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The purpose of this paper is to propose a simple electrothermal model of GaN Schottky diodes, and its usefulness for circuit-level electrothermal simulation of laboratory-made devices is proved.

The compact electrothermal model of this device has the form of a subcircuit for simulation program with integrated circuit emphasis. This model takes into account influence of a change in ambient temperature in a wide range as well as influence of self-heating phenomena on dc characteristics of laboratory-made GaN Schottky diodes. The method of model parameters estimation is described.

It is shown that temperature influences fewer characteristics of GaN Schottky diodes than classical silicon diodes. The discussed model accurately describes properties of laboratory made GaN Schottky diodes. Additionally, the measured and computed characteristics of these diodes are shown and discussed.

The presented model together with the results of measurements and computations is dedicated only to laboratory-made GaN Schottky diodes.

The presented investigations show that characteristics of laboratory-made GaN Schottky diodes visibly change with temperature. These changes can be correctly estimated using the compact electrothermal model proposed in this paper. The correctness of this model is proved for four structures of such diodes characterised by different values of structure area and a different assembly process.

This paper aims to propose the electrothermal dynamic model of the insulated gate bipolar transistors (IGBT) for SPICE.

The electrothermal model of this device (IGBT), which takes into account both electrical and thermal phenomena, is described. Particularly, the sub-threshold operation of this device is considered and electrical, and thermal inertia of this device is taken into account. Attention was focused on the influence of electrical and thermal inertia on waveforms of terminal voltages of the considered transistor operating in the switching circuit and on waveforms of the internal temperature of this device.

The correctness of the presented model is verified experimentally and a good agreement of the calculated and measured electrical and thermal characteristics of the considered device is obtained.

The presented model can be used for different types of IGBT, but it is dedicated for SPICE software only.

The form of the worked out model is presented and the results of experimental verification of this model are shown.

This paper aims to present the results of investigations that show the influence of soldering process parameters on the optical and thermal parameters of power LEDs.

The power LEDs were soldered onto metal core printed circuit board (MCPCB) substrates in different soldering ovens: batch and tunnel types, characterized by different thermal profiles. Three types of solder pastes based on Sn99Ag0.3Cu0.7 with the addition of TiO₂ were used. The thermal and optical parameters of the diodes were measured using classical indirect electrical methods. The results of measurements obtained were compared and discussed.

It was shown that the type of oven and soldering thermal profile considerably influence the effectiveness of the removal of heat generated in the LEDs tested. This influence is characterized by thermal resistance changes. The differences between the values of this parameter can exceed 20%. This value also depends on the composition of the soldering paste. The differences between the diodes tested can exceed 15%. It was also shown that the luminous flux emitted by the diode depends on the soldering process used.

The results obtained could be useful for process design engineers for assembling power LEDs for MCPCBs and for designers of solid-state light sources.

This paper presents the results of investigations into the influence of the soldering profiles and soldering pastes used on the effectiveness of the removal of heat generated in power LEDs. It shows and discusses how the factors mentioned above influence the thermal resistance of the LEDs and optical parameters that characterize the light emitted.

This paper aims to present the results of investigations that show the influence of ZnO composite soldering paste on the optical and thermal parameters of power light-emitting diodes (LEDs).

ZnO nanocomposite solder alloys were produced via the ball milling process from the solder paste Sn99Ag0.3Cu0.7 (SACX0307) and 1.0 wt% of ZnO nanoparticle reinforcements with different primary particle sizes (200 nm, 100 nm and 50 nm). Power LEDs were soldered onto a metal core printed circuit board. A self-designed LED test system was used to measure the thermal and optical characteristics of the LEDs.

The influence of the soldering paste on the thermal and optical parameters of LEDs was observed. In all solder alloys, ZnO ceramic reinforcement, at a level of 1 wt%, increased the thermal parameters of LEDs and decreased their luminous efficiency. Thermal resistance values were10% higher, and junction temperature change over ambient temperature was 20% higher for the samples soldered with composite solder pastes than the reference sample. At the same time, luminous efficiency dropped by 32%.

The results prove that ZnO ceramic reinforcement of solder paste influences the thermal properties of solder joints. As was proven, the quality of the solder joints influences the whole assembly.

The paper aims to consider the problem of the influence of mounting power metal-oxide semiconductor (MOS) transistors operating in the Totem–Pole circuit on energy losses in this circuit.

Using the computer simulation in SPICE software, the influence of such factors as on-state resistance of the channel of the MOS transistor, the self-heating phenomena in this transistor and resistance of wires connecting transistors with the other part of the circuit on characteristics of the considered circuit operating with resistor, inductor and capacitor (RLC) load is analyzed. The selected results of calculations are compared with the results of measurements.

On the basis of the obtained results of calculations, some recommendations concerning the manner of mounting the considered transistors, assuring a high value of watt-hour efficiency of the process of energy transfer to the load are formulated.

The investigations were performed in the wide range of the frequency of the signal stimulating the considered circuit, but the results of calculations were presented for 2 selected values of this frequency only.

The considered analysis was performed for the circuit dedicated to power supplied of an elecrolyser.

Presented results of calculations prove that in some situations, the value of watt-hour efficiency of the considered circuit is determined by the length and the cross-section area of the applied wires bringing the signal to the connectors of the transistors and to load. On the other hand, self-heating phenomena in the power MOS transistors can lead to doubling power losses in these devices.

This paper presents the results of the investigations of LED modules soldered with the use of different soldering pastes.

The tested power LED modules are soldered using different solder pastes and soldering processes. Thermal parameters of the performed modules are tested using indirect electrical methods. The results of measurements obtained for different modules are compared and discussed.

It was shown that the soldering process visibly influences the results of measurements of optical and thermal parameters of LED modules. For example, values of thermal resistance of these modules and the efficiency of conversion of electrical energy into light differ between each other even by 15%.

The obtained results of investigations can be usable for designers of the assembly process of power LED modules.

This paper shows the investigations results in the area of effective assembly of power LEDs to the metal core printed circuit board (MCPCB) using different soldering pastes (REL22, REL61, LMPA-Q6, OM-5100, OM-338-PT, M8, OM-340, CVP-390). It was shown that the best thermal and optical properties of these modules are obtained for the OM5100 paste by Alpha Assembly.

The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system.

A cooling system containing a heat-sink, a Peltier module and a fan was built by the authors and the measurements of temperatures and thermal resistance in various supply conditions of the Peltier module and the fan were carried out and discussed.

Conclusions from the research carried out answer the question if the use of Peltier modules in active cooling systems provides any benefits comparing with cooling systems containing just passive heat-sinks or conventional active heat-sinks constructed of a heat-sink and a fan.

The research carried out is the preliminary stage to asses if a compact thermal model of the investigated cooling system can be formulated.

In the paper, the original results of measurements and calculations of parameters of a cooling system containing a Peltier module and an active heat-sink are presented and discussed. An influence of power dissipated in the components of the cooling system on its efficiency is investigated.

This paper aims to present the results of measurements and calculations illustrating mutual thermal coupling between power Schottky diodes made of silicon carbide situated in the common case.

The idea of measurements of mutual transient thermal impedances of the investigated device is described.

The results of measurements of mutual transient thermal impedances between the considered diodes are shown. The experimentally verified results of calculations of the internal temperature waveforms of the considered diodes obtained with mutual thermal coupling taken into account are presented and discussed. The influence of mutual thermal coupling and a self-heating phenomenon on the internal temperature of the considered diodes is pointed out.

The presented methods of measurements and calculations can be used for constructing the investigated diodes made of other semiconductor materials.

The presented results prove that mutual thermal coupling between diodes mounted in the common case must be taken into account to calculate correctly the waveforms of the device internal temperature.

This paper aims to present the results of the influence of a manner of soldering light emitting diodes (LEDs) to the metal core printed circuit board on thermal parameters of the module LED containing these diodes.

Using the authors’ elaborated measuring method and the dedicated measurement set-up, transient thermal impedances of LED modules, mounted using different soldering processes and mounted to the heat-sink with different values of the moment of force, are measured. The obtained results of measurements are discussed.

It was shown experimentally that the manner of soldering could strongly influence efficiency of dissipation of heat generated in the module. The best thermal properties were obtained for soldering using vapour phase technology with vacuum and paste LFS-216LT. It was also proved that the moment of force used while mounting the considered modules on the heat-sink can result in a change of the value of thermal resistance of this module exceeding even 12 per cent.

The investigations were performed for five LED modules operating at one, arbitrarily selected value of power dissipated in these modules mounted on the heat-sink of arbitrarily selected dimensions.

The obtained results of measurements could be usable for designers of mounting processes of power LED modules.

This paper presents the results of investigations of thermal properties of LED modules, in which different techniques of soldering are used. It was shown experimentally that the manner of soldering could strongly influence efficiency of dissipation of heat generated in the module. It was also proved that the moment of force used while mounting the considered modules on the heat-sink is important.

The purpose of this paper is to present and discuss the results of measurements illustrating influence of the area of a thermal pad and the kind of the used base on thermal and optical parameters of LED modules.

LED modules including six power LEDs are designed. In the layout of these modules, different areas of a thermal pad of each LED are used. These modules are made using the classical FR-4 base and metal core printed circuit board (MCPCB). Thermal and optical parameters of all the tested modules are measured using the method elaborated by the authors.

The obtained results of measurements prove that increasing the area of a thermal pad causes a decrease in thermal resistance of the tested LED modules and an increase in power density of the emitted light. The role of the area of a thermal pad is more important for the classical FR-4 base than for MCPCB.

Investigations were performed for only two values of the area of thermal pads and selected values of LEDs forward current.

The presented results of investigations show how the used layout and type of the used base of these modules influence optical and thermal parameters of LED modules. Changing the base of a module can cause even a double decrease in thermal resistance and a double increase in power density of the emitted light.