IPC-T-50F_.pdf.pdf - 第66页
Shielding, Electronic 21.1527 A physical barrier , that is usually electrically conductive, that reduces the interaction of electric or magnetic fields upon devices, circuits, or portions of circuits. Short, Electrical (n…
Semiconductor Carrier 74.1290
A package for semiconductor die.
Sensitivity Control 91.1519
The provisions that allow a machine to be set to acceptance
and rejection thresholds that correspond to the end-use
requirements for the units being evaluated.
Sensitizing 53.1291
see ‘‘Activating.’’
Separable Component Part 30.1520
A replaceable component part with a body that is not
chemically bonded, excluding protective coatings, solder,
and potting compounds, to the base material.
Sequentially-Laminated Multilayer Printed Board
61.1521
A multilayer printed board that is formed by laminating
together through-hole plated double-sided or multilayer
boards. (Thus, some of its conductive layers are intercon-
nected with blind or buried vias.)
Serpentine Cut 77.1293
A trimming cut in a film component in the shape of an
wavy (serpentine) pattern.
Set-Up Time 92.1522
The time required to change hardware and software, to
set-up necessary windows, and to run calibration and veri-
fication tests in order to ensure that a system is ready for
operation.
Shadowing, Etchback 54.1294
A condition that occurs during an etchback process in
which the dielectric material immediately next to the foil is
not removed completely. (See Figure S-1.) (This can occur
even though an acceptable amount of etchback may have
been achieved elsewhere.)
Shadowless Illumination 24.1523
The illumination of the area of interest by the light source
of a magnifying device so that no shadows fall on the area
of interest from objects in the field of view that are not of
prime interest.
Shank 51.1295
The cylindrical part of a drill that is held in the spindle of
a drilling machine.
Shank Diameter 51.1297
The actual size of a drill shank.
Shank-to-Drill Body Concentricity 51.1296
The total variation of the location of the outside diameter
of a rotating drill shank.
Shear Strength 92.1298
The force required to shear apart adhesive-bonded (and
cured) materials and/or components. (See also ‘‘Lap Shear
Strength’’ and ‘‘Torsional Strength.’’)
Shear Test 92.1765
The maximum stress a material can withstand in shear; the
value of the force achieved when shearing stress is applied
to a solder joint or wire bond to determine the breaking
load.
Sheet Capacitance 92.1524
The electrical capacitance of a material as measured from
one electrode to another, expressed in a unit of capacitance
(e.g. farads or microfarads) per unit area.
Sheet Resistance 92.1525
The electrical resistance of a planar film of a resistive
material with uniform thickness as measured across oppo-
site sides of a unit square pattern, expressed in ohms per
square.
Sheet-Metal Contact 37.1299
A type of connector contact that consists of flat spring
metal that has been formed by either stamping or bending.
(See also ‘‘Machined Contact’’)
Shelf Life 90.1526
The length of time a material, substance, or product can be
stored, under specific environmental conditions, while it
meets all applicable specification requirements and remains
suitable for its intended use.
Shield (n.) 21.1300
The material around a conductor or group of conductors
that limits electromagnetic and/or electrostatic interference.
IPC-I-002323
Figure S–1 Shadowing
Shadowing
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Shadowing
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Shadowing
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Shielding, Electronic 21.1527
A physical barrier, that is usually electrically conductive,
that reduces the interaction of electric or magnetic fields
upon devices, circuits, or portions of circuits.
Short, Electrical (n.) 92.1301
A fault that causes to be connected two or more points that
are normally electrically separated.
Short-Term Capability 91.1302
The capability of a process that exhibits statistical control
over a brief period of time.
Shoulder Angle 51.0929
The angle of the blended transition from the drill shank
diameter to the drill body diameter.
Shuttle 44.0930
The device that holds the quill of the filling yarn and car-
ries it back and forth across the width of the fabric.
Sigma (ς) 94.0931
The lowercase Greek letter that is used to designate a stan-
dard deviation of a population.
Signal 21.0932
An electrical impulse of a predetermined voltage, current,
polarity and pulse width.
Signal Conductor 22.0934
An individual conductor that is used to transmit an
impressed electrical signal.
Signal Line 22.0935
A conductor used to transmit a logic signal from one part
of a circuit to another.
Signal Plane 22.0936
A conductor layer that carries electrical signals. (See also
‘‘Ground Plane’’ and ‘‘Voltage Plane.’’)
Signal-to-Noise Ratio (Process Control) 91.0933
A response variable that takes into consideration both
parameter mean and parameter variation values.
Silkscreening 52.0937
see ‘‘Screen Printing.’’
Silver Migration 92.0938
The ionic removal of silver and its redeposition in an adja-
cent area under the influence of migration-inducing condi-
tions.
Simulated Aging 92.0939
The artificial exposure of material to conditions of both
high and low temperature and humidity in an attempt to
produce changes that occur during its extended exposure to
normal environmental conditions.
Simulated Datum 92.0940
The surface or feature(s) on a fixture, used as a machine
reference, which is correlated to the original board or
assembly datum
Single-Image Production Master 24.0941
A production master that is used in the process of making
only one printed board. (See also ‘‘Multiple-Image Produc-
tion Master.’’)
Single-Inline Package (SIP) 31.0942
A component package with one straight row of pins or wire
leads.
Single-Layer Carrier Tape 36.1528
The carrier for conductors used in tape-automated bonding
that consists only of a metal foil. (See also ‘‘Multilayer
Carrier Tape,’’ ‘‘Two-Layer Carrier Tape,’’ and ‘‘Three-
Layer Carrier Tape.’’)
Single-Point Bonding 74.0943
The making of terminations one at a time. (See also ‘‘Gang
Bonding.’’)
Single-Sided Assembly 80.0944
A packaging and interconnecting structure with compo-
nents mounted only on one side. (See also ‘‘Double-Sided
Assembly.’’)
Single-Sided Printed Board 60.0945
A printed board with a conductive pattern on only one side.
Sizing 44.0948
The method of applying size i.e. starch to a group (width)
of warp yarns on a continuous basis.
Skin Effect 21.0946
The increase in resistance of a conductor at microwave fre-
quencies that is caused by the tendency of electric current
to concentrate at the conductor’s surface.
Skipping 52.0947
When a coating or resist does not cover the spaces between
adjacent conductors.
Slice 35.0949
see ‘‘Wafer.’’
Sliver 96.0950
A slender portion of plating overhang that is partially or
completely separated from a conductor edge.
IPC-T-50F June 1996
62
Slump 73.0951
The distance of a substance, e.g., adhesive, moves after it
has been applied and cured.
Smaller-the-Better Characteristic 91.1817
A parameter of quality that improves performance as its
value decreases. (See also ‘‘Larger-the-Better Characteris-
tic’’ and ‘‘Nominal-is-Best Characteristic’’).
Smear Removal 54.0953
see ‘‘Desmear.’’
Smeared Bond 74.0952
A bond impression that has been distorted or enlarged by
excess lateral movement of the bonding tool or holding
device fixture.
Socket Contact 37.0954
A female connector contact.
Solarization 24.0955
A decrease in density with increased exposure.
Solder 46.0956
A metal alloy with a melting temperature that is below
427-deg.C (800-deg.F).
Solder Ball 75.0959
A small sphere of solder adhering to a laminate, resist, or
conductor surface. (This generally occurs after wave solder
or reflow soldering.)
Solder Bath 75.1767
A container or vessel of molten solder into which compo-
nent parts or assemblies are immersed.
Solder Bridging 75.0960
The unwanted formation of a conductive path of solder
between conductors.
Solder Bump 74.0961
A round ball of solder used to make interconnections
between a flip-chip component and a base material during
controlled-collapse soldering.
Solder Coat 53.0962
A layer of solder that is applied directly from a molten sol-
der bath to a conductive pattern.
Solder Connection 75.0963
An electrical/mechanical connection that employs solder
for the joining of two or more metal surfaces. (See also
‘‘Cold Solder Connection,’’ ‘‘Disturbed Solder Connec-
tion,’’ ‘‘Excess Solder Connection,’’ ‘‘Insufficient Solder
Connection,’’ ‘‘Overheated Solder Connection,’’ ‘‘Preferred
Solder Connection,’’ ‘‘Rosin Solder Connection.’’
Solder Connection Pinhole 75.0964
A small hole that penetrates from the surface of a solder
connection to a void of indeterminate size within the sol-
der connection.
Solder Cream 46.0965
see ‘‘Solder Paste.’’
Solder Embrittlement 75.0966
The reduction in mechanical properties of a metal as a
result of local penetration of solder along grain boundaries.
Solder Fillet 75.0967
A normally concave surface of solder that is at the intersec-
tion of the metal surfaces of a solder connection.
Solder Levelling 53.1677
A solder coating process that causes redistribution and/or
partial removal of excess molted solder from a printed
board by applying sufficient heat and mechanical force.
Solder Mask 47.0973
see ‘‘Solder Resist.’’
Solder Meniscus 75.1766
The contour of a solder shape that is the result of the
surface-tension forces that take place during wetting.
Solder Paste 46.1818
Finely divided particles of solder, with additives to pro-
mote wetting and to control viscosity, tackiness, slumping,
drying rate, etc, that are suspended in a cream flux.
Solder-Paste Flux 75.0957
Solder paste without the solder particles.
Solder Plug 75.0974
A core of solder in a plated-through hole.
Solder Projection 75.0975
An undesirable protrusion of solder from a solidified solder
joint or coating.
Solder Resist 47.1674
A heat-resisting coating material applied to selected areas
to prevent the deposition of solder upon those areas during
subsequent soldering.
Solder Resist Aperture 22.0977
An opening in a solder resist.
Solder Side 22.0978
The secondary side of a single-sided assembly.
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