IPC-TM-650 EN 2022 试验方法.pdf - 第793页
5.2.2 The test sample shall be connected to the discontinu- ity monitor and a minimum current of 100 milliamperes shall be established in the series circuit comprising all contacts of the test sample. 5.2.3 The test samp…
velocity-change associated with the measured acceleration
pulse is V.
5.1.3 The monitoring transducer shall be mounted on the
test fixture immediately adjacent to the test specimen or
dummy load. Two consecutive shock applications to the cali-
bration load shall produce acceleration waveforms that fall
within the appropriate tolerance envelope; in addition, graphi-
cal integration of each recorded pulse shall indicate a velocity
change within 10% of the value specified in Table 1.
5.2 Test
5.2.1
The dummy load shall be replaced with the actual test
sample.
NOTE:
If all conditions, other than this substitution, remain
the same, the resulting test waveform shall be considered
satisfactory even though it may not conform to Figures 3 or 4,
as appropriate.
IPC-3-8-2
Figure 2 Parallel Connector Fixture (Suggested)
Table I
Test Conditions
Test
Condition
Peak
Acceleration
A-Gravity
Units
Nominal
Duration
D-Milli-
seconds Waveform
Velocity
Change
Vi
(G-MS)
A 50 11 Half-sine 350.30
B 75 6 Half-sine 286.62
C 100 6 Half-sine 382.16
D 500 1
1
Half-sine 318.47
E 1000 0.5
1
Half-sine 318.47
F 5000 0.5
1
Half-sine 477.70
G 50 10 Sawtooth 250.00
H 75 6 Sawtooth 225.00
I 100 6 Sawtooth 300.00
IPC-TM-650
Number
3.8
Subject
Mechanical Shock, Connectors
Date
7/75
Revision
A
Page3of5
5.2.2 The test sample shall be connected to the discontinu-
ity monitor and a minimum current of 100 milliamperes shall
be established in the series circuit comprising all contacts of
the test sample.
5.2.3 The test sample shall be subjected to three (3) shocks
in each direction along each of three (3) orthogonal axes (18
shocks total). During and after the application of each shock,
the contacts shall be monitored for discontinuities in excess of
1 microsecond.
NOTE:
The oscillogram should include a time about 3D long
with the pulse approximately in the center. The integration to
determine the velocity change should extend from 0.4D
before the pulse to 0.1D beyond the pulse. The peak accel-
eration,
magnitude of the sawtooth pulse is P and its duration is D.
Any measured acceleration pulse which can be contained
between the broken line boundaries is nominal terminal-peak
sawtooth pulse of nominal peak value, P, and nominal dura-
tion, D. The velocity-change associated with the measured
acceleration pulse is V.
6.0 Notes
6.1
Acceptance criteria shall be established in terms of one,
or any combination, of the following:
A. Loss of continuity during or after any imposed shock.
B. Mechanical damage,
IPC-3-8-3
Figure 3 Tolerances for Half Sine Shock Pulse
IPC-TM-650
Number
3.8
Subject
Mechanical Shock, Connectors
Date
7/75
Revision
A
Page4of5
IPC-3-8-4
Figure 4 Tolerances for Terminal-Peak Sawtooth Shock Pulse
IPC-3-8-5
Figure 5 Tolerance Limits for Measuring System Frequency Response
IPC-TM-650
Number
3.8
Subject
Mechanical Shock, Connectors
Date
7/75
Revision
A
Page5of5