IPC-SM-782A 表面安装设计和焊盘设计标准(带BGA).pdf - 第12页

• Small in size, real estate constrained • Able to accommodate large amounts of memory • Light in weight • Able to accommodate several large, high lead count com- plex ICs, such as ASICs and silicon arrays • Able to func…

IPC-782-1-1

Figure 1–1 Electrical assembly types

PLCC

CHIP COMPONENT

SOIC

DIP

PLCC

CHIP

COMPONENT

SOIC

DIP

PLCC

CHIP COMPONENT

SOIC

PLCC

2-Sided Thru-hole (NOT RECOMMENDED)

CHIP

COMPONENT

PLCC

CHIP

COMPONENT

CHIP

COMPONENT

SOIC

CHIP

COMPONENT

SOIC

DIP

SOLDER

PASTE

SOLDER

PASTE

SOIC

Through-hole

Simple

SMT

Simple

SMT/TH

Complex

Type 1

Type 2

SMT

Complex

TH/SMT

Simple

SMT/TH

FPT/CMT

Complex

SOLDER

PASTE

Adhesive (Optional)

FPT

Simple

Wire bond or

tab IC chip

attachment

FPT PKG.

(selectively attached)

December 1999 IPC-SM-782A

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• Small in size, real estate constrained

• Able to accommodate large amounts of memory

• Light in weight

• Able to accommodate several large, high lead count com-

plex ICs, such as ASICs and silicon arrays

• Able to function at high frequencies and speeds

• Able to transmit little or no noise, EMI and RFI resistant

• Able to be built in large volumes using automation

Currently, most SMT boards that have 50 or more compo-

nents use a combination of SMT and through-hole tech-

nologies. The mix is a function of component availability,

multiplicity of vendors, and cost. A mix of 80 percent SMT

and 20 percent through-hole parts is very common. How-

ever, the number of 100% SMT assemblies is increasing.

Fine Pitch Technology (FPT) involves a process change as

well as a packaging family, because the package to board

assembly steps are different than SMT. For example, sev-

eral commercially available FPT parts require lead excise

and forming prior to placement. They are encapsulated or

molded with plastic and delivered to users as a separate

packaged device, and these parts may be shipped with a

molded guard-ring or a slide carrier securing the leads in

place. The full encapsulated device will be used for direct

board mounting.

FPT packages are available under package names such as

PQFP (Plastic Quad Flat Pack), CQFP (Ceramic Quad Flat

Pack), QFP (Quad Flat Pack) and VSOIC (Very Small Out-

line Integrated Circuits).

2.0 APPLICABLE DOCUMENTS

The following documents, of the issue currently in effect

form a part of this document to the extend speciﬁed herein.

Other documents listed are for reference purposes to assist

the user.

2.1 IPC

IPC-A-48 Surface Mount Land Pattern Artwork (Mantech)

IPC-A-49

Surface Mount Land Pattern Artwork (IPC-SM-

782A)

IPC-T-50 Terms and Deﬁnitions

IPC-SC-60

Post Solder Solvent Cleaning Handbook

IPC-AC-62

Post Solder Aqueous Cleaning Handbook

IPC-2221

Generic Standard on Printed Board Design

IPC-6012

Qualiﬁcation and Performance Standard for

Rigid Printed Boards

IPC-D-330

Printed Wiring Design Guide

IPC-A-610

Acceptability of Printed Board Assemblies

IPC-7711

Rework of Electronic Assemblies

IPC-SM-780

Guidelines for Component Packaging and

Interconnection with Emphasis on Surface Mounting

IPC-SM-784

Guidelines for Chip-on-Board Technology

Implementation

IPC-SM-785

Guidelines for Accelerated Reliability Testing

of Surface Mount Solder Attachments

IPC-SM-786

Recommended Procedures for Handling of

Moisture Sensitive Plastic IC Packages

IPC-AJ-820

Assembly and Joining Handbook

IPC-CC-830

Electrical Insulating Compounds for Printed

Board Assemblies

IPC-SM-840

Qualiﬁcation and Performance of Permanent

Polymer Coating (Solder Mask) for Printed Boards

IPC-1902/IEC 60097

Grid System for Printed Circuits

2.2 Electronic Industries Association

IS-30

Surface Mount Resistors

JEDEC-95

JEDEC Registered and Standard Outlines for

Solid State Products

EIA-PDP-100

Registered and Standard Mechanical Out-

lines for Electronic Parts

RS-198

Ceramic Dielectric Capacitors

RS-228

Fixed Electrolytic Tantalum Capacitors

RS-367

Dimensional and Electrical Characteristics Deﬁn-

ing Receiver Type Sockets

RS-376

Fixed Film Dielectric Capacitors in Metallic and

Non- Metallic Cases for D.C. Application

RS-415

Dimensional and Electrical Characteristic Deﬁn-

ing Dual-In-Line-Type Sockets

RS-428

Type Designation System for Microelectronic

Devices

1. IPC, 2215 Sanders Road, Northbrook, IL 60062-6135

2. Electronic Industries Association, 2001 Eye Street N.W., Washington, DC 20006

IPC-SM-782A December 1999

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RS-471

Symbol and Label for Electrostatic Sensitive

Devices

RS-481

Tape and Reel Speciﬁcation

2.3 Joint Industry Standards (IPC)

J-STD-001

Requirements for Soldered Electrical and Elec-

tronic Assemblies

J-STD-002

Solderability Tests for Component Leads, Ter-

minations, Lugs, Terminals and Wires

J-STD-003 Solderability Tests for Printed Boards

2.4 American Society of Mechanical Engineers

ANSI Y14.5M—1982 Dimensioning and Tolerancing

3.0 DESIGN REQUIREMENTS

3.1 Terms and Definitions

Terms and deﬁnitions used

herein are in accordance with IPC-T-50 except as otherwise

speciﬁed. Note: Any deﬁnition denoted with an asterisk (*)

is a reprint of the deﬁnition deﬁned in IPC-T-50.

*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.

Assembly, double-sided – A packaging and interconnecting

structure with components mounted on both the primary

and secondary sides.

Assembly, multilayer printed circuit – a multilayer printed

circuit board on which separately manufactured compo-

nents and parts have been added.

Assembly, multilayer printed wiring – a multilayer printed

wiring board on which separately manufactured compo-

nents and parts have been added.

Assembly, packaging and interconnecting (P&IA) – The

generic term for an assembly that has electronic compo-

nents mounted on either one or both sides of a packaging

and interconnecting structure.

Assembly, printed board – an assembly of several printed

circuit assemblies or printed wiring assemblies, or both.

Assembly, printed circuit – a printed circuit board on

which

separately manufactured components and parts have been

added.

Assembly, printed wiring – a printed wiring board on

which

separately manufactured components and parts have been

added.

Assembly, single-sided – A packaging and interconnecting

structure with components mounted only on the primary

side.

*Base material – The insulating material upon which the

conductor pattern may be formed. The base material may

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

metal sheet.

Basic dimension – Theoretically exact location of a com-

ponent feature, indicated by a symbol or a number in a box.

(The tolerance on a basic dimension provides the limits of

the variation from the basic dimension location.)

Castellation – Metallized features that are recessed on the

edges of a chip carrier which are used to interconnect con-

ducting surfaces or planes within or on the chip carrier.

Chip carrier – A low-proﬁle rectangular component pack-

age, usually square, whose semiconductor chip cavity or

mounting area is a large fraction of the package size and

whose external connections are usually on all four sides of

the package.

Chip-on-board (COB) – Integrated circuit device mounted

directly to the printed board and interconnected with wire

bonds.

Coefficient of thermal expansion (CTE) – The linear ther-

mal expansion per unit change in temperature.

Component – A separable part of a printed board assembly

which performs a circuit function (e.g., a resistor, capaci-

tor, transistor, etc.)

Component mounting site – A location on a P&I structure

that consists of a land pattern and conductor fan-out to

additional lands for testing or vias that are associated with

the mounting of a single component.

*Conductive pattern – The conﬁguration or design of the

conductive material on the base material. (Includes conduc-

tors, lands, and through connections when these connec-

tions are in integral part of the manufacturing process.)

*Conductor – A single conductive path in a conductive

pattern.

Constraining core – A supporting plane that is internal to

a packaging and interconnecting structure.

*Dual in-line package (DIP) – A component which termi-

nates in two straight and parallel rows of pins or lead

wires.

Fine-pitch technology (FPT) – Surface mounted compo-

nents with a lead or termination pitchof 0.63 mm or less.

Fiducial – A feature of the PB used to provide common

measurable points for all steps in the assembly process.

Flat pack – A component with two straight rows of leads

(normally on 1.27 mm centers) which are parallel to the

component body.

3. Publications are available from the American Society of Mechanical Engineers, 345 East 47th St., New York, NY 10017

December 1999 IPC-SM-782A

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