MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS.pdf - 第109页

MIL-STD-883F METHOD 1017.2 25 August 1983 3 3.4 Exposure . The tes t devic es and dosi meter s shal l be exposed to t he neutron f luence as speci fied. The exposure level may be obtained by oper ating the r eact or in e…

MIL-STD-883F

METHOD 1017.2

25 August 1983

The conversion of the foil radioactivity into a neutron fluence requires a knowledge of the neutron spectrum incident on the

foil. If the spectrum is not known, it shall be determined by use of the following DoD adopted ASTM standards, or their

equivalent:

E720 - Standard Guide for Selection of a Set of Neutron-Activation Foils for Determining Neutron Spectra

used in Radiation-Hardness Testing of Electronics.

E721 - Standard Method for Determining Neutron Energy Spectra with Neutron-Activation Foils for

Radiation-Hardness Testing of Electronics.

E722 - Standard Practice for Characterizing Neutron Energy Fluence Spectra in Terms of an Equivalent

Monoenergetic Neutron Fluence for Radiation-Hardness Testing of Electronics.

Once the neutron energy spectrum has been determined and the equivalent monoenergetic fluence calculated,

then an appropriate monitor foil (such as

Fe, or

Ni) should be used in subsequent irradiations to determine the

neutron fluence as discussed in E722. Thus, the neutron fluence is described in terms of the equivalent monoenergetic

neutron fluence per unit monitor response. Use of a monitor foil to predict the equivalent monoenergetic neutron fluence is

valid only if the energy spectrum remains constant.

2.4.2 Dose measurements

. If absorbed, dose measurements of the gamma-ray component during the device test

irradiations are required, then such measurements shall be made with CaF

thermoluminescence dosimeters (TLDs), or

their equivalent. These TLDs shall be used in accordance with the recommendations of the following DoD adopted ASTM

standard:

E668 - Standard Practice for the Application of Thermoluminescence-Dosimetry (TLD) Systems for

Determining Absorbed Dose in Radiation-Hardness Testing of Electronic Devices.

3. PROCEDURE

3.1 Safety requirements

. Neutron irradiated parts may be radioactive. Handling and storage of test specimens or

equipment subjected to radiation environments shall be governed by the procedures established by the local Radiation

Safety Officer or Health Physicist.

NOTE: The receipt, acquisition, possession, use, and transfer of this material after irradiation is subject to the regulations of

the U.S. Nuclear Regulatory Commission, Radioisotope License Branch, Washington, DC 20555. A by-product

license is required before an irradiation facility will expose any test devices. (U.S. Code, see 10 CFR 30-33.)

3.2 Test samples

. A test sample shall be randomly selected and consist of a minimum of 10 parts, unless otherwise

specified. All sample parts shall have met all the requirements of the governing specification for that part. Each part shall

be serialized to enable pre and post test identification and comparison.

3.3 Pre-exposure

3.3.1 Electrical tests

. Pre-exposure electrical tests shall be performed on each part as required. Where delta parameter

limits are specified, the pre-exposure data shall be recorded.

3.3.2 Exposure set-up

. Each device shall be mounted unbiased and have its terminal leads either all shorted or all open.

For MOS devices or any microcircuit containing an MOS element, all leads shall be shorted. An appropriate mounting

fixture which will accommodate both the sample and the required dosimeters (at least one actuation foil and one CaF

TLD)

shall be used. The configuration of the mounting fixture will depend on the type of reactor facility used and should be

discussed with reactor facility personnel. Test devices shall be mounted such that the total variation of fluence over the

entire sample does not exceed 20 percent. Reactor facility personnel shall determine both the position of the fixture and the

appropriate pulse level or power time product required to achieve the specified neutron fluence level.

MIL-STD-883F

METHOD 1017.2

25 August 1983

3.4 Exposure

. The test devices and dosimeters shall be exposed to the neutron fluence as specified. The exposure level

may be obtained by operating the reactor in either the pulsed or power mode. If multiple exposures are required, the

post-radiation electrical tests shall be performed (see 3.5.1) after each exposure. A new set of dosimeters are required for

each exposure level. Since the effects of neutrons are cumulative, each additional exposure will have to be determined to

give the specified total accumulated fluence. All exposures shall be made at 20°C ±10°C and shall be correlated to a 1 MeV

equivalent fluence.

3.5 Post-exposure

3.5.1 Electrical tests

. Test items shall be removed only after clearance has been obtained from the Health Physicist at

the test facility. The temperature of the sample devices must be maintained at 20°C±10°C from the time of the exposure

until the post-electrical tests are made. The post-exposure electrical tests as specified shall be made within 24 hours after

the completion of the exposure. If the residual radioactivity level is too high for safe handling, this level to be determined by

the local Radiation Safety Officer, the elapsed time before post- test electrical measurements are made may be extended to

1 week. Alternatively, provisions may be made for remote testing. All required data must be recorded for each device after

each exposure.

3.5.2 Anomaly investigation

. Parts which exhibit previously defined anomalous behavior (e.g., nonlinear degradation of

.125) shall be subjected to failure analysis in accordance with method 5003, MIL-STD-883.

3.6 Reporting

. As a minimum, the report shall include the part type number, serial number, manufacturer, controlling

specification, the date code and other identifying numbers given by the manufacturer. Each data sheet shall include

radiation test date, electrical test conditions, radiation exposure levels, ambient conditions as well as the test data. Where

other than specified electrical test circuits are employed, the parameter measurement circuits shall accompany the data.

Any anomalous incidents during the test shall be fully explained in footnotes to the data.

4. SUMMARY

. The following details shall be specified in the request for test or, when applicable, the acquisition

document:

a. Part types.

b. Quantities of each part type to be tested, if other than specified in 3.2.

c. Electrical parameters to be measured in pre and post exposure tests.

d. Criteria for pass, fail, record actions on tested parts.

e. Criteria for anomalous behavior designation.

f. Radiation exposure levels.

g. Test instrument requirements.

h. Radiation dosimetry requirements, if other than 2.3.

i. Ambient temperature, if other than specified herein.

j. Requirements for data reporting and submission, where applicable (see 3.6).

MIL-STD-883F

METHOD 1017.2

25 August 1983

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