IPC-TM-650 EN 2022 试验方法.pdf - 第689页
6.1.1 Unless otherwise specified by the applicable perfor- mance specification, the following base material types/ temperature ratings are recommended. 6.2 Suggested sources for capable test equipment: Cambridge Technolo…
1.0
Scope
The
purpose of this method is to determine the
physical endurance of printed boards to sudden exposure to
extreme changes in temperature and the effect of alternate
exposures to these extremes. The exposure of the printed
board specimens to the high and low temperature extremes is
designed to cause physical damage, deterioration, or signifi-
cant changes in resistance.
2.0
Applicable Documents
IPC-D-275
Design
Standard for Rigid Printed Boards and
Rigid Printed Board Assemblies.
3.0
Test Specimen
Test
coupon ‘‘D’’ from IPC-D-275 or
other suitable test coupon (see 6.1a).
4.0
Apparatus
4.1
An
automatically controlled dual temperature environ-
mental test chamber or other dual chamber apparatus
capable of maintaining –65, –55, –40 or 0°C+0–5°C [–85,
–67, –40, +32°F+0–9°F] in the low temperature chamber
and 70, 85, 105, 125, 150 or 170 +5 –0°C [158, 185, 221,
257, 302 or 338° F+9–0°F] in the high temperature chamber.
NOTE: The temperature extremes (high and low) that are
required is dependent on the base material of the specimen
that is to be tested (see 6.1b ). The recovery capacity of the
test chambers shall be such that the internal chamber air tem-
perature shall reach the specified temperature within 2 min-
utes after the specimen(s) have been transferred to the test
chamber.
4.2
An
electrical resistance meter capable of accuracies of
0.5 milliohm or better with Kelvin (4 terminal) type leads. A
Kelvin type double bridge or potentiometer of the specified
accuracy may also be used (see 6.2).
5.1
Preparation
Wire
up test specimen with Kelvin-type
leads at the points where measurements will be made.
5.1.1
Operate
chamber (or chambers) and allow to stabilize
at the high and low temperature required. Clamp or suspend
specimen in the approximate center of the high temperature
chamber. First specimens shall be placed approximately 13
mm [0.5 in] apart and aligned in a manner to permit maximum
heat transfer to the test specimen(s).
5.2
Test
5.2.1 Thermal Shock Cycle
5.2.1.1
The
specimens shall be subjected to 100 tempera-
ture cycles in accordance with the applicable test condition of
Table 1.
5.2.1.2
Transfer
time between chambers shall be less than
2 minutes. The thermal capacity of the test chamber used
shall be such that the ambient temperature shall reach the
specified temperature within 2 minutes after the specimen has
been transferred to the appropriate chamber.
5.2.1.3
Interconnection
resistance measurements shall be
taken before the test, during the first cycle at high tempera-
ture, and during the last cycle at high temperature. In-cham-
ber resistance measurements should be taken during the last
few minutes of chamber exposure. Care should also be taken
to measure samples after approximately the same duration at
chamber temperature.
5.3
Evaluation
The
maximum change in resistance
between the first and 100th cycle shall be evaluated for
acceptability to the requirements of the applicable specifica-
tion.
6.0 Notes
6.1
The
following details are to be specified in the applicable
performance specification:
a. Test specimen, if other than specified in 3.0.
b. Test condition, if other than specified in 4.1.
c. Maximum change in resistance.
The
Institute for Interconnecting and Packaging Electronic Circuits
2215 Sanders Road • Northbrook, IL 60062-6135
IPC-TM-650
TEST
METHODS MANUAL
Number
2.6.7
Subject
Thermal
Shock & Continuity, Printed Board
Date
8/97
Revision
A
Originating Task Group
Rigid Board T.M. Task Group, 7-11d
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
age1of2
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
6.1.1
Unless
otherwise specified by the applicable perfor-
mance specification, the following base material types/
temperature ratings are recommended.
6.2
Suggested sources for capable test equipment:
Cambridge
Technology
Model 510A Micro-Ohmmeter
23 Elm Street
Watertown, MA 02172
(617) 923-1181
Hewlett-Packard
Model 4338A Milliohmmeter
9800 Muirlands Avenue
Irvine, CA 92718
(714) 472-3000
Keithly Instruments
Model 580
Micro-ohmmeter
28775 Aurora Road
Cleveland, OH 44139
(800) 552-1115
T
able 1
Step
T
est Condition A Test Condition B Test Condition C
Temperature Time Temperature Time Temperature Time
1
2
3
4
0, +0/-5
25, +10/-5
+70, +5/-0
25, +10/-5
15
0
15
0
-40, +0/-5
25, +10/-5
+85, +5/-0
25, +10/-5
15
0
15
0
-55, +0/-5
25, +10/-5
+105, +5/-0
25, +10/-5
15
0
15
0
Step
Test Condition D Test Condition E Test Condition F
Temperature Time Temperature Time Temperature Time
1
2
3
4
-55, +0/-5
25, +10/-5
+125, +5/-0
25, +10/-5
15
0
15
0
-65, +0/-5
25, +10/-5
+150, +5/-0
25, +10/-5
15
0
15
0
-65, +0/-5
25, +10/-5
+170, +5/-0
25, +10/-5
15
0
15
0
T
olerance shall be +2 and -0 minutes.
T
able 2
Rigid
Type NEMA Test Condition
A
GP, GT, GX, GY B
GE C
AF, BF, BI, CF, GF, GB D
GH, GM E
AI, GI, QI F
IPC-TM-650
Number
2.6.7
Subject
Thermal
Shock & Continuity, Printed Board
Date
8/97
Revision
A
P
age2of2
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ
1
Scope
This
test method is to determine the physical
endurance of applied conformal coating to sudden changes of
high and low temperature excursions that cause physical
fatigue.
2
Applicable Documents
IPC-CC-830
Qualification
and Performance of Electrical Insu-
lating Compound for Printed Board Assemblies
3
Test Specimens
Five
IPC-B-25A boards (see Figure 1)
coated with conformal coating per coating supplier’s recom-
mendations.
4
Apparatus
Test
chamber - automatically controlled dual
temperature environmental test equipment or two separate
chambers capable of maintaining -65° ± 5°C [-85° ± 9°F] and
250° ± 5°C [482° ± 9°F] respectively. Please note, while most
requests state 125° ± 5°C [257° ± 9°F] on the high side, there
are cases (such as polyimide board applications) where a
higher temperature will be required. Test conditions, if not
otherwise stated as below, shall be -65°C [-85°F] and 125°C
[257°F].
Class
Low Temperature High Temperature
1
N/A N/A
2 -40°C [-40°F] 125°C [257°F]
3 -65°C [-85°F] 125°C [257°F]
4 -65°C [-85°F] 250°C [482°F]
5 Procedure
5.1 Specimen Preparation
Operate
the chamber(s) to
high and low temperatures and stabilize. Clamp or suspend
the five conformal coated IPC-B-25A boards in the thermal
shock chamber.
5.1.1 Set
the cold portion of chamber at -65°C [-85°F] and
the hot portion of chamber at 125°C [257°F].
5.1.2
Set
the dwell time for 15 minutes.
5.1.3
Set
the temperature recovery time for less than two
minutes.
5.1.4
Set
the chamber for 100 cycles.
5.1.5
Activate
the test chamber and begin testing.
5.2
Evaluation
5.2.1
Upon
completion of the thermal shock test, the speci-
mens shall meet the requirements of appearance and dielec-
tric withstanding voltage in accordance with IPC-CC-830.
IPC-2671-1
Figure
1 IPC-B-25A Test Board
2215
Sanders Road
Northbrook, IL 60062-6135
IPC-TM-650
TEST
METHODS MANUAL
Number
2.6.7.1
(Supersedes
2.6.7.1 for Conformal Coating Tests)
Subject
Thermal Shock - Conformal Coating
Date
07/00
Revision
A
Originating Task Group
Conformal Coating Task Group (5-33a)
Material
in this Test Methods Manual was voluntarily established by Technical Committees of 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 IPC.
P
age1of1
ASSOCIA
TION CONNECTING
ELECTRONICS INDUSTRIES
电子技术应用 ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ