IPC-TM-650 EN 2022 试验方法--.pdf - 第122页

IPC-TM-650 Number Subject Date Revision Page 3 of 4 2.3.4.2 Chemical Resistance of Laminates, Prepreg, and Coated Foil Products, by Solvent Exposure 12/94 A 5.5.7 After 60 +5,-0 seconds from the time of removal from the …

IPC-TM-650

Number

Subject Date

Revision

Page 2 of 4

2.3.4.2

Chemical

Resistance

of

Laminates,

Prepreg,

and

Coated

Foil

Products,

by

Solvent

Exposure

12/94

A

and

of

a

thickness

when

cured

not

greater

than

0.13

mm

[0.005

in]

total,

using

the

prepreg

manufacturer's

recom¬

mended

press

cycle.

Laminate

over

0.5

mm

[0.020

in]

shall

be

treated

like

double

clad

laminate

without

lamination.

5.1.2

Resin-coated

Foil

Resin-coated

foil

samples

shall

be

laminated

together

using

at

least

two

plies

of

prepreg

between

the

coated

sides

of

the

foil.

The

prepreg

shall

be

of

the

same

basic

resin

type

and

of

a

thickness

when

cured

not

greater

than

0.127

mm

[0.005

in]

total,

using

a

press

cycle

and

any

subsequent

post

cure

which

meets

the

manufactur¬

er^

recommendations

for

both

the

coated

foil

and

prepreg.

(See

6.2.1.

1)

For

qualification

and

referee

tests,

a

0.50

±

0.10

mm

[0.02

in]

composite

core

is

to

be

built.

5.1.3

Laminate

with

Coated

Foil

Surfaces

Single-sided

laminate

shall

be

tested

after

lamination

as

in

5.1

.1

.

Double¬

sided

laminate

with

coated

foil

on

one

side

shall

have

the

foil

etched

from

the

uncoated

side

and

shall

subsequently

be

laminated

as

5.1.1.

Double-sided

laminate

with

coated

foil

on

both

sides

shall

be

tested

as

is.

5.1.4

Prepreg

Prepreg

shall

be

laminated

to

a

thickness

of

0.50

±

0.10

mm

[0.020

in]

using

treated

copper

foil

on

both

sides

and

following

the

prepreg

manufacturer's

recommended

press

and

post

cure

cycle.

(See

6.2.1

.1)

For

prepreg

less

than

0.13

mm

[0.005

in]

thick

when

cured,

at

least

two

plies

shall

be

bonded

to

either

side

of

an

etched

laminate

of

a

thickness

such

that

the

pressed

sample

satisfies

the

required

thickness.

5.1.5

Double-sided

Laminate

Double-sided

laminate

shall

be

submitted

for

testing

as

is.

5.2

Specimen

Preparation

5.2.1

Etching

Samples,

as

specified

in

3.0,

shall

be

etched

in

accordance

with

standard

industry

practices.

For

referee

purposes,

2.3.6,

2.3.7,

2.3.7.

1

,

or

2.3.7.2

shall

be

used.

5.2.2

Cut

the

specimens

to

size

per

3.2.

Cutting

shall

be

performed

using

apparatus

and

in

such

a

manner

that

pre¬

vents

edge

damage.

Edge

smoothing

is

recommended

to

prevent

excessive

absorption.

5.2.3

Markings

Each

specimen

shall

be

identified

by

mark¬

ing

with

a

lead

pencil

or

equivalent

technique

which

is

not

removed

by

the

solvent

and

which

doesn't

affect

the

results.

5.3

Preconditioning

5.3.1

Measure

and

record

nominal

thickness

of

the

test

specimen

using

IPC-TM-650,

Method

2.2.18.

5.3.2

Place

the

etched

specimens

vertically

in

the

metal

rack

and

dry

the

specimens

in

the

oven

for

60

±

5

minutes

at

105℃

[221

°F].

Air

flow

around

each

specimen

must

be

assured.

5.3.3

Remove

the

specimens

from

the

oven

and

immedi¬

ately

place

in

the

desiccator

to

cool

for

60

±

30

minutes.

5.4

Test

Condition

The

test

shall

be

performed

at

stan¬

dard

laboratory

conditions:

23

±

2

℃

[73

±

0.9°F]

and

50

±

5%

R.H.

5.5

Measurement

5.5.1

Fill

the

battery

jar

with

750

ml

of

solvent

and

maintain

the

solvent

temperature

at

23

±

0.5℃

[73

土

0.9°]

using

the

water

bath.

5.5.2

Remove

the

specimens

individually

from

the

desicca¬

tor

and

weigh

to

the

nearest

milligram

on

the

analytical

bal¬

ance.

Samples

must

be

weighed

within

60

seconds

of

removal

from

the

desiccator.

Record

these

weights

as

.

5.5.3

Place

the

rack

into

the

beaker

of

solvent,

start

the

60

minute

timer

and

using

tongs

place

the

specimens

in

the

rack

at

suitable

intervals

(recommend

approximately

2

minutes).

Insure

that

the

specimens

are

completely

immersed.

5.5.4

Place

the

metal

clip

on

the

balance

and

tare

it

out.

5.5.5

After

10

minutes

+15,

-0

seconds,

using

the

tongs

remove

the

first

specimen

from

the

solvent

and

start

the

60

second

timer.

5.5.6

Slowly

wag

the

specimen

in

the

air.

As

soon

as

the

specimen

is

free

of

surface

wetness,

but

no

longer

than

30

seconds,

place

the

specimen

on

the

balance

supporting

it

on

the

metal

clip

such

that

both

surfaces

of

the

specimen

are

exposed

(placing

the

specimen

flat

on

the

balance

pan

is

not

permitted

since

evaporation

from

the

side

next

to

the

pan

will

be

reduced.)

IPC-TM-650

Number

Subject Date

Revision

Page 3 of 4

2.3.4.2

Chemical

Resistance

of

Laminates,

Prepreg,

and

Coated

Foil

Products,

by

Solvent

Exposure

12/94

A

5.5.7

After

60

+5,-0

seconds

from

the

time

of

removal

from

the

solution,

note

the

weight

of

the

specimen

and

record

it

as

W2.

5.5.8

Repeat

5.5.5

-

5.5.7

for

the

remaining

specimens

insuring

the

immersion

time

of

each

specimen

is

kept

within

the

tolerance.

5.5.9

A

fresh

batch

of

solvent

shall

be

used

for

no

more

than

1

8

specimens

or

for

a

period

of

time

no

longer

than

8

hours.

5.6

Evaluation

5.6.1

Weight

Gain

5.6.1

.1

Subtract

the

dry

weight

of

each

specimen,

W

〕

,

from

the

final

weight,

W2

of

each

specimen

after

immersion.

Record

the

weight

gain

in

mg.

5.6.1.

2

Calculate

the

average

weight

gain

in

mg.

5.6.2

Appearance

Examine

the

specimens

using

20/20

vision

for

any

changes

to

the

appearance

of

the

material,

such

as

hazing,

whitening

or

swelling.

5.7

Report

5.7.1

Report

the

average

weight

gain

in

milligrams

for

the

material

tested.

5.7.2

Report

the

measured

specimen

thickness.

5.7.3

Report

actual

test

conditions

for

temperature

and

humidity

and

the

solvent

temperature.

5.7.4

Report

any

anomalies

in

the

test

or

any

variations

from

the

specified

procedures

or

tolerances.

5.7.5

Report

any

changes

in

the

visual

quality

of

the

speci¬

mens

as

determined

in

5.6.2.

6.0

Notes

6.1

Safety

Considerations

See

the

MSDS

sheet

for

the

solvent

used

before

running

this

test.

6.1.1

During

test,

the

beaker

with

the

test

solvent

should

be

covered

or

under

a

ventilation

hood.

6.1.2

Dispose

of

the

spent

solvent

in

accordance

with

local

regulations.

6.2

Factors

Affecting

Tests

6.2.1

Sample

6.2.1.

1

Same

Sample

The

results

obtained

on

the

same

sheet

of

material

may

be

significantly

affected

by

the

degree

of

cure

of

the

material

and

the

thermal

history

of

the

sample.

6.2.1.

2

Variation

Due

to

Thickness

of

Sample

There

is

a

very

small

difference

due

to

sample

thickness.

This

is

under

10%

on

typical

epoxy

materials

for

0.2

mm

[0.008

in]

to

1.5

mm

[0.060

in]

and

under

5%

on

more

chemical

resistant

material

from

0.13

mm

[0.005

in]

to

1.5

mm

[0.060

in].

6.2.2

Accuracy

Since

there

are

no

standards

for

this

type

of

test,

the

accuracy

of

the

method

cannot

be

established.

6.2.3

Precision

the

reproducibility

of

this

test

depends

on

the

degree

of

control

over

the

controlled

variables

and

some

other

variables

such

as

atmospheric

pressure,

which

are

gen¬

erally

not

controlled

in

industrial

laboratories.

Precision

between

laboratories

with

20%

to

50%

RH

was

10%

at

the

90

mg

level

and

16%

at

the

25

mg

level.

6.2.4

Desiccants

Desiccants

capable

of

0.002

mg

mois¬

ture

levels

include

P205>

Mg

(C1

04)

2

，

anhydrous

BaO

and

fused

KOH.

Some

other

desiccants

such

as

CaCI2

result

in

considerably

higher

moisture

levels

and

may

not

be

used

in

this

test.

(See

Weast

R.C.,

ORC

Handbook

of

Chemistry

and

Physics,

65th

edition,

E-37,

1

984.)

6.2.5

Humidity

Considerations

6.2.5.1

Effect

of

Humidity

Higher

humidity

will

produce

higher

solvent

pickup

due

to

retarded

solvent

evaporation.

6.2.5.2

Control

of

Humidity

Control

of

the

critical

environ¬

ment

can

be

obtained

in

uncontrolled

laboratories

using

an

enclosed

balance

with

a

saturated

salt

solution

of

Mg(No3)2,

6H

2

。

(for

50%

RH).

All

significant

openings

in

the

enclosure

are

sealed

with

tape

and

an

inner

door

is

fabricated

with

a

small

opening

for

sample

entry

and

exit.

A

shallow

pan

is

fabricated

to

occupy

most

of

the

balance

floor

without

contacting

the

weighing

IPC-TM-650

Number

Subject Date

Revision

Page 4 of 4

2.3.4.2

Chemical

Resistance

of

Laminates,

Prepreg,

and

Coated

Foil

Products,

by

Solvent

Exposure

12/94

A

pan.

If

the

balance

door

is

closed

immediately

after

sample

entry

and

exit,

50

土

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

℃

[9°F]

can

result

in

an

error

as

high

as

50%

relative

to

values

deter¬

mined

at

23℃

[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

2.3.42

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

IPG

Test

Methods

is

30%

maximum.