Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM

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Now showing 1 - 10 of 24
  • Publication
    Advanced mixed-mode bending test: A rapid, inexpensive and accurate method for fracture-mechanical interface characterisation
    ( 2012)
    Wunderle, B.
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    Schulz, M.
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    Keller, J.
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    May, D.
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    Maus, I.
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    Pape, H.
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    Michel, B.
    This paper presents a comprehensive method for obtaining urgently required critical interface delamination data of material pairings used in electronic packaging. The objective is to thereby enable rapid, inexpensive and accurate lifetime prediction for that failure mode. A new testing method is presented which allows maximum mode-angle range and enhanced throughput testing under multiple loading conditions, the coverage of which is usually a rather lengthy and resource-demanding procedure. The approach is specimen-centred in the sense that the accent is put on test-specimens which are easily manufacturable industrially, rather than having to adapt them to a special testing machine. The concept is also scalable, i.e. it has potential to work also for smaller samples cut from real devices. We show the first version of a newly developed test-stand and discuss the obtained results for copper-molding compound interfaces in the light of the current state of the art used for delamination testing in electronic packaging.
  • Publication
    Automated test system for in-situ testing of reliability and aging behaviour of thermal interface materials
    ( 2011)
    AboRas, M.
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    Haug, R.
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    Schacht, R.
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    Monory-Plantier, C.
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    May, D.
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    Wunderle, B.
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    Winkler, T.
    ;
    Michel, B.
    Thermal interface materials (TIMs) are widely needed to improve thermal contacts for facilitation heat transfer in electronic packaging, such as that associated with the flow of heat from microprocessor to a heat spreader or a heat sink in a computer. Due to thermal mismatch between these components mechanical strain occur which cause pump-out, cracks or delamination of TIM. In order to qualify the reliability and aging of TIMs, traditional power cycle test is commonly used to detect potential thermal failures. This traditional power cycle test is a time consuming process due to its long heating and cooling time. Therefore a new automated test system for in-situ reliability testing of TIMs is developed and will be presented in this paper. The new test system is designed to be able to analyze the aging and reliability behavior of most common TIMs. The TIMs can be measured in-situ and under real conditions as they are used in real applications.
  • Publication
    Design and development of a miniaturized black body device for in-situ IR-camera calibration
    ( 2010)
    Schacht, R.
    ;
    Gerner, Ch.
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    Nowak, T.
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    May, D.
    ;
    Wunderle, B.
    ;
    Michel, B.
    Nowadays very often IR-thermography is used to analyze the temperature on electronic device surfaces. To measure the absolute surface temperature correctly, the IR-camera detector has to be calibrated with a corresponding evaluation software using a black body calibration device. Commercially available black radiators are heavyweight and a calibration of macrolenses is not possible due to mismatch of the macro lens diameter and the structural design of the radiator. This paper describes the design and realization of a mobile, miniaturized black body calibration device (mass 500 g) which supports macro lenses as well. To realize a temperature range of -5°C to 130°C, a Peltier element as cooling source and a flip-chip mounted thermal test die (TTD) as black radiator heat source, with an including temperature measuring instrument, were used. First temperature stability and calibration tests for the new TTD black radiator show a suitable resolution of 0.1 K. A verification with a commercially available calibration device was done.
  • Publication
    Miniaturized black body radiator for IR- Detector calibration - Design and development
    ( 2010)
    Schacht, R.
    ;
    Gerner, Ch.
    ;
    Nowak, T.
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    May, D.
    ;
    Wunderle, B.
    ;
    Michel, B.
    Nowadays very often IR-thermography is used to analyze the temperature on electronic device surfaces. To measure the absolute surface temperature correctly, the IR-camera detector has to be calibrated with an corresponding evaluation software using a black body calibration device. Commercially available black radiators are heavyweight and a calibration of macro-lenses is not possible due to mismatch of the macro lens diameter and the structural design of the radiator. This paper describes the design and realization of a mobile, miniaturized black body calibration device (mass 500 g) which supports macro lenses as well. To realize a temperature range of -5°C to 130°C, a Peltier element as cooling source and a flip-chip mounted thermal test die (TTD) as black radiator heat source, with an including temperature measuring instrument, were used. First temperature stability and calibration tests for the new TTD black radiator show a suitable resolution of 0.1 K. An verificat ion with a commercially available calibration device was done.
  • Publication
    Influences of technological processing and surface finishes on thermal behaviour of thermal interface materials
    ( 2010)
    Abo Ras, M.
    ;
    Wunderle, B.
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    May, D.
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    Oppermann, H.
    ;
    Schacht, R.
    ;
    Michel, B.
    The ongoing need for miniaturization and speed in electronics industry has brought a requirement for better performing thermal management systems. One of the major bottlenecks in thermal management is the thermal interface resistance. Characterisation of thermal interface materials become even tougher a challenge at low bond line thicknesses and higher thermal conductivities of the interface materials as more accurate measurement techniques are required. In this paper a platform for characterisation of interface materials is presented. Moreover the influence of curing regime on thermal properties of thermal adhesive is investigated. A clear influence of curing parameters was found. For thermal characterisation of sintered silver a test stand has been developed still using steady state techniques. We the results process parameters could be optimized. Part of the work has been accomplished within the running EU Project "Nanopack".
  • Publication
    Advances in thermal interface technology: Mono-metal interconnect formation, processing and characterisation
    ( 2010)
    Wunderle, B.
    ;
    Klein, M.
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    Dietrich, L.
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    Abo Ras, M.
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    Mrossko, R.
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    May, D.
    ;
    Schacht, R.
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    Oppermann, H.
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    Michel, B.
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    Reichl, H.
    As the demand for new thermal technologies and materials has been increasing over the years to provide thermal solutions to the next generation of power electronics, microprocessors and high-power optical systems also thermal characterisation methods have to keep up with the pace of this development with respect to resolution and accuracy. We have developed both bulk and interface technologies to reduce thermal resistance using Ag and Au-based materials and low-T and low-p processes to render them eligible for the electronics industry. New processes to generate nano-enhanced surface structures as well as thermo-compression bonding are examined within this paper. Along with these processes especially designed test stands are described which are able to extract the effects achieved by the technological advances.
  • Publication
    Crack tip localization of sub-critical crack growth by means of IR-imaging and pulse excitation
    ( 2009)
    May, D.
    ;
    Wunderle, B.
    ;
    Schacht, R.
    ;
    Michel, B.
    Taking the advantage of the thermo-elastic effect, while using an infrared camera system, the mechanical stress could be made visible. The stress concentrations at the tip of a subcritical crack growth could clearly be detected. Through the observation during the periodic loading of a CT-specimen the crack growth rate can be determined. For this purpose, a specially developed loading stage will be presented. It is now possible to have further investigation in material class of polymers, which is very important in the field of system integration. First promising results will be presented.
  • Publication
    Nondestructive failure analysis and simulation of encapsulated 0402 multilayer ceramic chip capacitors under thermal and mechanical loading
    ( 2009)
    Wunderle, B.
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    Braun, T.
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    May, D.
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    Michel, B.
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    Reichl, H.
    The use of multilayer ceramic chip capacitors as integrated passive in, e.g., system in package applications needs methods to examine and predict their reliability. Therefore, a nondestructive failure analytical technique is described to detect cracks in the ceramic and the metallic layers within encapsulated 0402 surface mount device (SMD) capacitors. After choosing from techniques to reproducibly generate cracks, it is shown that an in situ capacitance measurement is a convenient method to detect these failures unambiguously. Finite element simulations support the experimental results. A reliability estimate for capacitor integrity under given loading conditions is given.