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696. Apparatus for determining the vacuum-tightness of seals
Classified
abstracts
691-700
enclosing the connector. The leak detection by pressure variation is also mentioned. L E Grimes, Conf Design of Leak-Tight Separable Fluid Connectors, Rep NASA-TM-X-60234, March 1964, 213-244 (Sri Tech Aerospace Reps, 5 (21), 3857, N67-35577). 27 691. Leakage
measurement
and evaluation.
(USA)
In order to establish rational tube leakage specification, an attempt was made to define the measurability of leakage rates and to establish conversion criteria between the leak rates measured with a tracer gas during testing and those produced by working fluid at the operating pressure. Calculations are presented on the technique of converting the leakage of the test gas to the leakage during operation. J W Marr, Conf Design of Leak-Tight Seuarable Fluid Connectors. Rep NASAlTM--X-602j4, &arch 1961, 2451306 (Sri Tech Aerospace Reps, 5 (21), 3857, N67-35578). 21 692. Analysis of integrated circuit package integrity using helium leak detectors. (USA)
Current integrated circuit packaging techniques, a compilation of applicable package hermeticity testing techniques, and the required theoretical fluid flow background necessary to evaluate integrated circuit package integrity, are presented including: the basic types of integrated circuit packages with the emphasis placed on defects in package construction and hermetic sealing techniques which can influence package integrity; a general description of standard hermeticity tests, and their inherent limitations, when used in determining leak rates; and the helium leak detection system and test procedures for package leak rate measurements. A complete review and analysis of the classical steady state helium gas flow rate equations are given. The time dependence corrections to the classical flow laws, required when an enclosed volume is imposed on the system, are derived and applied to the helium leak detection technique. The analysis includes a detailed determination of equivalent hole diameters based on the measured package leak rate. E A Doyle, Rep RADC-TR-67-52; AD-654695, May 1967, 79 pages (Sci Tech Aerospace
Reps, 5 (21), 3816, N67-35696). 27
693. Quantitative
leak test design guide.
checking leaks by studying the glow pattern of the residual gas is unreliable in view of the large pressure drop between the external atmosphere and the inside of the apparatus under test. In the improved method the apparatus is first filled with an inert gas such as neon, increasing the sensitivity as well as reducing the pressure drop. Examples of tests carried out by this method are presented and some practical hints are given on how to secure optimum efficiency under particular laboratory and industrial conditions. The method is particularly useful for express leak detection in the industrial production of electronic vacuum apparatus. V G Chaikovskii et al, USSR Patent 189,082, Appl 7th April 1965, Pub1 26th Dee 1966. 27 : 23 696. Apparatus for determining the vacuum-tightness of seals. (USSR) A new form of apparatus for determining the vacuum-tightness of
seals is described. The apparatus comprises a pumping system, a device for measuring vacuum and a vacuum, pipe-line connecting the space into which the leaks (if any) are penetrating to the pumpins system. This arrangement is distinguished by the fact that, in order to secure a quantitative determination of the leaks into the vacuum space, it is furnished with a reservoir containing compressed neutral gas and a condensation system joining the latter to the vacuum pipeline; gas leaking through the seal is condensed in this condenser and is determined by chemical or gravimetric methods. A I Kagaonova et al, USSR Patent 189,611, Appl 16th July 1964, Pub1 7th Jan 1967. 28. HEATING EQUIPMENT
AND THERMOMETERS 28
697. High-temperature
evaporators
for the electronograph
A.
(USSR)
The electronozraph EG-100 A is employed in the investigation of the interaction of an electron beam with a stream of vapours. A new evaporator was designed in which a sample is heated up to 3000°C by bombardment of electrons with the energy 3 kV and current 1.5A. Exchanging the tungsten cathode by conventional resistance heaters a sample may be heated up to 600°C by radiation. N P Levkin et al, Pribory Tekh Eksper, 12 (6), Nov-Dee 1967, 130-133 (in Russian)
(USA)
Rapid and accurate procedures for determining leak rates using a calibrated enclosure technique were developed. The test object is pressurized with helium and the helium leak rate determined, from which the leak rates of other gases can be estimated. Three different methods of using this technique are described and the results of experimental tests run by these methods are reported. All three methods involve pressurizing the test object with pure helium, enclosing the object in a bag or tent, sensing the helium content in the enclosure and determining the rate of current increase in a mass spectrometer tube, and calibrating the current increase in the mass spectrometer in terms of a helium rate by either comparing to known helium leaks, or injecting a known quantity of helium. The major equipment required for this procedure is described along with design criteria. The accuracy and speed of the calibrated enclosure technique vary with enclosure volume, test leak rate, and leak detector sensitivity and stability. J L Manganaro and D L Hollinger, Rep NASA-CR-88504, Aug 1967, 114 pages (Sci Tech Aerospace Reps, 5 (22), 4021, N67-37647). 27 system as
694. Feasibility study for a hydrogen gas leak detection (USA) required for use on intlight experiments. A breadboard model of the leak detector system consisting
of a Varadi rf mass spectrometer tube, a solid-state electrometer, and a two-frequency rf driver was fabricated and tested using standard laboratory power supplies. Results of these tests demonstrated the feasibility of this system for application on 100 millisecond response time over the pressure range from 7 x 1O-3 to 1 x 10m7 torr. The system detected less than I per cent Hz in a helium atmosphere at 1O-5 torr.
Anon, Raytheon Co, Rep NASA-CR-88629; U67-4041, Jan 1967, 107 pages (Sci Tech Aerospace Reps, 5 (21), 3845, N67-35358).
III. Vacuum
applications
30. EVAPORATION
AND SPUTTERING 30 of thin films.
(Germany) Solid samples are placed in the ion source of the mass spectrometer and bombarded by a beam of positive argon ions of energy 11 keV. The bombardment liberates partly neutral atoms and partly ions from the surface. This method allows quantitative analysis of thin film materials, once calibration data have been obtained for the secondary ion emission and matrix effects for the elements concerned. Data on the yield of secondary ions and matrix effects are presented for a variety of elements. 698. Mass spectrometer
for the examination
H Werner and H A M de Grafte, 3741 (in German).
Vakuum-Technik,
17 (2), Feb 1968,
699. Growth of crystalline silicon by vacuum evaporation. (Japan)
films on polycrystalline
(USSR)
An improved method of checking the vacuum-tightness of metal and glass electronic vacuum apparatus is described. The usual method of
30 substrates
Crystalline films of silicon were prepared on a tungsten substrate by vacuum evaporation. The technique used was crystal growth from a gold-silicon alloy zone on a rn:tal substrate. Growth of plane crystals or whisker crystals was observed depending on growth conditions such as substrate temperature, thickness of gold film and evaporation rate. The sizes of the crystals obtained were as large as several hundred microns. Their orientation was in the (I 11) plane, parallel to the substrate and their conductivity was n-type. Details of the growth technique and the examination of the films by optical and electron microscope are presented. K lshiwatari et al, J Vat Sot Japan, 10 (9), 1967,322-327 (in Japanese).
27 :31 695. Method of leak detection.
EG-100
700. Epitaxial growth of cubic vacuum. (Great Britain)
ZnS
by evaporation
30 in ultrahigh
In order to investigate the effect of clean conditions on the epitaxial 299
abstracts
691-700
enclosing the connector. The leak detection by pressure variation is also mentioned. L E Grimes, Conf Design of Leak-Tight Separable Fluid Connectors, Rep NASA-TM-X-60234, March 1964, 213-244 (Sri Tech Aerospace Reps, 5 (21), 3857, N67-35577). 27 691. Leakage
measurement
and evaluation.
(USA)
In order to establish rational tube leakage specification, an attempt was made to define the measurability of leakage rates and to establish conversion criteria between the leak rates measured with a tracer gas during testing and those produced by working fluid at the operating pressure. Calculations are presented on the technique of converting the leakage of the test gas to the leakage during operation. J W Marr, Conf Design of Leak-Tight Seuarable Fluid Connectors. Rep NASAlTM--X-602j4, &arch 1961, 2451306 (Sri Tech Aerospace Reps, 5 (21), 3857, N67-35578). 21 692. Analysis of integrated circuit package integrity using helium leak detectors. (USA)
Current integrated circuit packaging techniques, a compilation of applicable package hermeticity testing techniques, and the required theoretical fluid flow background necessary to evaluate integrated circuit package integrity, are presented including: the basic types of integrated circuit packages with the emphasis placed on defects in package construction and hermetic sealing techniques which can influence package integrity; a general description of standard hermeticity tests, and their inherent limitations, when used in determining leak rates; and the helium leak detection system and test procedures for package leak rate measurements. A complete review and analysis of the classical steady state helium gas flow rate equations are given. The time dependence corrections to the classical flow laws, required when an enclosed volume is imposed on the system, are derived and applied to the helium leak detection technique. The analysis includes a detailed determination of equivalent hole diameters based on the measured package leak rate. E A Doyle, Rep RADC-TR-67-52; AD-654695, May 1967, 79 pages (Sci Tech Aerospace
Reps, 5 (21), 3816, N67-35696). 27
693. Quantitative
leak test design guide.
checking leaks by studying the glow pattern of the residual gas is unreliable in view of the large pressure drop between the external atmosphere and the inside of the apparatus under test. In the improved method the apparatus is first filled with an inert gas such as neon, increasing the sensitivity as well as reducing the pressure drop. Examples of tests carried out by this method are presented and some practical hints are given on how to secure optimum efficiency under particular laboratory and industrial conditions. The method is particularly useful for express leak detection in the industrial production of electronic vacuum apparatus. V G Chaikovskii et al, USSR Patent 189,082, Appl 7th April 1965, Pub1 26th Dee 1966. 27 : 23 696. Apparatus for determining the vacuum-tightness of seals. (USSR) A new form of apparatus for determining the vacuum-tightness of
seals is described. The apparatus comprises a pumping system, a device for measuring vacuum and a vacuum, pipe-line connecting the space into which the leaks (if any) are penetrating to the pumpins system. This arrangement is distinguished by the fact that, in order to secure a quantitative determination of the leaks into the vacuum space, it is furnished with a reservoir containing compressed neutral gas and a condensation system joining the latter to the vacuum pipeline; gas leaking through the seal is condensed in this condenser and is determined by chemical or gravimetric methods. A I Kagaonova et al, USSR Patent 189,611, Appl 16th July 1964, Pub1 7th Jan 1967. 28. HEATING EQUIPMENT
AND THERMOMETERS 28
697. High-temperature
evaporators
for the electronograph
A.
(USSR)
The electronozraph EG-100 A is employed in the investigation of the interaction of an electron beam with a stream of vapours. A new evaporator was designed in which a sample is heated up to 3000°C by bombardment of electrons with the energy 3 kV and current 1.5A. Exchanging the tungsten cathode by conventional resistance heaters a sample may be heated up to 600°C by radiation. N P Levkin et al, Pribory Tekh Eksper, 12 (6), Nov-Dee 1967, 130-133 (in Russian)
(USA)
Rapid and accurate procedures for determining leak rates using a calibrated enclosure technique were developed. The test object is pressurized with helium and the helium leak rate determined, from which the leak rates of other gases can be estimated. Three different methods of using this technique are described and the results of experimental tests run by these methods are reported. All three methods involve pressurizing the test object with pure helium, enclosing the object in a bag or tent, sensing the helium content in the enclosure and determining the rate of current increase in a mass spectrometer tube, and calibrating the current increase in the mass spectrometer in terms of a helium rate by either comparing to known helium leaks, or injecting a known quantity of helium. The major equipment required for this procedure is described along with design criteria. The accuracy and speed of the calibrated enclosure technique vary with enclosure volume, test leak rate, and leak detector sensitivity and stability. J L Manganaro and D L Hollinger, Rep NASA-CR-88504, Aug 1967, 114 pages (Sci Tech Aerospace Reps, 5 (22), 4021, N67-37647). 27 system as
694. Feasibility study for a hydrogen gas leak detection (USA) required for use on intlight experiments. A breadboard model of the leak detector system consisting
of a Varadi rf mass spectrometer tube, a solid-state electrometer, and a two-frequency rf driver was fabricated and tested using standard laboratory power supplies. Results of these tests demonstrated the feasibility of this system for application on 100 millisecond response time over the pressure range from 7 x 1O-3 to 1 x 10m7 torr. The system detected less than I per cent Hz in a helium atmosphere at 1O-5 torr.
Anon, Raytheon Co, Rep NASA-CR-88629; U67-4041, Jan 1967, 107 pages (Sci Tech Aerospace Reps, 5 (21), 3845, N67-35358).
III. Vacuum
applications
30. EVAPORATION
AND SPUTTERING 30 of thin films.
(Germany) Solid samples are placed in the ion source of the mass spectrometer and bombarded by a beam of positive argon ions of energy 11 keV. The bombardment liberates partly neutral atoms and partly ions from the surface. This method allows quantitative analysis of thin film materials, once calibration data have been obtained for the secondary ion emission and matrix effects for the elements concerned. Data on the yield of secondary ions and matrix effects are presented for a variety of elements. 698. Mass spectrometer
for the examination
H Werner and H A M de Grafte, 3741 (in German).
Vakuum-Technik,
17 (2), Feb 1968,
699. Growth of crystalline silicon by vacuum evaporation. (Japan)
films on polycrystalline
(USSR)
An improved method of checking the vacuum-tightness of metal and glass electronic vacuum apparatus is described. The usual method of
30 substrates
Crystalline films of silicon were prepared on a tungsten substrate by vacuum evaporation. The technique used was crystal growth from a gold-silicon alloy zone on a rn:tal substrate. Growth of plane crystals or whisker crystals was observed depending on growth conditions such as substrate temperature, thickness of gold film and evaporation rate. The sizes of the crystals obtained were as large as several hundred microns. Their orientation was in the (I 11) plane, parallel to the substrate and their conductivity was n-type. Details of the growth technique and the examination of the films by optical and electron microscope are presented. K lshiwatari et al, J Vat Sot Japan, 10 (9), 1967,322-327 (in Japanese).
27 :31 695. Method of leak detection.
EG-100
700. Epitaxial growth of cubic vacuum. (Great Britain)
ZnS
by evaporation
30 in ultrahigh
In order to investigate the effect of clean conditions on the epitaxial 299