IPC-7527.pdf - 第6页

Table of Contents 1 GENERAL ................................................................... 1 1.1 Scope .................................................................... 1 1.2 Purpose .............................…

Acknowledgment

Any document involving a complex technology draws material from a vast number of sources across many continents.

Shown below are the principal members of the IPC-7527 development team including the Solder Paste Printing Task Group

Nordic (5-21JND) of the Component Mounting Subcommittee (5-21) of the Assembly and Joining Committee (5-20). It is

not possible to include all of those who assisted in the evolution of this standard. To each of them, the members of the IPC

extend their gratitude.

Assembly and Joining

Committee

Component Mounting

Subcommittee

Solder Paste Printing

Task Group Nordic

Chair

Leo P. Lambert

Chair

Peggi J. Blakley

NSWC Crane

Co-Chairs

Scott Pinney

Grundfos Management A/S

Steven Hansen

Vestas Control Systems

Technical Liaisons of the

IPC Board of Directors

Peter Bigelow

IMI Inc.

Sammy Yi

Flextronics International

Component Mounting Subcommittee

Sonic Lu, Autoliv (China) Electronics

Co., Ltd.

Claus Nielsen, BB Electronics A/S

Jens Chr. Jensen, Bent Hede

Elektronik A/S

Steven Perng, Cisco Systems Inc.

Jørgen Stenstrup, Danfoss Drives A/S

Torgrim Nordhus, EMG Norautron

David Qi, Flextronics Mfg. (Zhuhai)

Co. Ltd.

Jiyang Zhang, Flextronics Mfg.

(Zhuhai) Co. Ltd.

Renie Zhao, Flextronics Mfg.

(Zhuhai) Co. Ltd.

Henning Haubo, Flextronics Special

Business Solutions

Jesper Konge, Gaasdal

Bygningsindustri A/S

Scott Pinney, Grundfos Management

A/S

Svein Olav Kolbu, Hapro AS

Jens Andersen, Hytek

Alex Christensen, Hytek

Poul Juul, Hytek

Søren Træholt, Kai Toft Elektronik

ApS

Kim Poulsen, Kamstrup A/S

Erik Andresen, Linak A/S

Allan Sigfredsen, Necas A/S

Gregers Dybdal, Linak A/S

Kathrin Morgener Jensen, Protec

Electronics ApS

Steven Hansen, Vestas Control

Systems

May 2012 IPC-7525A

iii

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Table of Contents

1 GENERAL ................................................................... 1

1.1 Scope .................................................................... 1

1.2 Purpose ................................................................. 1

1.3 Background .......................................................... 1

1.4 Terms and Deﬁnitions ......................................... 1

1.4.1 Classiﬁcation ........................................................ 1

1.4.2 Disposition* ......................................................... 1

1.4.3 Slumping .............................................................. 1

1.4.4 Combined Conditions .......................................... 1

1.4.5 Designed Volume ................................................. 1

1.5 Specialized Designs ............................................. 1

1.6 Veriﬁcation of Dimensions .................................. 2

1.7 Magniﬁcation Aids ............................................... 2

1.8 Lighting ................................................................ 2

2 APPLICABLE DOCUMENTS .................................... 2

2.1 IPC ....................................................................... 2

2.2 ASTM ................................................................... 2

3 CHOICE OF TECHNOLOGY .................................... 2

4 MEASUREMENT OF SOLDER PASTE

DEPOSITS

................................................................. 3

5 SHAPE OF SOLDER PASTE DEPOSIT .................. 4

5.1 Solder Paste Deposit – Misalignment ................. 4

5.1.1 Slump ................................................................... 4

5.1.2 Misregistration of Solder Paste Deposits ............ 5

5.1.3 Solder Paste Deposit – Area ............................... 7

5.1.4 Solder Paste Deposit – Height ............................ 8

Appendix A Guideline for Operator Trouble-

shooting in the Solder Paste

Screen Printing Process

....................... 9

Figures

Figure 3-1 Squeegee Blade ............................................... 2

Figure 3-2 Enclosed Paste Print Head .............................. 3

Figure 3-3 Needle Dispense .............................................. 3

Figure 3-4 Paste Jet Dispense .......................................... 3

Figure 4-1 Sample of an Automated Machine Readout .... 3

Figure 4-2 Sample of an Automated Inspection Result ..... 3

Figure 4-3 Weighing Solder Paste ..................................... 3

Figure 5-1

Full Shape ........................................................ 4

Figure 5-2

Saddle Shape ................................................... 4

Figure 5-3

Roof Top Shape ................................................ 4

Figure 5-4

Pyramid Shape ................................................. 4

Figure 5-5

Full Shape ........................................................ 4

Figure 5-6 Centered Deposit .............................................. 5

Figure 5-7 Centered Deposit .............................................. 5

Figure 5-8 Offset – Acceptable .......................................... 5

Figure 5-9 Offset – Acceptable .......................................... 5

Figure 5-10 Offset – Acceptable .......................................... 5

Figure 5-11 Offset – Acceptable .......................................... 5

Figure 5-12 Offset – Acceptable .......................................... 6

Figure 5-13 Offset – Acceptable .......................................... 6

Figure 5-14 Offset – Defect .................................................. 6

Figure 5-15 Shorting – Defect .............................................. 6

Figure 5-16 Offset – Defect .................................................. 6

Figure 5-17 Area – Target .................................................... 7

Figure 5-18 Area – Target .................................................... 7

Figure 5-19 Area – Acceptable ............................................ 7

Figure 5-20 Area – Acceptable ............................................ 7

Figure 5-21 Area – Defect ................................................... 7

Figure 5-22 Height – Target ................................................. 8

Figure 5-23 Height – Target ................................................. 8

Figure 5-24 Height – Process Indicator ............................... 8

Figure 5-25 Height – Defect ................................................. 8

Figure A-1 Solder Paste Printing with Squeegee

Blades ............................................................... 9

Figure A-2 Solder Paste Printing with Enclosed Head

System .............................................................. 9

Figure A-3 Plastic from Packaging ..................................... 9

Figure A-4 Glass Fiber from PCB .................................... 10

Figure A-5 Effect of Solder Mask ..................................... 10

Figure A-6 Effect of Silk Screen ....................................... 10

Figure A-7 Effect of Solder Paste ..................................... 10

Figure A-8 Result of Silk Screen Interference ................. 10

Figure A-9 Saddle Shape Deposit .................................... 10

Figure A-10 Roof Top Shape Paste Deposit ...................... 10

Figure A-11 Spikes on Paste Deposit ................................ 11

Figure A-12 Increased Deposit Quantity ............................ 11

Figure A-13 Decreased Quantity ........................................ 11

Figure A-14 Slumping/Smearing ......................................... 11

Figure A-15 Paste Residues .............................................. 12

Figure A-16 Long Smear .................................................... 12

Figure A-17 Offset .............................................................. 12

Figure A-18 Excess Residue Along Direction of Travel ..... 12

Figure A-19 Residue Across Direction of Travel ................ 13

Figure A-20 Solder Balls .................................................... 13

Figure A-21 Close Up of Solder Balls ................................ 13

Tables

Table 1-1 Inspection Magniﬁcation (Land Width) ................ 2

IPC-7527 May 2012

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Requirements for Solder Paste Printing

1 GENERAL

1.1 Scope

This standard is a collection of visual quality

acceptability criteria for solder paste printing.

1.2 Purpose The purpose of this guideline document is

to support the user in the visual evaluation of the solder

paste printing process, which makes subsequent process

optimizing possible.

The purpose of this guideline is not to inspect and evaluate

the quality of the solder paste. For information on the

evaluation of solder paste, see J-STD-005, Requirements

for Soldering Pastes and IPC-HDBK-005.

The purpose is not to deﬁne requirements to stencil design.

For information on stencil design, see IPC-7525, Stencil

Design Guideline.

Appendix A provides different error types and suggested

solutions are listed. The guideline is intended to help/

improve the optimizing process for paste printing.

In the case of a discrepancy, the description or written

criteria always takes precedence over the illustrations.

1.3 Background Standards such as J-STD-001 and IPC-

A-610 provide tools that help to promote quality within the

electronics industry. However, the standards do not include

requirements of visual appearance of the paste deposit. The

industry has, for some time, expressed a wish for a stan-

dard to support the users in the solder paste printing pro-

cess. IPC-7527 will help improve the quality in this very

sensitive process.

1.4 Terms and Definitions Other than those terms listed

below, the deﬁnitions of terms used in this standard are in

accordance with IPC-T-50. Terms quoted from IPC-T-50

are marked with *.

1.4.1 Classification

CLASS 1 General Electronic Products

Includes products suitable for applications where the major

requirement is function of the completed assembly.

CLASS 2 Dedicated Service Electronic Products

Includes products where continued performance and

extended life is required, and for which uninterrupted ser-

vice is desired, but not critical. Typically the end-use envi-

ronment would not cause failures.

CLASS 3 High Performance Electronic Products

Includes products where continued high performance or

performance-on-demand is critical, equipment downtime

cannot be tolerated, or the end-use environment may be

uncommonly harsh.

Target Condition A condition that is close to perfect/

preferred, however, it is a desirable condition and not

always achievable and may not be necessary to ensure reli-

ability of the assembly in its service environment.

Acceptable Condition Indicates a condition that, while not

necessarily perfect, will maintain the integrity and reliabil-

ity of the assembly in its service environment.

Defect Condition A condition that may be insufficient to

ensure the form, ﬁt, or function of the assembly in its end

use environment. Defect conditions shall be dispositioned

by the manufacturer based on design, service, and customer

requirements. Disposition may be to rework, repair, scrap,

or use as is. Repair or use as is may require customer con-

currence.

A defect for Class 1 automatically implies a defect for

Class 2 and 3. A defect for Class 2 implies a defect for

Class 3.

1.4.2 Disposition* The determination of how defects

should be treated. Dispositions include, but are not limited

to, rework, use as is, scrap, or repair.

1.4.3 Slumping Solder paste ﬂows out after it is applied.

See more in IPC-HDBK-005.

1.4.4 Combined Conditions There may be situations

where a combination of maximum deviations in form,

placement, coverage, and height can result in lack of sol-

dering or wrong amount of solder paste. The manufacturer

is responsible for identiﬁcation of such conditions.

1.4.5 Designed Volume The designed volume is equal to

the area of the stencil aperture times the stencil thickness

(volume = length x width x height). Volume is not a visu-

ally inspectable condition.

1.5 Specialized Designs This standard, as an industry

consensus document, cannot address all of the possible

components and product design combinations. Where

uncommon or specialized technologies are used, it may be

necessary to develop unique acceptance criteria. However,

where similar characteristics exist, this document may pro-

vide guidance for product acceptance criteria. Often,

unique deﬁnition is necessary to consider the specialized

characteristics while considering product performance cri-

teria. The development should include customer involve-

ment or consent. For Class 3, the criteria shall include

agreed deﬁnition of product acceptance.

May 2012 IPC-7527

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