Gerbach, R., Ebert, M., Brokmann, G., Hein, T., Bagdahn, J.
In this paper investigations for the non-destructive characterization of MEMS (Micro-Electro-Mechanical-Systems) are presented that can be applied in the production monitoring in early stages....
Constitutive behaviour of copper ribbons used in solar cell assembly processes (2009)
Wiese, S., Meier, R., Kraemer, F., Bagdahn, J.
One of the driving factors for a steady reduction in wafer and cell thickness is the present shortage of polysilicon feedstock combined with the need to reduce manufacturing costs in photovoltaic...
Tensile testing of individual ultrathin electrospun poly(L-lactic acid) fibers (2009)
Jaeger, D., Schischka, J., Bagdahn, J., Jaeger, R.
The mechanical properties of ultrathin electrospun poly(L-lactic acid) (PLLA) fibers were studied by performing tensile tests on individual fibers. The tests were carried out on microelectronic...
High-cycle fatigue and strengthening in polycrystalline silicon (2008)
Boroch, R.E., Müller-Fiedler, R., Bagdahn, J., Gumbsch, P.
The reliability of MEMS-based sensors for automotive applications critically depends on their high-cycle load-bearing capacity. To investigate the influence of high-frequency cyclic loading on...
Mechanical strength of mono- and multicrystalline wafers (2008)
Schönfelder, S., Bohne, A., Bagdahn, J.
Thin silicon wafers are used for the majority of solar cells produced today. The strength behavior of such wafers has to be understood to avoid wafer breakage during manufacturing. In this work,...
Mechanical characterization and micro structure diagnostics of glass frit bonded interfaces (2008)
Boettge, B., Dresbach, C., Graff, A., Petzold, M., Bagdahn, J.
In this paper, results of mechanical strength investigations for glass frit bonded components using tensile and micro chevron testing are presented. Specific attention is given to the formation of...
Dietrich, S., Ebert, M., Bagdahn, J.
Solar modules mounted to a subsystem are directly affected by natural weathering. It has been found that certification processes including simulated weathering of UV-radiation, heat and moisture can...
Solarmodul sowie Verfahren zur Herstellung eines Solarmoduls (2008)
(A1) Beschrieben wird ein Solarmodul sowie ein Verfahren zur Herstellung eines Solarmoduls mit einer elektrisch verschalteten, flaechig ausgebildeten Solarzellenanordnung, an deren Rueckseite eine...
Schönfelder, S., Ebert, M., Landesberger, C., Bock, K., Bagdahn, J.
Thin silicon offers a variety of new possibilities in microelectronical, solar and micromechanical industries, e.g. for 3D-integration (stacked dies), thin microelectromechanical packages or thin...
Boroch, R., Wiaranowski, J., Mueller-Fiedler, R., Ebert, M., Bagdahn, J.
The aim of this work is to characterize the strength properties of polycrystalline silicon (polysilicon) with the use of tensile and bending test specimens. The strength of thin polysilicon films...
Comparison of test methods for strength characterization of thin solar wafer (2007)
Schönfelder, S., Bohne, A., Bagdahn, J.
The Photovoltaic industry still tends towards thinner wafers with larger area leading to higher breakage rate in production processes. Strength characterization is needed in order to understand the...
Ebert, M., Naumann, F., Gerbach, R., Bagdahn, J.
In the paper basic investigations for the nondestructive quality testing methods for MEMS (Micro-Electro- Mechanical Systems) are presented that can be applied on wafer level in early stage of the...
Schönfelder, S., Ebert, M., Landesberger, C., Bock, K., Bagdahn, J.
Thin silicon offers a variety of new possibilities in microelectronical, solar and micromechanical industries, e.g. for 3D-integration (stacked dies), thin microelectromechanical packages or thin...
Mechanical properties of glass frit bonded micro packages (2006)
Dresbach, C., Krombholz, A., Ebert, M., Bagdahn, J.
Frit glass bonding is a widely used technology for encapsulation of surface micro-machined structures like inertial sensors or gyroscopes on wafer level. Since for sensors in automotive applications,...
Ebert, M., Gerbach, R., Bagdahn, J., Michael, S., Hering, S.
In the paper a new, nondestructive quality testing methods for MEMS will be presented that can be applied on wafer level in early stage of the manufacturing process. The approach was applied to...
Drop simulation and stress analysis of MEMS devices (2006)
Hauck, T., Li, G., McNeill, A., Knoll, H., Ebert, M., Bagdahn, J.
Drop testing of micro-machined accelerometers from the height of a table top to a solid surface shows that a moderate impact can result in severe damage of transducer elements. The relative high...
Strength characterization of laser diced silicon for application in solar industry (2006)
Schönfelder, S., Bagdahn, J., Baumann, S., Kray, D., Mayer, K., Willeke, G., ...
Laser technologies are used in a wide range of process steps in solar industry. In this paper novel laser dicing technologies like LaserMicroJet® and Laser Chemical Etching (LCE) are investigated...
Strength characterization of directly bonded silicon (2006)
Wiemer, M., Fischer, C., Bernasch, M., Bagdahn, J.
In this paper a test wafer for the characterization of the bond quality of directly bonded silicon is described. The 6`` test wafer contains samples for dicing yield, tensile strength and surface...
Room temperature bonding of nanostructured silicon wafers and mechanical characterization (2006)
Stubenrauch, M., Fischer, M., Bernasch, M., Bagdahn, J.
A new method for bonding of two silicon wafers at room temperature is presented. The technique is based on the interlocking of needle-like structured surfaces. The required nano structure (black...
Influence of moulding process on strength of glass frit bonded structures (2006)
Ebert, M., Bagdahn, J., Knechtel, R.
The glass frit layer in wafer-bonded MEMS is subjected to mechanical and thermo mechanical stresses during production steps such as moulding. In this work the influence of the moulding process on the...
Identification of geometrical parameters of MEMS from measured resonant frequencies (2006)
Gerbach, R., Ebert, M., Bagdahn, J., Hering, S.
In this paper a new method is presented to identify geometrical parameters of MEMS non-destructively. The used identification methodology is based on a combination of dynamic measurements using a...
Fracture mechanical life-time investigation of glass-frit bonded MEMS sensors (2006)
Petzold, M., Dresbach, C., Ebert, M., Bagdahn, J., Wiemer, M., Glien, K., ...
The long-term mechanical stability of the wafer level package is an important aspect in the reliability approach of MEMS products.Glass frit bonding is one of the most widely used bonding...
Knechtel, R., Knaup, M., Bagdahn, J.
In this paper a test structure is introduced, which allows the evaluation of the quality of an anodic bond interface in terms of surface energy. It is based on the creation of small non-bonded areas...
Influence of the frequency on fatigue of directly wafer-bonded silicon (2006)
Bagdahn, J., Bernasch, M., Petzold, M.
Fatigue tests on directly wafer-bonded silicon samples were performed using pre-cracked Micro-Chevron samples applying cycling loading frequencies between 0.3 a nd 40 Hz. The experimental lifetime...
Mechanical properties of glass frit bonded micro packages (2006)
Dresbach, C., Krombholz, A., Ebert, M., Bagdahn, J.
Frit glass bonding is a widely used technology for encapsulation of surface micro-machined structures like inertial sensors or gyroscopes on wafer level. Since for sensors in automotive applications,...
Fracture and delamination of thin multilayers on ultra-thin silicon (2005)
The paper analyzes delamination propagation and crack kinking between CMOS layers on the ultra thin silicon chip. Based on the fracture mechanics approach, a four-point bending specimen is analyzed...
Strength analysis of etched silicon pressure sensors (2005)
Ebert, M., Knaup, M., Stelzer, T., Bagdahn, J., Bartuch, H., Brokmann, G.
The strength of relative pressure sensors are experimentally and numerically investigated. The sensors are produced with different eching processes and have different sizes because of different...
Investigations of strength properties of ultra-thin silicon (2005)
Schönfelder, S., Bagdahn, J., Ebert, M., Petzold, M., Bock, K., Landesberger, C.
Thin silicon offers a variaty of new possibilities in microelectronical and micromechanical industries, e.g. for 3D-integration (stacked dice) or optoelectronic components (LED). The thin wafers are...
Reliability of wafer bonding in microsystem technologies (2005)
Reliability tests and fracture mechanics models for wafer-bonded components are presented which can be applied during the development of bonding technologies, for the yield improvement and failure...
NON-destructive strength testing of anodic bonded glass-silicon wafer compounds (2005)
Knechtel, R., Knaup, M., Bagdahn, J., Wiemer, M.
In this paper a non-destructive test structure for monitoring the strength of anodic bonded glass silicon wafer compounds is introduced. The realisation of the structure, the calculation of the...
Mechanical reliability of directly bonded silicon MEMS components (2005)
Bagdahn, J., Wiemer, M., Petzold, M.
Duringe use, directly wafer-bonded devices such as acceleration sensors, gyroscopes, micropumps, or microvalves are oxposed to continuously or periodically acting mechanical stresses particularly due...
Silizium-basierte Mikrosysteme werden heute auch in sicherheitsrelevanten Anwendungen der Automobil- und Medizintechnik industriell eingesetzt. Sowohl für eine zuverlässige Auslegung der Bauteile,...
Mechanical failure behavior of glass frit bondet structures (2005)
Ebert, M., Dresbach, C., Krombholz, A., Bagdahn, J., Glien, K., Graf, J., ...
The long term mechanical stability of the wafer level package is an important aspect in the reliability approach of MEMS products. One of the most widely used bonding technologies is the glass frit...
Strength and reliability testing for silicon based MEMS (2004)
Petzold, M., Bagdahn, J., Katzer, D.
In this paper, theoretical fracture mechanics concepts as well as strength and fatigue testing methods will be presented which can be applied for strength and lifetime prediction, design...
Debonding of wafer-bonded interfaces for handling and transfer applications (2004)
Based on the fracture mechanics analysis of crack propagation, the phenomenon of subcritical crack growth was utilized for a controlled debonding of directly wafer-bonded interfaces. The approach...
Determination of residual stress in glass frit bonded MEMS by finite element analysis (2004)
Glass frit bonding is an universal technique with intermediate glass layer for the packaging of Micro-Electro-Mechanical Systems (MEMS). The joining of two wafers is required to protect surfaced...
Strength and reliability properties of glass frit bondet micro packages (2004)
Glien, K., Graf, J., Müller-Fiedler, R., Höfer, H., Ebert, M., Bagdahn, J.
The hermetic package is one crucial element to ensure high reliability and lifetime of micro mechanical sensors in automotive applications. In a proactive approach fundamental reliability limiting...
Fatigue testing of polysilicon - a review (2004)
Measurement of the mechanical properties of thin-film materials such as polysilicon is difficult because of the small sizes, forces, and displacements involved as well as the need for special...
A new approach for handling and transferring of thin semiconductor materials (2003)
Bagdahn, J., Knoll, H., Wiemer, M., Petzold, M.
Based on the fracture mechanics analysis of crack propagation, the phenomenon of subcritical crack growth was utilized for a controlled debonding of directly wafer-bonded interfaces. The approach...
Fatigue of polycrystalline silicon under long-term cyclic loading (2003)
The long-term mechanical behavior of 3.5 µm thick and 50 µm wide polysilicon tensile specimens under tension-tension cyclic loading was investigated. The use of an external actuator allows the...
A failure criterion for interface notches in silicon/glass anodic bonds (2003)
Knaup, M., Busch, M., Bagdahn, J.
A common approach for joining silicon - structured using anisotropic etching - and glass is anodic bonding. The combination of these two techniques (etching and bonding) lead to problems concerning...
Fracture strength of polysilicon at stress concentrations (2003)
Bagdahn, J., Sharpe, W.N., Jadaan, O.
Mechanical design of MEMS requires the ability to predict the strength of load-carrying components with stress concentrations. The majority of these microdevices are made of brittle materials such as...
Tensil testing of MEMS materials recent progress (2003)
Sharpe, W.N., Bagdahn, J., Jackson, K., Coles, G.
Tension tests, while standardized for common structural materials, are currently being developed and used for MEMS materials by a small number of researchers. This paper presents recent progress at...
Probabilistic Weibull behavior and mechanical properties of MEMS brittle materials (2003)
Jadaan, O.M., Nemeth, N.N., Bagdahn, J., Sharpe, W.N.
The objective of this work is to present a brief overview of a probabilistic design methodology for brittle structures, review the literature for evidence of probabilistic behavior in the mechanical...
Strength and long-term reliability testing of wafer-bonded MEMS (2002)
Petzold, M., Katzer, D., Wiemer, M., Bagdahn, J.
Wafer bonding techniques are frequently used for MEMS/MOEMS fabrication. In this paper, the potential application and methodical limitations of different strength testing approaches including tensile...
Einsatz von Niedertemperaturbondverfahren für die Fertigung von Sensoren (2001)
Wiemer, M, Otto, T., Gessner, T., Hiller, K., Kapser, K., Seidel, H., ...
A new approach for handling and transferring of thin semiconductor materials (2001)
Bagdahn, J., Katzer, D., Petzold, M., Wiemer, M., Alexe, M., Dragoi, V., ...
Fatigue of directly wafer-bonded silicon under static and cyclic loading (2001)
Fatigue tests were performed to investigate the reliability properties of wafer-bonded single crystalline silicon exposed to static or cyclic mechanical loading. A distinct decrease of strength with...
Investigation of bonding behaviour of different borosilicate glasses (2000)
Wiemer, M, Hiller, K., Gessner, T., Kloss, T., Schneider, K., Leipold-Haas, U., ...
New investigations were carried out in order to characterise the anodic bonding behaviour of borosilicate glass Borofloat 33 in comparison with different suppliers of borosilicate glass wafers....
Lifetime investigations of directly wafer-bonded samples under static and cyclic loading (2000)
Bagdahn, J., Petzold, M., Sommer, E.
Strength and fatigue tests were performed to investigate the reliability properties of Si wafer-bonded samples exposed to static or cyclic mechanical loading. A distinct strength decrease with...
Strength analysis of a micromechanical acceleration sensor by fracture mechanical approaches (2000)
Bagdahn, J., Petzold, M., Seidel, H.
The strength properties of a micromechanical acceleration sensor for airbag application fabricated from single crystalline silicon were analyzed using fracture mechanical concepts. The investigations...
Untersuchungen zum subkritischen Rißwachstum gebondeter Siliziumwafer (1998)
Bagdahn, J., Katzer, D., Petzold, M.
In der vorliegenden Arbeit wurde erstmalig das Auftreten des subkritischen Rißwachstums bei wafergebondeten Siliziumbauteilen nachgewiesen. Die mit Hilfe eines für die Prüfungen an wafergebondeten...
Mechanical reliability of silicon wafer-bonded components (1998)
Bagdahn, J., Katzer, D., Petzold, M.
Sufficient mechanical strength and reliability are important prerequisites for the industrial application to technical components. Frequently, wafer bonding technologies are involved to fabricate...
Plößel, A., Scholz, R., Bagdahn, J., Stenzel, H., Tu, K.N., Gösele, U.
The bonding of solids with atomically clean surfaces represents a low-temperature wafer direct bonding technique with potential applications electronics and micromechanics. Upon contact at room...
Mechanical reliability tests for bonded wafers (1997)
Bagdahn, J., Petzold, M., Reiche, M., Wiemer, M.
The fabrication of micromechanical components, such as acceleration sensors, pressure sensors, valves or micropumps, requires special joining technologies, like direct or anodic wafer bonding. An...
The influence of sharp notches on the strength of directly bonded components (1997)
Bagdahn, J., Katzer, D., Petzold, M., Wiemer, M.
The influence of sharp notches in the interface of directly bonded components, of the oxide layer thickness and of the annealing temperature on the tensile strength of bonded samples was...
Bagdahn, J., Petzold, M., Reiche, M., Gutjahr, K.
The influence of the specimen geometry, the elastic anisotropy the testing conditions and measurement errors on the determination of the interface energy of directly bonded wafers with the double...
Investigations of the interface strength of bonded silicon wafers (1995)
Bagdahn, J., Heinzelmann, M., Petzold, M., Reiche, M.
Tensile tests were applied to determine the strength properties of bonded contacts (prepared by Direct Wafer Bonding) in micromechanical components. In addition to material properties, as the...