IPC-CM-770D-1996.pdf - 第20页

January

1996

IPC-CM-770

3.1 *Assembly

A number of parts of subassemblies or

any combination thereof joined together.

Note: When this term is used in conjunction with other

terms listed herein, the following definitions shall prevail.

printed wiring assembly

-

An assembly that uses a

printed wiring board for component mounting and

interconnecting purposes.

multilayer printed wiring assembly

-

An assembly

that uses a multilayer printed wiring board for com-

ponent mounting and interconnecting purposes.

printed circuit assembly

-

An assembly that uses a

printed circuit board for component mounting and

interconnecting purposes.

multilayer printed circuit assembly

-

A multilayer

printed circuit board on which separately manufac-

tured components and parts have been added.

printed board assembly

-

An assembly of several

printed circuit assemblies or printed wiring assem-

blies, or both.

3.2 *Base Material

The insulating material upon which

the conductor pattern may be formed. (The base material

may be rigid or flexible or both. It may be a dielectric sheet

or insulated metal sheet.

3.3 *Castellations

A recessed metallized features on the

edge of a leadless chip carrier that is used to interconnect

conducting surfaces or planes within or on the chip carrier.

3.4 *Chip Carrier

A low-profile, usually square, surface

mount component semiconductor package whose die cavity

or die mounting area is a large fraction of the package size

and whose external connections are usually on all four

sides of the packaged. (It may be leaded or leadless.)

3.5 *Clinched Leads

A component lead that is inserted

through a hole in a printed board and is then formed in

order to retain the component in place and in order to make

metal-to-metal contact with a land prior to soldering. (See

also “Partially-Clinched Lead.”)

3.6 Coefficient of Thermal Expansion (CTE)

The linear

thermal expansion per unit change in temperature.

3.7 *Coefficient of Thermal Expansion Mismatch

(CTE)

The linear dimensional change of a material per

unit change in temperature. (See also “Thermal Expansion

Mismatch.”)

3.8 *Component

The individual part or combination of

parts that, when together, perform a design function(s).

(See also “Discrete Component.”)

3.9 *Component Lead Hole

A hole used for the attach-

ment and electrical connection of component terminations,

including pins and wires, to the printed board.

3.10 *Component Mounting Site

A location on a pack-

aging and interconnection structure that consists of a land

pattern and conductor fan out to additional lands for test-

ing or vias that are associated with the mounting of a single

component.

3.11 *Conductive Pattern

The configuration or design

of the conductive material on the base material. (Includes

conductors, lands, vias, heatsinks and passive components

when these are an integral part of the printed board manu-

facturing process.)

3.12 *Conductor

A single conductive path in a conduc-

tive pattern.

3.13 *Constraining Core

A supporting plane that is

internal to a packaging and interconnecting structure.

3.14 *Double-Sided Assembly

A packaging and inter-

connecting structure with components mounted on both the

primary and secondary sides. (Also see “Single-Sided

Assembly.”)

3.1

5

*Dual lnline Package (DIP)

A basically -rectangular

component package that has a row of leads extending from

each of the longer sides of its body that are formed at right

angles to a plan that is parallel to the base of its body.

3.1 6 *Edge Board Connector

A connector designed spe-

cifically for making nonpermanent interconnections

between the edge-board contacts on a printed board.

3.17 *Flat Pack

A rectangular component package that

has a row of leads extending from each of the longer sides

of its body that are parallel to the base of its body.

3.1 8 *Footprint

(see preferred term “Land Pattern”)

3.1 9 *Grid

An orthogonal network of two sets of parallel

equidistant lines used for locating points on a printed

board.

3.20 Integrated Circuit (IC)

An assembly of miniature

electronic components simultaneously produced in batch

processing, on or within a single substrate to perform an

electronic circuit function.

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COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services

COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services

IPC-CM-770

Januaty

1996

3.21 *Jumper Wire

A discrete electrical connection that

is part of the basic conductive pattern formed on a printed

board. (See also “Haywire.”)

3.22 *Land

A portion of a conductive pattern usually

used for making electrical connections, for component

attachment, or both.

3.23 *Land Pattern

A combination of lands that is used

for the mounting, interconnection and testing of a particu-

lar component.

3.24 *Lead Projection

The distance which a component

lead protrudes through the printed board on the side oppo-

site from which the component is mounted.

3.25 Leadless Chip Carrier

A chip carrier whose exter-

nal connections consist of metallized terminations.

3.26 Leaded Chip Carrier

A chip carrier whose external

connections consist of leads around and down the sides of

the package.

3.27 *Master Drawing

A document that shows the

dimensional limits or grid locations that are applicable to

any or all parts of a product to be fabricated, including the

arrangement of conductors and non-conductive patterns or

elements; size, type, and location of holes; and any other

information.

3.28 *Mixed Component-Mounting Technology

A com-

ponent mounting technology that uses both through-hole

and surface-mounting technologies on the same packaging

and interconnecting structure.

3.29 *Module

A separable unit in a packaging scheme.

3.30 *Mounting Hole

A hole that is used for the

mechanical support of a printed board or for the mechani-

cal attachment of components to the printed board.

3.31 Packaging and Interconnecting Assembly (P&lA)

The general term for an assembly that has electrical com-

ponents mounted on either one or both sides of a packag-

ing and interconnecting structure.

3.32 *Packaging and Interconnecting Structure (P&lS)

The general term for a completely processed combination

of base materials, support planes or constraining cores, and

interconnection wiring that are used for the purpose of

mounting the interconnecting components.

3.33 *Plated-Through Hole (PTH)

A hole with plating on

its walls that makes an electrical connection between con-

ductive patterns on internal layers, external layers, or both

of the printed board.

3.34 *Primary Side

That side of the packaging and inter-

connecting structure that is

so

defined on the master draw-

ing. (It is usually the side that contains the most complex

or the most number of components.)

3.35 *Printed Board

The general term for completely

processed printed circuit or printed wiring configurations.

(This includes single-sided, double-sided and multilayer

boards with rigid, flexible, and rigid-flex base materials.)

3.36 *Printed Board Assembly

The generic term for an

assembly that uses a printed board for component mount-

ing and interconnecting purposes.

3.37 *Printed Wiring

A conductive pattern that provides

point-to-point connections, but not printed components, in

a predetermined arrangement or a common base. (See also

“Printed Circuit Board.”)

3.38 *Production Master

A 1-to-1 scale pattern that is

used to produce rigid or flexible printed boards within the

accuracy specified on the master drawing. (See also

“Multiple-Image Production Master: and Single-Image

Production Master.”)

3.39 *Register Marker

A symbol used as a reference

point to maintain registration.

3.40 *Registration

The degree of conformity of the posi-

tion of a pattern, (or a portion thereof), a hole, or other

feature to its intended position on a product.

3.41 *Secondary Side

That side of the packaging and

interconnecting structure that is opposite and the primary

side. (It is the same as the “solder side” in through-hole

mounting technology.)

3.42 Single ln-Line Package (SIP)

A component which

terminates in one straight row of pins or lead wires.

3.43 *Single-Sided Assembly

A packaging and intercon-

necting structure with components mounted only on one

side. (See also “Double-Side Assembly.”)

3.44 Static Electricity

An electrical charge that has

accumulated or built up on the surface of a material. The

material may be conductive or non-conductive. In conduc-

tors, the charge can pass through the material. In non-

conductors, the charge cannot pass and is in effect locked

in place, hence the term static electricity.

3.45 Static Electricity Control

A technique where mate-

rials and systems are employed to eliminate/discharge

static electricity build-up by providing continuous dis-

charge paths.

1-6

COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services

COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services

January

1996

IPC-CM-770

3.46 *Supported Hole

A hole in a printed board that has

its inside surface plated or otherwise reinforced.

3.47 *Supporting Plane

A planar structure that is a part

of a packaging and interconnecting structure in order to

provide mechanical support, thermo-mechanical constraint,

thermal conduction and/or electrical characteristics. (It may

be either internal or external to the packaging and intercon-

necting structure.) (see also “Constraining Core.”)

3.48 *Surface Mounting

The electrical connection of

components to the surface of a conductive pattern that does

not utilize component holes.

3.49 Thermal Expansion Mismatch

The absolute differ-

ence in thermal expansion of two components, usually a

component and a packaging and interconnecting structure,

due to the influence of heat dissipation of an operating cir-

cuit and/or to changes in ambient temperature. (This term

is not to be confused with Coefficient of Thermal Expan-

sion Mismatch).

3.50 *Through Connection

An electrical connection

between conductive patterns on opposite sides of an insu-

lating base, e.g., plated-through hole or clinched jumper

wire.

3.51 *Tooling Feature

A physical feature that is used

exclusively to position a printed board or panel during a

fabrication, assembly or test process. (See also “Locating

Edge,” “Locating Edge Marker,” “Locating Notch,”

“Locating Slot,” and “Tool Hole.”)

3.52 *Unsupported Hole

A hole in a printed board that

does not contain plating or other type of conductive rein-

forcement.

3.53 *Via Hole

A plated-through hole that is used as a

interlayer connection, but in which there is no intention to

insert a component lead or other reinforcing material. (See

also “Blind Via” and “Buried Via”.)

Blind Via

-

A plated-through hole connected to either the

primary side or secondary side and one or more internal

layers of a multilayer packaging and interconnecting

structure.

Buried Via

-

A plated-through hole connected to neither

the primary side nor the secondary side of a multilayer

packaging and interconnecting structure: i.e., it connects

only internal layers.

Tented Via

-

A blind or through via whose exposed sur-

face(s) is fully covered by a masking material, such as

dry

film polymer coating (solder mask), preimpregnated glass

cloth (prepreg), etc., in order to prevent hole access by

process solutions, solder, or contamination.

*Through Via

-

A plated-through hole that connects the

primary side and secondary side of a packaging and inter-

connecting structure.

4.0 COM PONENT TYPE

This section contains a general introduction to the kinds of

components that will be discussed in detail in Parts Two

through Four (Sections

5

through

19).

Common character-

istics of components, component selection and general

issues will be considered here.

Components are selected for electrical, thermal, or

mechanical characteristics that are determined by the

requirements of the contents of the package. The material

composition, finish and configuration of both the body and

the terminations of a component must be considered in the

choice of assembly methods.

All components must be qualified for the assembly pro-

cesses to be used. The physical dimensions of the compo-

nent must adequately mate with the physical handling

devices of the placement equipment. The parts must not be

degraded, physically or electrically, by soldering or other

high temperature processes used. Also, the parts must be

able to tolerate exposure to the chemicals used in adhesive

bonding, soldering, cleaning or any other chemical process-

ing.

Electronic components come in a great variety of package

styles and shape. This relates not only to the electrical

functions which the components perform but sometimes

the same function is available in different packaging con-

figuration.

Component selection should consider the following factors

when applicable:

Electrical Characteristics

Electrical Performance

Mating Forces

Environmental Requirements

Durability

Repairability

Manufacturing Methods

Mechanical Requirements

Thermal Requirements

Electrical Environment

PlacemendAttachment Equipment

Polarization

Cleaning

Corrosion

Part IdentificationNerification

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COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services

COPYRIGHT Association Connecting Electronics Industries

Licensed by Information Handling Services