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The issues of selecting the frequency and power of high-frequency heating in soldering electronic modules and device enclosures are thoroughly examined. High-frequency electromagnetic energy is explored for its efficient non-contact heating capabilities, enabling rapid heating to soldering temperatures through the induction of eddy currents in the metal components and solder. Compared to convective heat sources, high-frequency heating can achieve heating rates up to 10 times faster, with the heating zone precisely localized within the area defined by the inductor design. Methods and device schematics for high-frequency soldering processes are provided, alongside descriptions of the technological equipment and fixtures utilized in these processes. Transistor generators operating at medium (66 kHz) and high frequencies (440 and 1760 kHz) have gained widespread adoption for high-frequency heating applications. To enhance the quality of solder joints and increase product yield, computer-controlled thermal profiles are essential for high-frequency soldering processes. The advantages of high-frequency heating, including locality, simplicity of design, high environmental cleanliness, and the ability to leverage electromagnetic forces for improving solder flow, make it an optimal choice for surface mounting of electronic modules. Induction devices constructed on magnetic cores are also viable for soldering power contacts, connectors, and wires to printed circuit boards, coaxial cables, and sealing metal-glass housings of integrated circuits. These applications highlight the versatility and efficacy of high-frequency heating techniques in modern electronic assembly processes. [ABSTRACT FROM AUTHOR]

The operating temperature of integrated magnetic components can be critical. Excessively high temperature can significantly modify the properties of components, especially those of magnetic material, such as saturation magnetization and magnetic permeability. This article introduces an experimental characterization method using two different sensors. We compare the results obtained from these sensors. Initially, the method is validated using a "meander component, and subsequently, it is applied to planar spiral inductors, both with and without magnetic material. [ABSTRACT FROM AUTHOR]

The problem of creating a wireless power transmission system for aviation technology, providing power to onboard equipment with a power of at least 30 W in accordance with the planned update of the Qi standard, is considered. A prototype of a wireless power transmission system for aviation technology, which is resistant to external influences, was made. Numerical calculations of the load capacity of the wireless power transmission system are carried out. [ABSTRACT FROM AUTHOR]

In this paper we discuss problems of selection of components for the construction of wireless power transmission systems and present theoretical foundations of the induction method of wireless energy transfer. A test bed for the study of wireless power transmission was developed. The possibility of standard inductance coils usage in wireless energy transmission devices was studied experimentally. [ABSTRACT FROM AUTHOR]

In new hybrid sheet-stamping technologies, the workpiece is subjected simultaneously to static and magnetic-pulse loading. To that end, inductors connected to a magnetic-pulse system are embedded in tool dies. A die for drawing and margin removal is considered. The initial data for its design are derived from computer simulation of the static–dynamic processes associated with folding and relief generation. [ABSTRACT FROM AUTHOR]

Modern installations of induction heat treatment of large rolls of rolling mills are considered. The equipment and technology of induction heat treatment of mill rolls should be designed so as to guarantee heat-treatment quality. The main electrotechnical problems arising when designing induction heat treatment equipment for large rolls of rolling mills are formulated. The power supply circuits of the installation for hardening of the rolls were selected and justified, and the main problems arising when developing inductors are set out. The choice of operating current frequency is considered. A new structure of inductors for hardening of large rolls is proposed. Computer models for calculating the electromagnetic and temperature fields upon heat treatment of rolls are developed. A universal method of digital design of induction heat treatment installations is considered. The energy characteristics of inductors for hardening of the rolls of rolling mills are analyzed. The developed digital twin of inductors makes it possible to significantly shorten the experimental investigations of induction hardening of the rolls and the conditions of startup works and use digital control systems to achieve the highest quality of heat treatment of the rolls. [ABSTRACT FROM AUTHOR]

The inductive power transfer (IPT) systems have been drawing much attention in the wide variety of industrial and automotive electric power applications such as battery chargers in automated guided vehicles and electric vehicles (EVs) these days. At the heart of this IPT system are two mutually coupled coils also known as charging pad. Among different existing charging pads, circular charging pad is the most widely adopted charging pad for stationary charging of EV. This is mainly due to ease of manufacturing, symmetric coupling profile, ease of experimental characterization and its non-directional characteristics which ensure simplicity of use by a driver. Circular charging pads consist of coils in the form of Archimedean spirals. For the design of Archimedean spiral, i.e., calculation of number of turns, outer and inner diameter, air gap between primary and secondary coil is often done using finite element analysis software (FEA). However, FEA simulations are complicated and may require a significant number of iterations before achieving the final design goals and therefore are time-consuming. Therefore, the aim of this paper is to formulate simple analytical expressions to design Archimedean spiral from given electrical parameters. An analytical expression for self-inductance as well mutual inductance has been presented. Analytical expressions have been validated using five different coil-pairs fabricated for the same electrical parameters. Usefulness and limitations of the analytical expressions have been discussed. [ABSTRACT FROM AUTHOR]

The efficiency of induction ring-type heating systems and on an unclosed magnetic circuit, as applied to soldering parts and electronic components, is sized up during assembly of electronic modules. For inductors on the magnetic circuit, owing to the concentration of the electromagnetic field in a working gap, the efficiency of heating of parts increases and the heating zone is localized. Simulation of the parameters of both the electric and magnetic fields in COMSOL gives the temperature profiles of heating of surfacemounted components over a frequency range of 22-100 kHz. The highest heating rate of 12-15°С/s is attained at lower frequencies, where the penetration of the electromagnetic field is deeper. [ABSTRACT FROM AUTHOR]

Metal-polymer composites were investigated for their microwave properties in the frequency range of 30-1000 MHz to assess their application as inductor cores and electromagnetic isolation shield structures. NiFe and Fe nanoparticles were dispersed in epoxy as nanocomposites, in different volume fractions. The permittivity, permeability, and loss tangents of the composites were measured with an impedance analyzer and correlated with the magnetic properties of the particle such as saturation magnetization and field anisotropy. Fe-epoxy showed lower magnetic permeability but improved frequency stability, compared to the NiFe-epoxy composites of the same volume loading. This is attributed to the differences in nanoparticle's structure such as effective metal core size and particle-porosity distribution in the polymer matrix. The dielectric properties of the nanocomposites were also characterized from 30 MHz to 1000 MHz. The instabilities in the dielectric constant and loss tangent were related to the interfacial polarization relaxation of the particles and the dielectric relaxation of the surface oxides. [ABSTRACT FROM AUTHOR]

This paper presents a new structure of single-stage flyback power factor correction (PFC) converter with a controllable coupled negative magnetic feedback (NMF) winding. NMF winding is used to reduce the bulk capacitor voltage at high line voltages and light loads. However, it would cause line current distortion at zero crossing condition. In the proposed circuit, a series winding is used with NMF inductor to eliminate the NMF inductor at low line voltages. As a result, the dead angle of the input current, near zero voltage crossing, is eliminated and the power factor is increased. The presented experimental results of the proposed PFC converter confirm the integrity of the new idea and the theoretical analysis. [ABSTRACT FROM AUTHOR]

n amplifier topology based on a transformer-coupled cascode stage is presented and compared with the most used solutions for sub-μm CMOS power amplifiers, which are the common-source stage, cascode stage, and capacitive-coupled cascode stage. The comparison was carried out by designing each amplifier in a 65-nm CMOS technology and for a 60-GHz operating frequency. The design was optimized for a trade off among power gain, saturated output power, and linearity. Operating from a 1.2-V supply voltage, the proposed amplifier improves both small-signal and large-signal performance with respect to the most common approaches, thus demonstrating effectiveness with sub-μm CMOS technologies and mm-wave operation. [ABSTRACT FROM AUTHOR]

A detailed analysis of a gyrator-based inductance using operational transconductance amplifiers is presented. The advantages of such integrated inductances over passive spirals include higher quality factors and the ability to tune inductance values. Design equations are derived using a practical high-frequency model of each transconductor, and operating constraints are provided to mitigate the effects of parasitics and to ensure optimal performance and stability. [ABSTRACT FROM AUTHOR]