IPC-TM-650 EN 2022 试验方法--.pdf - 第75页
NOTE: NOTE: NOTE: IPC-TM-650 Number Subject Date Revision Page 3 of 4 2.2.13.1 Thickness, Plating in Holes Microhm Method 1/83 A 4 steady reading indicates that the probes am mak¬ ing good contact. Trial settings to obta…
IPC-OI-645
IPC-A-600E
The Institute for Interconnecting and Packaging Electronic Circuits
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Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only
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Page 1 of 1
IPC-TM-650
TEST
METHODS
MANUAL
1
.0
Scope
This
method
is
intended
to
describe
optically
enhanced
measurement
techniques
for
dimensions
of
3
mm
or
less,
typically
referenced
on
a
Printed
Board
drawing.
This
method
will
not
cover
mechanical
dimensional
verification
which
is
covered
by
IPC-TM-650,
Method
2.2.1
.
This
method
is
intended
to
supersede
IPC-TM-650,
Method
2.2.3.
2
.0
Applicable
Documents
Standard
for
Visual
Optical
Inspection
Aids
Acceptability
of
Printed
Boards
3
.0
Test
Specimens
3.1
The
test
specimen(s)
shall
be
defined
in
the
applicable
performance
specification
or
standard.
4
.0
Apparatus
or
Material
4.1
Optical
inspection
aid
capable
of
a
magnification
where
the
feature(s)
to
be
measured
occupies
at
least
20%
of
the
field
of
view.
(See
IPC-OI-645
for
detailed
description.)
4.2
Reticle
or
Filar
Micrometer
attachment
to
Optical
Inspec¬
tion
Aid
that
contains
gradiations
or
a
scale,
which
will
provide
a
minimum
measurement
resolution
of
50%
of
the
last
signifi¬
cant
digit
of
the
referenced
dimensional
requirement.
The
Reticle
or
Filar
Micrometer
should
be
calibrated
at
the
given
magnification
to
ascertain
the
distance
in
mm
(inches)
between
each
division.
5
.0
Procedure
Number
2.2.2
Subject
Optical
Dimensional
Verification
Date
8/97
Revision
B
Originating
Task
Group
Rigid
Board
T.M.
Task
Group,
7-1
Id
5.2
Adjust
the
optical
aid
so
that
both
the
feature(s)
to
be
measured
and
the
reticle
or
filar
micrometer
attachment
are
in
focus.
5.3
Align
the
reticle
or
filar
micrometer
so
that
the
measure¬
ment
scale
is
visible
and
aligned
with
the
edges
of
the
fea-
ture(s)
to
be
measured.
5.4
Read
the
reticle
or
filar
micrometer
to
obtain
the
number
of
divisions
between
feature
edges.
5.5
To
obtain
the
actual
dimensions
of
the
feature,
multiply
the
number
of
divisions
read
by
the
calibration
data
previously
obtained
for
the
reticle
or
filar
micrometer
in
(|im/division)
(inches/division)
at
the
given
magnification.
5.6
Record
the
dimensions
for
the
attribute(s)
measured
using
the
same
number
of
significant
digits
specified
by
the
drawing,
standard,
or
specification
as
a
minimum
or
maximum
limiting
value.
6
.0
Notes
6.1
For
a
thorough
description
of
the
requirements,
defini¬
tions,
and
certification
provisions
for
optical
inspection
aids,
see
IPC-OI-645.
6.2
IPC-A-600
contains
figures
and
diagrams
which
depict
measurement
techniques
for
certain
attributed.
5.1
Select
an
optical
aid
which
allows
for
clear
viewing
of
the
area(s)
containing
the
attributes
to
be
measured.
NOTE:
NOTE:
NOTE:
IPC-TM-650
Number
Subject Date
Revision
Page 3 of 4
2.2.13.1
Thickness,
Plating
in
Holes
Microhm
Method
1/83
A
4
steady
reading
indicates
that
the
probes
am
mak¬
ing
good
contact.
Trial
settings
to
obtain
the
minimum
resis¬
tance
value
will
indicate
when
the
probes
are
properly
located
over
the
interconnection.
5.2.5
If
poor
electrical
contact
is
evidenced,
relocate
the
probes
until
a
minimum
resistance
is
indicated.
During
the
microscopic
inspection
(30X)
of
the
edges
of
the
plated-through
hole
and
the
adjacent
areas
on
the
ter¬
minal
area,
there
shall
be
no
detectable
damage
to
the
sur¬
faces
by
contact
with
the
probes
during
testing.
In
the
absence
of
such
surface
defects,
the
microhm
testing
can
assuredly
be
considered
nondestructive.
5.2.6
Read
and
record
the
microhm
value.
5.2.7
Compare
the
microhm
value
with
the
plating
thickness
of
the
standardization
curve
as
illustrated
in
Fig.
3.
The
theo¬
retical
curves
shown
in
Fig.
3
indicate
to
within
0.2-rail
thick¬
ness
the
plating
in
the
through
connection
and
for
all
practical
purposes
are
representative
of
the
resistance-
plating
thick¬
ness
relationships
encountered
in
practice.
This
comparison
shall
indicate
if
the
plating
thickness
of
the
through
connection
meets
the
acceptable
thickness
requirements
5.2.8
When
this
method
is
used,
any
reading
above
the
specified
allowable
microhm
reading
shall
be
reason
for
fur¬
ther
investigation
of
the
defect
for
conformance
to
the
require¬
ments
of
the
applicable
fabrication
specification.
5.2.9
Plating
thickness
curves
shall
be
generated
by
the
user.
6.0
Resistance
Curves
6.1
Curves
for
the
resistances
of
plated-through
holes
of
three
different
diameters
in
1/16"
printed
wiring
boards
are
presented
in
this
test
method
(Fig.
3).
Over
coatings
of
gold,
tin-lead,
etc.,
can
have
an
effect
on
the
micro-ohm
readings
depending
on
the
electrical
resistance
relative
to
the
copper.
Resistivity
of
tin-lead
is
approximately
ten
times
that
of
cop¬
per,
while
gold
is
of
the
same
resistivity.
6.2
To
eliminate
material
and
equipment
variables,
the
user
should
develop
thickness-resistance
curves
for
his
particular
condition
based
on
metallographic
cross-section
measure¬
ments
(TM-650
Method
2.2.13).
These
curves
may
be
used
as
guides
for
acceptance
of
product.
IPC-TM-650
Number
Subject Date
Revision
Page 2 of 2
2.2.4
Dimensional
Stability,
Flexible
Dielectric
Materials
5/98
C
Twenty-four
hour
stabilization
is
referee
method.
5.2
Method
A
Dimensional
stability
of
unclad
material
due
to
thermal
exposure
—
standard
condition.
(1)
Place
test
specimen
unconstrained
in
an
oven
maintained
at
150℃
±
2
℃
for
30
±
2
minutes.
(2)
Cool
specimen
to
standard
conditions
of
23℃
±
2
℃
and
50%
±
5%
RH
for
24
hours
minimum
(see
5).
(3)
Remeasure
separation
of
holes/lines
and
record
as
final
measurement
after
thermal
exposure
(F).
5.3
Method
B
Dimensional
stability
of
metal
clad
dielectrics
due
to
metal
removal.
(1)
Chemically
erode
the
metal
away
except
for
the
target
areas,
which
can
have
up
to
13
mm
x
13
mm
square
metal,
using
an
etchant
that
has
no
detrimental
effect
on
either
the
dielectric
or
adhesive.
Wash
and
dry.
The
test
specimen
should
be
unconstrained
during
the
etching,
washing,
and
drying
operation.
(2)
Stabilize
test
specimen
for
24
hours
at
23℃
±
2
℃
and
50%
±
5%
RH
(see
5.1).
(3)
Remeasure
separation
of
holes/lines
and
record
as
final
measurement
after
etching
(F2).
5.4
Method
C
Dimensional
stability
of
dielectric
due
to
thermal
exposure
and
metal
removal,
using
specimens
from
Method
B.
Place
unconstrained
etched,
conditioned,
and
measured
specimen
from
Method
B
in
an
oven
maintained
at
150℃
土
2
℃
for
30
±
2
minutes.
(2)
Stabilize
specimen
at
23℃
±
2
℃
and
50%
±
5%
RH
for
24
hours
and
remeasure
separation
of
holes
(see
5.1).
(3)
Remeasure
separation
of
holes/lines
and
record
as
final
after
etching
and
thermal
exposure
(F3).
5.5
Calculate
the
linear
dimensional
changes
as
follows:
(Start
with
initial
reading
(I)
from
5.1)
(A—B)f
-
(A-B)|
(O-D)F
-
(C-D)|
，八
c、
+
e
c、
(A-C)f
-
(
A-C)|
(B-D)f
-
(
B-D)|
(A-C)|
*
(B-D)!
I
.U.
—
2
Where:
M.D.
=
%
change
in
machine
dimension.
T.D.
=
%
change
in
transverse
dimension.
I
=
Initial
Reading.
F
二
Final
Reading
(Either
F1
,
F2,
or
F3).
A-B
=
Distance
Between
Points
A
&
B.
A-C
=
Distance
Between
Points
A
&
C.
C-D
=
Distance
Between
Points
C
&
D.
B-D
=
Distance
Between
Points
B
&
D.
6
Notes
The
alternate
method
for
marking
clad
samples
allows
the
use
of
scribed
lines.
Caution
must
be
used
to
pro¬
tect
scribed
lines
during
etch
operation.
x
100
x
100