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The paper aims to investigate the structure and thermal stability of newly developed lead-free Sn-based alloys which can be used as novel materials in the soldering of electronic components.

Rapid solidification was used to prepare the alloys.

The results showed that the microstructure of these solders exhibited uniform distribution and small-sized intermetallic compounds. Also, smaller crystalline size can be expected compared to commercially available counterparts. The analyses revealed a uniform and homogenous distribution of the small intermetallic particles of Cu₆Sn₅ and Ag₄Sn in the microstructure of solders. The practical implications mean an improvement in mechanical properties and thermal stability of such solder joints, which is a precondition of low mechanical, thermo-mechanical stresses in their structure.

The originality lies in the production of these alloys by the melt spinning technique which was not previously used in the electronics industry.

The purpose of this paper was to investigate an influence of a low temperature pressureless sintering process of silver paste on the quality of sintered joints.

The authors analyzed various curing conditions of the paste during its sintering process: 175°C/90 min, 200°C/60 min, 250°C/30 min, 250°C/60 min, 350°C/30 min and 350°C/60 min. They analyzed an influence of the surface plating applied on a ceramic substrate/layer (Cu, Ag, AgPt and Au thick film) on the joints quality. The authors analyzed microstructure and electrical resistance of the joints. They evaluated these properties from the point of view of thermal aging process and changing resistance, after a constant current loading of the sintered joints.

The nanoscale pressureless silver paste can be applied for replacing a pressure-assisted micro-sized silver paste. It was found that the quality of the metal plating applied on the ceramic substrate/layer has a significant impact on the quality of the sintered joints. Copper and AgPt plating have better impact on quality of sintered joints in compare with Ag plating.

This investigation of the quality of the pressureless sintered joints at the silver-silver interface reveals an evident cracking immediately after the silver paste curing. Rapid sintering process typical for silver-based films on the substrate is because of the inter-diffusion between the micro and nanoparticles of silver at interfacial interface.

The purpose of this paper is to analyse the influence of various firing profiles on microstructural and dielectric properties of low-temperature, co-fired ceramic (LTCC) substrates in a GHz frequency range. According these analyses, sintering process can be controlled and modified to achieve better performance of devices fabricated from LTCC substrates.

Samples from LTCC substrates GreenTape 951 and GreenTape 9K7 were sintered by four firing profiles. Basic firing profile recommended by the manufacturer was modified by increasing the peak temperature or the dwell time at the peak temperature. The influence of firing profile on microstructural properties was analysed according to measurements by X-ray diffractometer (application of the Cu K-alpha radiation and the Bragg-Brentano method), and the influence on dielectric properties (dielectric constant and dielectric losses) was analysed according to measurements by split cylinder resonator method at 9.7 and 12.5 GHz.

Rising of the peak temperature or extension of dwell time at this temperature has influence on all analysed properties of LTCC substrates. Size of crystallites can be changed by modification of firing profile as well as microdeformation. In addition, dielectric properties can be changed too by modification of the firing profile. Correlation between microdeformation and dielectric losses was observed.

The novelty of this work lies in finding the mutual relationship between changes in microstructural (size of grains and microdeformation) and dielectric properties (dielectric constant and dielectric losses) caused by different firing profiles.