IPC-TM-650 EN 2022 试验方法-- - 第180页
6.3.2 Determine the surface area per Section 3. 6.3.3 Cal ibrat ion A pr ecise quant ity of s odium chlo ride calibration solution is injected into a designated volume o f the test solvent m ix ture in the sample measure…
to accelerate extraction of ionic soils from poorly accessible
places such as under surface mounted components.
5.3 Procedure
5.3.1 Solvent Systems
Industry has established two differ-
ent standard test solutions that are used worldwide:
75 % / 25 %, nominal v/v 2-propanol/DI water
50 % / 25 %, nominal v/v 2-propanol/DI water
Select the solution required by the specification (e.g., industry
standards, engineering drawing specifications, contract docu-
mentation, etc.).
5.3.2
Determine the surface area per Section 3.
5.3.3 Calibration
Once the fluid in the system has estab-
lished a stable level of conductivity, a precise quantity of a
sodium chloride calibration solution is injected into the test
solution in the test tank. This is done according to the calibra-
tion instructions provided by the manufacturer of the equip-
ment.
System calibration should be verified daily, when used.
5.3.4 Testing
Once the system has been calibrated or veri-
fied in accordance with 5.3.3, immerse the test specimen into
the sample tank. The test time should be in accordance with
the monitoring plan criteria (set time or auto-shutoff). Use
clean gloves when handling the samples to be tested. Finger
dirt contains ionic soils which may contribute to false read-
ings. During the course of the measurement, the conductivity
will rise from the initial baseline level and then gradually return.
When it has returned to the baseline level, no additional ionic
material can be removed and the measurement is complete.
5.4 Interpretation of Test Data
The number obtained
from this type of measurement indicates the total amount of
ionic material extracted from the entire sample in terms of
equivalent amounts of sodium chloride (assuming the calibra-
tion was done with sodium chloride). This should be divided
by the total surface area of the sample from which the ions
were extracted to determine the surface ionic density of the
original sample.
The following parameters must be
specified:
a) Solvent composition
b) Solvent volume for static method or flow rate for dynamic
method
c) Test temperature
d) Calibration of system
e) Sample area calculation
f) Test time
g) Equipment type and model number
The actual surface ionic density is most commonly calculated
by programming the area into the instrument’s microproces-
sor system. The total ionic amount will then be automatically
divided by the area to indicate surface ionic density in terms
of micrograms of sodium chloride equivalence per unit of sur-
face area (µg NaCl eq./cm
2
).
6 Static Extraction Method
6.1 Description
In the static extraction method, a mea-
sured volume of freshly deionized 2-propanol/DI water mixture
is introduced into the test tank and its resistivity (or conductiv-
ity) measured continuously while the 2-propanol/DI water mix-
ture is agitated. Once the system has been calibrated or veri-
fied in accordance with 6.3.3 and solution has been run
through the ion exchange columns, the test specimen is
immersed into the tank. The test time should be in accor-
dance with the monitoring plan criteria (set time or auto-
shutoff). Care must be taken not to handle the sample or any
of the appliances used to insert it into the tank. Finger dirt
contains ionic soils which may contribute to spurious read-
ings. During the course of the measurement, the conductivity
will rise from the initial baseline and then level off. When it has
stabilized and no additional ionic material can be removed
then the measurement is complete. After the test is completed
the solvent mixture is passed through ion exchange columns
to remove ionic materials and regenerate the 2-propanol/DI
water solvent mixture to its original high resistivity level for fur-
ther tests.
6.2 Test Equipment
A static conductivity measurement
system includes a test tank, a temperature-compensated
conductivity cell and monitor, means for solution agitation and
a means for removing, deionizing and re-introducing the sol-
vent mixture into the test tank before a new test is started.
The equipment may also have the capability of heating the
2-propanol/DI water mixture to accelerate and improve the
efficiency of extraction of ionic material from poorly accessible
regions, such as under surface-mounted components.
6.3 Procedure
6.3.1 Solvent Systems
See 5.3.1.
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
—
Note:
Important
Parameters
Page
4
of
5
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.