IPC-TM-650 EN 2022 试验方法.pdf - 第728页

1.0 Scope This procedure is a rapid means for evaluating glass epoxy laminate integrity on different lots of base lami- nate materials before placing materials on the production floor, and thereby reducing the cost of pr…

held

for 30 minutes. The humidity should then be increased to

93%RH.

5.6.3.3

Expose specimen to the above environment for 240

hours (10 days). M and H fluxes may be tested in the cleaned,

as well as uncleaned, condition. Specimens shall be cleaned

per the manufacturers instructions.

5.7

Evaluation

5.7.1

After

the exposure period, remove test specimens

from humidity chamber, examine at 20X magnification and

compare with observations noted in 6.5 (see 8.2).

5.7.2

For

purposes of this test method, the following defini-

tion of corrosion shall prevail: ‘‘A chemical reaction between

the copper, the solder, and the constituents of the flux resi-

dues, which occurs after soldering and during exposure to the

above environmental conditions.‘‘ Corrosion for this test is

classified as follows:

5.7.2.1

Minor Corrosion

Any

initial change of color, which

may develop when the test panel is heated during soldering,

is disregarded. Discrete white or colored spots in the flux resi-

dues or a color change to green-blue without pitting of the

copper or formation of excrescences is regarded as

minor

corrosion.

5.7.2.2

Major Corrosion

Any

initial change of color which

may develop when the test panel is heated during soldering is

disregarded. Subsequent development of green-blue discol-

oration with observation of pitting of the copper panel or

excrescences at the interfaces of the flux residue and copper

boundary, is regarded as

major

corrosion.

Notes

6.1

Questionable

results may be confirmed by analyzing the

suspected corrosion via Energy Dispersive X-ray Spectros-

copy (EDS) for the presence of copper.

6.2

Color

photos before and after the test are valuable tools

in identifying and documenting corrosion.

6.3

Safety

Observe

all appropriate precautions on MSDS

for chemicals involved in this test method.

IPC-TM-650

Number

2.6.15

Subject

Corrosion,

Flux

Date

06/04

Revision

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1.0

Scope

This

procedure is a rapid means for evaluating

glass epoxy laminate integrity on different lots of base lami-

nate materials before placing materials on the production

floor, and thereby reducing the cost of processing material

which may later prove to be defective.

2.0

Applicable Documents

IPC-A-600

Acceptability

of Printed Boards

IPC-MI-660

Guidelines

for Incoming Inspection of Raw Mate-

rials

3.0

Specimens

The

samples of qualification or incoming

production test coupons shall be 4.0 inch x 4.0 inch x 1/16

inch thick (see 7.1) and etched using the standard commer-

cial practices procedure of the individual test facility. The test

coupons can be taken from any part of the laminate. The test

strip may be sheared, but the individual test coupons shall be

sawed and their edges sanded.

4.0

Number of Test Coupons to be Tested

Five

coupons

shall be tested and may arbitrarily contain a known ‘‘pass’’

and ‘‘fail’’ control coupon. However, if a failure mode is estab-

lished, a second set of 5 samples shall be tested from another

laminate and this set must contain a pass and fail control. The

number of test coupons tested at any one time should be lim-

ited to the capacity of the pressure vessel being used.

5.0

Apparatus

5.1

Any

standard laboratory autoclave pressure vessel hav-

ing a 6-quart capacity. A commercial household 6-quart stain-

less steel pressure cooker capable of developing 15 psi pres-

sure (the 15 psi pressure set at the location of the test) may

be used if equipped with a properly calibrated pressure gauge

to maintain 15 psi ± 0.5 psi pressure.

5.2

laboratory solder pot capable of maintaining a solder

bath (SN 60) at 500°F–0°+10°F.

5.3

Stop

watch.

5.4 Solder

pot containing SN 60/40 solder.

6.0

Test

6.1 Preparation

6.1.1

Cut test coupons only by sawing, and sand the edges

of the specimens so they are smooth.

6.1.2

Etch

specimens to remove metal foil except in any

areas which may have identification codes.

6.1.3 Apply

permanent identification markings on speci-

mens on the end that will not be immersed in the solder pot.

6.1.4

The

specimens will be placed in a suitable rack for

suspending in the pressure vessel. The specimens should not

be drilled for suspension as this creates a path for moisture

incursion, giving false results.

6.1.5

Pour

water into pressure vessel to approximately 1.0

inch depth. Cover and bring to a boil without pressurizing.

6.2

Test

6.2.1

When

steam is observed at the vent, uncover and

suspend specimens vertically over boiling water, being careful

not to allow specimens to touch each other or the walls of the

pressure vessel. This step must be done rapidly to avoid

undue cooling of the water and pressure vessel.

6.2.2

The

heat-up time should be controlled at 7 minutes ±

1 minute.

6.2.3

After

reaching 15 psi. maintain this condition for 30

minutes+2–0minutes.

Note:

Other

pressure vessel dwell times may be agreed upon

between user and vendor.

6.2.4

the end of the exposure time, cool and vent the

pressure vessel as recommended by the manufacturer.

6.2.5

Carefully

remove the hot specimens from the pressure

vessel and blot dry with paper towel (see caution notes).

6.2.6

The

specimens shall be maintained at ambient tem-

perature, and within 10 minutes it shall be immersed vertically

(with the edge parallel to the solder surface) into the solder

bath which is maintained at either 500°F–0+10°F for 20

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.6.16

Subject

Pressure

Vessel Method for Glass Epoxy Laminate

Integrity

Date

7/85

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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seconds.

Immersion and withdrawal rates should not exceed

2 seconds. Do not allow test coupons to touch bottom of sol-

der bath.

Note:

Other

solder bath temperatures maybe agreed upon by

user and vendor.

6.3 Evaluation

6.3.1

not evaluate areas within 1/8 inch from all edges,

including solder line.

6.3.2

Grading

Grade

specimens on the evaluation scale of

5 through 1 (below) according to degree of severity of the

attack. In order for the grading to be more meaningful, the

tester should also provide comments on the overall specimen

appearance. For additional description and illustrations of

measles, blisters, weave texture, delamination, etc., refer to

IPC-A-600, Acceptability Guidelines for Printed Wiring.

alue Condition

The samples have no measles, blisters, or sur-

face erosion.

4 Occasional minute (1/32 inch or less) measles.

3 Minute measles scattered across the speci-

men.

2 Occasional minor blisters (two to four adjacent

weave intersections).

1 Large blisters, delamination, or convolution.

If five test coupons are evaluated, the test may use a total

performance points-rating (e.g.,5x5=25).

7.0 Notes

7.1

This

test method is developed for 1/16 inch thick mate-

rial. Different results are to be expected for other thicknesses.

Therefore, the time of exposure and grading values may

change for different thicknesses and must be agreed upon

between user and vendor.

7.2

Warning

Pressure

vessel must always be opened with

extreme caution to be certain pressure has been released.

7.3

Warning

Samples

could retain some moisture. There-

fore, care should be taken in immersing the sample in the sol-

der bath. It is recommended that the operator work behind a

suitable protective screen and use a glove to protect the hand

holding the sample. The wet specimens will react violently

during the immersion into the solder pot, splaying and sput-

tering bits of molten solder about the fume hood. Proper pre-

cautionary measures must be taken.

IPC-2616-1

CONDITION

IPC-2616-2

CONDITION

IPC-TM-650

Number

2.6.16

Subject

Pressure

Vessel Method for Glass Epoxy Laminate Integrity

Date

7/85

Revision

age2of3

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