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Specially formulated frit materials have been applied in thick film superconductors similar to the standard thick film materials in order to achieve processing parameters closely compatible with conventional thick film technology and alumina substrates. The applied frits have improved the adhesion and superconductor properties at the same time due to a superconductor bridge formation between the grains. Both YBCO and BSCCO systems have been analyzed. The results are promising.

In microfluidic channel fabrication in low temperature co‐fired ceramics (LTCC), one of the biggest challenges is the elimination of channel deformation during lamination. The purpose of this paper is to describe the expected deformation of the substrate and the sacrificial layer (starch powder and 3D printed UV polymerized material) during the lamination process of microfluidic structure fabrication.

Uniaxial compression and Jenike shear test were used to obtain the mechanical parameters of starch sacrificial volume material (SVM). To determine the stress‐strain characteristics of LTCC a uniaxial compression experiment was conducted. The shape of the laminated LTCC containing embedded channel was modeled by finite element method using the mechanical parameters obtained by the measurements.

It was found that the choice of SVM plays an important role in channel deformation. A design rule is given considering the channel width and the choice of SVM based on the simulation results.

Until now the lamination step of LTCC technology was only optimized in an empirical way.

This paper aims to develop a method to measure the length of cracks inside solder joints, which enables the validation of computed tomography (CT) crack length measurements.

Cracks were formed inside solder joints intentionally by aging solder joints of 0603 size resistors with thermal shock (TS) test (−40 to +140°C, 2,000 cycles), and CT images were captured about them with different rotational increment (1/4, 1/2 and 1°) of sample projection. The length of cracks was also measured with our method, which is based on capturing high-resolution radiography X-ray images about the cracks in two perpendicular projection planes. The radiography results were compared to the CT measurements. The percentage error for the different CT rotational increment settings was calculated, and the optimal CT settings have been determined.

The results have proven that reducing the rotational increment increases the sharpness of the captured images and the accuracy of crack length measurements. Nevertheless, the accuracy compared to high-resolution radiography measurements is only slightly better at 1/4° rotational increment than in the case of 1/2° rotational increment. It should be also noted that the 1/4° increment requires twice as much time for capturing the images as the 1/2° increment. So, the 1/2° rotational increment of sample projection is the optimal setting in our investigated case for measuring crack lengths.

The developed method is applicable to find the optimal settings for CT crack length measurements, which provides faster analysation of large quantity samples used, e.g. at life-time tests.

There is a lack of information in the literature regarding the optimisation of CT measurement set-up, e.g. a slightly larger value of the sample rotational increment can provide acceptable resolution with much faster processing time. Thus, the authors developed a method and performed research about optimising CT measurement parameters.

The paper aims to present a comparative study of various thermocouple (TC) attaching methods for the proper measurement of soldering temperature profiling during vapour phase soldering (VPS). The heat transfer process during VPS is different from common methods, while the required heat for reflow is provided by the condensation. The condensate is a flowing layer on the board, where the dynamic behaviour also affects the local conditions on the surfaces. Temperature measurements based on TCs are also affected this way; it is important to investigate the process for deeper understanding.

Bare printed circuit boards (PCBs) were prepared for standard K-Type TCs attachment with industry standard materials: kapton polyimide tape, aluminium tape, SMD adhesive and high-temperature solder (HTS). Heating experiments were performed in a batch-type VPS oven with Galden LS240 fluid and fixed oven parameters.

According to the specific attachment requirements, HTS and Alu-tape are the suggested methods for better profiling reliability and repeatability. Alu-tape is the preferred all-around method, for fast, exchangeable, cheap, reliable and repeatable profiling in a VPS oven. It was presented that the heating factor (Q?) gives more reliable comparison overview; the time period-based comparisons may be affected by the thermal inertia, while heating factor also includes temperature conditions at the given time points.

The paper presents the reliability of the presented methods for VPS and present suggestions for the use of different TC ends and attaching materials during condensation heating of the PCBs. Also a new approach on profiling data evaluation based on the heating factor is presented and suggested for wider use.

The members of the chapter at the annual meeting held on 27 November 1992 in Brno decided not to split after the separation of Czechoslovakia. It was suggested to organise a larger chapter from the Central European States to provide greater co‐operation and better functioning of the smaller chapters. A new name for the chapter was proposed — Central European Chapter (CEC) — to express neutrality and to point out that the chapter is open to other neighbouring chapters and to new members from the states where no national chapter yet exists.

‘The Choice between Chip and Wire and High Density Surface Mount Packages (MCM‐X, COB, etc.)’ was the title of the above event. One of a regular series held by ISHM‐France, this technical seminar was attended by over 100 members and non‐members of ISHM who were eager to hear of the latest developments in the field of multichip modules. The eight papers presented are summarised below:

At the Annual General Meeting of ISHM‐France, held on 12 June 1991, the following were elected:

The International Society for Hybrid Microelectronics invites the submission of technical papers for presentation at the above event. All original unpublished papers on microelectronics related topics are welcomed.