MIL-STD-750F
4.3.7 Handling precautions.
4.3.7.1 UHF and microwave devices. Handling precautions for UHF and microwave devices shall be as follows:
a. Ground all equipment.
b. Make hand contact to the equipment while holding the base end and maintain hand contact with the equipment until the device is in place.
c. Where applicable, keep devices in metal shields until they are inserted in the equipment or until necessary to remove for test.
4.3.7.2 Electrostatic discharge sensitive devices. Handling precautions should be observed in accordance with MIL-HDBK-263 during testing of Electrostatic Discharge Sensitive (ESDS) devices. The area where ESDS device tests are performed shall meet the requirements of an ESD Protected Area of MIL-STD-1686.
4.4 Continuity verification of burn-in and life tests. The test set-up shall be monitored at the test temperature initially and at the conclusion of the test to establish that all devices are being stressed to the specified requirements. The following is the minimum acceptable monitoring procedure:
a. Device sockets. Initially, and at least each 6 months thereafter, each test board or tray shall be checked to verify continuity to connector points to assure that the correct voltage bias will be applied. Except for this initial and periodic verification, each device, or device socket, does not have to be checked; however, random sampling techniques shall be applied prior to each time a board is used and shall be adequate to assure that there are correct and continuous electrical connections to the device under test (DUT).
b. Connectors to test boards or trays. After the test boards are loaded with devices, inserted into the system, and brought up to the specified operating conditions, each required test voltage and signal condition shall be verified in at least one location on each test board or tray so as to ensure electrical continuity and the correct application of specified electrical stresses, or bias, for each connection or contact pair for the DUT used in the applicable test configuration. If the system (chamber) must be is opened for performing these tests, the system may be opened for a maximum of 10 minutes. Where possible, the test node points shall be accessible external to the oven chamber (HTRB) to avoid opening the door since that immediately reduces operating temperature. This can also influence leakage currents and bias to DUT with resistors in series for power supply protection.
c. At the conclusion of the test period, prior to removal of devices from temperature and bias conditions, the voltage and signal condition verification of 4.4.b shall be repeated.
d. For class S devices, each test board or tray and each test socket shall be verified prior to test to assure that the specified bias conditions are applied to each device. This may be accomplished by verifying the device functional response at each device output(s) or by performing a socket verification on each socket prior to loading. An approved alternate procedure may be used.
4.4.1 Bias interruption. Where failures, or open contacts, occur which result in removal of the required bias stresses for any period of the required bias duration, the bias time shall be extended to ensure actual exposure for the total minimum specified test duration. Any loss(es) or interruption(s) of bias while the chamber is at temperature during the final 8 hours of burn-in shall require extension of the bias duration for an uninterrupted 8 hours (minimum) since the last interruption. Incidental, or momentary power interruptions less than or equal to 10 seconds can be ignored.
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