IPC-TM-650 EN 2022 试验方法.pdf - 第205页

1 Scope This test method is used to determine the con- centration of fluorides in soldering flux. The fluoride content is reported as the weight percentage of fluoride to the non- volatile portion of the flux. Ion specif…

Scope

This

test method is designed to determine the

presence (if any) of fluoride(s) in soldering flux by visual exami-

nation after placement of a drop of liquid test flux in a zirco-

nium - alizarin purple lake.

Applicable Documents

IPC J-STD-004

Requirements

for Soldering Fluxes

Test Specimen

3.1

minimum of 10 ml of first article or production speci-

men of liquid flux, solder paste, paste flux, or extracted flux

from preform or wire.

3.2

The

extraction of preforms or wire should be carried out

in accordance with J-STD-004.

3.3

For

paste flux or solder paste, dilute the sample in

2-propanol or another suitable solvent. A minimum amount of

solvent should be used just allowing for the sample to be

dropped from a dropper.

Note: The solvent used in dilution/extraction must be water

miscible.

Apparatus and Reagents

4.1 Apparatus

4.1.1

White

spot plate

4.1.2

Glass

droppers

4.1.3

Glass

rods

4.2

Reagents

4.2.1

Zirconium nitrate solution: 0.05 g dissolved in 50 ml of

deionized water.

4.2.2

Sodium

alizarin sulfate solution: 0.05 g dissolved in 50

ml of deionized water acidified with 10 ml of hydrochloric acid.

Procedure

5.1 Preparation

Prepare

a fresh zirconium - alizarin purple

lake in three spots of the white spot plate by adding one drop

each of zirconium nitrate and sodium alizarin sulfate solutions.

5.2

Test

5.2.1

Add

one drop of the test flux to each of the spots.

5.2.2

Mix

each spot with a clean glass rod.

5.2.3

Examine

for any color change.

5.3

Evaluation

change in color of the lake from purple to

yellow is an indication of the presence of fluoride(s). A color

change is typically seen at concentrations between 100 and

150 parts per million fluoride.

Notes

6.1 Safety

Observe

all appropriate precautions on MSDS

for chemicals involved in this test method.

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.35.1

Subject

Fluorides

By Spot Test, Fluxes-Qualitative

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.

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Scope

This

test method is used to determine the con-

centration of fluorides in soldering flux. The fluoride content is

reported as the weight percentage of fluoride to the non-

volatile portion of the flux. Ion specific electrodes are used for

the determination. This method uses Orion equipment and

solutions.

Applicable Documents

IPC-TM-650

Test

Methods Manual

2.3.34 Solids Content, Flux

IPC-J-STD-004

Requirements

for Soldering Fluxes

Test Specimen

3.1

minimum of 50 ml of first article or production speci-

men of liquid flux or prepared flux solution.

3.2

For

solid or paste flux, 50 ml of the diluted material.

3.3

For

solder paste, preform, and cored wire, 50 ml of the

extracted flux.

3.4

The

solids content of the sample must be known or

determined by IPC-TM-650, Test Method 2.3.34.

Note: Recommended procedures for dilution of solid or paste

flux, and extraction of solder paste, cored wire, or preforms,

can be found in J-STD-004.

Apparatus and Reagents

4.1 Apparatus

4.1.1

Autocalibrating

ion analyzer.

4.1.2

Fluoride

specific electrode.

4.1.3

Double

junction reference electrode.

4.1.4 Magnetic

stirrer and stir bars.

4.1.5

250

ml and 500 ml beakers, glass or polypropylene.

4.1.6 Funnel

stand and funnel.

4.1.7

ml graduated cylinders.

4.1.8

100

ml and 1000 ml volumetric flasks.

4.1.9

ml and 100 ml pipettes.

4.1.10

Analytical

balance capable of 0.001 g.

4.2

Reagents

4.2.1

Deionized

water with a resistivity of at least 18.0

megohm centimeter.

4.2.2

Sodium

fluoride, reagent grade.

4.2.3 Chloroform,

reagent grade.

4.2.4

Total

ionic strength adjustment buffer.

4.2.5

Whatman

#41 ashless filter paper, or equivalent.

Procedure

5.1 Sample Preparation - Water Soluble Flux

Depend-

ing

on the expected concentration of fluoride, use the follow-

ing amount of sample and deionized water.

ppm

Fluoride Sample ml DI Water ml

0.1-1.0

25 50

1.0-10.0 5 50

5.1.1

Tare

a beaker and add sample. Record the weight of

the flux to 0.001 gram.

5.1.2

Add

DI water and mix with stirrer for 10 minutes. Stop

mixing and allow to stand for five minutes.

5.1.3

Pour

solution through filter paper in funnel into a clean

beaker. Allow sample to drain completely.

5.2

Sample Preparation - Nonwater Soluble Flux

5.2.1

Depending

on the expected concentration of fluoride,

use the following amount of sample and chloroform.

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.35.2

Subject

Fluoride

Concentration, Fluxes-Quantitative

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.

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ppm

Fluoride Sample ml Chloroform ml

0.1-1.0

25 25

1.0-10.0 5 5

5.2.2

Tare

a beaker and add sample. Record the weight of

the flux to 0.001 gram.

5.2.3

Add

chloroform and 50 ml DI water and mix with stir-

rer for 10 minutes. Stop mixing and allow to stand for five

minutes.

5.2.4

Carefully

decant the water solution through filter paper

in funnel into a clean beaker. Allow sample to drain com-

pletely.

5.3

Standard Solutions

5.3.1

ppm fluoride (0.001%) – This standard can be pur-

chased ready-to-use. Alternately, a solution can be prepared.

Weigh 0.0221 gram reagent grade NaF (dried to 140 °C

[284 °F]). Add 500 ml DI water. Dilute to one liter in a volumet-

ric flask with total ionic strength adjustment buffer (TISAB).

5.3.2 1.0

ppm fluoride (0.0001%) – This standard can be

purchased ready-to-use. Alternately, a solution can be pre-

pared. Weigh 0.0023 gram reagent grade NaF (dried to

140 °C [284 °F]). Add 500 ml DI water. Dilute to one liter in a

volumetric flask with TISAB.

5.3.2.1

Another

method is to dilute 100 ml of 10 ppm fluo-

ride standard with 450 ml DI water and dilute to one liter in a

volumetric flask with TISAB.

5.3.3

0.1

ppm fluoride (0.00001%) – This standard is pre-

pared by diluting 100 ml of 1.0 ppm fluoride standard with

450 ml DI water and diluting to one liter in a volumetric flask

with TISAB.

5.3.3.1

Another

method is to dilute 10 ml of 10 ppm fluoride

standard with 495 ml DI water and dilute to one liter in a volu-

metric flask with TISAB.

5.4

Double Reference Electrode Filling Solutions

Inner

chamber filling solution saturated with AgCl.

Outer chamber filling solution filled with 10% KNO

5.5

Test

For

accurate results, allow all samples and stan-

dards to reach the same temperature before attempting a

measurement. Stir the samples and standards while a mea-

surement is being made.

5.5.1

Prepare

two standards that differ in concentration by

a factor of 10. The standards should bracket the expected

sample concentration.

5.3.2

Dilute

50 ml of the two standard solutions, each with

50 ml of DI water.

5.5.3

While

stirring with a magnetic stirrer, immerse elec-

trodes in the more dilute standard solution.

5.5.4

Remove

and rinse electrodes with DI water. Immerse

electrodes in the more concentrated standard solution.

5.5.5

the sample prepared per instructions for water

soluble flux, add 25 ml TISAB. While stirring, immerse elec-

trodes. Record indicated value.

5.6

Evaluation

The

fluoride value is typically displayed in

parts per million (ppm) fluoride. To obtain fluoride as weight

percentage of the nonvolatile content, use the following for-

mula:

Fluoride % of Solids =

(MS)100

Where:

is indicated value in ppm

M is mass of the flux sample in grams

S is the percentage of solids (nonvolatile chemicals) in the flux

sample

Notes

6.1 Standardization and Limits

Restandardization

should

be done every few hours or as recommended by the equip-

ment manufacturer to compensate for electrode drift.

6.1.1

Reproducibility is typically ± 2% obtainable with hourly

recalibration. Temperature fluctuation, drift and noise will limit

reproducibility.

6.1.2

Detection

limits are 0.02 ppm minimum and no known

maximum. A list of possible interfering ions has not yet been

determined for this electrode method.

6.1.3

Using

the same batch of DI water for dilutions will

eliminate the need to run blanks.

IPC-TM-650

Number

2.3.35.2

Subject

Fluoride

Concentration, Fluxes-Quantitative

Date

06/04

Revision

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