MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第134页
MIL-STD-883F METHOD 1020.1 15 November 1991 6 Adjust t he radiat ion sour ce to oper ate in t he speci fied mode t o deliver t he spec ified dos e. Veri fy as f ollows : Step 7: Put dos imet ry in pos ition and expose t …
MIL-STD-883F
METHOD 1020.1
15 November 1991
5
Before testing LSI/VLSI circuits, an analysis is often required to determine likely latchup paths and requirements for bias
conditions, exposure states, and functional testing. These large circuits often have too many outputs to be monitored
individually, and through the analysis, monitored outputs can be limited to those most apt to show a change should latchup
occur.
3.5 Production testing
. Prior to production testing, characterization testing shall be performed at least once for new or
unfamiliar device types (i.e., new design or process, unfamiliar or very complex devices with little or not latchup test history).
The results of the characterization tests are used to develop the requirements for the production tests (see 3.4). These
requirements are specified in the applicable test plan or procedure and include those items listed in 1.2.
3.5.1 General requirements for production tests
. Unless otherwise specified, the dose per pulse shall be 500 ±200
rad(Si) with a pulse width between 20 and 100 ns, inclusive. Circuits shall be exposed to radiation pulses in at least two
difference states (for digital devices) as specified in the test plan or procedure. Unless otherwise specified, determination of
latchup shall be based on a combination of DUT supply current and output signal (voltage) recovery within the specified time
limits and the results of post-irradiation in-situ functional tests. Power supplied to the DUT shall not be interrupted until after
the post-irradiation in-situ tests are completed. The DUT supply current shall be measured immediately before and at the
specified time after the radiation pulse to determine if the supply current has returned to within specified limits. A functional
test shall be performed immediately after the recovery period to demonstrate that the device functions properly. Unless
otherwise specified, tests shall be performed at the highest device operating temperature in the system application or 15°C
below the maximum rated temperature of the device, whichever is less. Current limiting resistors are allowed only if prior
approval is obtained from the acquiring activity and the value of the resistor is less than or equal to that in the system
application. Unless otherwise specified, endpoint electrical tests (group A, subgroups 1 and 7, as a minimum) shall be
performed pre- and post-latchup testing. These group A tests are generally not performed in-situ, and there is no time limit
on performing the group A tests. If group A testing is performed as part of another test (e.g., post-burn in, final electrical
acceptance), the group A tests need not be duplicated as long as the test sequence is: Group A tests - latchup testing -
group A tests.
3.5.2 Production test sequence
.
CAUTION: Exercise caution when handling devices, particularly with regard to pin alignment in the carriers and holding
fixture and when attaching devices to the test circuit. Insure that bias voltage are off before attachment. Observe ESD
handling procedures for the class of devices being tested.
The latchup test system, including test circuitry, cables, monitoring, and recording equipment, shall be assembled to provide
the specified biasing and output monitoring. Place the DUT in position for the specified dose; ensure that the system is
functioning as follows:
Step 1: Apply and verify the bias voltages at the interface fixture with the device removed.
Step 2: Adjust timing control system to provide the required time interval between radiation pulse and post-
irradiation measurements.
Step 3: Remove bias voltages and install a control sample device (identical to devices to be tested).
Step 4: Turn on bias voltages and verify proper device function in accordance with performance requirements.
Step 5: Verify proper operation of all recording, monitoring, and timing control equipment.
Step 6: Remove bias voltages and control device, in that order.
MIL-STD-883F
METHOD 1020.1
15 November 1991
6
Adjust the radiation source to operate in the specified mode to deliver the specified dose. Verify as follows:
Step 7: Put dosimetry in position and expose to radiation pulse. Verify that the dose recording equipment is working
properly and that the appropriate dose was delivered.
When the latchup test system, radiation source, and dosimetry system have been verified to be working properly, continue
as follows for each device type to be tested:
3.5.2.1 Combinational logic
. Latchup tests for combinational logic circuits shall be performed as follows:
Step 8: Install the DUT in the proper position in front of the radiation source, and bring the device to test
temperature.
Step 9: Bias the device in accordance with the test plan or procedure and verify proper device functional operation.
Step 10: Load the specified test pattern and verify correct output conditions.
Step 11: Irradiate the device (maintaining above input condition) and record the dose and parameters required by the
test plan or procedure.
Step 12: To verify recovery time, measure the DUT supply current at the specified time after the radiation pulse.
Verify that the supply current and output voltages have returned to within the specified limits.
Step 13: Perform another functional test and determine if the device passes.
Step 14: Put the device in complement state and repeat steps 10-13. (The number of states in which the device is to
be tested shall be specified in the test plan or procedure.)
Step 15: Remove bias voltages and device, in that order.
A combinational device fails the latchup test if the output after the recovery time is not in the proper state, it fails the post-
irradiation in-situ functional test, or if the supply current does not return to within specified limits within the specified time
after irradiation.
3.5.2.2 Sequential logic
. Latchup tests for sequential logic circuits shall be performed as follows:
Step 8: Install the DUT in the proper position in front of the radiation source, and bring the device to test
temperature.
Step 9: Bias the device in accordance with the test plan or procedure and verify proper device functional operation.
Step 10: Load the specified test pattern and verify correct output conditions.
Step 11: Irradiate the device (maintaining above input condition) and record the dose and parameters required by the
test plan or procedure.
Step 12: To verify recovery time, measure the DUT supply current at the specified time after the radiation pulse.
Verify that the supply current and output voltages have returned to within the specified limits.
Step 13: Perform functional test to determine if the device passes.
MIL-STD-883F
METHOD 1020.1
15 November 1991
7
Step 14: Change the conditions of the initial output to the complement state and repeat steps 10-13. (The number of
states in which the device is to be tested shall be specified in the test plan or procedure.)
Step 15: Remove bias voltages and device, in that order.
In sequential logic devices, the radiation pulse can cause logic state changes at the output as well as within internal storage
registers. Therefore, the post-radiation verification of recovery must be determined from a combination of device supply
current and post-exposure functional test results. A sequential logic device fails the latchup test if the supply current does
not return to within specified limits within the specified recovery period or if it fails the functional test requirements. The
specified supply current limits must take into account changes in the supply current that may result from changes in the
internal logic state and internal registers.
3.5.2.3 Linear devices
. Latchup testing for linear devices is inherently device and application specific because of the
large number of types of linear circuits and application conditions. Latchup in linear devices is detected through a
combination of monitoring the device supply current, monitoring of the output waveform, and in-situ functional tests. The
minimum number of monitored outputs shall be as specified in the test plan or procedure, but the in-situ functional test shall
exercise all outputs. The transient response of the device output is monitored through the use of an oscilloscope with a
camera, or a transient digitizer. An example is shown on figure 1020-2. Trace A shows a device output which operated
properly after the radiation pulse, and trace B shows an output that failed. Note that the device will not respond properly to
the oscillating input after the radiation exposure. Testing of linear devices is performed as follows:
Step 8: Install the DUT in the proper position in front of the radiation source, and bring the device up to test
temperature.
Step 9: Bias the device in accordance with the test plan or procedure and verify proper device functional operation.
Step 10: Adjust input signal as specified in the test plan or procedure and verify correct output level.
Step 11: Irradiate the device and record the dose. Monitor the supply current and output voltages during and after
the pulse, and measure the recovery times of the supply current and the output voltages. Monitor the
waveform of the output.
Step 12: After the recovery period, determine if the device supply currents have returned to within the specified limits.
Step 13: Determine if the output voltages have returned to within specified limits in the specified recovery time.
Ensure device responds properly to input commands, and compare pre-rad and post-rad waveforms.
Step 14: Change the conditions of the input as specified in the test plan or procedure and repeat steps 10-13. (The
number of conditions in which the device is to be tested shall be specified in the test plan or procedure.)
Step 15: Remove the bias voltages and device, in that order.
A linear device fails the latchup test if the supply current or the output signals (or voltages) do not recover within the
recovery period specified in the test plan, or if the outputs do not respond properly to an input signal.