) 51.0312
An internal condition that occurs in reinforced laminate
base material whereby glass fibers are separated from the
resin at the weave intersections. (This condition manifests
itself in the form of connected white spots or crosses that
are below the surface of the base material.) It is usually
related to mechanically-induced stress. (See ‘‘Measling.’’)
Crazing (Conformal Coating) 76.0313
A network of fine cracks on the surface of, or within, a
conformal coating.
Crease 92.0314
A ridge in a material that is caused by a fold or wrinkle
being placed under pressure.
Creel 44.0315
A device used as a yarn package rack to hold warp ends for
a section beam.
Creep 40.0316
Time-dependent strain occurring under stress.
Crevice Corrosion 97.0317
Localized corrosion that is the result of the formation of a
crevice between a metal and a nonmetal, or between two
metal surfaces.
Crimp Contact 37.0318
A type of connector contact whose nonmating end is a hol-
low cylinder that can be crimped onto a wire inserted
within it.
Critical Current Density 53.0319
The current density above which a new and sometimes
undesirable reaction occurs.
Critical Defect 94.0320
Any anomaly specified as being unacceptable.
Critical Humidity 76.1371
The relative humidity above which the atmospheric corro-
sion rate of a given metal increases sharply or above which
the insulation decreases sharply.
Critical Operation 91.0321
One procedure of a total process that has a significant
impact on the characteristics of the completed product.
Critical Solution Temperature 76.0322
The temperature above or below which two liquids are
miscible in all proportions.
Crop Marks 22.0323
see ‘‘Corner Marks.’’
Cross-Sectioning 92.0324
see ‘‘Microsectioning’’
Crosshatching 22.0325
The breaking up of large conductive areas by the use of a
pattern of voids in the conductive material.
Crossing Count 22.1372
The unit for measuring optimum component placement
characteristics that is based on the number of times there
are crossovers of the signal conductor that are used to pro-
vide electrical interconnection between devices.
Crosslink 40.0326
The formation of chemical bonds between molecules in a
thermosetting resin.
Crosstalk 21.0327
The undesirable interference caused by the coupling of
energy between signal paths. (See also ‘‘Backward
Crosstalk’’ and ‘‘Forward Crosstalk.’’)
Crystalline Polymer 40.0328
A polymer with a regular, structured molecular configura-
tion.
Cubic Components 30.1737
A part with a three-dimensional shape having the form of a
cube.
June 1996 IPC-T-50F
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Cumulative Tolerance 22.1373
The summation of the tolerances that are permitted
between funtionally- related features. (See also ‘‘Baseline
Dimensioning,’’ ‘‘Basic Dimension,’’ ‘‘Chain Dimension-
ing’’ and ‘‘Direct Dimensioning.’’)
Cup Solder Terminal 37.0329
A cylindrical solder terminal with a hollow opening into
which one or more wires are placed prior to soldering. (See
Figure C-7.)
Cure 56.0330
A chemical reaction that changes the physical properties of
a substance, e.g., an adhesive.
Cure Time 56.0331
The time at which ultimate physical properties of a curing
thermosetting plastic composition are reached.
Curing Agent 56.0332
A chemical substance that can react with a resin in order to
physically harden the resin.
Current 21.1795
The flow or movement of electrons in a conductor as the
result of a voltage difference between the ends of the con-
ductive path.
Current-Carrying Capacity 21.1374
The maximum electrical current that can be carried con-
tinuously by a conductor, under specified conditions, with-
out causing objectable degradation of electrical and
mechanical properties of the product.
Customer Detail Specification (CDS) 26.1779
A document that establishes the specific requirements,
noted in a detailed specification, in order to tailor these to
meet the needs of a custom product, material, or service.
Cusum Chart 91.0333
A diagram that depicts cumulative deviation from a target.
Cut-and-Peel 24.0334
see ‘‘Cut-and-Strip.’’
Cut-and-Strip 24.0335
The making of artwork by cutting a pattern in a resist and
stripping away the unwanted areas or resist.
Cut-Off 74.0336
The operation that follows the final bonding step that sepa-
rates the bond from the source of the wire.
Cylindrical Components 30.1738
A part having the shape of a cylinder.
D
D Curve 24.0347
see ‘‘Characteristic Curve’’
Data Capture 25.0340
The automatic collection of information from a given
machine or other information source.
Data File 11.0341
A database organized in a specific manner for a specific
application.
Data Layer 25.0342
A specific group of related records that are within any indi-
vidual data- information module.
Data Logging 11.0343
The ability of a host computer or test analyzer to store ana-
lyzed data along with statistical data.
Data-Entry Device 25.0337
A device terminal used to enter information into a com-
puter system. (See also ‘‘Control Console).
Data-Information Module (DIM) 25.0338
A group of records that contain related data that describe a
specific function or task.
Database 11.0339
A comprehensive collection of information that is so struc-
tured that some or all of its data may be used to create
queries about related items contained within it.
Date Code 30.1739
Marking of products to indicate their date of manufacture.
Datum 22.0344
The theoretically-exact point, axis or plane that is the ori-
gin from which the location of geometric characteristics of
features of a part are established.
IPC-I-000000
Figure C–7 Cup Solder Terminal
IPC-T-50F June 1996
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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.
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