IPC J-STD-003B.pdf - 第10页

This Page Intentionally Left Blank IPC J-STD-003B March 2007 viii Copyright Association Connecting Electronics Industries Provided by IHS under license with IPC Not for Resale No reproduction or networking permitted with…

6.1 Correction for Buoyancy ............................. 23

6.2 Preheat .......................................................... 23

6.3 Baking .......................................................... 23

6.4 Prebaking ..................................................... 23

6.5 Safety Note .................................................. 23

6.6 Use of Nonactivated Flux ........................... 23

6.7 Solder Contact ............................................. 23

APPENDIX A Calculation of Maximum

Theoretical Force for a

Rectangular Cross-Section

............ 24

APPENDIX B Calculation of Area Under

the Wetting Curve

........................... 25

APPENDIX C Informative Annex ........................... 26

APPENDIX D Test Protocol for Wetting

Balance Gauge Repeatability

and Reproducibility (GR&R)

Using Copper Foil Coupons

............. 27

APPENDIX E J-STD-002/J-STD-003 Activated

Solderability Test Flux Rationale

Committee Letter

............................. 28

Figures

Figure 3-1 Contact Angle ................................................... 3

Figure 3-2 Example Reticle ................................................ 5

Figure 4-1 Edge Dip Solderability Test .............................. 7

Figure 4-2 Suggested Test Specimen for Plated-

Through Holes .................................................. 8

Figure 4-3 Suggested Test Specimen for Surface

Mount Features ................................................ 8

Figure 4-4 Rotary Dip Test ................................................. 9

Figure 4-5 Effectiveness of Solder Wetting of

Plated-Through Holes - Class 3 ..................... 10

Figure 4-6 Examples of Solder Wetting of Plated-

Through Holes - Class 3 ................................ 10

Figure 4-7 Wetting Balance Apparatus ............................ 18

Figure 4-8 Suggested Wetting Balance Test

Specimens and Soldering Immersion ............ 18

Figure 4-9 Wetting Balance Test Soldering Immersion ... 19

Figure 4-10 Set A Wetting Curve ....................................... 20

Figure 4-11 Set B Wetting Curve ....................................... 20

Figure 5-1 Aid to Evaluation ............................................ 22

Tables

Table 1-1 Test Method Selection ......................................... 2

Table 1-2 Conditioning and Test Requirements .................. 3

Table 3-1 Flux Composition ................................................ 4

Table 3-2 Maximum Limits of Solder Bath Contaminant .... 5

Table 4-1 Stencil Thickness Requirements ....................... 12

Table 4-2 Reﬂow Parameter Requirements ...................... 12

Table 4-3 Stencil Thickness Requirements ....................... 17

Table 4-4 Lead-Free Reﬂow Parameter Requirements .... 17

Table 4-5 Wetting Balance Parameter and

Suggested Criteria ............................................ 19

Table 4-6 Wetting Balance Parameter and

Suggested Criteria ............................................ 21

March 2007 IPC J-STD-003B

vii

Provided by IHS under license with IPC

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IPC J-STD-003B March 2007

viii

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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Solderability Tests for Printed Boards

1 GENERAL

1.1 Scope

This standard prescribes test methods, defect

deﬁnitions and illustrations for assessing the solderability

of printed board surface conductors, attachment lands, and

plated-through holes. This standard is intended for use by

both vendor and user.

1.2 Purpose The solderability determination is made to

verify that the printed board fabrication processes and sub-

sequent storage have had no adverse effect on the solder-

ability of those portions of the printed board intended to be

soldered. This is determined by evaluation of the solder-

ability test specimen portion of a board or representative

test specimen which has been processed as part of the

panel of boards and subsequently removed for testing per

the method selected.

1.3 Objective The objective of the solderability test

methods described in this standard is to determine the abil-

ity of printed board surface conductors, attachment lands,

and plated-through holes to wet easily with solder and to

withstand the rigors of the printed board assembly pro-

cesses.

1.3.1 Shall or Should The word ‘‘shall’’ is used in the

text of this document wherever there is a requirement for

materials, preparation, process control or acceptance of a

soldered connection or a test method. The word ‘‘should’’

reﬂects recommendations and is used to reﬂect general

industry practices and procedures for guidance only.

1.3.2 Document Hierarchy In the event of conﬂict, the

following descending order of precedence applies:

1. Procurement as agreed between user and supplier.

2. Master drawing or master assembly drawing reﬂecting

the user’s detailed requirements.

3. When invoked by the customer or per contractual agree-

ment, this document, J-STD-003.

4. Other documents to extent speciﬁed by the customer.

1.4 Performance Classes Three general classes have

been established to reﬂect progressive increases in sophis-

tication, functional performance requirements and testing/

inspection frequency. It should be recognized that there

may be an overlap of equipment categories in different

classes. The user has the responsibility to specify in the

contract or purchase order the performance class required

for each product and shall indicate any exceptions to spe-

ciﬁc parameters, where appropriate.

Class 1 – General Electronic Products

Includes consumer products, some computer and computer

peripherals suitable for applications where cosmetic imper-

fections are not important and the major requirement is

function of the completed printed board.

Class 2 – Dedicated Service Electronic Products

Includes communications equipment, sophisticated busi-

ness machines, instruments where high performance and

extended life is required and for which uninterrupted ser-

vice is desired but not critical. Certain cosmetic imperfec-

tions are allowed.

Class 3 – High Performance Electronic Products

Includes the equipment and products where continued per-

formance or performance on demand is critical. Equipment

downtime cannot be tolerated and must function when

required such as in life support items or ﬂight control sys-

tems. Printed boards in this class are suitable for applica-

tions where high levels of assurance are required and ser-

vice is essential.

1.5 Method Classification This standard describes test

methods by which both the surface conductors (and attach-

ment lands) and plated-through holes may be evaluated for

solderability. Test A, Test B, Test C, Test D and Test E for

tin/lead solder processes and Test A1, Test B1, Test C1,

Test D1 and Test E1 for lead-free solder processes, unless

otherwise agreed upon between vendor and user. Test A

and Test C for tin/lead solder processes, Test A1 and Test

C1 for lead-free solder processes are to be used as a default

solderability tests.

Provisions are made for this determination to be performed

at the time of manufacture, at the receipt of the boards by

the user, or just prior to assembly and soldering. User and

vendor shall agree to the appropriate method to be used

and their correlation.

Standard dwell times are deﬁned in some of the methods

called out in this standard. Variations in board heat capac-

ity may necessitate the use of longer solder dwell times

(see 6.2). Any change in solder dwell shall be agreed upon

by user and vendor.

1.5.1 Visual Acceptance Criteria Tests

Tin Lead Solder Alloy

Test A – Edge Dip Test For surface conductors and

attachment lands only (see 4.2.1)

Test B – Rotary Dip Test For plated-through holes, sur-

face conductors and attachment lands, solder source side

(see 4.2.2)

March 2007 IPC J-STD-003B

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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