IPC-TM-650 EN 2022 试验方法--.pdf - 第181页

IPC-TM-650 W ARNING: NOTE: Material in this T est M ethods Manual was voluntarily establis hed by T echni cal Committees of IPC. Thi s mat erial is a dvisory only and its use or adaptation is entirely voluntary . IPC dis…

100%1 / 824
6.3.2
Determine the surface area per Section 3.
6.3.3 Calibration
A precise quantity of sodium chloride
calibration solution is injected into a designated volume of the
test solvent mixture in the sample measurement cell. This is
done according to the calibration or verification instructions
provided by the manufacturer of the equipment being used.
6.3.4 Testing
Once the system has been calibrated or veri-
fied in accordance with 6.3.3, the sample tank is filled as
directed by the procedures of the equipment manufacturer
and the test specimen is immersed in the tank. The minimum
starting resistivity for this type of equipment is machine
dependent. Use clean gloves when handling the samples to
be tested. Finger dirt contains ionic materials which may con-
tribute to spurious reading. During the course of the measure-
ment, the resistivity will fall continually as ionic material is
extracted into solution. If conductivity is being monitored, it will
initially be very low, rising continually as ionic material is dis-
solved from the sample. The test can be terminated when
there is no further change, in time, of the resistivity or conduc-
tivity function. This can be established electronically in most
commercially available equipment. The initial and final values
together with the volume of the solvent mixture in the test
tank, and sample surface area are used by the system to cal-
culate the ionic levels which were present on the sample sur-
face prior to the test.
6.3.5
Refer to the manufacturer’s equipment manual for
optimal operation.
6.4 Interpretation of Test Data
See 5.4.
7 Notes
7.1 Temperature
Higher solution temperatures will result
in higher levels of extracted ionic material. Most machines
have calculation algorithms which incorporate the solution
temperature. Refer to the machine documentation to under-
stand how temperature affects the ionic contamination read-
ing.
For process control testing, temperature should be set at a
constant value for periodic measurements. All calibrations of
the equipment should be made at the same solution tempera-
ture used to run the test.
7.2
It is critical to always use test solution with the same
composition of electronic grade 2-propanol (isopropyl
alcohol)/DI water for all comparative data discussions.
7.3
It is also suggested that a solution blank of 5 mL of
2-propanol/DI water be run at time of calibration to determine
the foundational cleanliness of the testing system.
7.4
Specific pieces of test equipment only have contamina-
tion output displays of two digits, if results are greater than or
equal to 100 the actual results will be lost and only the last
two digits will be displayed.
7.5
An extremely ‘‘dirty’’ sample can exceed machine maxi-
mums. Refer to the equipment documentation to determine
the maximum reading of the instrument.
8 References
Ionic Analysis of Circuit
Boards by Ion Chromatography
Circuit Board Ionic Cleanliness Measurement:
What Does It Tell Us?
Handbook and Guide to Supplement J-STD-
001
Number
2.3.25
Subject
Detection and Measurement of Ionizable Surface Contaminants by
Resistivity of Solvent Extract (ROSE)
Date
11/12
Revision
D
IPC-TM-650
IPC-TM-650,
Test
Method
2.3.28
IPC-TP-1113
IPC-HDBK-001
Page
5
of
5
IPC-TM-650
WARNING:
NOTE:
Material in this Test Methods Manual was voluntarily established by Technical Committees of 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 IPC.
Page 1 of 4
r
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).