IPC J-STD-003B - 第39页

which promote global standardization for the electronics industry . The standard activated ﬂux composition selected and tested by the committees has been utilized in the International Electrotechnical Commission (IEC) 60…

APPENDIX E

J-STD-002/J-STD-003 Activated Solderability

Test Flux Rationale Committee Letter

The current J-STD-002/J-STD-003 speciﬁcation includes a

departure in the test ﬂux methodology used in past solder-

ability testing. The table in 3.2.2 Flux is:

The J-STD-002/J-STD-003 committees understood that

any proposed change to the use of ROLO (formerly desig-

nated type R) would be heavily scrutinized and would

require test data showing the applicability of using a stan-

dard activated ﬂux composition. The J-STD-002/J-STD-

003 has spent signiﬁcant resources working this ﬂux

change issue, discussing the chemistry details and conduct-

ing multi-company Design of Experiment investigations.

The J-STD-002 committee chairmen, Dave Hillman [Rock-

well Collins], Doug Romm [Texas Instruments], Mark

Kwoka [Intersil], Jack McCullen [Intel], feel that the com-

mittee has compiled a signiﬁcant data set and held through

topic discussions supporting the proposed ﬂux material

change. The four rationales for proposing/supporting the

ﬂux change are summarized below:

1) A Proactive Solderability Testing Approach To The

Implementation of Non-Tin Finishes

A number of industry studies (1996 NEMI Surface Fin-

ishes Task Group Report, 1997 NCMS Lead-Free Solder

Project, 2000 National Physical Laboratory CMMT (A)

284 Report) have shown that an incompatibility of ‘‘R

type’’ ﬂux with non-tin surface ﬁnishes such as palla-

dium, organic solderability preservatives (OSPs), and

immersion gold. The introduction of these various

metallic surface ﬁnishes on components and printed wir-

ing boards is no longer the exception but has/is quickly

becoming the norm. The use of a ‘‘R type’’ ﬂux contain-

ing only naturally occurring activators has resulted in

producing ‘‘false negative’’ solderability test results

which impact both the component/board fabricator and

the assembler negatively in terms of cost and schedule.

2) Reduced Solderability Test Variability

The J-STD-002/003 solderability committees enlisted

the assistance of Dr. Carol Handwerker and the

resources of the National Institute of Standards & Tech-

nology (NIST) to investigate/compare a standard acti-

vated ﬂux composition versus the ‘‘R type’’ ﬂux compo-

sition. A detailed statistical analysis by Bill Russell,

Raytheon Systems, and NIST statisticians revealed the

use of a standard activated ﬂux composition greatly

reduced the amount of solderability test variation. One

of the major goals of the J-STD-002/003 solderability

committees is to develop test methods and standards

which promote consistency across the industry.

3) Concerns of A Loss of Solderability Assessment

Safety Margin

The two major historical rationale for using an ‘‘R

type’’ ﬂux: 1) colophony or rosin contains only naturally

occurring ﬂux activator constituents and thus is not sub-

jected to the problems/complications of chemistry for-

mulas by the ﬂux supplier; 2) it was an accepted indus-

try acknowledged fact that if a component or printed

wiring board surface was found to have acceptable sol-

derability test results using ‘‘R type’’ ﬂux then the more

active ﬂux formulations used in the assembly process

would produce acceptable solder process results. This

solderability assessment safety margin was a self

imposed, industry consensus decision. The J-STD-002/

003 committees understood the historical relevance

behind the decision to use ‘‘R type’’ ﬂux and had a

equally strong desire to maintain a solderability assess-

ment safety cushion. However, committees ﬁelded a

number of industry inputs to reassess the solderability

ﬂux composition based on the technology improvements

in surface ﬁnishes, improvements in the ﬂux chemistry

formulations from ﬂux suppliers, and the desire to not

have excessive safety margin which would impact cost

and schedule in an non-value added manner. The com-

mittees conducted a number of tests (Wenger, Kwoka,

ACI) demonstrating, using a speciﬁc standard level of

activation on real world, industry supplied component

and printed wiring board cases, that the occurrence of a

‘‘false acceptable’’ solderability test result was

extremely low. There was no case that exhibited a ‘‘pass

ROL1 test - fail ROL0 test - Fail during board assembly

‘‘sequence. In fact the use of both ROL1 and ROL0 are

more likely to create a ‘‘false reject ‘‘dip and look sol-

derability test result when compared to board level sol-

dering performance.

4) Standardization of Solderability Test Flux Composi-

tion On A Global Scale

A second major goal of the J-STD-002/003 solderability

committees is to develop test methods and standards

Table 3-1 Flux Composition

Constituent

Composition by

Weight Percent

Flux #1 Flux #2

Colophony 25 ± 0.5 25 ± 0.5

Diethylammonium hydrochloride

(CAS 660-68-4)

0.15 ± 0.01 0.39 ± 0.01

Isopropyl Alcohol (IPA) Balance Balance

Weight of Chlorine as % of solids 0.2 0.5

IPC J-STD-003B March 2007

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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which promote global standardization for the electronics

industry. The standard activated ﬂux composition

selected and tested by the committees has been utilized

in the International Electrotechnical Commission

(IEC) 60068-2-20 Soldering speciﬁcation. The IEC

speciﬁcation is successfully utilized for solderability

testing. Having compatibility of ﬂux composition

requirements between the J-STD-002/003 speciﬁcation

and the IEC speciﬁcations is a win-win situation for

electronics assemblers and component/printed wiring

board fabricators.

A number of the major ﬂux chemistry suppliers have

been queried on the electronics industry ability to pur-

chase the standard activated ﬂux composition and a

positive response was received. If you have any ques-

tions please contact the IPC Technical Staff to obtain

additional answers/clariﬁcation.

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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IPC J-STD-003B March 2007

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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