MIL-PRF-19500/550C
4.4.3.1 Group C inspection, appendix E, table E-VII of MIL-PRF-19500.
Subgroup
Method
Condition
C2
2036
Tension, test condition A, weight = 10 pounds, t = 15s.
C2
2036
Bending stress, test condition F, method B; weight = 15 pounds, t = 15 s.
C2
2036
Seal torque, test condition D1, torque = 3 inch-pound, t = 15 s.
C2
2036
Stud torque, test condition D2, torque = 30 inch-pound, t = 15 s.
25 percent rated IO ≤ IO applied ≤ rated IO, 6,000 cycles (see 4.5.2).
C6
1037
4.5 Methods of inspection. Methods of inspection shall be as specified in the appropriate tables and as follows.
4.5.1 Pulse measurements. Conditions for pulse measurements shall be as specified in section 4 of
MIL-STD-750.
4.5.2 DC intermittent operation life. A cycle shall consist of an "on" period, when power is applied suddenly, not
gradually, to the device for the time necessary to achieve a delta case temperature of +85°C, +15°C, -5°C, followed
by an "off" period, when the power is suddenly removed for cooling. Auxiliary (forced) cooling is permitted during the
off period only. 30 s ≤ theating ≤ 180 s.
4.5.3 Reverse recovery time. The reverse recovery time shall be measured as shown in circuit A on figure 6 or
equivalent. Care should be exercised to minimize stray inductances in the test circuit and to ensure that the total
resistance of the reverse current loop can be adjusted sufficiently low that more than two amperes will flow if not
blocked by the diode being tested. Switch SW shall be activated and the regulated voltage source adjusted to
achieve the following characteristics of the waveform:
a.
The di/dt shall be the specified value between the forward 0.5 ampere point and the reverse 0.2 ampere
point.
b.
The ir(rec) shall be the maximum value obtainable, except that if it exceeds 2 amperes, the
reverse-recovery time shall then be determined from the current waveform as shown in circuit B on figure 3.
4.5.4 Thermal resistance. Thermal resistance measurements shall be performed in accordance with method 4081
or method 3101 of MIL-STD-750. The case reference temperature shall be held to equilibrium within the range of
20°C to 80°C during the power application and shall be measured at the hex flat. The maximum limit of RθJC shall be
0.8°C/W. The following parameter measurements shall be used:
a. IH = IF ≥ 10 A.
b. IM ≤ 250 mA.
c. tMD ≤ 250 μs.
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