N.E. Sadkovskaya – Dr.Sc.(Eng.), Associate Professor,
Department «Innovation Management», Moscow Aviation Institute (National Research University)
E-mail: natsadkovskaya@yandex.ru
V.I. Tarasov – Post-graduate Student,
Department «Innovation Management», Moscow Aviation Institute (National Research University)
E-mail: vov1187@yandex.ru
B.A. Slabikov – Chief Welder of the Technological Department,
JSC «NPP «Kvant» (Moscow)
I.V. Androsovich – Post-graduate Student,
Department «Technology of Design and Operation of Aircraft Engines»,
Moscow Aviation Institute (National Research University)
E-mail: irishapd-35@mail.ru
S.P. Kritsky – Leading Specialist,
Department of Technology Development of Silicon Photo Converters and Assembly Processes, JSC «NPP «Kvant» (Moscow)
E.P. Ivanova – Engineer,
Department of Research and Manufacturing of Photo Converters, JSC «NPP «Kvant» (Moscow)
The modern spacecrafts (SС) make a big contribution to researches of innovative technologies and the scientific equipment. In most cases, all spacecraft systems are powered by solar panels (SP). In this connection, the SP is subject to high requirements for the quality of connections of elements (switching) of photo converters (FC) in the section, for mechanical strength and for signalternating temperature loads when bringing the SP into space. Therefore, the sections must have high operational stability.
The purpose of this work is to study and create innovative technology of welding silver current leads to silver and gold coating of contact pads of gallium arsenide-based photo converters. Research and development of ways of innovative development were carried out at JSC «NPP» Kvant», which specializes in SS production.
For stable operation of single-sided spot welding plant, the main criterion ensuring quality of welded joints is preparation of parts and welding tool (WT). WT is a split electrode having a pyramidal shape of a working part. During long-term operation, the WT is oxidized, thereby increasing the WT – detail contact resistance. Argon feeding is introduced to reduce oxidation and protect the welding site zone. An increase in resistance can result in non-failure of the weld point or thermal shock. In case of thermal shock at welding places, peeling of silver coating can occur, as well as occurrence of microcracks on FС.
With the constant development of space systems, there is a tendency to reduce weight, which concerns the design of solar panels, in particular the thickness of FC. With decreasing thickness of the gallium arsenide-based FC from 150 mcm to 130 mcm and less, assembly of the FC with current-withdrawing tyres puts higher requirements to the tooling, ranging from transportation to assembly and welding operations. A 130 mcm thickness FP bonder showed that when operating on installations without an automated compression mechanism drive, the quality of welding is directly dependent on the performer. The presence of an automated system of compression and control mechanism using software allows to start the welding process excluding the influence of the performer. Technological samples of gallium arsenide type FС (37×76 mm) with thickness of 0.13±0.01 mm and silver current-withdrawing contacts (tires) with width of 2…3 mm and thickness of 0.03 mm were taken for experimental works.
As a result of welding process samples with different combinations of parameters and subsequent tests for the removal of current outlets from the gallium arsenide FC, welding modes were established, providing the necessary strength of welded joints for removal (50 grams during 10 seconds). Chips and cracks of FC plates were not observed during welding.
Control samples with measurements of electrical characteristics before and after welding were welded at established modes. The electrical characteristics of the elements after welding have not changed. According to the results of the work, the availability of an automated compression mechanism system and the possibility of programming the process modes guarantees the stability of welding silver foil leads 0.03 mm to the silver coating of gallium arsenide FC and provides 100% strength of welded joints.
Tests have proved that combining welding parameters at «UMS» ultrasonic welding installations within a wider range allows selecting the most suitable modes for obtaining a high-quality and stable joint.
Switching to machines with automated systems guarantees not only increased stability of welding quality and elimination of influence of the performer, but also possibility of automated process of solar panels assembly.
Introduction into welding production of JSC «NPP «Kvant» of ultrasonic welding plants «UMS» with the system of automated compression mechanism WT and programming of operation modes allows to carry out constantly improving technology on assembly of FC with current leads.
- Sadkovskii B.P., Tarasov V.I., Slabikov B.A., Sadkovskaya N.E., Kritskii S.P. Issledovanie protsessa ultrazvukovoi mikrosvarki tokovyvodyashchikh kontaktov s fotopreobrazovatelyami kosmicheskogo naznacheniya. Naukoemkie tekhnologii. 2018. № 1. S. 22−26. (In Russian).
- Tarasov V.I., Slabikov B.A., Grigoreva I.V., Sadkovskii B.P. Progressivnye tekhnologii kommutatsii fotopreobrazovatelei kosmicheskogo naznacheniya v proizvodstve solnechnykh batarei. Tezisy 17-i Mezhdunar. konf. «Aviatsiya i kosmonavtika 2018». 2018. 536 s. (In Russian).
- Sadkovskii B.P., Tarasov V.I., Slabikov B.A., Sadkovskaya N.E., Kritskii S.P. Issledovanie protsessa ultrazvukovoi mikrosvarki tokovyvodyashchikh kontaktov s fotopreobrazovatelyami kosmicheskogo naznacheniya. Materialy 4-i Mezhdunar. konf. «Additivnye tekhnologii: nastoyashchee i budushchee». 2018. 391 s. (In Russian).