IPC-TM-650 EN 2022 试验方法-- - 第182页

NOTE: NOTE: NOTE: Figure 1 No mogram of Conductivity vs. Solution Concentration Conductivity Solution Concentr ation in micrograms NaCl/Liter IPC-TM-650 Page 2 of 4 Number 2.3.25.1 Revision Subject Ionic Cleanliness Test…

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IPC-TM-650
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NOTE:
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Page 1 of 4
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ASSOCIATION
CONNECTING
/
ELECTRONICS
INDUSTRIES
®
221
5
Sanders
Road
Northbrook,
IL
60062-6135
IPC-TM-650
TEST
METHODS
MANUAL
1
Scope
This
test
is
used
to
determine
the
total
ionic
con¬
tent
extractable
from
on,
and
absorbed
within,
the
surface
of
printed
wiring
boards
(PWBs),
for
the
purposes
of
process
control.
The
conductivity
of
the
extract
solution
is
measured
and
the
results
are
expressed
as
sodium
chloride
equivalence
per
unit
area.
2
Applicable
Documents
Test
Method
2.3.25,
Detection
and
Measure¬
ment
of
Ionizable
Surface
Contaminants
by
Resistivity
of
Sol¬
vent
Extract
(ROSE)
3
Test
Specimens
The
test
specimen
may
be
any
unpopulated
PWB.
The
num¬
ber
of
specimens
depends
on
the
process
control
plan
or
product
drawings/prints.
4
Apparatus
or
Material
•
An
automated
Resistivity
of
Solvent
Extract
(ROSE)
tester
•
Conductivity
dip
probe
with
appropriate
meter
with
tem¬
perature
compensation
•
Hydrometer
(0.800
-
0.900)
for
ROSE
tester
calibration
•
Thermometer
for
ROSE
tester
calibration
•
Clean
room
(non-ionic)
gloves
or
forceps
•
KAPAK™
plastic
bags
or
equivalents
(see
6.9)
•
Bag
sealing
equipment
•
Water
bath,
capable
of
sustaining
an
80℃
土
2
℃
[176°F
土
3.6°F]
temperature
•
Second
water
bath
capable
of
sustaining
a
25℃
±
1
℃
[77°F
土
1
.8°F]
temperature
•
Precision
solvent
measurement
equipment,
such
as
class
A
pipettes
•
Volumetric
glassware
•
Plastic
ware
-
high
density
polyethylene,
polymethylpentene
(polypentene)
or
equivalent.
•
Extract
solution:
25%
v/v
deionized
water
(18
MQ-cm
nomi¬
nal
resistivity),
75%
v/v
2-propanol
(electronic
or
HPLC
grade).
No
alternative
solution
or
composition
is
allowed.
Number
2.3.25.1
Subject
Ionic
Cleanliness
Testing
of
Bare
PWBs
Date
Revision
October
2000
Originating
Task
Group
Bare
Board
Cleanliness
Assessment
Task
Group
5-32c
•
Sodium
chloride
-
reagent
grade
•
Analytical
balance
accurate
to
0.0001
grams
2-propanol
is
a
flammable
material.
The
2-propanol
/
water
mixture
is
also
flammable.
Exercise
caution
when
using
this
solution.
5
Procedure
5.1
Extraction
Throughout
this
procedure,
do
not
touch
the
sample
boards
with
bare
hands.
Use
the
clean
room
gloves
specified
or
use
clean
forceps.
5.1.1
Calculate
the
surface
area
of
the
PWB
using:
Area
(in
cm2)
二
Length
x
Width
x
2
5.1.2
Prepare
a
volume
of
extract
solution
specified
in
4.
5.1.3
Using
clean
room
gloves
or
clean
forceps,
place
the
PWB
into
virgin
KAPAK™
bags.
Choose
the
bag
size
to
give
at
least
an
additional
2.5
cm
[1.0
in]
on
each
side
of
the
board
to
minimize
the
amount
of
extract
solution
used.
Allow
at
least
an
additional
5
cm
[2.0
in]
above
the
board
top.
5.1
.4
Using
a
pipette
or
graduated
cylinder,
add
a
volume
of
the
extract
solution
into
the
bag.
The
amount
will
depend
on
the
area
of
the
board
surface.
This
usually
varies
from
0.8
mL/cm2
[5.2
mUin2]
up
to
about
3
mL/cm2
[19
mMn2].
For
example,
a
1
0
cm
x
11
.5
cm
[3.94
in
x
4.53
in]
board
would
require
about
100
mL
of
solution.
The
amount
of
solution
should
just
cover
the
board
completely
when
most
of
the
air
is
forced
out
of
the
bag.
5.1.5
Force
most
of
the
air
from
the
bag
and
heat
seal
the
bag.
This
involves
contact
with
a
hot
metal
bar.
Take
reason¬
able
precautions
to
keep
extract
solution
from
contacting
the
hot
bar.
Alternatively,
the
top
of
the
bag
may
be
folded
over
and
clipped
shut.
5.1.6
Place
the
bag(s)
vertically
in
a
water
bath
which
has
stabilized
at
80℃
[176°F].
Make
sure
that
the
boards
do
not
float
above
the
water
line.
Do
not
allow
the
water
from
the
bath
to
enter
the
bag
or
for
extract
solution
to
leak
out
of
the
bag.
NOTE:
NOTE:
NOTE:
Figure 1 Nomogram of Conductivity vs. Solution
Concentration
Conductivity
Solution Concentr
ation
in micrograms NaCl/Liter
IPC-TM-650
Page 2 of 4
Number
2.3.25.1
Revision
Subject
Ionic
Cleanliness
Testing
of
Bare
PWBs
Date
October
2000
5.1.7
Allow
the
boards
to
extract
in
this
manner
for
a
period
of
time
of
60
±
5
minutes.
5.1.8
Following
the
extraction
of
5.1
.7,
remove
the
bags
from
the
water
bath
and
allow
the
extract
solution
to
cool
for
at
least
30
minutes,
with
the
specimen
still
in
the
bag.
5.1.9
Using
clean
tongs
or
forceps,
remove
the
PWB
from
the
bag.
5.2
Measurement
-
DIP
Probe
Method
5.2.1
Calibration
of
Bridge
This
is
essential
in
this
method
because
there
can
be
no
correlation
between
resistivity/
conductivity
readings
and
NaCI
equivalents
without
calibra¬
tion.
5.2.1.
1
Prepare
a
standard
NaCI
solution
from
a
weight
of
dry
reagent
grade
NaCI
salt
dissolved
in
deionized
water
to
produce
a
final
diluted
concentration
of
0.06
g/liter
NaCI
(5
mL
equals
300
pg
NaCI).
5.2.
1.2
Place
1
liter
of
the
2-propanol
water
solution
(at
the
calibration
temperature
of
the
bridge
in
use)
in
a
plastic
bea¬
ker.
The
75
%
v/v
2-propanol
solution
must
be
used
in
this
calibration.
Water
cannot
be
used
since
it
is
not
the
test
solu¬
tion
used
in
the
procedure.
The
test
solution
used
in
this
cali¬
bration
can
be
recleaned
by
passing
through
the
DI
column
until
the
required
resistivity/conductivity
is
obtained.
5.2.
1.3
From
a
50
mL
burette,
add
to
the
liter
of
test
solu¬
tion,
5
mL
of
the
standard
0.06
g/liter
NaCI
solution.
Stir
and
measure
resistivity/conductivity.
5.2.
1.4
From
a
50
mL
burette,
add
to
the
liter
of
test
solu¬
tion,
20
additional
mL
of
the
standard
0.06
g/liter
NaCI
solu¬
tion,
for
a
total
of
25
mL.
Stir
and
measure
resistivity/
conductivity.
5.2.
1.5
From
a
50
mL
burette,
add
to
the
liter
of
test
solu¬
tion,
25
additional
mL
of
the
standard
0.06
g/liter
NaCI
solu¬
tion,
for
a
total
of
50
mL
Stir
and
measure
resistivity/
conductivity.
5.2.1.
6
Plot
a
three
point
nomogram
of
Conductivity
vs.
Solution
Concentration
(in
pg/liter
NaCI).
See
Figure
1
for
example.
You
should
get
a
linear
relationship.
Use
a
best
fit
line
obtained
with
a
piecewise
linear
method.
5.2.2
Test
Procedure
-
DIP
Probe
If
desired,
this
test
can
be
run
at
other
temperatures;
however,
the
calibration
process
must
be
repeated
for
the
alternative
temperature.
This
calibration
process
need
only
be
done
once,
providing
the
conductivity
cell
has
not
been
exposed
to
harsh
chemicals
which
would
alter
the
cell
con¬
stants.
If
the
conductivity
cell
is
routinely
used
on
harsh
chemical
solutions
(e.g.,
plating
baths),
then
the
calibration
should
be
repeated
before
every
test
run.
5.2.2.1
Place
the
Kapak™
bags
containing
the
extract
solu¬
tions
into
the
25℃
[77°
F]
water
bath
and
allow
the
extract
solutions
t
。
reach
25℃
[77°F].
S.2.2.2
Insert
the
conductivity
probe
into
the
Kapak™
bag
containing
the
room-temperature
extract
solution.
It
is
impor¬
tant
that
the
extract
solution
be
measured
at
the
same
tem¬
perature
used
for
the
calibration
solutions.
Immerse
the
probe
to
a
suitable
depth.
A
"suitable
depth”
is
one
which
covers
the
cell
elec¬
trodes,
but
not
an
immersion
which
covers
the
wiring.
Many
cells
are
marked
with
a
scribed
line
which
indicates
the
proper
immersion
depth.
S.2.2.3
Gently
agitate
the
solution.
Read
the
conductivity
of
the
solution.
The
time
between
immersion
of
the
cell
and
tak¬
ing
the
reading
should
be
the
same
as
used
for
the
calibration
curve.
Sufficient
time
should
be
allowed
for
the
reading
to
come
to
equilibrium
(no
change
for
two
minutes).
NOTE:
NOTE:
IPC-TM-650
Page 3 of 4
Number
2.3.25.1
Revision
Subject
Ionic
Cleanliness
Testing
of
Bare
PWBs
Date
October
2000
Between
measurements,
rinse
the
cell
with
deionized
water
and
leave
the
cell
soaking
in
virgin
extract
solution.
Never
use
a
dry
cell
as
this
is
bad
technique.
5.2.2.4
Using
the
linear
relationship
formed
in
5.2.1
.6,
determine
the
concentration
of
sodium
chloride
correspond¬
ing
to
the
conductivity
reading.
Use
the
equation
given
below
to
determine
the
total
micrograms
of
sodium
chloride
equiva¬
lence
per
square
centimeter
(pg
NaCI
Eq.
/cm2)
Using
the
nomogram:
Conductivity
of
Unknown
一
Concentration
of
Unknown
Concentration
Volume
of
Extract
Solution
(pg/liter)
x
(liter)
Extracted
Surface
Area
(cm2)
二
pg
NaCI
Eq.
/cm2
5.2.2.5
If
the
conductivity
of
the
unknown
solution
is
outside
of
the
bounds
represented
on
the
existing
nomogram,
then
continue
the
technique
used
to
generate
the
nomogram
(see
5.2.1)
until
the
bounds
contain
the
conductivity
of
the
unknown
solution.
5.3
Measurement
-
Static
ROSE
Tester
Method
This
section
was
developed
using
an
Omegameter
600SMD
with
a
1
0,000
mL
cell.
Make
appropriate
changes
to
the
procedure
to
accommodate
other
static
ROSE
testers.
5.3.1
Perform
a
system
verification
check.
5.3.2
Set
the
instrument
to
an
appropriate
amount
of
sol¬
vent
volume.
A
target
solution
level
should
be
1.5
mL
for
one
cm2
of
board
surface.
It
is
not
necessary
to
cover
the
spray
jets
(if
applicable).
If
the
lid
is
on
the
test
cell,
the
C02
mixing
is
minimized.
5.3.3
Enter
the
appropriate
surface
area
into
the
instrument.
5.3.4
To
allow
for
the
volume
of
solvent
that
is
to
be
added,
the
instrument
setup
volume
will
be
set
at
the
minimum
vol¬
ume
(e.g.,
2300
mL)
plus
the
volume
of
solution
in
the
extrac¬
tion
bag
(e.g.,
100
mL).
Dwell
time
or
run
time:
2
minutes
Pass
/
Fail
Value:
None
Begin
the
test
and
follow
the
test
prompts.
Remove
the
cell
cover.
5.3.5
Carefully
open
the
test
bag
and
quickly
pour
the
extract
solution
into
the
test
cell.
To
minimize
CO2
absorption,
the
addition
should
be
made
as
quickly
as
possible
and
the
cell
cover
quickly
replaced.
5.3.6
The
instrument
should
very
quickly
reach
equilibrium
(10-15
seconds)
and
then
should
remain
essentially
unchanged
for
the
remainder
of
the
two
minute
run.
5.3.7
Log
the
reading
in
total
pg
of
sodium
chloride
equiva¬
lence
per
cm2.
5.3.8
Static
ROSE
Calculation
Example:
Testing
a
bare
board,
10
cm
x
20
cm
[3.9
in
x
7.9
in]
Surface
area
is
1
0
cm
x
20
cm
x
2
=
400
cm2
[62
in2]
Bag
size
should
be
about
1
5
cm
x
30
cm
[5.9
in
x
12
in]
or
larger
Extract
solution
would
be
about
620
mL
ROSE
volume
input
to
4620
mL
(4000
mL
to
cover
sprays
and
620
mL
from
extraction)
ROSE
tester
cell
volume
set
to
4000
mL
Run
time
-
2
minutes
5.4
Measurement
-
Dynamic
ROSE
Tester
Method
5.4.1
Perform
a
system
verification
check.
5.4.2
Program
the
instrument
with
the
appropriate
surface
area
of
the
board.
5.4.3
Cycle
the
instrument
to
the
beginning
cleanliness
point.
5.4.4
Carefully
open
the
test
bag
and
quickly
pour
the
extract
solution
into
the
test
cell.
To
minimize
CO2
absorption,
the
addition
should
be
made
as
quickly
as
possible
and
the
cell
cover
quickly
replaced.
5.4.5
When
the
instrument
completes
the
test,
log
the
read¬
ing
in
total
pg
of
sodium
chloride
equivalence
per
cm2.
6
Notes
6.1
The
background
for
this
test
method
may
be
found
in
technical
papers:
11
Rationale
and
Methodology
for
a
Modified
Resistivity
of
Sol¬
vent
Extract
Test
Method/'
Philip
W.
Wittmer,
I
PC
1995
Fall
Meeting
Proceedings,
S13-4.