No abstract

Thromboelastometry ROTEM (Pentapharm, Munich, Germany) is a viscoelastic method of whole blood clotting assessment with applications in perioperative hemostasis and hematology. The different tests available for the investigation of distinct coagulation aspects are performed with combinations of liquid reagents. The use of liquid reagents for the ROTEM measurement requires several pipetting steps, which complicates their application in clinical routine even though pipetting is performed semiautomatically. New single portion reagents (SPR) containing in one vial all lyophilized reagents necessary for each test have been recently developed. SPR require only addition of blood into the single-use reagent vial in a unique pipetting step in order to mix reagents with the blood sample. Our study compared SPR and standard liquid reagents (Pentapharm) in 21 blood samples from normal subjects and 46 samples from patients in three study centers. Following ROTEM tests were performed: EXTEM (extrinsically activated TEM), INTEM (intrinsically activated TEM), FIBTEM (fibrin-based TEM), APTEM (aprotinin-controlled TEM) and HEPTEM (heparin-insensitive TEM). In the second part of the study, the stability of SPR at 37 degrees C was also assessed on 23 blood samples in one center. Very good correlation was found between SPR and liquid reagents for all clotting parameters (correlation coefficient between 0.85-0.99). The SPR reagents showed excellent stability against thermic stress and the measurements were easier to perform than with the conventional liquid reagents system.

Commercially known as Innolot, the highly reliable lead-free alloy, allowing for high operating temperatures, is a Tin-Silver-Copper (SAC) metallurgical system with additional elements to harden the alloy and to improve its creep strength in order to significantly improve the reliability of solder joints. Compared to traditional SAC alloys, the characteristic lifetime can be enhanced on the base of temperature cycle tests (TCT) from −40°C to +125°C or even extended to 150°C. Assemblies in the automotive industry increasingly require higher reliability for safety relevant and emerging applications such as Advanced Driver Assistance Systems (ADAS). Cost-reduction requirements demand a new approach for optimized soldering processes and materials. As the current reflow process prefers Nitrogen atmosphere for low defects in high reliability soldering, our research focuses around the partial and/or complete change to air soldering processes. Furthermore, we investigate the influence of different surface finishes such as Chemical Sn, NiAu, and Cu OSP, and modified alloy compositions in the soldering performance. Apart from initial characterizations for various assemblies, reliability tests on Heraeus Reliability1 printed circuit boards as well as temperature cycle tests from −40 to +150°C for up to 2500 cycles are reported and resulting failure modes are discussed. This paper furthermore describes the potential for cost reductions via process and/or material optimizations without diminishing the high reliability performance for such automotive applications.