MIL- STD-883F 2004 TEST METHOD STANDARD MICROCIRCUITS - 第110页

MIL-STD-883F METHOD 1017.2 25 August 1983 4 This page i ntenti onally lef t blank

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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MIL-STD-883F

METHOD 1018.4

18 June 2004

METHOD 1018.4

INTERNAL WATER-VAPOR CONTENT

1. PURPOSE

. The purpose of this test is to measure the water-vapor content of the atmosphere inside a metal or

ceramic hermetically-sealed device. It can be destructive (procedures 1 and 2) or nondestructive (procedure 3).

2. APPARATUS

. The apparatus for the internal water-vapor content test shall be as follows for the chosen procedure:

2.1 Procedure 1

. (Procedure 1 measures the water-vapor content of the device atmosphere by mass spectrometry.) The

apparatus for procedure 1 shall consist of:

a. A mass spectrometer meeting the following requirements:

(1) Spectra range

. The mass spectrometer shall be capable of reading a minimum spectra range of 1 to 100

atomic mass units (AMUs).

(2) Detection limit. The mass spectrometer shall be capable of reproducibly detecting the specified

moisture content for a given volume package with signal to noise ratio of 20 to 1 (i.e., for a specified limit

of 5,000 ppmv, .01 cc, the mass spectrometer shall demonstrate a 250 ppmv minimum detection limit to

moisture for a package volume of .01 cc). The smallest volume shall be considered the worst case.

(3) Calibration

. The calibration of the mass spectrometer shall be accomplished at the specified moisture

limit (±20 percent) using a package simulator which has the capability of generating at least three known

volumes of gas ±10 percent on a repetitive basis by means of a continuous sample volume purge of

known moisture content ±10 percent. Moisture content shall be established by the standard generation

techniques (i.e., 2 pressure, divided flow, or cryogenic method). The dew point analyzer shall be

recalibrated a minimum of once per year using equipment traceable to NIST or by a suitable commercial

calibration services laboratory using equipment traceable to NIST standards,. Calibration records shall

be kept on a daily basis. Gas analysis results obtained by this method shall be considered valid only in

the moisture range or limit bracketed by at least two (volume or concentration) calibration points (i.e.,

5,000 ppmv between .01 -.1 cc or 1,000 – 5,000 ppmv between .01 - .1 cc). A best fit curve shall e used

between volume calibration points. Systems not capable of bracketing may use an equivalent procedure

as approved by the qualifying activity. Corrections of sensitivity factors deviation greater than 10 percent

from the mean between calibration points shall be required.

NOTE: It is recommended that the percentage of water vapor contained in a gas flowing through the gas

humidifier be compared to the dewpoint sensor reading for accuracy of the sensor. The following

equation may be used to calculate the percent of water vapor contained in a gas flowing through the gas

humidifier.

PaPg

mmmbmb/psi

/33.1 68.95

)(100

, where

= vapor pressure of water in the GPH based on water temperature in degrees centigrade,

= gauge pressure in psi, and

= atmospheric pressure in mm Hg.

(4) Calibration for other gases

. Calibration shall be required for all gases found in concentrations greater

than .01 percent by volume. As a minimum, this shall include all gases listed in 3.1c. The applicable

gases shall be calibrated at approximately 1 percent concentrations as part of the yearly calibration

requirements, with the exception of fluorocarbons, which may use a concentration of approximately 200

ppmv; nitrogen, which may use a concentration of approximately 80 percent or more; helium, which may

use a concentration of approximately 10 percent; and oxygen, which may use a concentration of

approximately 20 percent.