A study of the performance of different Sn based solder alloys applied for large to small sized solder interconnects was undertaken. From the theoretical and experimental investigations on creep, fatigue and brittle fracture behaviors the paper focuses on the low cycle fatigue performance in test and field thermal environments. Special focus was put on a newly developed highly creep resistant solder alloy "Innolot" (SnAg3.8Cu0.7Bi3.0Sb1.4Ni0.2). In addition to results of previous studies on lead free materials, particularly their longterm durability and their microstructure-properties dependence was addressed. Phenomenological models based on finite element analyses including solder creep behaviors were applied to study the component and cyclic regime dependent creep straining and creep dissipation in several joints to assess solder failure. For this purpose, creep properties of several solders were measured for ball-type joint sized specimens.

This contribution deals with capacitively actuated Ohmic switches in series single pole single throw (SPST) configuration for DC up to 4 GHz signal frequency (<0.5 dB insertion loss, 35 dB isolation) and in shunt switch SPST configuration for a frequency range from DC up to 80 GHz (<1.2 dB insertion loss, 18 dB isolation at 60 GHz). A novel high aspect ratio MEMS fabrication sequence in combination with wafer level packaging is applied for fabrication of the samples and allows for a relatively large actuation electrode area, and for high actuation force resulting in fast onresponse time of 10 s and off-response time of 6 s at less than 5 V actuation voltage. Large actuation electrode area and a particular design feature for electrode over travel and dynamic contact separation lead to high contact force in the closed state and to high force for contact separation to overcome sticking. The switch contacts, which are consisting of noble metal, are made in one of the latest process steps. This minimizes contamination of the contact surfaces by fabrication sequence residuals. A life time of 1 Billion switch cycles has been achieved. This paper covers design for reliability issues and reliability test methods using accelerated life time test. Different test methods are combined to examine electric and mechanical motion parameters as well as RF performance

No abstract

No abstract

The knowledge of deformation and fatige behaviour is vital for understanding reliability problems and builds the basis for mechanical simulations, which quantify strains, stresses and even product life-times. The focus of this paper is the AuSn interconnect in the form of eutectic AuSn and fine pitch flip-chip interconnects consisting in this example of an Au-phase and a zetha-phase. In the fist place local elasticplastic properties are analysed by nanoindentation giving information about the process influences on material properties. To analyse the fracture, damage and fatigue behaviour of eutectic AuSn interconnects, special set-ups have been developed. Normal lap shear samples enable the analysis under pure mechanical load and thermal lap shear specimen enable the analysis under combindeed thermal and mechanical load. Thus different failure modes are outlined, which can be the focus for futher quantitative analysis