At the Department of Electronics Technology high amount offailure analysis inspections have been carried out during the last five years, thus an outstanding number of results and reports have been accumulated by the Failure Analysis Group. The results and experiences gained in the past by these analyses can provide useful information in the present and future infurther cases which show similarities to former problems. Such knowledge can only be exploited if the analysis results are organized in a suitable structure and the researchers do not have to rely on their own memory. A suitable system should handle queries based on various approaches i.e. type offailure, involved component, during which process the failure occurred, applied analysis method, etc. So the analysis result storage system has to provide a possibility to find any earlier analysis result which can be in connection with current cases to provide us the previously gained experiences and conclusions. In case a lecturer wants to illustrate a presentation with images ofa certain failure type or ofa given analysis method then the time needed to find the right pictures can be significantly reduced by the help ofthe analysis database.

The lifetime of electronic systems is highly influenced by the quality of the built-in electronic parts, so it is especially important that we could choose from a wide range ofparts with the best fit to the conditions of usage. The aim of this paper is to describe what proportion of the die attach of a component will be delaminated beside different conditions. The following factors were taken into account: the physical parameters of the part, the conditions of the assembling and the conditions ofthe end usage. A test plan was set up with different types ofcomponents. Every group of components was separated into subgroups, these subgroups were exposed to different assembling and usage conditions. This test procedure provided information about whether the lead-free reflow process decreases the reliability ofthe die attach layer.

In electronic industry shear test is a commonly used method to classify the mechanical properties and reliability of solder joints. The aim of this paper is to investigate how the shear test conditions (shear rate, shear height) affect the measured shear strength values. To study this, a series of experiments have been conducted on 0603 sized chip resistors. The experiments showed that increasing the shear rate results in slightly higher measured shear strength in the 60..600 µm/s range. The higher the shear height the lower the measured shear force was, thus it is advisable to perform the shear tests with the lowest reproducible shear height. In case of the tested components the fracture always formed between the ceramic body of the resistor and its metallization.

Microhardness and sound velocity were measured in case of differently prepared solder samples. The used Pb-10Sn solder samples were melted then cooled down applying different cooling rates. These procedures caused variant microstructure thus different microhardness and sound velocity values. The sound velocity was measured by means of scanning acoustic microscopy. Characterization of solder materials by acoustic microscopy gives the possibility to non-destructively estimate mechanical and reliability parameters of the given material.

Scanning acoustic microscopy is an analysis tool capable for revealing the inner structure of the samples and detecting inhomogeneities inside them, for material characterization and for measuring the thickness of a given layer. A standard method for thickness measurements is based on observing a so called A-mode echo signal. In this paper the authors present pilot results of a method for thickness measurements based on analyzing the grayscale value of the Cmode image. The method can be used only under certain circumstances, but has the advantage to estimate the thickness of a layer using only the C-mode image.