MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第152页

MIL-STD-883F METHOD 1023.2 19 August 1994 4 3.2 Radiat ion saf ety . All personnel shall adhere to t he health and s afety requi rements establ ished by t he local radiat ion safet y offi cer or health phys ici st. 3.3 S…

MIL-STD-883F

METHOD 1023.2

19 August 1994

2.3 Dose Rate Test System

. The instrumentation shall be capable of establishing the required test conditions and

measuring and recording the required parameters in the specified time frame. Components other than the device under test

(DUT) shall be insensitive to the expected radiation levels, or they shall be shielded from the radiation. The system used for

dose rate testing shall contain the following elements:

2.3.1 Remote Test circuit

. The remote portion of the test circuit includes power sources, input and control signal

generators, instrumentation for detecting, measuring and recording transient and steady state response, and may also

include automated test equipment (ATE). The remote portion of the test equipment is shielded from radiation and from

radiation induced electromagnetic fields. Specified signals shall be measured and recorded during the radiation pulse, and

the logic pattern shall be verified after the pulse (when applicable).

2.3.2 Interconnect fixture

. The interconnecting fixture is located in the radiation exposure chamber and is connected to

the remote portion of the test circuit via the cabling system. It serves as a power and signal distribution box and contains

the line drivers that buffer the various DUT output signals. The characteristics of the line drivers (e.g., linearity, dynamic

range, input capacitance, transient response and radiation response) shall be such that they accurately represent the

response of the DUT output. The interconnect fixture shall be located as close as practical to the exposure fixture, and must

be appropriately shielded against scattered radiation fields so that radiation induced effects do not adversely affect the

fidelity of the output response being measured.

2.3.3 Test circuit

. The test circuit for each device type shall provide worst case bias and load conditions for the DUT, and

shall enable in-situ functional testing of the DUT as specified in the test plan or procedure. The test circuit accommodates

the DUT, output loads, and the supply stiffening capacitors connected directly to the DUT supply pins or its socket (see

2.3.4). To avoid ground loops, there shall be only one ground plane (or ground rings connected to a single ground) on the

test circuit. Test Circuit parasitic resistance shall be kept to a minimum.

2.3.4 Stiffening capacitors

. A high frequency capacitor shall be placed at each bias supply pin of the DUT with lead

lengths as short as practicable. These capacitors should be large enough such that the power supply voltage drop at the

DUT is less than 10% during the radiation pulse (typical values are between 4.7 and 10 µF). In parallel with this capacitor

should be a low inductance capacitor (e.g., 0.1 µF), again as close as possible to the supply pin and with lead lengths as

short as practical. In addition, for each supply line into the DUT, a larger capacitor, >

100 µF, may be placed a short

distance away from the DUT and shielded from radiation.

2.3.5 Current Limiting Series resistor

. A current limiting resistor in series with the power supply may only be used with

prior approval of the acquiring activity. Note that a current limiting resistor may degrade the upset performance of the DUT.

2.3.6 Timing control

. A timing control system shall be incorporated into the test system such that post-irradiation in-situ

functional testing is performed at the specified time, and that recovery of the signal and supply current can be monitored.

2.4 Cabling

. The remote test circuit shall be connected to the interconnect and exposure fixtures by means of shielded

cables terminated in their characteristic impedance. Additional shielding provisions (e.g., doubly shielded cables, triax,

zipper tubing, aluminum foil) may be required to reduce noise to acceptable levels.

2.5 Measuring and recording equipment

. Oscilloscopes or transient waveform digitizers shall be used to measure and

record the transient signal and the recovery period of the output voltage and supply current. The rise time of these

instruments shall be such that they are capable of accurately responding to the expected pulse width(s).

3. PROCEDURE

3.1 Device identification

. In all cases, devices shall be serialized, and the applicable recorded test data shall be

traceable to each individual device.

MIL-STD-883F

METHOD 1023.2

19 August 1994

3.2 Radiation safety

. All personnel shall adhere to the health and safety requirements established by the local radiation

safety officer or health physicist.

3.3 Stress limits.

3.3.1 Total ionizing dose limit

. Unless otherwise specified, any device exposed to more than 10% of its total ionizing

dose limit shall be considered to have been destructively tested. The total dose limit shall be determined (or data obtained)

for each device type to be tested. The total ionizing dose limit shall be specified in the test plan.

3.3.2 Burnout Limit.

A device exposed to greater than 10% of the level at which photocurrent burnout occurs shall be

considered destructively tested. The burnout level shall be specified in the test plan/procedure. The burnout level may be

specified as the maximum dose rate level at which the device type has been tested and does not burnout. Note that dose

rate testing causes surge currents ranging from 20 ns to 500 ns (typically) in duration, which may exceed the manufacturers'

maximum ratings for current and power for that time period.

3.4 Characterization testing

. Characterization tests shall be performed or data obtained to determine device performance

as a function of dose rate and to establish requirements for production testing, if applicable. The following are examples of

information gained from characterization testing:

a. Parameter behavior over dose rate and pulse width.

b. Upset threshold as a function of radiation dose rate and pulse width.

c. Determination of susceptible circuit conditions.

d. Identification of the most susceptible circuits of a device, and the appropriate outputs to monitor.

e. Effect of temperature on upset or failure.

f. Upset, recovery time and failure criteria to be specified in the device specification or drawing.

g. Group A electrical parameter degradation subsequent to dose rate testing.

h. Worst case power supply voltage.

i. Maximum surge currents and duration, and photocurrent burnout level.

3.5 Production testing

. Prior to production testing, characterization testing shall be performed or characterization data

obtained for each device type. The results of the characterization tests (paragraph 3.4), or the existing data, will be used to

develop the requirements for the production tests. These requirements are specified in the applicable test plan or procedure

and include those items listed in paragraph 1.2.

3.5.1 General requirements for production tests.

Production tests shall be performed at the specified dose rates (and

pulse widths), with bias and load conditions as specified in the test plan or procedure. The measured response shall be

compared to the upset criteria and determination of pass/fail shall be made. Devices having storage elements shall be

loaded with the applicable test pattern prior to exposure and post-exposure functional test shall be performed to the extent

necessary to verify the stored pattern.

3.6 Testing of Complex Linear Devices

. Testing of complex linear devices, such as analog to digital and digital to

analog converters, shall be performed using the necessary (as specified in the test plan or procedure) exposure conditions

to ensure adequate coverage. Often, four or more exposure conditions are required. To the greatest extent practical, the

most susceptible exposure conditions (i.e., most favorable for upset to occur) shall be used. For linear devices that have

storage elements, each exposure state shall consist of a stored test pattern plus the external bias. Each test pattern shall

be loaded prior to exposure, and following the application of the radiation pulse, functional testing of the device must be

performed to the extent necessary to verify the pattern.

MIL-STD-883F

METHOD 1023.2

19 August 1994

3.7 Dose Rate Test Sequence

3.7.1 Facility Preparation

. The radiation source shall be adjusted to operate in the specified mode and provide a radiation

pulse within the specified pulse width range. The required dosimeters shall be installed as close as practical to the DUT.

3.7.2 Test Circuit preparation

. The dose rate test system, including all test circuitry, cables, monitoring and recording

equipment shall be assembled to provide the specified bias and load conditions and output monitoring. The test circuit shall

be placed in position such that the DUT will receive the specified dose. Unless otherwise specified, dose rate testing shall

be performed at 25° +

5°C. (The test temperature shall be specified in the test plan/procedure.)

3.7.3 Test circuit noise check

. With all circuitry connected, a noise check, including radiation induced noise, shall be

made. Noise signals shall be kept as low as practicable. The circuitry and cabling system shall be modified until the noise

signals are below an acceptable level (usually less than 10% of the expected response).

3.7.4 Test Procedure

CAUTION: Exercise caution when handling devices, particularly with regard to pin alignment in the and holding fixture

and when installing devices in the test circuit. Ensure that voltages are off before inserting the DUT. Observe ESD

handling procedures for the class of devices being tested, as appropriate.

Step 1: Adjust timing control system to provide the required time interval between radiation pulse and

post-irradiation measurements.

Step 2: Remove bias voltages and install a control sample device (same type as devices to be tested).

Step 3: Turn on bias voltages and verify proper device function in accordance with performance

requirements.

Step 4. Verify proper operation of all recording, monitoring and timing control equipment. Monitor and

record noise level and temperature.

Step 5. Remove bias voltages and control device, in that order.

Adjust the radiation source to operate in the specified mode to deliver the specified dose. Verify as follows:

Step 6: 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 dose rate test system, radiation source and dosimetry system have been verified to be working properly, continue

as follows for each device type to be tested:

Step 7: Ensure bias is removed from the test circuit and install DUT.

Step 8: Bias the device and load the test patterns (if applicable) in accordance with the test plan or

procedure. Verify proper device functional operation.

Step 9: Expose the DUT to the radiation pulse and measure the response of the specified outputs, as

well as the recovery characteristics.

Step 10: Compare the DUT response to upset criteria, if applicable.

Repeat steps 8-10 for each exposure state and for each radiation dose rate.

Step 11: Remove bias and DUT in that order.

Note that the upset threshold shall be reported as the maximum dose rate at which the DUT does not upset.