Now showing 1 - 10 of 12
  • Publication
    Laboratory X-ray Microscopy of 3D Nanostructures in the Hard X-ray Regime Enabled by a Combination of Multilayer X-ray Optics
    ( 2024)
    Lechowski, Bartlomiej
    ;
    Kutukova, Kristina
    ;
    Grenzer, Jörg
    ;
    Panchenko, Juliana
    ;
    Krüger, Peter
    ;
    ;
    Zschech, Ehrenfried
    High-resolution imaging of buried metal interconnect structures in advanced microelectronic products with full-field X-ray microscopy is demonstrated in the hard X-ray regime, i.e., at photon energies > 10 keV. The combination of two multilayer optics—a side-by-side Montel (or nested Kirkpatrick–Baez) condenser optic and a high aspect-ratio multilayer Laue lens—results in an asymmetric optical path in the transmission X-ray microscope. This optics arrangement allows the imaging of 3D nanostructures in opaque objects at a photon energy of 24.2 keV (In-Kα X-ray line). Using a Siemens star test pattern with a minimal feature size of 150 nm, it was proven that features < 150 nm can be resolved. In-Kα radiation is generated from a Ga-In alloy target using a laboratory X-ray source that employs the liquid-metal-jet technology. Since the penetration depth of X-rays into the samples is significantly larger compared to 8 keV photons used in state-of-the-art laboratory X-ray microscopes (Cu-Kα radiation), 3D-nanopattered materials and structures can be imaged nondestructively in mm to cm thick samples. This means that destructive de-processing, thinning or cross-sectioning of the samples are not needed for the visualization of interconnect structures in microelectronic products manufactured using advanced packaging technologies. The application of laboratory transmission X-ray microscopy in the hard X-ray regime is demonstrated for Cu/Cu6Sn5/Cu microbump interconnects fabricated using solid–liquid interdiffusion (SLID) bonding.
  • Publication
    Sensor Systems for Extremely Harsh Environments
    Sensors are key elements for capturing environmental properties and are today indispensable in the industry for monitoring and control of industrial processes. Many applications are demanding for highly integrated intelligent sensors to meet the requirements on safety, clean and energy efficient operation or to gain process information in the context of industry 4.0. While in many everyday objects highly integrated sensor systems are already state of the art, the situation in an industrial environment is clearly different. Frequently the use of sensor systems is impossible, due to the fact that the extreme ambient conditions of industrial processes like high operating temperatures or strong mechanical loads do not allow a reliable operation of sensitive electronic components. Eight Fraunhofer Institutes have bundled their competencies and have run the Fraunhofer Lighthouse Project ‘eHarsh’ to overcome this situation. The project goal was to realize sensor systems for extremely harsh environments, whereby sensor systems are not only pure sensor elements, rather containing one or multiple sensor elements and integrated readout electronics. Various technologies which are necessary for the realization of such sensor systems have been identified, developed and finally bundled in a technology platform. These technologies are e. g. MEMS and ceramic based sensors, SOI-CMOS based integrated electronics, board assembly and laser based joining technologies. All these developments have been accompanied by comprehensive tests, material characterization and reliability simulations. Based on the platform a pressure sensor for turbine applications has been realized to prove the performance of the eHarsh technology platform.
  • Publication
    A novel hermetic encapsulation approach for the protection of electronics in harsh environments
    Technologies and building blocks for the realization of reliable electronic systems for the use in harsh environments are attracting increasing intention. Harsh environments are for instance high temperature, pressure, mechanical stress and/or submerge into corrosive liquids, or the combination thereof. In the first place electronic components like integrated circuits or passive components which constitute the electronic system need to be operational under harsh conditions. On system level also the interconnections and package materials need to withstand the loading conditions. Printed circuit board embedding technology is a highly promising approach to realize this kind of electronic systems. Embedded semiconductors and passive components are mechanically protected from the environmental stresses by the epoxy/glass fibre compound into which they are encapsulated. Furthermore, novel types of high temperature laminate materials are commercially available since a few years. In an electroless plating process a fully hermetic metallic encapsulation can be added to the modules. This encapsulation acts as a protective barrier when they are immersed into corrosive liquids or gases. The external electrical connections out of the package are realized by ceramics with metallic feed throughs. They are assembled onto the modules (prior to the metallic encapsulation) using sinter-lamination-technology, i.e. the simultaneous build-up lamination and a sintering process. Two application demonstrators were realized in order to show the general viability of the encapsulation process. All used materials are commercially available. Industrial process equipment was used throughout the manufacturing. Subsequent reliability tests provide evidence for the general robustness and functionality of the modules under harsh environmental conditions. This work was part of the Fraunhofer lighthouse project “eHarsh” which was funded by the Fraunhofer Society.
  • Publication
    Sensor Systems for Extremely Harsh Environments
    Sensors are key elements for capturing environmental properties and are today indispensable in the industry for monitoring and control of industrial processes. Many applications are demanding for highly integrated intelligent sensors to meet the requirements on safety, clean, and energy-efficient operation, or to gain process information in the context of industry 4.0. While in many everyday objects highly integrated sensor systems are already state of the art, the situation in an industrial environment is clearly different. Frequently, the use of sensor systems is impossible due to the fact that the extreme ambient conditions of industrial processes like high operating temperatures or strong mechanical loads do not allow a reliable operation of sensitive electronic components. Eight Fraunhofer Institutes have bundled their competencies and have run the Fraunhofer Lighthouse Project “eHarsh” to overcome this situation. The project goal was to realize sensor systems for extremely harsh environments, whereby sensor systems are more than pure sensors, rather these are containing one or multiple sensing elements and integrated readout electronics. Various technologies, which are necessary for the realization of such sensor systems, have been identified, developed, and finally bundled in a technology platform. These technologies are, e.g., MEMS and ceramic-based sensors, SOI-CMOS-based integrated electronics, board assembly and laser-based joining technologies. All these developments have been accompanied by comprehensive tests, material characterization, and reliability simulations. Based on the platform, a pressure sensor for turbine applications has been realized to prove the performance of the eHarsh technology platform.
  • Publication
    Sensor Systems for Extremely Harsh Environments
    Sensors are key elements for the detection of environmental properties and are indispensable in industrial applications for process monitoring and intelligent control of processes. While highly integrated sensor systems are already state -of-theart in many everyday areas, the situation in an industrial environment is significantly different. The use of sensor systems is often not possible because the extreme environmental conditions of industrial processes such as high operating temperatures or strong mechanical loads do not allow the reliable operation of sensitive electronic components. As part of the Fraunhofer Lighthouse project eHarsh, eight institutes have bundled their competencies and created a technology platform as a basis for the development of sensor systems for extremely harsh environments.
  • Publication
    Smart sensor systems for extremely harsh environments
    Sensors systems are key elements for capturing environmental properties and are increasingly important in industry 4.0 for the intelligent control of processes. However, under harsh operating conditions like high temperatures, high mechanic load or aggressive environments, standard electronics cannot be used. Eight Fraunhofer institutes have therefore bundled their competencies in sensors, microelectronics, assembly, board design, laser applications and reliability analysis to establish a technology platform for sensor systems working under extreme conditions.
  • Publication
    A high temperature SOI-CMOS chipset focusing sensor electronics for operating temperatures up to 300 °C
    Sensors are key elements for capturing environmental properties and are increasingly important in the industry for the intelligent control of industrial processes. While in many everyday objects highly integrated sensor systems are already state of the art, the situation in an industrial environment is clearly different. Frequently the use of sensor systems is impossible, because the extreme ambient conditions of industrial processes like high operating temperatures or strong mechanical load do not allow a reliable operation of sensitive electronic components. Fraunhofer is running the Lighthouse Project 'eHarsh' to overcome this hurdle. In the course of the project an integrated sensor readout electronic has been realized based on a set of three chips. A dedicated sensor frontend provides the analog sensor interface for resistive sensors typically arranged in a Wheatstone configuration. Furthermore, the chipset includes a 32-bit microcontroller for signal conditioning and sensor control. Finally, it comprises an interface chip including a bus transceiver and voltage regulators. The chipset has been realized in a high temperature 0.35 micron SOI-CMOS technology focusing operating temperatures up to 300 °C. The chipset is assembled on a multilayer ceramic LTCC-board using flip chip technology. The ceramic board consists of 4 layers with a total thickness of approx. 0.9 mm. The internal wiring is based on silver paste while external contacts were alternatively manufactured in silver (sintering/soldering) or in gold-alloys (wire bonding). As interconnection technology, silver sintering has been applied. It has already been shown that a significant increase in lifetime can be reached by using silver sintering for die attach applications. Using silver sintering for flip chip technology is a new and challenging approach. By adjusting the process parameter geared to the chipset design and the design of the ceramic board high quality flip chip interconnects can be generated.
  • Publication
    Functional integration - structure-integrated wireless sensor technology targeting smart mechanical engineering applications
    Functional integration on the micro/nano scales enables smart functionalities in mechanical engineering systems. Here, exemplarily shown for a ball screw drive, a structure-integrated wireless sensor technology is implemented into a manufacturing system for advanced process control and status monitoring - even at machine components being not yet accessible or difficult to access. This includes also a miniaturized, networked and energy-efficient information and communication technology (ICT) integrated into the machine.
  • Publication
    Characterization of anodic bondable LTCC for wafer-level packaging
    ( 2016)
    Hu, Xiaodong
    ;
    ;
    MacKowiak, Piotr
    ;
    Zhang, Yucheng
    ;
    Hoelck, Ole
    ;
    ; ; ;
    Hansen, Ulli
    ;
    Maus, Simon
    ;
    Gyenge, Oliver
    ;
    ; ;
    Lang, Klausdieter
    ;
    Ngo, Haduong
    This work helps to clarify the effects on bondable Low Temperature Cofiered Cofired Ceramic(LTCC) material from Fraunhofer IKTS under different bonding conditions as changes in temperature, voltage and time. The Paper investigates silicon bonded to LTCC and silicon with a thin aluminum layer bonded to LTCC and compares both with anodic bonding of standard Borofloat 33® from Schott GmbH to silicon. The result of this work provides a comprehensive overview of bonding parameters for the materials Borofloat 33® and LTCC. An inspection of the bonding quality is carried out, which includes the optical inspection of the bonded area and interface observation via a scanning electron microscope (SEM). The bonding quality is also shown with the charge transfer during the bonding process. This paper can be used to achieve a higher degree of freedom in the design of hermetic wafer level packaging for various Micro-Electro-Mechanical System(MEMS)devices made of glass and ceramic materials.
  • Publication
    HOT-300 - a multidisciplinary technology approach targeting microelectronic systems at 300 °C operating temperature
    Several applications in the fields of industrial sensors and power electronics are creating a demand for high operating temperature of 300 °C or even higher. Due to the increased temperature range new potential defect risks and material interactions have to be considered. As a consequence, innovation in semiconductor, devices and packaging technologies has to be accompanied by dedicated research of the reliability properties. Therefore various investigations on realizing high temperature capable electronic systems have shown that a multidisciplinary approach is necessary to achieve highly reliable solutions. In the course of the multi-institute Fraunhofer internal research program HOT-300 several aspects of microelectronic systems running up to 300 °C have been investigated like SOI-CMOS technology and circuits, silicon capacitor devices, a capacitive micromachined ultrasonic transducer (CMUT), ceramic substrates and different packaging and assembly techniques. A ceramic molded package has been developed. Die attach on different leadframe alloys were investigated using silver sintering and transient liquid phase bonding (TLPB). Copper and gold wire bonding was studied and used to connect the chips with the package terminals. Investigations in flip chip technology were performed using Au/Sn and Cu/Sn solder bumps for transient liquid phase bonding. High operating temperatures result in new temperature driven mechanisms of degradation and material interactions. It is quite possible that the thermomechanical reliability is a limiting factor for the technology to be developed. Therefore investigations on material diagnostics, reliability testing and modeling have been included in the project, complementing the technology developments.