RU2644455C1 - Method of testing radioelectronic equipment of spacecrafts for resistance to secondary arcformation - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention can be used in land-based experimental simulate and with acceptance testing electronics spacecraft on resistance to initiation of secondary arc when operating equipment at voltages excess capacity drop on the arc, in conditions simulating outer space, including the plasma environment that imitates the primary plasma discharge. The method for testing the radioelectronic device of spacecrafts for resistance to secondary arc formation consists in the action of plasma, simulating the primary discharge plasma on the test equipment in the active (working) state at a voltage exceeding the potential drop on the arc. Immediately before the test of the running equipment in plasma and in a single loop with test procedure runs polymer deposition in places of violations of protective polymer coating, deposition of polymer using same source plasma, which is used to generate a plasma environment simulated primary plasma discharge.

EFFECT: elimination of end-to-end defects in the continuity of the protective coating by restoring the polymer coating on live conductors of the equipment under test, which reduces the risk of damage to electronic equipment during the test while maintaining the reliability of the tests.

4 cl, 2 dwg

Description

The invention relates to a test technique and can be used for ground experimental testing and acceptance tests of electronic equipment of spacecraft.

A known method of testing electronic equipment of spacecraft for resistance to electrostatic discharges [1], based on a simulation of one of the conditions of outer space, radiation exposure, before testing the resistance to electrostatic discharges. This approach improves the reliability of the test results in electronic circuits of electronic equipment of spacecraft.

The disadvantage of this method is the inability to detect defects in electronic equipment that are not associated with radiation exposure, but can lead to a decrease in the resistance of electronic equipment to electrostatic discharges, which may result in secondary arcing.

A known method of testing the elements of electronic equipment of spacecraft for resistance to arcing [2]. The method is based on the initiation of a primary arc discharge and the plasma action of this discharge on the test element in order to determine its resistance to secondary arc initiation.

The disadvantage of this method is the risk of failure of the test object if the method is applied not to structural components of the equipment, but to operable electronic equipment, including not having sufficient resistance to arcing. This is due to the presence of defects that reduce electrical strength.

The initiation of an arc discharge in insulating gaps occurs as a result of electrical breakdown. For breakdown of vacuum gaps, electric fields of more than 100 kV / cm are required, which at a voltage level of 100 V used in power supply systems of spacecraft can occur in gaps of less than 10 microns. Insulating gaps of such a short length are not used in the design of electronic equipment. Therefore, the problem of arcing in the equipment of the spacecraft is most acute in the initial period of operation of the device, in the process of putting it into orbit and degassing in orbit. During this period, the insulation conditions inside the apparatus are not vacuum and it is possible to initiate an arc by the breakdown mechanism of the gas-filled gap described by the Paschen law. Breakdown voltage is reduced in the presence of low-pressure metal-insulator-gas contact points, and to prevent breakdown, the circuit boards of electronic equipment after the installation of radio electronic products are coated with a protective polymer film based on epoxy resins, polyurethane or parylene.

Before installation in a spacecraft, the electronic equipment is tested in working condition, including resistance to electrostatic discharges (ISO 11221: 2011 "Space systems. Space solar panels. A spacecraft charged by an induced electrostatic discharge. Test methods"), under simulated operating conditions apparatus, including the pressure range corresponding to the removal of the apparatus from the launch pad to the orbit, and the presence of a primary electrostatic discharge plasma. However, if there are through defects in the continuity of the protective dielectric coating, there is a risk of initiating an arc discharge, which may result in failure of the tested equipment.

The objective of the proposed technical solution is to reduce the risk of damage to electronic equipment during its testing in plasma for resistance to arcing at operating voltages exceeding the potential drop across the arc and maintaining the reliability of the tests.

The technical result of this invention is to eliminate end-to-end continuity defects of the protective coating by restoring the polymer coating on the conductive conductors of the test equipment.

The specified technical result is achieved due to the fact that immediately before testing the operating equipment in a plasma environment at operating voltages exceeding the potential drop across the arc, and in a single cycle with the test, the procedure of polymer recovery on the surface of the through continuity defects of the protective polymer coating is performed. For this purpose, equipment in an inactive (inoperative) state is simultaneously affected by plasma and a reaction gas consisting of two or more components, one or more of which is capable of polymerizing in plasma, while the equipment is at a positive bias potential relative to the plasma potential, and in absolute value not exceeding the potential drop across the arc.

The reaction gas used consists of an inert gas and a monomer or dimer in a gaseous state.

In addition, when a plasma is exposed to a test apparatus in an inactive state, the potential for the bias of the apparatus relative to the plasma potential in absolute value exceeds the first ionization potential of inert gas atoms.

To restore the polymer, the same plasma source is used, which is used to form a plasma environment simulating a primary discharge plasma.

The technical essence of the invention is as follows. Before electronic equipment is tested at operating voltages in excess of the potential drop across the arc for resistance to arcing by exposure to a plasma simulating a primary discharge plasma, the tested equipment is exposed to the same plasma, but in an inactive state. Such exposure is not dangerous to the equipment, but does not produce any effect. To achieve a positive effect when a plasma acts on an electronic equipment in an inactive state, a reaction gas stream is formed, consisting of an inert gas and a monomer or dimer capable of polymerizing under the influence of plasma, and this stream is directed to the equipment. If, at the same time, a bias voltage of positive polarity relative to the plasma is applied to the equipment under test that exceeds the first inert gas ionization potential in absolute value, then in the places where the protective polymer coating is broken, non-self-sustaining glow discharge will ignite on the current-carrying conductors of the equipment, which does not go into the arc due to insufficiently high for ignition of a voltage arc. In this case, the cathode of the glow discharge is the entire working chamber filled with plasma, and the anode is the current-carrying conductors of the tested equipment, which are not covered with a protective film. Since the cathode area is many times larger than the anode area, the glow of the discharge will be concentrated in the places where the polymer coating is broken on the current-carrying conductors of the tested equipment. Due to the plasma-chemical reactions on the surfaces in contact with the plasma, the polymerization of the monomer or dimer will occur [3], moreover, this process will occur most intensively in places of higher plasma concentration, that is, in places where the polymer coating is broken. As soon as all open current-carrying places of the tested equipment become covered with a polymer film, the burning of a non-self-contained glow discharge stops, which is accompanied by the extinction of the anode glow and serves as an indicator of the readiness of the tested equipment for tests on resistance to arc formation in the active state.

This method can be implemented using the circuits shown in FIG. 1 and FIG. 2.

For plasma exposure of the equipment in an inactive state in accordance with the circuit of FIG. 1 test module of electronic equipment 1, to which a cable of input circuits 2 and a cable of output circuits 3 are connected, is placed in an argon atmosphere of 100 Pa pressure, in which the module is tested for resistance to arcing in a plasma 4 created by a plasma source 5. Before testing, the cables 2 and 3 are connected in such a way that all the conductors of cables 2 and 3 are connected at one point and connected to a source of bias voltage +18 V. This voltage is higher than the first argon ionization potential +15.8 V, but lower than the potential drop iala to arc discharge, exceeding 20 for the B cold cathode arc. Due to the existence of plasma 4 around the test equipment 1, in the presence of a place of exposure of the current-carrying conductors of equipment 1, a non-self-contained gas discharge is ignited in the places of exposure. When such a discharge is detected, a stream of reaction gas 8 is generated, directed towards the test equipment 1, using source 7. The reaction gas consists of di-para-xylene and argon. In places where a non-self-sustained gas discharge is burning on the surface of exposed conductive conductors, poly-para-xylene is deposited due to the plasma-chemical reaction. As a result of the growth of a poly-paraxilelene film over a period of several minutes, a non-self-sustained discharge is extinguished. The absence of a self-discharge at a bias voltage of +18 V of the tested equipment 1 in plasma 4 is the basis for performing tests on resistance to arcing at operating voltages of the level of 100 V in accordance with the circuit in FIG. 2. For this purpose, the input circuit cable 2 is connected to the input circuit simulator 9, the output circuit cable is connected to the output circuit simulator 10, and the apparatus 1 is put into active state at operating voltages in the plasma environment 4 created by the plasma source 5. Moreover, the absence of exposed current-carrying parts of the apparatus 1, accessible to the surrounding plasma 4, guarantees the absence of arc initiation due to the existence of through defects in the continuity of the protective polymer coating.

Information sources

1. Anisimov A.V., Novoselov Yu.I. A method for testing spacecraft electronic equipment for resistance to electrostatic discharges // RF Patent (19) RU (11) 2157545 (13) C1 (51), IPC G01R 31/28, G05F 1/56. - Declared. 11/12/1999. - Publ. 10/10/2000.

2. Batrakov A.V., Karlik K.V., Popov S.A. A method for determining the resistance to arcing of elements of electronic equipment of spacecraft // RF Patent (19) RU (11) 2539964 (13) C1 (51), IPC G01R 31/28, H01J 37/00. - Declared. 08/08/2013. - Publ. 01/27/2015.

3. V. Shirshova, A. Izbushkin, E. Fomchenko. Polyparaxylene coatings in REA technology. State, prospects // Printed editing. - 2010. - No. 1. - p. 22-27.

Claims (4)

1. A method of testing the electronic equipment of spacecraft for resistance to secondary arcing, in which a plasma simulating a primary discharge plasma is exposed to the tested equipment in an active (working) state under a voltage exceeding the potential drop across the arc, characterized in that immediately before the test active equipment effect the equipment in an inactive (inoperative) state simultaneously by plasma and reaction gas, including, at the edge at least one gaseous component capable of polymerizing in plasma, while the equipment is at a positive bias potential relative to the plasma potential, and in absolute value not exceeding the potential drop across the arc. 2. The method according to p. 1, characterized in that the reaction gas consists of an inert gas and a monomer or dimer in a gaseous state. 3. The method according to p. 1, characterized in that when the plasma is exposed to the test equipment in an inactive state, the absolute bias potential of the equipment relative to the plasma potential exceeds the first ionization potential of the molecules of at least one of the components of the reaction gas. 4. The method according to p. 1, characterized in that the effect on the test equipment in the active and inactive state is carried out by the plasma in a single cycle from a single plasma source.

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