IPC-TM-650 EN 2022 试验方法-- - 第404页
5.10.2 Use low-pressure c ompressed or c ann ed air t o gen- tly flush any remaining dye from un der the part unti l no further dye runs out. 5.10.3 Dry the sample in an oven, no t to e xceed 100 °C o r as appropriate fo…
5.3.2
If there is a metal heat spreader on the BGA, it must
be left in place until after the dye-drying step (5.11).
5.4
Section out the desired component area leaving about
19 mm to 38 mm [0.75 in to 1.5 in] of board around the part.
If the board is small enough to fit the pull fixture, leave the
board intact.
5.4.1
A diamond sectioning saw is recommended to per-
form this step. Other sectioning equipment (e.g., diamond
saw, milling tool, water jet, etc.) can be used if it does not
induce stress on the sample area.
5.5
A detailed visual examination under stereomicroscope is
required at this stage. If needed, clean the sectioned part with
only water and compressed air. It is important to not use sol-
vent for this step.
5.5.1
A thorough visual examination can detect signs of
mechanical damage/stress, which are indicated by fractured/
broken-up flux around the SMT solder joint (see Figure 1 and
Figure 2).
5.5.2
If the SMT part utilizes corner-applied adhesive which
was not easily visible before, examine it now. Document the
glue coverage per IPC-7095 or as determined between the
lab and the customer.
5.5.3
Document the findings in lab notes and with photos.
5.6
Clean any flux residue from around the SMT solder joints
using the appropriate flux remover.
Isopropyl alcohol is not acceptable due to its inability to
dissolve flux.
5.6.1
The sectioned part/board area should be submerged
in liquid flux remover for at least one hour. The goal is to fully
remove the flux residue. The exact amount of time the part/
board is submerged depends on the sample conditions.
5.6.1.1
Approximately two to three times during soak, gen-
tly swirl the beaker containing the sectioned part for at least
20 seconds. This will aid the flux solvent in removing the flux
ring residue.
5.6.2
Reworked samples may require additional time in the
liquid flux remover.
5.6.3
Examine the sample under a microscope to determine
if additional time is needed to remove the flux ring.
5.6.4
After using the liquid flux remover, use a spray can flux
remover to thoroughly flush all four sides of the component.
5.6.4.1
Removing all flux residues and other particles/oils
enables the dye to penetrate the fractures.
5.6.4.2
Failure to completely remove the flux from around
the solder joint will prevent dye penetration and give false indi-
cations of a good solder joint.
5.7
Use low-pressure compressed air to blow off excess flux
solvent.
5.7.1
If desired, perform a final rinse with isopropyl alcohol
or acetone at this time.
5.8
Pour the dye into a small tray until the sectioned sample
is completely immersed in the dye.
5.8.1
If dye is being reused, ensure it has sufficient viscos-
ity. Viscosity is critical to the ability of the dye to penetrate into
cracks within the parts being dyed. If there are any concerns
with dye viscosity, discard the old dye and use fresh, new
dye.
5.9
Place the tray containing the sectioned sample into a
vacuum chamber.
5.9.1
Draw a 67.7 kPa [20 in Hg] vacuum for three to four
minutes.
5.9.2
Partially vent and then reapply vacuum to the chamber
to aid in dye penetration.
5.9.3
Leave the part submerged in dye for a minimum of 30
minutes with a constant vacuum of 67.7 kPa [20 in Hg].
5.9.3.1
Do not exceed 67.7 kPa [20 in Hg] of vacuum at any
time, or the dye will start to boil off.
5.10
Vent the vacuum chamber slowly and remove the
sample from the tray.
5.10.1
Allow the excess dye to drain off the sample.
Number
2.4.53
Subject
Dye and Pull Test Method (Formerly Known as Dye and Pry)
Date
8/2017
Revision
Page 2 of 11
IPC-TM-650
Note:
5.10.2
Use low-pressure compressed or canned air to gen-
tly flush any remaining dye from under the part until no further
dye runs out.
5.10.3
Dry the sample in an oven, not to exceed 100 °C or
as appropriate for the sample. If possible, allow the part to dry
overnight at ambient conditions. Wet dye can smear during
component separation, resulting in false conclusions.
5.11
Remove the sectioned part from the oven and allow it
to cool.
5.12
Perform the pull operation to physically/mechanically
remove the part from the board.
5.12.1
Abrade the surface to allow for an improved bonding
of the structural adhesive.
One way to perform this is to use a small piece of
coarse-grit sandpaper to lightly sand and roughen the part top
surface. This will remove the dried dye and will allow the top
surface to bond with the anchored tee nut.
5.12.2
Bond the tee nut to the top of the part using struc-
tural adhesive. Allow the structural adhesive to cure.
5.12.3
Use a pull-test fixture with a uniform tensile force to
separate the part from the board.
5.13
Examine the board and component for dye indications.
If necessary, gently dust with canned air or dry, filtered and
regulated compressed air to the separated part to clear away
pull debris (flakes of dye, solder mask, etc.).
5.13.1
Any fractured interface that was present will be
stained with dye. Usually, both sides are stained in a common
(mirrored) pattern.
5.14
Take photos of dyed regions and plot results as agreed
upon between the lab and the customer.
5.15 Test Report
Include the following (or as agreed upon
between the lab and the customer):
• Initial visual observations (see 5.2 and 5.5)
• Dyed interface separation location
• If required, dye indication amount/percentage (acceptability
criteria to be determined between laboratory and customer)
Other items that can be included in the test report include:
• Mapping of all separation locations
6 Notes/Figures
The figures in this section are included for informational pur-
poses only. They do not depict a correct or incorrect method
for conducting this test method.
Number
2.4.53
Subject
Dye and Pull Test Method (Formerly Known as Dye and Pry)
Date
8/2017
Revision
Page 3 of 11
IPC-TM-650
Example:
Figure
1
Ball
Grid
Array
(BGA)
With
Disturbed
Flux,
Indicating
Possible
Solder
or
Laminate
Fractures
Figure
2
Ball
Grid
Array
(BGA)
Without
Disturbed
Flux
Figure 3 Three View Drawing of a Steel Clamping Bar
(See 5.1.1) Cut to Length for the 50.8 mm L Value
(Extended #4-40 Threaded Rod Both Ends is Not Shown)
Figure 4 Three View Drawing of a Copper Ground Plate
(See 5.1.2) for the 50.8 mm L Value
IPC-TM-650
Page 4 of 11
Number
2.5.5.5.1
Revision
Subject
Stripline
Test
for
Complex
Relative
Permittivity
of
Circuit
Board
Materials
to
14
GHz
Date
3/98
Such
instruments
may
be
operated
either
manually
or
under
computer
control
with
suitable
programming
to
locate
the
resonant
frequency
and
the
frequencies
above
and
below
resonance
where
transmitted
power
is
3
dB
below
that
at
resonance.
Network
analyzers
have
several
advantages
over
the
instrumentation
described
in
4.1.
Data
collection
is
rapid
and
may
be
continuously
refreshed
with
averaging.
The
log
magnitude
response
curve
for
ratio
of
transmitted
to
incident
power
(the
S21
parameter)
as
dB
versus
frequency
is
visible
on
a
screen
for
easy
verification
of
a
valid
resonance.
A
large
number
of
dB,
frequency
data
points
near
the
resonance,
are
readily
available
for
optional
use
of
non-linear
regression
analysis
techniques
to
determine
the
frequency
and
Q
values
with
statistically
better
degrees
of
uncertainty
than
those
attainable
by
the
three
point
(fr,
and
f2)
method
in
either
section
6.2
or
6.3.
5.0
Test
Fixture
5.1
Fixture
Parts
for
Clamping
L
is
the
selected
length
for
the
specimen.
A
fixture
may
include
hardware
for
more
than
one
value
of
L.
Suggested
L
values
are
50.8,
76.2,
152.4,
and
304.8
mm.
Since
the
fundamental
resonant
frequency
and
its
harmonics
are
inversely
proportional
to
the
value
of
L
for
a
given
£r,
the
selection
of
an
L
value
determines
the
low
fre¬
quency
at
which
the
material
may
be
measured
for
and
tan
8.
Figure
1
shows
the
end
views
of
a
series
of
specimen
con¬
figurations
and
includes
the
parts
for
clamping.
5.1.1
For
each
L
value,
two
ground
tool
steel
clamping
bars
25.4
mm
x
28.58
mm
x
(L-6.35),
as
shown
in
Figure
3.
These
are
intended
to
provide
uniformly
distributed
force
along
the
length
of
the
specimen,
transferred
through
part
5.1
.2.
A
rec¬
ommended
practice
is
to
provide
these
with
a
small
diameter
threaded
rod,
such
as
#4-40,
centered
on
each
end
and
extending
about
20
mm
to
serve
as
a
means
for
attaching
the
probe
assembly
of
5.2
used
in
6.1.5
or
the
alignment
jig
of
5.1
.3
used
in
6.1
.1
.
5.1.2
For
each
L
value,
two
pure
copper
ground
plates
25.4
mm
x
9.52
mm
x
L
with
all
edges
sharp
as
in
Figure
4.
These
provide
at
the
ends
a
copper
surface
perpendicular
to
the
specimen
length
direction,
which
serves
as
a
contact
area
over
a
range
of
specimen
thicknesses
for
making
ground
con¬
tinuity
to
the
coaxial
probe.
When
these
are
clamped
with
5.1
.1
as
described
in
6.1
.1
,
the
inside
corners
at
each
end
between
the
outer
face
of
5.1
.2
and
the
end
surface
of
5.1
.1
form
reference
locations
equidistant
from
the
center
line
of
the
stripline
resonator
element
that
are
used
by
the
probe
assem¬
bly
5.2
to
align
the
coaxial
probe
with
that
center
line.
IPC-25551-3
Drill
#43
(2.26
mm)
L
—
6.35
mm
L
LEAVE
ALL
EDGES
SHARP
5.1.3
A
stacking
alignment
jig
as
used
in
6.1
.1
of
an
appro¬
priate
design.
Figure
5
shows
a
suggested
design.
5.1.4
A
low
profile
mechanical
force
gage
with
4.45
kN
compression
capacity
such
as
a
Dillon
Model
U,
PN
30482-
0053,
available
from
Dillon
Quality
Plus,
Inc.,
11
40-T
Avenida
Acaso,
Camarillo,
GA
993012.
One
is
needed
for
each
of
part
5.1.5.
5.1.5
A
clamping
arrangement
with
5.1.4
properly
mounted
in
the
line
of
force
and
with
alignment
parts
for
assuring
the
line
of
force
is
properly
located
through
the
stack
assembled