IPC-TM-650 EN 2022 试验方法.pdf - 第385页

1.0 Scope This test method specifies a qualitative method for assessment of the tackiness of soft soldering flux residues. The method is applicable to fluxes of types L and M. the method is particularly appropriate for a…

5.2.5

Remove

the coupon in a horizontal position and place

on a flat surface, allowing the melted solder to solidify undis-

turbed.

5.2.6

Repeat

steps 5.2.2 through 5.2.5 to test four addi-

tional specimens.

5.2.7

Use

a suitable solvent to remove all flux residue from

the test coupons.

5.3

Evaluation

5.3.1

Measure

each solder spread area by comparing to

circles (predrawn) with areas similar to those listed in Table 1.

Report the mean of the spread (area in mm

)

of the five tested

specimens.

Table 1 is intended as an aid in defining areas in mm

able 1 Typical Spread Areas Deﬁned in mm

Diameter

in mm Area in mm

10.00

78.54

10.70 90.00

11.28 100.00

6 Notes

6.1 Safety

Observe

all appropriate precautions on MSDS

for chemicals involved in this test method.

IPC-TM-650

Number

2.4.46

Subject

Spread

Test, Liquid, Paste or Solid Flux,

or Flux Extracted from Solder Paste, Cored

Wires or Preforms

Date

06/04

Revision

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1.0

Scope

This

test method specifies a qualitative method

for assessment of the tackiness of soft soldering flux residues.

The method is applicable to fluxes of types L and M. the

method is particularly appropriate for applications where flux

residues are left in place on soldered electronic and electrical

equipment.

2.0

Applicable Documents

ISO 1634

Wrought-Copper

and Copper Alloy Plate; Sheet

and Strip

ISO

9453

Soft

Solder Alloys

ISO

9455

Parts

1 and 2 Soft Soldering Fluxes

3.0

Test Specimen

minimum of 0.035 grams by weight

is required per test for fluxes in solid or paste form. For liquid

fluxes, a volume sufficient to contain a minimum of 0.035

grams of non-volatile matter is required per test. For samples

of flux cored solder, a minimum 1 gram is required per test

and for solder paste, a minimum of 0.5 grams is required per

test.

4.0

Apparatus and Reagents

4.1 General

the test use only reagents of recognized

analytical quality and only distilled, or deionized, water.

4.2

Acid Cleaning Solution

Add

cautiously, with stirring,

75 ml of sulfuric acid (density 1.84 g/ml) to 210 ml of water

and mix. Cool, add 15 ml of nitric acid (density 1.42 g/ml) and

mix the solution thoroughly.

4.3

Degreasing

solvent, such as 2-propanol, acetone, tolu-

ene or petroleum ether.

4.4 Powdered

chalk.

4.5

0.5

mm thick copper sheet complying with ISO 1634:

Part 1, grad Cu - ETP, condition HA.

4.6

Acetone

4.7

Solder

wire, or pellets, complying with QQ-S-ALLOY

XXX or ISO 9453 grade S-Sn60Pb40.

4.8

Solder

bath, either circular with diameter not less than

120 mm, or rectangular with dimensions not less than 100

mm X 75 mm, containing tin-lead solder having a liquidus less

than 200°C. The depth of the solder in the bath shall not be

less than 40 mm. The bath shall be capable of being main-

tained at a temperature of 235 +/-5°C.

4.9

Cupping

Device. This shall be fitted with a 27 mm diam-

eter die and a 20 mm diameter ball.

4.10

Drying

oven, suitable for use at 110 +-2°C.

4.11

Tongs,

or other suitable mechanical device, to lift the

test piece from the surface of the molten solder bath.

4.12

Soft

brush, of diameter approximately 7 mm.

4.13

Ordinary

laboratory apparatus.

5.0

Procedure

5.1 Preparation of Copper Test Pieces

5.1.1

From

the sheet of half hard copper, approximately 0.5

mm thick (4.5), cut test pieces each 50 mm X 50 mm.

5.1.2

Clamp each of the test pieces, in turn, centrally onto

the 27 mm die of the cupping device (4.9). Using the 20 mm

diameter ball, make a depression in the center of each test

piece 3 mm deep, by forcing the ball into the die. One corner

of the test piece may be bent up to facilitate handling with the

tongs.

5.1.3

Immediately

before the test, use the solvent (4.3) to

degrease each test piece, and immerse the test pieces for 20

seconds in the acid cleaning solution (4.2). Remove the test

pieces from the cleaning solution, wash well under running

water, rinse in acetone (4.6) and dry by air blowing at room

temperature.

5.1.4

Test

For solid, paste and liquid flux samples:

5.1.4.1

Weigh

1.00 +/-0.05g of the solder wire or pellets

(4.7), previously degreased in the solvent (4.3), and transfer it

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.47

Subject

Flux

Residue Dryness

Date

1/95

Revision

Originating Task Group

Flux Specifications Task Group (5-24a)

Material

in this Test Methods Manual was voluntarily established by Technical Committees of the 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 the IPC.

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the center of the depression in one of the cleaned copper

test pieces (5.1).

Note:

This

may conveniently be done, if solder wire is used,

by forming the wire into a tight spiral.

5.1.4.2

the flux under test is in solid or paste form—weigh

between 0.035g and 0.040g of the solid or paste flux and add

this to the solder in the depression of the test piece.

5.1.4.3

the flux under test is in liquid form—first determine

it’s non-volatile matter content by the use of the method

described in ISO 9455: Part 1 or Part 2. Then add the appro-

priate volume of the liquid flux, to contain between 0.035g and

0.040g of non-volatile matter, to the solder in the depression

of the test piece. Evaporate the solvent at 60°C for 10 minutes

in the drying oven (5.3).

Note:

the liquid flux has low non-volatile content, it may be

necessary to add the flux in two increments, carrying out the

evaporation procedure after each addition.

5.1.5

For

flux cored solder samples. Degrease the surface

of a suitable length of the cored solder sample, using a cloth

dampened with the solvent (4.3). Weigh 1.00 +/–0.05g of the

degreased sample, form it into a small flat coil and place it in

the center of the depression in one of the cleaned copper test

pieces (5.1).

5.1.6

For solder paste samples. Weigh 0.50 +/–0.05g of the

solder paste sample into the center of the depression in one

of the cleaned copper test pieces (5.1).

5.2

Heating

the test piece.

5.2.1

Using

the tongs (4.11), or other suitable means, care-

fully lower the prepared test piece from 7.1 onto the surface

of the molten solder, maintained at 235 +/–5°C in the solder

bath (4.8).

5.2.2

Allow

the test piece to float on the solder bath until the

solder melts and leave the test piece in this position for a fur-

ther 5 seconds. Remove the test piece carefully from the bath

and allow it to cool, in air, in a horizontal position for 30 min-

utes.

5.3

Examination

of the test piece. Dust the surface of the

flux residue on the test piece liberally with the powdered chalk

(4.4). Lightly brush the chalked surface with the soft brush

(4.12).

5.4

Evaluation

If the chalk powder is easily removed by

brushing, the flux is deemed to be ‘‘not tacky.’’ If the chalk

powder cannot be removed by brushing, or can be removed

only with difficulty, the flux is deemed to be ‘‘tacky.’’

IPC-TM-650

Number

2.4.47

Subject

Flux

Residue Dryness

Date

1/95

Revision

age2of2

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