IPC-TM-650 EN 2022 试验方法--.pdf - 第489页
IPC-TM-650 Number Subject Date Revision Page 3 of 3 2.5.6 Dielectric Breakdown of Rigid Printed Wiring Material 5/86 B 6.1 The dielectric breakdown of the material may be adversely affected if the drilling process used t…
Note:
Note:
Note:
Table 1 Voltage increments for Step by Step Test
Breakdown Voltage (KV) Increment KV
less than 12.5 0.5
over 12.5 to 25 1.0
over 25 to 50 2.5
over 50 to 100 5
over 100 10
IPC-TM-650
Number
Subject Date
Revision
Page 2 of 3
2.5.6
Dielectric
Breakdown
of
Rigid
Printed
Wiring
Material
5/86
B
5.2
Test
Condition
The
test
shall
be
performed
at
ambient
temperature
(23℃
±
5
℃).
Relative
humidity
is
not
significant
as
the
tests
are
performed
under
oil.
5.3
Equipment
Set
Up
5.3.1
Adjust
the
transformer
on
the
high
voltage
tester
(manually
for
most
models)
to
the
position
which
will
allow
for
the
necessary
voltage
to
be
achieved
with
adequate
current
capacity
for
breakdown.
5.3.2
Set
the
machine
for
testing
using
a
500
volt
per
sec¬
ond
rate
of
rise.
5.4
Test
5.4.1
Remove
a
preconditioned
specimen
from
the
ambient
temperature
water
and
wipe
dry
with
a
lint
free
paper
towel.
5.4.2
Insert
the
first
specimen
into
the
fixture
(inserting
the
tapered
pins
from
opposite
sides)
and
immerse
in
the
oil
bath.
5.4.3
Attach
leads
(if
not
permanently
wired)
so
that
one
high
voltage
lead
is
connected
to
one
tapered
pin
electrode
and
the
ground
lead
is
connected
to
the
other
tapered
pin
electrode.
5.4.4
Operate
the
tester
such
that
the
voltage
is
applied
with
a
500
volts
per
second
rate
of
rise
and
observe
the
specimen
until
an
electrical
breakdown
occurs.
5.4.5
Record
the
voltage
at
which
breakdown
occurs,
using
the
meter
memory
device
if
available.
If
the
breakdown
appears
to
be
in
the
oil
and
no
specimen
damage
is
obvious
it
is
recommended
that
the
same
sample
be
retested.
If
the
specimen
still
will
not
breakdown
due
to
breakdown
of
the
oil,
the
oil
should
be
filtered
or
replaced.
5.4.6
Determine
the
starting
voltage
and
steps
for
the
remaining
specimens
from
the
same
sample
from
Table
1
.
547
Change
the
high
voltage
tester
to
manual
(or
pro¬
grammed
stepped)
operation,
remove
a
specimen
from
the
water
bath,
wipe
dry,
and
insert
the
second
specimen.
5.4.8
Set
the
voltage
to
the
50%
value
(plus
or
minus
the
value
of
one
step)
and
apply
the
voltage
for
60
seconds.
5.4.9
If
no
breakdown
occurs
increase
the
voltage
in
steps
per
Table
1
until
the
material
breaks
down
or
the
breakdown
capacity
of
the
machine
or
oil
is
reached.
Record
the
break¬
down
voltage
to
the
nearest
kilovolt
or
record
"N.
B.''
if
there
is
no
breakdown
of
the
material.
If
the
minimum
value
required
by
the
material
specification
is
not
exceeded,
but
material
breakdown
does
not
occur,
it
is
necessary
to
replace
or
filter
the
oil.
5.4.10
Repeat
steps
5.
4.
7-5.
4.9
for
the
remaining
speci¬
mens
from
the
sample.
5.5
Calculation
5.5.1
Average
the
values
for
the
three
specimens
tested
using
the
stepped
technique
and
round
to
the
nearest
kilovolt.
Even
if
some
specimens
do
not
break
down,
the
maximum
individual
voltages
will
be
used
to
calculate
an
average.
If
the
accuracy
of
the
meter
on
the
machine
is
not
within
5%
for
all
values
in
the
range,
apply
a
correction
obtained
from
the
last
machine
calibration
to
each
reading
to
determine
the
actual
value
for
the
dielectric
breakdown.
5.6
Report
5.6.1
Report
the
average
value
of
the
dielectric
breakdown
(if
all
specimens
actually
breakdown),
e.g.,
85KV
average.
5.6.2
Report
the
average
with
a
plus
after
the
value
if
one
or
two
specimens
do
not
break
down,
e.g.,
82
+
KV
average
2NB.
5.6.3
Report
the
minimum
value
at
which
the
oil
broke
down,
if
no
actual
specimen
breakdowns
are
obtained,
e.g.,
75
+
KV
N.B.
5.6.4
Report
any
anomalies
in
the
test
or
any
variations
from
prescribed
procedures
or
tolerances.
6.0
Notes
IPC-TM-650
Number
Subject Date
Revision
Page 3 of 3
2.5.6
Dielectric
Breakdown
of
Rigid
Printed
Wiring
Material
5/86
B
6.1
The
dielectric
breakdown
of
the
material
may
be
adversely
affected
if
the
drilling
process
used
to
produce
the
holes
is
inadequate.
Use
of
a
sharp
high
speed
drill
is
recom¬
mended
to
prevent
burning
the
material
or
producing
rough
holes.
6.2
This
test
requires
voltages
which
are
life
threatening.
The
High
Voltage
Tester
must
be
installed
and
operated
in
accor¬
dance
with
the
manufacturer's
instructions.
If
the
test
cham¬
ber
is
not
totally
enclosed,
with
a
safety
interlock,
extreme
care
must
be
exercised
in
performance
of
the
test.
1 Scope
The dielectric strength test (also called high-
potential [Hi-Pot], over potential, or voltage breakdown) con-
sists of the application of a test voltage for a specific time
between mutually insulated portions of a printed board or
between insulated portions and ground. This is used to prove
that the printed board can operate safely at its rated voltage
and withstand momentary overpotentials due to switching,
surges, and other similar phenomena.
2 Applicable Documents
Standard Test Method for Dielectric Break-
down Voltage and Dielectric Strength of Solid Electrical Insu-
lation Materials at Commercial Power Frequencies
3 Test Specimen
Three 102 mm x 102 mm [4.016 in x
4.016 in] squares of glass epoxy laminate materials having
1 ounce (0.0343 mm [0.00135 in] nominal) copper foil lami-
nates on one side, and having the test specimen polymer film
applied to the copper surface (see specimen preparation).
4 Apparatus
4.1
Any high voltage potential test equipment capable of
providing voltage increases of 500 VDC per second, up to at
least 10,000 VDC (see Section 6).
4.2
A standard Type 1 electrode per ASTM D 149, with a 51
mm [2.0 in] diameter, 25 mm [1.0 in] thick, with edges
rounded to 6.4 mm [0.25 in.] radius to cover the test surface.
5 Procedure
5.1 Preparation of Test Specimen
5.1.1
Cut the laminate specimen to 102 mm x 102 mm
[4.016 in x 4.016 in] and sand the edges lightly.
5.1.2
If double clad material is used, etch off all copper foil
on one side.
5.1.3
Clean the copper foil surface thoroughly, per the poly-
mer manufacturer’s recommendations, prior to applying poly-
mer coating.
5.1.4
Apply a film of the polymer test material on an area of
76.2 mm x 76.2 mm [3.0 in x 3.0 in] at the center of the cop-
per clad surface. A pinhole free film is essential.
5.1.5
Cure the polymer coating per manufacturer’s recom-
mendations.
5.2 Test
5.2.1
Clip the ground terminal of the tester over the thick-
ness of the copper foil and substrate, being careful not to let
the clip extend inward to the polymer coating (see Figure 1).
5.2.2
Place the positive electrode on top of test panel at the
center. Make certain the electrode and clip are electrically iso-
lated by the test polymer film.
5.2.3
Set up the potential voltage tester. Increase the volt-
age 500 VDC per second, until specimen exceeds require-
ment or breakdown occurs.
5.2.4
Measure the coating thickness of each of the test
specimens to the nearest 0.0025 mm [0.0001 in] in at least
four locations. Compute the average coating thickness and
standard deviation.
5.3 Evaluation
Determine the dielectric strength, E
D
, using:
E
D
=
V
BD
t
where t is the thickness of the specimen, to the nearest
0.0025 mm [0.0001 in], measured in 5.2.4 and V
BD
is
the breakdown voltage measured in 5.2.3. Record results as
‘‘V/mm’’ or ‘‘V/in.’’
6 Notes
6.1
Suggested source for tester: Hipotronics Model HD-140
from Hipotronics, Inc. Brewster, NY 10509, or equivalent.
6.2
Safety must be exercised because of the potential dan-
ger of electrical shock.
IPC-2561-1
3000 Lakeside Drive, Suite 309S
Bannockburn, IL 60015-1249
IPC-TM-650
TEST METHODS MANUAL
Number
2.5.6.1
Subject
Solder Mask - Dielectric Strength
Date
03/07
Revision
B
Originating Task Group
Solder Mask Performance Task Group (5-33b)
ASSOCIATION CONNECTING
ELECTRONICS INDUSTRIES
®
ASTM
D
149
Figure
1
Material
M
this
历
sf
Methods
Manual
was
voluntarily
established
by
Technical
Committees
of
IPC.
This
material
is
advisory
only
and
its
use
。厂
adaptation
is
entirely
voluntary.
IPC
disclaims
liability
of
any
k/nd
as
to
the
use,
application,
or
adaptation
of
this
material.
Users
are
also
wholly
responsible
for
protecting
themselves
against
claims
or
liabililies
for
patent
infringement.
Equipment
referenced
/s
for
the
convenience
of
the
user
and
does
not
imply
endorsement
by
IPC.
Page
1
of
1