IPC-T-50F_.pdf.pdf - 第48页

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 e…

Microcomponents 30.0758

Small discrete components.

Microelectronics 30.0759

The area of electronic technology with, or applied to, the

realization of electronic systems from extremely-small

electronic elements, devices or parts.

Microprobe 92.0760

A small sharp-pointed object with a positional handle that

is used to make temporary electrical contact to a land on a

semiconductor for testing purposes.

Microsectioning 92.1447

The preparation of a specimen of a material, or materials,

that is to be used in a metallographic examination. (This

usually consists of cutting out a cross-section, followed by

encapsulation, polishing, etching, staining, etc.)

Microstrip 21.0761

A transmission-line conﬁguration that consists of a conduc-

tor that is positioned over, and parallel to, a ground plane

with a dielectric between them.

Microwave Integrated Circuit 21.0762

An integrated circuit that performs at microwave frequen-

cies.

Migration Rate 96.0763

The distance over which metal migration proceeds in a

given unit of time.

Migration Velocity 96.0764

see ‘‘Migration Rate.

Minimum Annular Ring 22.0766

see ‘‘Minimum Annular Width.’’

Minimum Annular Width 22.0765

The minimum width of metal(s) at the narrowest point

between the edge of a hole and the outer edge of a circum-

scribing land. (This determination is made to the drilled

hole on internal layers of multilayer printed boards and to

the edge of the plating on external layers of multilayer and

double-sided printed board.)

Minimum Electrical Spacing 21.1451

The minimum allowable distance between adjacent con-

ductors, at a given voltage and altitude, that is sufficient to

prevent dielectric breakdown, corona, or both, from occur-

ing between the conductors.

Minor Defect 91.0767

A defect that is not likely to result in a failure of a unit or

product or that does not materially reduce its usability for

its intendeded purpose.

Mirrored Pattern 24.0768

A pattern whose orientation denotes a transposition from

right reading. (See Figure M-2.)

Mis-Pick 44.0769

A break in the pattern of cloth from selvage to selvage that

is caused by a missing ﬁlling yarn.

Mislocated Bond 74.0770

see ‘‘Off Bond.’’

Misregistration 50.0771

Imperfect registration.

Mixed Component-Mounting Technology 70.1452

A component mounting technology that uses both through-

hole and surface- mounting technologies on the same pack-

aging and interconneting structure.

Mixed-Effects Model 91.0772

An experimental treatment that contains elements of both

ﬁxed-effects and random-effects models.

Mixed Technology 70.1757

In surface mounting, refers to mixing through hole compo-

nent and surface mounting components on the same side of

a printed circuit board.

Modal Form 25.0773

The technique whereby a data description or other pertinent

command is given only once at the beginning of a related

set of data.

Modification 77.0774

The revision of the functional capability of a product in

order to satisfy new acceptance criteria.

Module 80.0775

A separable unit in a packaging scheme.

Molecular Dye-Imaging Material 24.0776

see ‘‘Diazo Material’’

Monolithic Integrated Circuit 30.0777

An integrated circuit in the form of a monolithic structure.

Montreal Protocol 76.1758

An agreement by industrialized nations, at a meeting held

in Montreal, Canada, to eliminate chloroﬂuorocarbons

from all processes by 1995.

Mother Board 85.0778

A printed board assembly that is used for interconnecting

arrays of plug-in electronic modules. (See also ‘‘Back-

plane.’’)

June 1996 IPC-T-50F

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