Utjecaj razlaganja plinova koji sadrze ugljik na kontaktni otpor prekidača na jezičac

During the operation of reed switches, a continuous increase of the contact resistance was observed. After the life time test, AES analyses of the contact surfaces showed an appearance of carbon, which originally wasn\u27t present. In order to find the origin of carbon on the surface, model reed switches were prepared, evacuated, and than filled with a protective gas with intentionally added carbon containing gases. After the lifetime test of the reed switch models, the contact resistance of switches filled with N2 + H2 , N2 + H2 + CO and N2 + H2 + CO +CO2 remained low while the resistance of switches filled with N2 +CO + CO2 and N2 +H2 + C2H2 increased substantially. AES analyses have shown that the quantity of carbon deposited on contacts of switches filled with N2 + H2 + C2H2 was much greater than that deposited on contacts of switches filled with the other gases. Since gas chromatographic analysis showed an appreciable lowering of the C2H2 concentration, we concluded that C2 H2 decomposed on the contact surfaces causing the increase of the contact resistance.Tijekom upotrebe prekidača na jezičac opaža se postupan porast kontaktnog otpora. Analize dodirnih površina Augerovom elektronskom spektroskopijom pokazale su pojavu ugljika na njima. Radi ispitivanja nastanka sloja ugljika načinjen je poseban prekidač na jezičac koji se mogao prazniti i puniti raznim plinskim smjesama: N2+H2, N2+H2+CO, N2+H2+CO+CO2 i N2+H2+CO+C2H2. Plinskom kromatografskom analizom je utvrđeno da je najveći uzrok naslaga ugljika plin C2H2 koji se raspada i taloži na kontaktnim površinama

Djelovanje kisikove plazme na polietersulfon

Polyether sulphone was found to be a useful material for production of high reliability humidity sensors. In order to obtain best properties of the sensors, the polymer surface should be activated before a thin layer of metal is deposited. A way to do it is exposition of the polymer to oxygen plasma. In order to prevent destructive action of the plasma, a very mild inductively coupled RF oxygen plasma was created in a vacuum system. The plasma density was of the order of 1016 m-3, and the electron temperature 4 eV. Active particles produced in plasma interact with the polymer causing oxidation of the surface layer and a continuous thinning of the polymer foil. In our case the rate of thinning was 25 mm per hour.Polietersulfon je pogodan materijal za osjetljive slojeve vrlo pouzdanih proba za vlažnost. Radi postizanja dobrih svojstava, površina polimera mora se aktivirati prije naparavanja metalne elektrode. Jedna od metoda je izlaganje polimera blagoj, induktivno proizvedenoj kisikovoj plazmi. Aktivirane čestice u plazmi uzrokuju oksidaciju površine polimera i njegovo stanjivanje. Primjenjivali smo stanjivanje brzinom 25 µm na sat

Utjecaj nečistoća na otpor električnih kontakata

Influence of surface cleaning methods on contact materials as well as on the contact resistance of stationary and sliding electrical contacts was investigated. Two cleaning methods were studied: cleaning with fluorochlorohydrogencarbon (FCHC) and low temperature cleaning in reductive plasma. Contact materials for professional electronics were investigated. Dependence of the contact resistance on contact force was measured. All measurements were performed with a computer controlled system, constructed and developed in our laboratory.Ispitivane su metode čišćenja površina kontaktnih materijala i kontaktni otpor mirnih i kliznih električnih priključaka za profesionalnu elektroniku. Proučavano je čišćenje fluoroklorougljikovodikom i niskotemperaturno čišćenje u reducirajućoj plazmi. Mjerena je ovisnost kontaktnog otpora o pritisku. Sva su mjerenja načinjena pomoću sustava vodenog računalom, razvijenog u našem laboratoriju

Antibacterial activity and cytotoxicity of immobilized glucosamine/chondroitin sulfate on polylactic acid films

Polylactic acid (PLA) is one of the most produced polymeric materials, due to its exceptional chemical and mechanical properties. Some of them, such as biodegradability and biocompatibility, make them attractive for biomedical applications. Conversely, the major drawback of PLA in the biomedical field is their vulnerability to bacterial contamination. This study focuses on the immobilization of saccharides onto the PLA surface by a multistep approach, with the aim of providing antibacterial features and evaluting the synergistic effect of these saccharides. In this approach, after poly (acrylic acid) (PAA) brushes attached non-covalently to the PLA surface via plasma post-irradiation grafting technique, immobilization of glucosamine (GlcN) and chondroitin sulfate (ChS) to the PAA brushes was carried out. To understand the changes in surface properties, such as chemical composition, surface topography and hydrophilicity, the untreated and treated PLA films were analyzed using various characterization techniques (contact angle, scanning electron microscopy, X-ray photoelectron spectroscopy). In vitro cytotoxicity assays were investigated by the methyl tetrazolium test. The antibacterial activity of the PLA samples was tested against Escherichia coli and Staphylococcus aureus bacteria strains. Plasma-treated films immobilized with ChS and GlcN, separately and in combination, demonstrated bactericidal effect against the both bacteria strains and also the results revealed that the combination has no synergistic effect on antibacterial action. © 2019 by the authors.Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2019/004]; Czech Science Foundation [17-05095S]; Slovenian Research Agency [L2-8179

Modeling of the effect of radicals on plasmas used for etching in microelectronics

Plazma nagrizanje predstavlja jedan od kritičnih koraka u izradi integrisanih kola. Dalja optimizacija plazma uređaja je potrebna jer nove generacije u tehnologiji zahtevaju različitu plazma hemiju. U ovom radu bavimo se uticajem radikala na plazma karakteristike, što je često zanemarivano u plazma modelima. Radikali dominiraju zahvatom elektrona čineći da je bazna smeša za nagrizanje slabo elektronegativna, a oni takođe modifikuju brzinu drifta preko modifikovanog balansa momenta. Mi smo koristili numerička rešenja Bolcmanove jednačine i Monte Karlo simulacije (MCS) za određivanje transportnih koeficijenata elektrona.Plasma etching represents one of the critical steps in manufacturing of integrated circuits. Further optimization of plasma equipment is needed since new generations in technology require different plasma chemistry. In this paper, we will study the influence of radicals on the plasma characteristics, since it was often neglected in plasma models. The radicals dominate attachment of electrons as the basic etching mixture is weakly electronegative and they also affect the drift velocity through modified momentum balance. We have used numerical solutions to the Boltzmann equation and Monte Carlo simulations (MCS) to determine the transport coefficients of electrons

Modeling of the effect of radicals on plasmas used for etching in microelectronics

Plazma nagrizanje predstavlja jedan od kritičnih koraka u izradi integrisanih kola. Dalja optimizacija plazma uređaja je potrebna jer nove generacije u tehnologiji zahtevaju različitu plazma hemiju. U ovom radu bavimo se uticajem radikala na plazma karakteristike, što je često zanemarivano u plazma modelima. Radikali dominiraju zahvatom elektrona čineći da je bazna smeša za nagrizanje slabo elektronegativna, a oni takođe modifikuju brzinu drifta preko modifikovanog balansa momenta. Mi smo koristili numerička rešenja Bolcmanove jednačine i Monte Karlo simulacije (MCS) za određivanje transportnih koeficijenata elektrona.Plasma etching represents one of the critical steps in manufacturing of integrated circuits. Further optimization of plasma equipment is needed since new generations in technology require different plasma chemistry. In this paper, we will study the influence of radicals on the plasma characteristics, since it was often neglected in plasma models. The radicals dominate attachment of electrons as the basic etching mixture is weakly electronegative and they also affect the drift velocity through modified momentum balance. We have used numerical solutions to the Boltzmann equation and Monte Carlo simulations (MCS) to determine the transport coefficients of electrons