Laboratory Vacuum Phototool for PCB Exposure

The work deals with laboratory multifunction exposure equipment for exposure of patterns in printed circuit boards (PCB) technology. It is intended for using in electrotechnologic laboratory for research, development and education. Fixation system is vacuum type, timing system is microcontroller-based with keyboard, display and memory. The equipment was tailored by preparation and evaluation of experimental samples of PCB testing patterns

Degradation of Al-1%Si wires bonded onto copper pads

The current load and its influence on degradation of Al-1%Si wires bonded onto copper pads is presented in this paper. The current load was chosen to occur the electromigration phenomenon during ageing. Our attention was paid to the direction of current from Cu pad to Al wire, and as well as reversed from Al wire to Cu pad. The dependencies of electrical resistance (ΔR/R0) relative change vs time as well as dependencies of mechanical strength vs time for different types of current stresses (direct current IDC and pulse current IPULSE) were obtained and evaluated. The results were evaluated in relation to all above mentioned conditions moreover thermal ageing at 100°C/1000 h was applied and evaluated too

Degradation of Al-1%Si wires bonded onto copper pads

The current load and its influence on degradation of Al-1%Si wires bonded onto copper pads is presented in this paper. The current load was chosen to occur the electromigration phenomenon during ageing. Our attention was paid to the direction of current from Cu pad to Al wire, and as well as reversed from Al wire to Cu pad. The dependencies of electrical resistance (ΔR/R0) relative change vs time as well as dependencies of mechanical strength vs time for different types of current stresses (direct current IDC and pulse current IPULSE) were obtained and evaluated. The results were evaluated in relation to all above mentioned conditions moreover thermal ageing at 100°C/1000 h was applied and evaluated too

Influence of Various Technologies on the Quality of Ultra-Wideband Antenna on a Polymeric Substrate

The design, simulation, realization, and measurement of an ultra-wideband (UWB) antenna on a polymeric substrate have been realized. The UWB antenna was prepared using conventional technology, such as copper etching; inkjet printing, which is regarded as a modern and progressive nano-technology; and polymer thick-film technology in the context of screen-printing technology. The thick-film technology-based UWB antenna has a bandwidth of 3.8 GHz, with a central frequency of 9 GHz, and a frequency range of 6.6 to 10.4 GHz. In addition to a comparison of the technologies described, the results show that the mesh of the screens has a significant impact on the quality of the UWB antenna when utilizing polymeric screen-printing pastes. Last but not least, the eco-friendly combination of polyimide substrate and graphene-based screen-printing paste is thoroughly detailed. From 5 to 9.42 GHz, the graphene-based UWB antenna achieved a bandwidth of 4.42 GHz. The designed and realized UWB antenna well exceeds the Federal Communications Commission’s (FCC) standards for UWB antenna definition. The modification of the energy surface of the polyimide substrate by plasma treatment is also explained in this paper, in addition to the many types of screen-printing pastes and technologies. According to the findings, plasma treatment improved the bandwidth of UWB antennas to 5.45 GHz, and the combination of plasma treatment with graphene provides a suitable replacement for traditional etching technologies. The characteristics of graphene-based pastes can also be altered by plasma treatment in terms of their usability on flexible substrates

ANISOTROPIC CONDUCTIVE JOINTS UTILIZATION FOR JOINING OF FLEXIBLE CABLES AT RIGID SUBSTRATES

Key motivation of this work is the industrial task of standard lead based solders joints elimination in electronics, which comes out from the European Council requirement to exclude lead from the soldering process before the middle of 2006. The main emphasis was laid on the new approaches in tasks solving by using standard electrotechnologies and available production facilities. Results of this work were based on two types of anisotropic interconnections usability as an alternative of soldered joints in the production process, which is generally used for a reflow of the standard SnPb solder between the contact areas. Practical results of the performed study indicate that realized joints with applied anisotropic conductive adhesive have comparable electrical resistance with soldered interconnections. The lower mechanical strength is less relevant with concerning of operating conditions. The anisotropic conductive paste application demonstrates their suitability for copper-to-gold plated contacts conductive joining; however, adhesive joints realized by an anisotropic conductive tape were not satisfactory