IPC-TM-650 EN 2022 试验方法.pdf - 第155页

1.0 Scope This test method is designed to measure the Resin Flow Percent by weight in prepreg. 2.0 Applicable Documents None 3.0 Test Specimens 3.1 Size and Configuration A specimen shall consist of multiple plies of pre…

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5.5
Report
5.5.1
Average
the individual specimen weight and report the
average per ply treated weight to the nearest 0.001g per 25.4
sq mm [1.0 sq in] .
6.0 Notes
6.1 The
volatile content of the prepreg (excluding moisture)
is considered part of the treated weight using this method. If
it is desired to exclude volatile content, the specimen should
be baked for an appropriate time and temperature.
6.2
The
effect of static charges may present a serious prob-
lem in weighing material if the specimen size is greater than
the sample pan.
6.3
If
it is desired to check variation across or along the
web, individual specimens should be taken from the location
in question.
6.4
If
it is desirable to check the weight uniformity of
the reinforcement, this can be done by burn-off similar to IPC-
TM-650, Method 2.3.16, if inorganic.
6.5
Calculations
Treated
weight can be used to specify
and/or predict prepreg thickness and resin content. Equations
to calculate thickness and resin content for woven fabric ‘‘E’’-
glass reinforced epoxy FR-4 prepreg are given below. The
calculations assume a resin specific gravity of 1.37 gr/cc and
an ‘‘E’’-Glass specific gravity of 2.59 gr/cc.
Woven ‘‘E’’-glass fabric nominal dry weights and tolerances
are assumed the values given in IPC-EG-140.
The
nominal
dry weights and tolerances for other reinforcements, such
as ‘‘S’ glass, woven aramid, and quartz fabric, can be
found in IPC-SG-141, IPC-A-142, IPC-QF-143.
Appropriate
values
for the specific gravities of other resins and rein-
forcements and the basis weights of other reinforcements
are the responsibility of the vendor or can be negotiated
between vendor and user. Inorganic reinforcement basis
weight can be measured as given in 6.4.
6.5.1
Resin Content
The
resin content can be calculated
from the average per ply treated weight and the measured or
nominal unit glass fabric weight. Conversely, the treated
weight can be calculated from the resin content. Equations to
calculate both are shown below:
RC
=
(
1
BW
TW
)
x
100
TW = BW
1
(RC/100)
Where:
RC = resin content by weight
TW = treated weight (weight per area per ply)
BW = unit basis weight (weight per area per ply)
6.5.2
Prepreg Thickness
The
average prepreg thickness
can be calculated using the average per ply treated weight
and the measured or nominal unit glass fabric weight. Equa-
tions to calculate prepreg thickness for Scaled Flow test sized
specimens (38.5 square inches per ply) are given below:In
general:
H
0
=
1.585TW
1.585W
f
(d
f
–d
r
)
d
r
d
f
d
r
For
‘‘E’’-glass reinforced FR-4 epoxy prepreg:
H
o
=
1.157 TW 0.545 W
f
Where:
H
o
=
prepreg thickness (mils per ply)
TW = treated weight (weight per 38.5 sq in per ply)
W
f
=
unit glass fabric weight (weight per 38.5 sq in per
ply)
d
r
=
resin density (grams per cubic centimeter)
d
f
=
fabric fiber density (grams per cubic centimeter)
6.6
Desiccator Conditions
The
Test Methods Task Group
determined that a great majority of test laboratories are unable
to consistently hold the Relative Humidity in a desiccator to
less than 20%. Based on data from participating company lab
management, the lowest practically feasible RH for use with
the affected IPC Test Methods is 30% maximum.
IPC-TM-650
Number
2.3.16.2
Subject
Treated
Weight of Prepreg
Date
12/94
Revision
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1.0
Scope
This
test method is designed to measure the
Resin Flow Percent by weight in prepreg.
2.0
Applicable Documents
None
3.0
Test Specimens
3.1 Size and Configuration
A
specimen shall consist of
multiple plies of prepreg cut 102 ± 0.25 mm [4.0 ± 0.010 in]
by 102 ± 0.25 mm [4.0 ± 0.010 in]. If the reinforcement is a
continuous fiber woven fabric, the sides shall be cut on a bias
to the fabric weave. Unless otherwise specified, the test
specimen shall have four plies.
(Note:
an alternative specimen
configuration commonly used is a stack that weighs approxi-
mately 20 g.)
3.2
Quantity and Sampling
Unless
otherwise specified,
the number of specimens tested shall be as follows: for quali-
fication testing, 3 specimens shall be tested with the pieces
for each specimen taken from areas of the prepreg that rep-
resents the center and both sides of the material as impreg-
nated. For lot testing, one specimen shall be tested, with the
pieces randomly taken. Pieces shall be taken no closer to the
selvage (or cut edge) than a distance equal to one-tenth of the
width of the roll.
4.0
Apparatus or Material
4.1 Laminating Press
Unless
otherwise specified, laminat-
ing press capable of maintaining a temperature of 171 ± 3°C
[340 ± 5°F] and capable of providing a pressure of 1380 ± 70
kPa [200 ± 10 psi] on the test specimen (see 6.1).
4.2
Analytical Balance
Analytical
balance capable of
weighing to the nearest 0.001 gram.
4.3
Plates
Caul
plates approximately 3.2 mm [0.125 in]
thick and at least 152 mm x 152 mm [6.0 in x 6.0 in], but no
larger than the press platen size, and made from type 304
steel, or equivalent.
4.4
Circle Punch
A
punch or die set capable of cutting a
circle 81.1 mm [3.192 in] in diameter.
4.5
Desiccator
Desiccation
chamber capable of maintain-
ing an atmosphere of less than 30% R.H. at 23°C [73°F].
4.6
Release Material
The
release material shall be Tedlar,
Type MR, (polyvinyl fluoride, PVF) or equivalent, cut at least as
large as the caul plates.
5.0
Procedure
5.1 Specimen Preparation
5.1.1
The
prepreg shall be cut to conform with the speci-
men size and configuration, see 3.1.
5.1.2
For
referee purposes only, specimens shall be desic-
cated for a minimum of 4 hours.
5.2
Measurement
5.2.1
Determine
the weight of each specimen to the nearest
0.005 gram. Record this as the original weight, or W
o
.
5.2.2
Stack
the plies of prepreg for one specimen with the
grain of the cloth aligned in the same direction and place
between two pieces of release film. Place this package
between two caul plates that are at room temperature.
5.2.3 Place
specimen and caul plates in a preheated lami-
nating press maintained at the specified temperature and
immediately apply pressure such that the specified pressure is
achieved within 5 seconds after press closure. Unless other-
wise specified, the temperature shall be 171 ± 3°C [340 ± 5°F]
and the pressure shall be 200 ± 10 psi [1380 ± 70 kPa].
5.2.4
Maintain
the specified pressure for 10 + 6, 0
minutes.
5.2.5
Open
press, remove specimen, and allow to cool to
room temperature.
5.2.6
If
applicable, post cure the test specimen in accor-
dance with the manufacturer’s post cure method (in order to
prevent specimen damage by cutting).
5.2.7
Using
the punch and die set, remove a circular disc
measuring 81.1 mm [3.192 in] in diameter from the center of
the specimen.
The
Institute for Interconnecting and Packaging Electronic Circuits
2215 Sanders Road Northbrook, IL 60062-6135
IPC-TM-650
TEST
METHODS MANUAL
Number
2.3.17
Subject
Resin
Flow Percent of Prepreg
Date
8/97
Revision
D
Originating Task Group
MIL-P-13949 Test Methods Task Group (7-11b)
Material
in this Test Methods Manual was voluntarily established by Technical Committees of the 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 the IPC.
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5.2.8
Weigh
the circular specimen on the analytical balance
to the nearest 0.005 gram. Record this as the disc weight, or
W
D
.
5.3
Calculation
The
resin flow is calculated as follows:
Resin Flow, Percent =
(
W
O
2W
D
W
O
)
x
100
W
o
=
Original weight of the specimen
W
D
=
Disc weight of the specimen (cut from the specimen
after pressing)
5.4
Report
The
resin flow, percent, for each specimen
tested and the average of all specimens tested shall be
reported.
6.0 Notes
None
6.1
Other
resins may require different temperature settings
to achieve flow. Pressure may also be dependent on the resin
chemistry. Agreement of temperature and pressure by sup-
plier and user other than as specified should be included in
the report, see 5.4.
6.2
Desiccator Conditions
The
Test Methods Task Group
determined that a great majority of test laboratories are unable
to consistently hold the Relative Humidity in a desiccator to
less than 20%. Based on data from participating company lab
management, the lowest practically feasible RH for use with
the affected IPC Test Methods is 30% maximum.
IPC-TM-650
Number
2.3.17
Subject
Resin
Flow Percent of Prepreg
Date
8/97
Revision
D
P
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