IPC-T-50F_.pdf.pdf - 第49页

N Nail Heading 51.0794 The ﬂared condition of copper on an inner conductive layer of a multilayer printed board that is caused by hole-drilling. (See Figure N-1.) Nail 92.0792 see ‘ ‘Probe, T est.’ ’ Nailhead Bond 74.079…

Mounting Hole 20.0779

A hole that is used for the mechanical support of a printed

board or for the mechanical attachment of components to a

printed board.

Muffle 75.0780

An enclosure that is located between the heating elements

and the parts being processed that contains the atmosphere

required for the reﬂow soldering process.

Multi-Vari 91.0781

A nonmathematical method for determining the sources of

variation.

Multichip Integrated Circuit 86.0782

see ‘‘Multichip Module.’’

Multichip Microcircuit 86.0783

see ‘‘Multichip Module.’’

Multichip Module (MCM) 86.0784

A microcircuit module consisting primarily of closely-

spaced unpackaged semiconductor dice or chip scale pack-

ages, that have a silicon area density of usually more than

of the module area.

Multilayer Carrier Tape 36.0785

Carrier tape with two or more conductor layers.

Multilayer Printed Board 60.1227

The general term for a printed board that consist of rigid or

ﬂexible insulation materials and three or more alternate

printed wiring and/or printed circuit layers that have been

bonded together and electrically interconnected.

Multilayer Printed Circuit Board 60.0786

A multilayer printed board with two or more printed circuit

layers.

Multilayer Printed Circuit Board Assembly 80.0787

An assembly that uses a multilayer printed circuit board for

component mounting and interconnecting purposes.

Multilayer Printed Wiring Board 60.0788

A multilayer printed board with only printed wiring for its

conductive layers.

Multilayer Printed Wiring Board Assembly 80.0789

An assembly that uses a multilayer printed wiring board for

component mounting and interconnecting purposes.

Multilevel Experiment 91.0790

The evaluation of a small number of factors at a large

number of levels.

Multiple Image Production Master 24.1643

A production master having at least two1:1scale patterns

Multiple Indications 91.0791

An anomaly that is detected and reported more than once.

Multiple Pattern 24.1645

The arrangement of two or more1:1scale patterns con-

tained within the size of one panel.

Multiple Printed Panel 50.1646

A printed panel in which one of more patterns occur two

or more times, processed as a single unit and subsequently

divided.

IPC-I-001207

Figure M–2 Mirrored and right-reading patterns

1 2 3 4

Primary Side Viewing

Right Reading Pattern Mirrored Pattern

NOTE: Phototooling emulsion for the right reading pattern is by definition the same as for the

mirrored pattern. That is, both are either emulsion up or both emulsion down.

1 2 3 4

Primary Side Viewing

IPC-T-50F June 1996

Nail Heading 51.0794

The ﬂared condition of copper on an inner conductive layer

of a multilayer printed board that is caused by hole-drilling.

(See Figure N-1.)

Nail 92.0792

see ‘‘Probe, Test.’’

Nailhead Bond 74.0793

see ‘‘Ball Bond.’’

Near-End Crosstalk 21.0795

see ‘‘Backward Crosstalk.’’

Neckbread 74.0796

A break in a bond immediately above a ball bond.

Negative Etchback 54.0798

Etchback in which the inner conductor layer material is

recessed relative to the surrounding base material. (See

Figure N-2.)

Negative (n.) 24.0797

An artwork, artwork master, or production master in which

the pattern being fabricated is transparent to light and the

other areas are opaque.

Negative Pattern 24.1639

An artwork, artwork master, or production master in which

the pattern being fabricated is transparent to light and the

other areas as opaque.

Negative-Acting Resist 52.1448

A resist that is polymerized by light and which, after expo-

sure and development, remains on a surface in those areas

that were under the transparent areas of a production mas-

ter.

Neighborhood Processing 92.0799

The determination of information about a location or pixel

by the use of information obtained about its neighbors.

Nesting 25.1176

Embedding data in levels of other data so that certain rou-

tines may be executed or accessed continuously in loops.

Net 21.1177

An entire string of electrical connections from the ﬁrst

source point to the last target point, including lands and

vias.

Net List 21.1178

A list of alphanumeric representations, each of which is

used to describe a group of two or more points that are

electrically common.

Nick (n.) 60.1179

A cut or notch in a wire or in the edge of a conductor.

Node 21.1180

The endpoint of an electrical network branch or the junc-

tion of two or more branches.

Nodule 60.1181

A mass or small lump with an irregular shape that is con-

vex to a surface.

Noise (Process Control) 91.1182

Factors in a manufacturing process that are uncontrollable

or too costly to control.

Nominal Cured Thickness 55.1449

The thickness of a multilayer printed board, or the distance

between two two adjacent layers of a multilayer printed

board, after the prepreg has been cured at the temperature

and pressure speciﬁed for that particular class of resin flow.

Nominal-Is-Best Characteristic 91.1450

A parameter of quality that optimizes performance at its

nominal value. (See also ‘‘Larger-the-Better Characteris-

tic’’ and ‘‘Smaller-the-Better Characteristic.’’)

IPC-I-001045

Figure N–1 Nail heading

NAIL HEADING

BASE MATERIAL

COPPER CONDUCTOR

LAYER

IPC-I-001032

Figure N–2 Negative etchback

Negative 

Etchback

▼

Base Material

Copper

Conductive

Layer

June 1996 IPC-T-50F

Nonactivated Flux 75.1183

A natural or synthetic-resin ﬂux without activators.

Nonconductive Pattern 22.1184

A conﬁguration that is formed by the functional noncon-

ductive material of a printed circuit, e.g., dielectric, resist,

etc.

Nonfunctional Interfacial Connection 22.1453

A plated through hole in a double-sided printed board that

electrically connects a printed conductor on one side of the

board to a nonfunctional land on the other side of the

board. (See Figure N-3.)

Nonfunctional Land 22.1185

A land that is not connected electrically to the conductive

pattern on its layer.

Nonfunctional Terminal Area 22.1186

see ‘‘Nonfunctional Land.’’

Nonionic Contaminant 76.1187

A residue that does not readily ionize in water.

Nonpolar Matter 76.1188

A substance that cannot be dissolved in water that is

soluble in hydrophobic solvents.

Nonpolar Solvent 76.1454

A liquid that is not ionized to the extent that it is electri-

cally conductive, that can dissolve nonpolar compounds

(such as hydrocarbons and resins), and cannot dissolve

polar compounds (such as inorganic salts.)

Nonwetting (Solder) 75.1189

The partial adherence of molten solder to a surface that it

has contacted and basis metal remains exposed. (See Fig-

ure N-4.)

Normal Distribution 94.1191

A mathematically-deﬁned continuous distribution of values

that has a bell shape that is perfectly symmetrical about a

mean value.

Normal-Mode Rejection (NMR) 21.1190

The amount of noise superimposed on the input signal of a

direct-current (DC) digital voltmeter that the instrument is

capable of rejecting.

Null Hypothesis 91.1455

The supposition that no signiﬁcant difference exists

between the desired results of two comparable populations.

(See also ‘‘Alternative Hypothesis’’ and ‘‘Statistical

Hypothesis.’’)

Numerical Control (machine) (NC) 25.1193

The automatic control of electromechanical devices by

means of a digital input to an electronic controller.

Numerical Control (math.) (NC) 20.1192

The use of mathematics to deﬁne, design or test geometric

quantities that are used in a computer-aided technology.

Object Code 25.0801

The output from a computer compiler or assembler that is,

or is suitable for, processing into executable machine

codes.

Object-Oriented Database 11.0800

A database that combines graphics and text to describe

objects.

Occluded Contaminant 76.0802

A contaminant that is totally contained in an insulating

material.

Occlusion 76.0803

Uniform molecular adhesion between a precipitate and a

soluble substance, or between a gas and a metal.

Off Bond 74.0804

A termination that has some portion of the bonding area

extending off the bonding land.

Offset Land 22.0805

A land that is intentionally not in physical contact with its

associated component hole.

IPC-I-001046

Figure N–3 Nonfunctional interfacial connection

Conductor

Non-

functional

Land

▼

IPC-I-001042

Figure N–4 Nonwetting

NONWETTING

SOLDER

BASIS METAL

BASE MATERIAL

IPC-T-50F June 1996