MIL-STD-750 Test Methods For Semiconductor DevicesThis standard establishes uniform methods and procedures for testing semiconductor devices suitable for use within Military and Aerospace electronic systems. The methods and procedures in the various parts of this standard cover basic environmental, physical, and electrical tests to determine resistance to deleterious effects of natural elements and conditions surrounding military and space operations. For the purpose of this standard, the term quot;devicesquot; includes such items as transistors, diodes, voltage regulators, rectifiers, tunnel diodes, and other related parts. This standard is intended to apply only to semiconductor devices. The test methods and procedures described in the various parts of this multipart test method standard have been prepared to serve several purposes: a. To specify suitable conditions obtainable in the laboratory that give test results equivalent to the actual service conditions existing in the field and to obtain reproducibility of the results of tests. The test methods described by this standard are not to be interpreted as an exact and conclusive representation of actual service operation in any one geographic location since it is known that the only true test for operation in a specific location is an actual service test at that point. b. To describe, in a series of standards, all of the test methods of a similar character which now appear in the various joint-services semiconductor device specifications so that these test methods may be kept uniform and thus result in conservation of equipment, man-hours, and testing facilities. In achieving this objective, it is necessary to make each of the general test methods adaptable to a broad range of devices. c. The test methods described by this standard for environmental, physical, and electrical testing of semiconductor devices shall also apply, when applicable, to parts not covered by an approved military sheet-form standard, specification sheet, or drawing.

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MIL-STD-750F

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4.3 General precautions. The following precautions shall be observed in testing the devices.

4.3.1 Transients. Devices shall not be subjected to conditions in which transients cause the rating to be exceeded.

4.3.2 Test conditions for electrical measurements. Unless otherwise required for a specified test method, semiconductor devices should not be subjected to any condition that will cause any maximum rating of the device to be exceeded. The precautions should include limits on maximum instantaneous currents and applied voltages. High series resistances (constant current supplies) and low capacitances are usually required. If low cutoff or reverse current devices are to be measured; for example, nanoampere units, care should be taken to ensure that parasitic circuit currents, or external leakage currents are small compared with the cutoff or reverse current of the device to be measured.

4.3.2.1 Thermal resistance measurements (test method series 3100). For thermal resistance measurements, at least three temperature sensitive parameters (TSP) of the transistor can be used; the collector to base cutoff current, ICBO; the forward voltage drop of the emitter to base diode, VEB; and the forward voltage drop of the collector to base diode, VCB. The methods described in this test method standard refer to the thermal resistance between specified reference points of the device. For this type of measurement, power is applied to the device at two values of case, ambient, or other reference point temperature, such that identical values of ICBO, VEB, or VCB are read during the cooling portion of the measurement.

4.3.2.2 Low frequency tests (test method series 3200). Unless otherwise specified, the measurements shall be made at the electrical test frequency, 1,000 ±25 Hz. At 1,000 Hz, the reactive components may not be negligible.

4.3.2.3 High frequency tests (test method series 3300). Care shall be taken that, in designing the circuit and transistor mounting, adequate shielding and decoupling are provided and that series inductances in circuits are negligible.

4.3.2.4 Electrical characteristics tests for MOS field effect transistors (test method series 3400). Circuits are shown for n-channel field-effect transistors in one circuit configuration only. They may readily be adapted for p- channel devices and for other circuit configurations.

4.3.2.5 Steady-state dc measurements (test method series 4000). Unless otherwise specified, all steady-state dc parameters are defined using steady-state dc conditions.

4.3.2.6 Pulse measurements (test method series 4000). When device static or dynamic parameters are measured under pulsed conditions, in order to avoid measurement errors introduced by device heating during the measurement period, the following items should be covered in the performance specification sheet:

a. The statement "pulsed test" shall be placed by the test specified.

b. Unless otherwise specified, the pulse time (tp) shall be s10 milliseconds and the duty cycle shall be a maximum of 2 percent; within this limit the pulse shall be long enough to be compatible with test equipment capability and the accuracy required, and short enough to avoid heating.