IPC-TM-650 EN 2022 试验方法.pdf - 第124页

1.0 Scope This test method is designed for use in deter- mining the resistance of core (dielectric) materials used in printed wiring boards to methylene chloride at laboratory ambient temperature. 2.0 Applicable document…

pan.

If the balance door is closed immediately after sample

entry and exit, 50 ± 5% RH can be maintained.

Verification of conditions in the enclosure during a simulated

test can be made using a rapid response humidity probe;

however, this should be done with unconditioned specimens

since solvents will affect the response of many humidity

probes.

6.2.6

Temperature Considerations

The

effect of the sol-

vent temperature on results is severe. A variation of 5°C[9°F]

can result in an error as high as 50% relative to values deter-

mined at 23°C [73°F].

6.3

Consideration of Other Test Parameters

6.3.1 Using Same Solvent

Shorter

dwell times, e.g., 3

minutes, generally result in better discrimination between

material of varying chemical resistance. However, test variabil-

ity is generally increased. Shorter tests are excellent for side

by side comparisons of materials.

Longer tests, e.g., 30 minutes, often do not differentiate

adequately between materials, and while useful on homoge-

neous material, variability on material with surface coatings

may be excessive.

6.3.2

Other Solvent Blends

Other

solvents and various

methylene chloride based combinations have been commonly

used in the industry. However, results and precision of the test

may vary significantly and the added problem of variability in

solution make-up is introduced.

6.4

Supercession

This

test method supersedes 2.3.4.2,

dated 5/86, and 2.3.4.3, dated 5/86.

6.5

Desiccator Conditions

The

Test Methods Task Group

determined that a great majority of test laboratories are unable

to consistently hold the Relative Humidity in a desiccator to

less than 20%. Based on data from participating company lab

management, the lowest practically feasible RH for use with

the affected IPC Test Methods is 30% maximum.

IPC-TM-650

Number

2.3.4.2

Subject

Chemical

Resistance of Laminates, Prepreg, and Coated Foil

Products, by Solvent Exposure

Date

12/94

Revision

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1.0

Scope

This

test method is designed for use in deter-

mining the resistance of core (dielectric) materials used in

printed wiring boards to methylene chloride at laboratory

ambient temperature.

2.0

Applicable documents

IPC-TM-650

Method

2.3.6, Etching, Ammonium Persulfate

Method

IPC-TM-650

Method

2.3.7, Etching, Ferric Chloride Method

IPC-TM-650

Method

2.3.7,1, Etching, Cupric Chloride

Method

3.0

Test specimens

3.1 Dimensions

The

test specimens shall be 2.00 in. x

2.00 in. X thickness of material. Tolerance on the 2.00 in.

dimensions shall be ± .03 in.

3.2

Edge finish

The

edges of the specimens shall be

milled or sanded smooth with 400 grit sandpaper.

3.3

Number of specimens

Three

specimens shall be used

for this test.

3.4

Removal of metal cladding

The

metal cladding shall

be removed by etching per IPC-TM-2.3.6, 2.3.7, 2.3.7.1 or

other suitable method which does not affect the surface of the

pressed sample.

4.0

Apparatus

4.1 Oven

Circulating

air oven capable of maintaining a uni-

form temperature of 105° to 110°C (221° to 230°F).

4.2

Desiccator

4.3 Analytical balance

5.0 Procedure

5.1 Conditioning

The

specimens shall be conditioned by

drying in an oven for 1 hour at 105° to 110°C (221° to 230°F),

then cooled to room temperature in a desiccator.

5.2

Fill

a 3000 ml beaker with methylene chloride to a depth

of 3 in. and maintain at 23°±2°C in a well-ventilated fume

hood. Place a rack in the bottom of the beaker to hold the

samples upright and apart.

5.3

Exposure

Remove

each specimen from the desiccator

and immediately weigh to the nearest 0.1 milligram, recording

the initial weight as ‘‘A’’. Immerse each specimen in the meth-

ylene chloride for 30 ± 0.5 minutes. Remove from the beaker,

air dry for 10 minutes ± 30 seconds, weigh immediately and

record the final weight as ‘‘B.’’ Drying time includes weighing

time.

5.4

Evaluation

5.4.1 Calculation

Calculate

and record the percent

change in weight for each specimen to the nearest 0.01 per-

cent as follows:

Change in weight, percent =

B − A

100

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.4.3

Subject

Chemical

Resistance of Core Materials to

Methylene Chloride

Date

5/86

Revision

Originating Task Group

N/A

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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1.0

Scope

determine the quality of the dielectric mate-

rial after etching with ammonium persulfate.

2.0

Applicable Document

None.

3.0

Test Specimen

Specimen

2 in. x 2 in. X thickness of

one ounce or two ounces copper clad.

4.0

Apparatus

4.1 Heated Electrical Equipment

for

etching the speci-

men.

4.2

Air Circulating Chamber

capable

of maintaining 80°C ±

3°C (176°F).

4.3

Equipment and Chemicals

needed

to perform this test

are as follows: Rubber or polyethylene gloves, lint-free cloth,

grade FFF pumice and plastic scrubbing brushes, distilled

water, 10% solution oxalic acid, ammonium persulfate solu-

tion, methylethyl ketone, toluol, and trichlorethylene.

5.0

Procedure

5.1 Preparation of Specimen

Remove

rough edges from

the specimen by sanding or other suitable means.

5.2

Etching

Etch

specimen with vigorous agitation for the

minimum time in 66° BAUME ammonium persulfate solution

monitored at 43°C ± 3° (109.4°F). After removal of the copper,

immediately wash the specimen with running tap water for 2

to 5 minutes and keep the specimen from drying until the

specimen is placed in the chamber. Immerse the specimens

in a 10% solution of oxalic acid in distilled water 25°C ± 8°

(77°F) for 15 to 20 minutes providing gentle circulation of the

oxalic acid solution during this period. Flush the specimen

with tap water for 2 to 5 minutes, then scrub the specimens

with pumice to remove resist. Wipe the resist off with a lint free

cloth moistened with a suitable solvent. Scrub the specimen

with a plastic bristled brush under running tap water for 2 to 5

minutes. Rinse the specimen again in distilled water.

5.3

Condition

Dry

the specimens for 1 hour in a chamber

maintained at 80°C (176°F). If specimens are for electrical

tests, handle only with rubber or polyethylene gloves.

5.4

Evaluation of Test

Examine

specimens for white

deposits or other surface contaminants, loss of surface resin,

softness, delaminations, blistering or measling. Clad speci-

mens also should be evaluated for blisters or delamination of

the copper foil.

6.0 Notes

6.1

the etching time exceeds 15 minutes for 1 ounce cop-

per or 30 minutes for 2 ounces copper, renew the etching

solution.

6.2

Oxalic

acid is very toxic and extreme care should be

exercised.

6.3

The

time to produce a clean pattern with a minimum of

undercutting is approximately 7 minutes for 1 ounce copper

and 15 minutes for 2 ounces copper, using fresh solution.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.6

Subject

Etching

Ammonium Persulfate Method

Date

7/75

Revision

Originating Task Group

N/A

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.

age1of1

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