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This paper aims to investigate voiding phenomena in solder joints under thermal pads of light-emitting diodes (LEDs) assembled in mass production environment by reflow soldering by using seven low-voiding lead-free solder pastes.

The solder pastes investigated are of SAC305 type, Innolot type or they are especially formulated by the manufacturers on the base of (SnAgCu) alloys with addition of some alloying elements such as Bi, In, Sb and Ti to provide low-void contents. The SnPb solder paste – OM5100 – was used as a benchmark. The solder paste coverage of LED solder pads was chosen as a measure of void contents in solder joints because of common usage of this parameter in industry practice.

It was found that the highest coverage and, related to it, the least void contents are in solder joints formed with the pastes LMPA-Q and REL61, which are characterized by the coverage of mean value 93.13% [standard deviation (SD) = 2.72%] and 92.93% (SD = 2.77%), respectively. The void diameters reach the mean value equal to 0.061 mm (SD = 0.044 mm) for LMPA-Q and 0.074 mm (SD = 0.052 mm) for REL61. The results are presented in the form of histograms, plot boxes and X-ray images. Some selected solder joints were observed with 3D computer tomography.

The statistical analyses are carried out on the basis of 2D X-ray images with using Origin software. They enable to compare features of various solder pastes recommended by manufacturers as low voiding. The results might be useful for solder paste manufacturers or electronic manufacturing services.

The paper aims to examine the concept of architectural design communication (ADC) for updating design studio dynamics in architectural education during the Covid-19 pandemic. Within this perspective, the changing and transforming contents of architectural education, the thinking, representation and production mediums are examined through the determined components of ADC. There are five components in the study, which are (1) Effective Language Use, (2) Effective use of Handcrafts, (3) Effective Technical Drawing Knowledge, (4) Effective Architectural Software Knowledge and (5) Outputs.

The research method is based on qualitative and quantitative methods; a survey study is applied and the comparative results are evaluated with the path analysis method. The students in the Department of Architecture of two universities have been selected as the target audience. Case study 1 survey is applied to Altinbas University (AU) and Case study 2 survey is applied to Universitat Politecnica de Valencia (UPV) students during the COVID-19 pandemic; ‘19-‘20 spring term, online education.

As a result, two-path analysis diagrams are produced for two universities, and a comparative analysis is presented to reveal the relationships of the selected ADC components.

This paper fulfills an identified need to study how ADC can be developed in online education platforms.