IPC-TM-650 EN 2022 试验方法.pdf - 第196页

5.2.4 Immediately also place one drop of the control stan- dard flux adjacent to the test flux. Do not allow the drops to touch. 5.2.5 Place the test panel in a horizontal position in the dust free cabinet at 23 ± 2 °C […

Scope

This

test method is designed to determine the

removal effect the flux has (if any) on the bright copper mirror

film which has been vacuum deposited on clear glass.

2 Applicable Documents

IPC J-STD-004

Requirements

for Soldering Fluxes

ASTM

E104

Maintaining

Constant Relative Humidity by

means of Aqueous Solutions

Federal

Speciﬁcation LLL-R-626

Rosin,

Gum, Rosin Wood

and Rosin Tall Oil

Test Specimen

minimum of 10 ml of liquid flux, a rep-

resentative container of solder paste, dissolved paste flux,

extracted solder preform flux or extracted cored wire flux. The

reflow/extraction process should be carried out in accordance

with J-STD-004.

Apparatus and Reagents

4.1

Control

standard rosin flux, class A, type II, grade WW,

of Federal Specification LLL-R-626.

4.2

Reagent

grade (99% pure) 2-propanol.

4.3

Copper

Mirrors (see 6.2 and 6.3).

4.4

500

ml of reagent grade 0.5% solution of ethylene

diamine tetra acetic acid (EDTA).

4.5 Reagent

grade ethanol or methanol.

4.6

Deionized

water with a resistivity of at least 18.0

megohm centimeter.

4.7

Glass

dropper.

4.8

Test

cabinet capable of achieving 23 ± 3 °C [73.4 ±

5.4 °F] and 50 ± 5% relative humidity.

4.9

relative humidity gauge havinga±2%accuracy, or

better, shall be used to continuously monitor the test environ-

ment. The gauge should be calibrated periodically.

Procedures

5.1 Preparation

5.1.1 Control Standard Flux

Dissolve

35 g of Federal

Specification LLL-R-626 rosin into 100 ml of reagent grade

(99% pure) 2-propanol and stir thoroughly.

5.1.2

Temperature/Humidity Chamber

When

acid or salt

solutions (such as reported in ASTM E104) are used, the envi-

ronment shall be monitored for a minimum of 48 hours prior

to exposing the copper mirror samples, to assure compliance

with the 50% ± 5% relative humidity requirement.

5.1.3

Copper Mirror Test Panels

5.1.3.1

Immediately

before testing, immerse the copper mir-

ror in a 5 g/l solution of EDTA for one minute for copper oxide

removal. Mirrors stored in a nonoxidizing environment do not

require cleaning with the EDTA solution prior to testing. The

cleaning step must be used if test results are in dispute.

5.1.3.2

Rinse

the mirror thoroughly in running deionized

water, immerse in clean ethanol or methanol, and dry with

clean, oil free air.

5.1.3.3

Carefully

examine the mirror before testing. There

must be no oxide.

5.2

Test

5.2.1

Place

the copper mirror test panel on a flat surface,

mirror side up, and protect from dust and dirt at all times.

5.2.2

Place

one drop of test flux or extract to be tested

(approximately 0.05 ml) on the copper mirror test panel. Do

not allow the dropper to touch the test panel.

5.2.3 Apply

solder paste directly to the mirror without

scratching the copper surface. Use a volume approximating

0.5 mm [0.197 in] thickness and 8.0 mm [0.350 in] diameter.

(It has been determined that significant variations from this

quantity have little effect for most materials.)

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.32

Subject

Flux

Induced Corrosion (Copper Mirror Method)

Date

06/04

Revision

Originating Task Group

Flux Specification Task Group (5-24a)

Material

in this Test Methods Manual was voluntarily established by Technical Committees of IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by IPC.

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5.2.4

Immediately

also place one drop of the control stan-

dard flux adjacent to the test flux. Do not allow the drops to

touch.

5.2.5

Place

the test panel in a horizontal position in the dust

free cabinet at 23 ± 2 °C [73.4 ± 3.6 °F] and 50 ± 5% relative

humidity for 24 ± 1/2 hours.

5.2.6 At

the end of the 24 hour period, remove the test

panel and remove the test flux and control standard flux by

immersion in clean 2-propanol.

5.3

Evaluation

5.3.1

Carefully

examine the test panel for possible copper

removal or discoloration.

5.3.2

See

J-STD-004 for evaluation criteria.

5.3.3

the control flux fails the L category, repeat the entire

test using a new copper mirror test panel.

5.3.4

Discoloration

of the copper film due to a superficial

reaction or only a partial reduction of the copper film thickness

is not considered a failure.

5.3.5

number of chemicals can cause failure of copper

mirror: free halides, stronger organic and inorganic acids and

free amines.

Notes

6.1 Safety

Observe all appropriate precautions on MSDS

for chemicals involved in this test method.

6.2

Preparation of Copper Mirrors

6.2.1

Apply,

by vacuum deposition, a film of copper metal

on one surface of a flat sheet of clear, polished glass.

6.2.2

Apply

a uniform thickness of approximately 50 nm,

and assure that the finished mirror permits 10 ± 5% transmis-

sion of normal incident light of nominal wave length of 500

nm. This may be determined using a suitable photoelectric

spectrophotometer.

6.2.3

Prevent

oxidation of the copper mirror by storing in a

closed container which has been flushed with nitrogen.

IPC-TM-650

Number

2.3.32

Subject

Flux

Induced Corrosion (Copper Mirror Method)

Date

06/04

Revision

age2of2

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Scope

This

qualitative test method is designed to deter-

mine the presence of chlorides and bromides in soldering flux

by visual examination after placement on test paper.

Applicable Documents

IPC J-STD-004

Requirements

for Soldering Fluxes

Test Specimen

minimum of 10 ml of liquid flux, a rep-

resentative container of solder paste, reflowed solder paste

flux, extracted solder preform flux or extracted cored wire flux.

The reflow/extraction process should be carried out in accor-

dance with J-STD-004.

Apparatus and Reagents

4.1

Six

pieces of silver chromate test paper 51 mm x

51 mm.

4.2

250

ml of reagent grade 2-propanol.

4.3

Six

glass microscope slides.

4.4

Spatula.

Procedures

5.1 Preparation

5.1.1

The

silver chromate paper is extremely light sensitive

and must be stored in a closed container away from light until

used for testing.

5.1.2

avoid contamination, the paper must be handled

with forceps and must never be touched with bare hands.

5.2

Test for Liquid Flux or Flux Extract Solution

5.2.1

Place

one drop of test flux or flux extract (approxi-

mately 0.05 ml) on each piece of silver chromate test paper.

Allow the droplet to remain on each test paper for a minimum

of 15 seconds.

5.2.2

After

the 15 seconds, immediately immerse each test

paper in clean 2-propanol to remove the residual organic

materials.

5.2.3

Allow

each test paper to dry and examine for color

change.

5.3

Test for Paste Flux or Solder Paste Flux as Obtained

from the Supplier

5.3.1

Clean

six glass microscope slides with 2-propanol and

air dry.

5.3.2

Moisten

each piece of silver chromate reagent paper

with deionized water.

5.3.3

Apply

a wet paper to each glass slide and remove the

excess water with blotting paper.

5.3.4

Using

a spatula, apply a thin coating of the paste flux

or solder paste directly onto each moist reagent paper.

5.3.5

Allow

the paste flux or solder paste to remain in con-

tact with the paper for 15 seconds, then remove the flux with

2-propanol or other appropriate solvent without disturbing the

paper.

5.3.6

Allow

each test paper to dry and examine for color

change.

5.4

Evaluation

Carefully

examine each test sheet for pos-

sible color change. A change to off-white or yellow-white indi-

cates the presence of chlorides or bromides (see Figure 1).

5.4.1

Interferences

number of chemicals besides free

halides may cause test failures. (Representative examples are,

but are not limited to, amines, cyanides, and isocyanates.)

5.4.2

Certain

acidic solutions may react with the reagent

paper to produce a color change similar to that obtained with

chlorides and bromides. When a color change is observed, it

is advisable to check the acidity of the affected area by means

of a pH indicating paper. If pH values of less than 3 are

obtained, the presence of chlorides and bromides should be

verified by other analytical means.

5.4.3

is possible that the metal present in a solder paste

sample may leave a white residue that is difficult to distinguish

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.33

Subject

Presence

of Halides in Flux, Silver Chromate

Method

Date

06/04

Revision

Originating Task Group

Flux Specifications Task Group (5-24a)

Material

in this Test Methods Manual was voluntarily established by Technical Committees of IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by IPC.

age1of2

ASSOCIA

TION CONNECTING

ELECTRONICS INDUSTRIES

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ