IPC-TM-650 EN 2022 试验方法.pdf - 第70页
Appendix A: [Photos of dicy in lowest, medium, high, and extreme levels.] Degree 1 Degree 2 Degree 1 Degree 2 IPC-TM-650 Number 2.1.10 Subject Visual Inspection for Undissolved Dicyandiamide Date 12/94 Revision A P a g e…
1.0
Scope
This
inspection method is designed to visually
inspect for dicyandiamide, commonly called ‘‘dicy,’’ that is not
dissolved in the resin of prepreg materials in which it is used
as a curing agent, by means of polarized lighting.
2.0
Applicable Documents
None.
3.0
Test Specimens
Unless
otherwise specified, one ply of
prepreg cut to 101.6 x 101.6 mm [4.0 x 4.0 in].
4.0
Apparatus or Material
4.1
An
incidental light source such as a photographic light
box, light table or illuminated microscope base. Light intensity
shall be sufficient to detect small features of the specimen
under fully polarized conditions, such as a 60 watt light bulb
used in a light box.
4.2
A
matched pair of polarizing filter lens.
4.3
A
microscope capable of magnification at least 30X to
100X.
5.0
Procedure
5.1 Preparation
5.1.1
Place
one polarizing filter directly over the light source.
Place the specimen over the filter.
5.1.2
Place
second polarizing filter over the specimen
directly in line with the first filter.
5.1.3
Set
microscope to desired magnification between 30X
and 100X and position over the approximate center of the fil-
ters. For referee purposes, magnification shall be at 100X.
5.1.4
Focus
microscope on the specimen through the top
filter.
5.1.5
Rotate
top filter 90° from bottom filter (see Figure 1).
5.2
Evaluation
5.2.1
Examine
for the presence of dicy over the entire speci-
men, excluding the edges. The dicy (if present) will cause
scattering of the polarized light which can then pass through
the second filter in sufficient intensity to be visible.
5.2.2
Careful
scrutiny must be used to eliminate consider-
ation of dust or cracks in the resin as dicy, because they will
also diffuse polarized light. Severe incidence of undissolved
dicy may be observed using partially or non-polarized light.
5.3
Report
Presence
of dicy shall be noted as per the
degrees shown in Appendix A. Appearance as to the form,
i.e., crystal, flake, or cluster, shall be reported.
6.0
Notes
6.1
Dicy
is a curing agent used with epoxy resin; it is intro-
duced at the resin mixing stage. If the mix is not homoge-
neous or is improperly done, particles of dicy may not dissolve
or may be recrystallized. Dicy may also recrystallize during the
treating operation. During lamination of the prepreg, dicy may
contribute to the formation of voids or other defects.
6.2
Dicy Flake
A
loose mass of crystals, usually in the form
of crystals radiating from a center point.
6.3
Dicy Cluster
A
concentration of crystals or flakes.
Figure
1 Dicy inspection set-up (expanded view)
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IPC-TM-650
TEST
METHODS MANUAL
Number
2.1.10
Subject
Visual
Inspection for Undissolved Dicyandiamide
Date
12/94
Revision
A
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.
P
age1of3
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Appendix
A:
[Photos
of dicy in lowest, medium, high, and
extreme levels.]
Degree
1
Degree
2
Degree
1
Degree
2
IPC-TM-650
Number
2.1.10
Subject
Visual
Inspection for Undissolved Dicyandiamide
Date
12/94
Revision
A
P
age2of3
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
Degree
3
Degree
4
Degree
4
Degree
2
Degree
4
Degree
5
IPC-TM-650
Number
2.1.10
Subject
Visual
Inspection for Undissolved Dicyandiamide
Date
12/94
Revision
A
P
age3of3
DEGREES
OF DICYANDIAMIDE (DICY) CRYSTALS
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ