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Vergleich von Stützstrukturen für die additive Fertigung: CreoParametric/Simulate4.0 <-->ProTOpCI
Get PDFDurch die Verwendung von 3D-Druck-Verfahren wird die Gestaltung der Komponenten revolutioniert, weil die Form nicht mehr abhängig vom Fertigungsverfahren ist. Dabei werden auch optimale Gitterstrukturen innerhalb der Komponenten immer wichtiger. Diese Stützstrukturen können in Creo Parametric 4.0 mit dem neuen «Lattice-Feature» modelliert und Creo Simulate analysiert werden. Parallel dazu kann man mit ProTopCI (Hersteller CAESS, PTC Partner Advantage, Silver) eine Topologieoptimierung mit Stützstrukturen durchführen. Der Vortrag beleuchtet die Unterschiede dieser 2 Methoden
Infrared welding of continuous fibre-reinforced thermoplastics – Investigations on overlapping joints
Get PDFContinuous fibre-reinforced thermoplastics often are offered as impregnated and consolidated semi-finished products which are known as organic sheets. The thermoplastic matrix leads to several advantages including the thermoformability and weldability.
Parts made of organic sheets are frequently produced by forming the semi-finished product into half-shells and stiffening those shells in the course of the process e.g. by the injection moulding of ribs. Larger and more complex parts with hollow body structures can be manufactured e.g. by forming the semi-finished products into half-shells and joining the half-shells. However, the currently available manufacturing technologies for parts made of organic sheets have cap profile shaped joints which prevent the use of the reinforcing fibres across the joint plane.
Investigations have proven that overlapping weld joints in organic sheets show much higher strengths than cap profile shaped joints which can be explained by the fibre use across the joint plane. Furthermore, the infrared welding technology was verified as an appropriate process for the welding of organic sheets since no need for additional welding material is given, short heating times can be realized and no contact of the infrared emitters to the joining parts is required. Therefore, the present study shall reveal the high potential of the overlapping welding of organic sheets. Influences on the weld strengths of infrared welded organic sheets are described and potential improvements concerning the materials to be welded as well as the welding process are shown
A Single Gyroscope Can Be Used to Accurately Determine Peak Eversion Velocity during Locomotion at Different Speeds and in Various Shoes
Get PDFGyroscopes have been used in previous studies to measure the peak angular velocity of the shoe or foot in the frontal plane (evVel). However, it is not clear whether different test conditions (footwear hardness or locomotion speed) can influence the accuracy of evVel. The purpose of the present study was to compare the accuracy of gyroscopes and electrogoniometers when measuring evVel and the time until evVel (t_evVel) in 12 different conditions using a single axis gyroscope attached to the heel cap. Twenty-four recreational runners were instructed to walk and run on a 15-m indoor track at four locomotion speeds (1.5, 2.5, and 3.5 m/s, and individual running speed) and in three footwear conditions (low to high hardness). The gyroscope data and electrogoniometer data were sampled at a rate of 1000 Hz. Comparisons between both measurement devices showed small mean differences up to 49.8 ± 46.9 deg/s for evVel and up to 5.3 ± 3.5 ms for t_evVel. Furthermore, strong relationships between gyroscope and electrogoniometer data were found for evVel as well as for t_evVel for all conditions. It can be concluded that gyroscopes can be used to accurately determine evVel and t_evVel under a variety of conditions
Which Method Detects Foot Strike in Rearfoot and Forefoot Runners Accurately when Using an Inertial Measurement Unit?
Get PDFAccelerometers and gyroscopes are used to detect foot strike (FS), i.e., the moment when the foot first touches the ground. However, it is unclear whether different conditions (footwear hardness or foot strike pattern) influence the accuracy and precision of different FS detection methods when using such micro-electromechanical sensors (MEMS). This study compared the accuracy of four published MEMS-based FS detection methods with each other and the gold standard (force plate) to establish the most accurate method with regard to different foot strike patterns and footwear conditions. Twenty-three recreational runners (12 rearfoot and 11 forefoot strikers) ran on a 15-m indoor track at their individual running speed in three footwear conditions (low to high hardness). MEMS and a force plate were sampled at a rate of 3750 Hz. Individual accuracy and precision of FS detection methods were found which were dependent on running styles and footwear conditions. Most of the methods were characterized by a delay which generally increased from rearfoot to forefoot strike pattern and from high to low midsole hardness. It can be concluded that only one of the four methods can accurately determine FS in a variety of conditions
3D-Wafer Level Packaging approaches for MEMS by using Cu-based High Aspect Ratio Through Silicon Vias
No full textFor mobile electronics such as Smartphones, Smartcards or wearable devices there is a trend towards an increasing functionality as well as miniaturisation. In this development Micro Electro- Mechanical Systems (MEMS) are an important key element for the realisation of functions such as motion detection. The specifications given by such devices together with the limited available space demand advanced packaging technologies. The 3D-Wafer Level Packaging (3D-WLP) enables one solution for a miniaturised MEMS package by using techniques such as Wafer Level Bonding (WLB) and Through Silicon Vias (TSV). This technology increases the effective area of the MEMS device by elimination dead space, which is typically required for other approaches based on wire bond assembly. Within this thesis, different TSV technology concepts with respect to a 3D-WLP for MEMS have been developed. Thereby, the focus was on a copper based technology as well as on two major TSV implementation methods. This comprises a Via Middle approach based on the separated TSV fabrication in the cap wafer as well as a Via Last approach with a TSV implementation in either the MEMS or cap wafer, respectively. For each option with its particular challenges, corresponding process modules have been developed. In the Via Middle approach, the wafer-related etch rate homogeneity determines the TSV reveal from the wafer backside Here, a reduction of the TSV depth down to 80 μm is favourable as long as the desired Cu-thermo-compression bonding (Cu-TCB) is performed before the thinning. For the TSV metallisation, a Cu electrochemical deposition method was developed, which allows the deposition of one redistribution layer as well as the bonding patterns for Cu-TCB at the same time. In the Via Last approach, the TSV isolation represents one challenge. Chemical Vapour Deposition processes have been investigated, for which a combination of PE-TEOS and SA-TEOS as well as a Parylene deposition yield the most promising results. Moreover, a method for the realisation of a suitable bonding surface for the Silicon Direct Bonding method has been developed, which does not require any wet pre treatment of the fabricated MEMS patterns. A functional MEMS acceleration sensor as well as Dummy devices serve as demonstrators for the overall integration technology as well as for the characterisation of electrical parameters.:Bibliographische Beschreibung 3
Vorwort 13
List of symbols and abbreviations 15
1 Introduction 23
2 Fundamentals on MEMS and TSV based 3D integration 25
2.1 Micro Electro-Mechanical systems 25
2.1.1 Basic Definition 25
2.1.2 Silicon technologies for MEMS 26
2.1.3 MEMS packaging 29
2.2 3D integration based on TSVs 33
2.2.1 Overview 33
2.2.2 Basic processes for TSVs 34
2.2.3 Stacking and Bonding 47
2.2.4 Wafer thinning 48
2.3 TSV based MEMS packaging 50
2.3.1 MEMS-TSVs 50
2.3.2 3D-WLP for MEMS 52
3 Technology development for a 3D-WLP based MEMS 57
3.1 Target integration approach for 3D-WLP based MEMS 57
3.1.1 MEMS modules using 3D-WLP based MEMS 57
3.1.2 Integration concepts 58
3.2 Objective and requirements for the proposed 3D-WLP of MEMS 60
3.2.1 Boundary conditions 60
3.2.2 Technology concepts 63
3.3 Selected approaches for TSV implementation in MEMS 64
3.3.1 Via Last Technology 64
3.3.2 Via Middle technology 69
4 Development of process modules 75
4.1 Characterisation 75
4.2 TSV related etch processes 77
4.2.1 Equipment 77
4.2.2 Deep silicon etching 78
4.2.3 Etching of the buried dielectric layer 84
4.2.4 Patterning of TSV isolation liner – spacer etching 90
4.2.5 Summary 92
4.3 TSV isolation 93
4.3.1 Principle considerations 93
4.3.2 Experiment 95
4.3.3 Results 97
4.3.4 Summary 102
4.4 Metallisation of TSV and RDL 103
4.4.1 Plating base and experimental setup 103
4.4.2 Investigations related to the ECD process 106
4.4.3 Pattern plating 117
4.4.4 Summary 123
4.5 Wafer Level Bonding 124
4.5.1 Silicon direct bonding 124
4.5.2 Thermo-compression bonding by using ECD copper 128
4.5.3 Summary 134
4.6 Wafer thinning and TSV back side reveal 134
4.6.1 Thinning processes 134
4.6.2 TSV reveal processes 136
4.6.3 Summary 145
4.7 Under bump metallisation and solder bumps 146
5 Demonstrator design, fabrication and characterisation 149
5.1 Single wafer demonstrator for electrical test 149
5.1.1 Demonstrator design and test structure layout 149
5.1.2 Demonstrator fabrication 150
5.1.3 Electrical measurement 151
5.1.4 Summary 153
5.2 Via Last based TSV fabrication in the MEMS device wafer 153
5.2.1 Layout of the MEMS device with TSVs 153
5.2.2 Fabrication of TSVs and wafer thinning 154
5.2.3 Characterisation of the fabricated device 155
5.2.4 Summary 156
5.3 Via Last based cap-TSV for very thin MEMS devices 157
5.3.1 Design 157
5.3.2 Fabrication 158
5.3.3 Characterisation 161
5.3.4 Summary 162
5.4 Via Middle approach based on thinning after bonding 163
5.4.1 Design 163
5.4.2 Results and characterisation 164
5.4.3 Summary 166
6 Conclusion and outlook 167
Appendix A: Typical requirements on a MEMS package and its functions 171
Appendix B: Classification of packaging and system integration techniques 173
B.1 Packaging of electronic devices in general 173
B.2 Single Chip Packages 174
B.3 System integration 175
B.4 3D integration based on TSVs 180
Bibliography 183
List of figures 193
List of tables 199
Versicherung 201
Theses 203
Curriculum vitae 205
Own publications 207Im Bereich mobiler Elektronik, wie z.B. bei Smartphones, Smartcards oder in Kleidung integrierten Geräten ist ein Trend zu erkennen hinsichtlich steigender Funktionalität und Miniaturisierung. Bei dieser Entwicklung spielen Mikroelektromechanische Systeme (MEMS) eine entscheidende Rolle zur Realisierung neuer Funktionen, wie z.B. der Bewegungsdetektion. Die Anforderungen derartiger Bauteile zusammen mit dem begrenzten zur Verfügung stehenden Platz erfordern neuartige Technologien für die Aufbau- und Verbindungstechnick (engl. Packaging) der Bauteile. Das 3D-Wafer Level Packaging (3D-WLP) ermöglicht eine Lösung für eine miniaturisierte MEMS-Bauform unter Nutzung von Techniken wie dem Waferlevelbonden (WLB) und den Siliziumdurchkontaktierungen (TSV von engl. Through Silicon Via). Diese Technologie erhöht die effektive aktive Fläche des MEMS Bauteils durch die Reduzierung von Toträumen, welche für andere Ansätze wie der Drahtbond-Montage üblich sind. In der vorliegenden Arbeit wurden verschiedene Technologiekonzepte für den Aufbau von 3D-WLP für MEMS erarbeitet. Dabei lag der Fokus auf einer Kupfer-basierten Technologie sowie auf zwei prinzipiellen Varianten für die TSV-Implementierung. Dies umfasst den Via Middle Ansatz, welcher auf der TSV Herstellung auf einem separaten Kappenwafer beruht, sowie den Via Last Ansatz mit einer TSV Herstellung entweder im MEMS-Wafer oder im Kappenwafer. Für beide Varianten mit individuellen Herausforderungen wurden entsprechende Prozessmodule entwickelt. Beim Via Middle Ansatz ist die Wafer-bezogene Ätzratenhomogenität des Siliziumtiefenätzen entscheidend für das spätere Freilegen der TSVs von der Rückseite. Hier hat sich eine Reduzierung der TSV-Tiefe auf bis zu 80 μm vorteilhaft erwiesen insofern, das Kupfer-Thermokompressionsbonden (Cu-TKB) vor dem Abdünnen erfolgt. Zur Metallisierung der TSVs wurde ein Cu Galvanikprozess erarbeitet, welcher es ermöglicht gleichzeitig eine Umverdrahtungsebene sowie die Bondstrukturen für das Cu-TKB zu erzeugen. Beim Via Last Ansatz ist die TSV Isolation eine Herausforderung. Es wurden CVD (Chemische Dampfphasenabscheidung) Prozesse untersucht, wobei eine Kombination aus PE-TEOS und SA-TEOS sowie eine Parylene Beschichtung erfolgversprechende Ergebnisse liefern. Des Weiteren wurde eine Methode zur Erzeugung bondfähiger Oberflächen für das Siliziumdirektbonden erarbeitet, welche eine Nass-Vorbehandlung des MEMS umgeht. Ein realer MEMS-Beschleunigungssensor sowie Testaufbauten dienen zur Demonstration der Gesamtintegrationstechnologie sowie zur Charakterisierung elektrischer Parameter.:Bibliographische Beschreibung 3
Vorwort 13
List of symbols and abbreviations 15
1 Introduction 23
2 Fundamentals on MEMS and TSV based 3D integration 25
2.1 Micro Electro-Mechanical systems 25
2.1.1 Basic Definition 25
2.1.2 Silicon technologies for MEMS 26
2.1.3 MEMS packaging 29
2.2 3D integration based on TSVs 33
2.2.1 Overview 33
2.2.2 Basic processes for TSVs 34
2.2.3 Stacking and Bonding 47
2.2.4 Wafer thinning 48
2.3 TSV based MEMS packaging 50
2.3.1 MEMS-TSVs 50
2.3.2 3D-WLP for MEMS 52
3 Technology development for a 3D-WLP based MEMS 57
3.1 Target integration approach for 3D-WLP based MEMS 57
3.1.1 MEMS modules using 3D-WLP based MEMS 57
3.1.2 Integration concepts 58
3.2 Objective and requirements for the proposed 3D-WLP of MEMS 60
3.2.1 Boundary conditions 60
3.2.2 Technology concepts 63
3.3 Selected approaches for TSV implementation in MEMS 64
3.3.1 Via Last Technology 64
3.3.2 Via Middle technology 69
4 Development of process modules 75
4.1 Characterisation 75
4.2 TSV related etch processes 77
4.2.1 Equipment 77
4.2.2 Deep silicon etching 78
4.2.3 Etching of the buried dielectric layer 84
4.2.4 Patterning of TSV isolation liner – spacer etching 90
4.2.5 Summary 92
4.3 TSV isolation 93
4.3.1 Principle considerations 93
4.3.2 Experiment 95
4.3.3 Results 97
4.3.4 Summary 102
4.4 Metallisation of TSV and RDL 103
4.4.1 Plating base and experimental setup 103
4.4.2 Investigations related to the ECD process 106
4.4.3 Pattern plating 117
4.4.4 Summary 123
4.5 Wafer Level Bonding 124
4.5.1 Silicon direct bonding 124
4.5.2 Thermo-compression bonding by using ECD copper 128
4.5.3 Summary 134
4.6 Wafer thinning and TSV back side reveal 134
4.6.1 Thinning processes 134
4.6.2 TSV reveal processes 136
4.6.3 Summary 145
4.7 Under bump metallisation and solder bumps 146
5 Demonstrator design, fabrication and characterisation 149
5.1 Single wafer demonstrator for electrical test 149
5.1.1 Demonstrator design and test structure layout 149
5.1.2 Demonstrator fabrication 150
5.1.3 Electrical measurement 151
5.1.4 Summary 153
5.2 Via Last based TSV fabrication in the MEMS device wafer 153
5.2.1 Layout of the MEMS device with TSVs 153
5.2.2 Fabrication of TSVs and wafer thinning 154
5.2.3 Characterisation of the fabricated device 155
5.2.4 Summary 156
5.3 Via Last based cap-TSV for very thin MEMS devices 157
5.3.1 Design 157
5.3.2 Fabrication 158
5.3.3 Characterisation 161
5.3.4 Summary 162
5.4 Via Middle approach based on thinning after bonding 163
5.4.1 Design 163
5.4.2 Results and characterisation 164
5.4.3 Summary 166
6 Conclusion and outlook 167
Appendix A: Typical requirements on a MEMS package and its functions 171
Appendix B: Classification of packaging and system integration techniques 173
B.1 Packaging of electronic devices in general 173
B.2 Single Chip Packages 174
B.3 System integration 175
B.4 3D integration based on TSVs 180
Bibliography 183
List of figures 193
List of tables 199
Versicherung 201
Theses 203
Curriculum vitae 205
Own publications 20
Effiziente Technologien zur Herstellung von endlosfaserverstärkten, schmierungsfreien Antriebs- und Förderketten
No full textIm Beitrag sind Überlegungen hinsichtlich der optimalen Geometrie des Kettengliedes dargestellt. Daraus wurde ein Innenglied mit zwei gewickelten Einlegern entwickelt. Das äußere Kettenglied entspricht dem einer Rollenkette. Die Geometrie der Einleger wurde mithilfe der FEM optimiert, sodass durch zwei Einleger aus Glasfaser die Dehnung auf ca. 57% bzw. für Kohlefaser auf ca. 39% reduziert werden konnte.The article presents considerations regarding the optimal geometry of chain links. From this, an inner link with two wound inserts was developed. The outer chain link corresponds to that of a roller chain. The geometry of the inserts was optimized by a FEM analysis. With two inserts it is possible to reduce the elongation to approx. 57% (glass fiber) and approx. 39% (carbon fiber)
Entwicklung Statischer Analysen für AUTOSAR Steuergerätesoftware
Get PDFDurch die Einführung der Systemarchitektur AUTOSAR im automobilen Umfeld, können Applikationen unabhängig von der verwendeten Hardware oder der genutzten Kommunikationssysteme entwickelt werden. Dadurch können Funktionen wieder verwendet werden, was Zeit und Ressourcen einsparen kann. So können Funktionen, die sich etabliert haben, in späteren Entwicklungen durch Anpassung in der Konfiguration genutzt werden ohne dabei den Quellcode zu ändern. Jedoch stellt die große Zahl an Parametern in der AUTOSAR Architektur große Herausforderungen an die Absicherung eines Steuergerätes. Dieser Aspekt wird durch eine meist heterogene Toollandschaft verstärkt. Umso wichtiger ist es, dass während der Entwicklung von AUTOSAR Steuergeräten statische Analysen die Software und die Konfiguration überprüfen, um so die Softwarequalität sicherstellen zu können. In der Masterarbeit werden eine Menge von AUTOSAR spezifischen statischen Analysen für die einzelnen Schichten eines AUTOSAR Steuergerätes entwickelt. Für die Analyse werden Einstellungsdateien (nach Standard und Firmenspezifische) und der Quellcode an sich genutzt. Die Analysen geben optional Korrekturvorschläge an den Entwickler. Die Umsetzung erfolgt in einem C# Prototyp und wird an der Lichtsteuerung des Automotive Demonstrator YellowCar angewendet werden
A Novel, User-Friendly Indoor Mapping Approach for OpenStreetMap
Get PDFThe community project OpenStreetMap (OSM), which is well-known for its open geographic data, still lacks a commonly accepted mapping scheme for indoor data. Most of the previous approaches show inconveniences in their mapping workflow and affect the mapper's motivation. In our paper an easy to use data scheme for OSM indoor mapping is presented. Finally, by means of several rendering examples from our Android application, we show that the new data scheme is capable for real world scenarios
Experimental observation and quantum chemical investigation of thallium(I) (Z)-methanediazotate: synthesis of a long sought and highly reactive species
Get PDFFor the first time, successful synthesis and characterisation of the missing (Z)-isomer of thallium(I) methanediazotate has been accomplished, utilising low-temperature NMR monitoring analysis. The title compound was synthesised from N-methyl-N-nitrosourea and thallium(I) propoxide, under sub-ambient temperature conditions, as a highly moisture sensitive entity. Quantum chemical calculations, performed at the CCSD(T) level, depict excellent conformity to experimental results. Indeed, compared to its (E) counterpart, the formation of the title compound is thermodynamically less favoured, but preferred by means of kinetic control owing to a hindered isomerisation
Advanced scanning magnetoresistive microscopy as a multifunctional magnetic characterization method
Get PDFAdvanced scanning magnetoresistive microscopy (SMRM) — a robust magnetic imaging and probing technique — is presented. It utilizes conventional recording heads of a hard disk drive as sensors. The spatial resolution of modern tunneling magnetoresistive sensors is nowadays comparable with more commonly used magnetic force microscopes. Important advantages of SMRM are the ability to detect pure magnetic signals directly proportional to the out-of-plane magnetic stray field, negligible sensor stray fields, and the ability to apply local bipolar magnetic field pulses up to 10 kOe with bandwidths from DC up to 1 GHz. The performance assessment of this method and corresponding best practices are discussed in the first section of this work.
An application example of SMRM, the study on chemically ordered L10 FePt is presented in a second section. A constructed heater unit of SMRM opens the path to investigate temperature-dependent magnetic properties of the medium by recording and imaging at elevated temperatures. L10 FePt is one of the most promising materials to reach limits in storage density of future magnetic recording devices based on heat-assisted magnetic recording (HAMR). In order to be implemented in an actual recording scheme, the medium Curie temperature should be lowered. This will reduce the power requirements, and hence, wear and tear on a heat source — integrated plasmonic antenna. It is expected that the exchange coupling of FePt to thin Fe layers provides high saturation magnetization and elevated Curie temperature of the composite. The addition of Cu allows adjusting the magnetic properties such as perpendicular magnetic anisotropy, coercivity, saturation magnetization, and Curie temperature. This should lead to a lowering of the switching field of the hard magnetic FeCuPt layer and a reduction of thermally induced recording errors. In this regard, the influence of the Fe layer thickness on the switching behavior of the hard layer was investigated, revealing a strong reduction for Fe layer thicknesses larger than the exchange length of Fe. The recording performance of single-layer and bilayer structures was studied by SMRM roll-off curves and histogram methods at temperatures up to 180 °C
In the last section of this work, SMRM advantages are demonstrated by various experiments on a two-dimensional magnetic vortex lattice. Magnetic vortex is a peculiar complex magnetization configuration which typically appears in a soft magnetic structured materials. It consists of two coupled sub-systems: the core, where magnetization vector points perpendicular to the structure plane, and the curling magnetization where magnetic flux is rotating in-plane. The unique properties of a magnetic vortex making it an object of a great research and technological interest for spintronic applications in sensorics or data storage. Manipulation of the vortex core as well as the rotation sense by applying a local field pulse is shown. A spatially resolved switching map reveals a significant "write window" where vortex cores can be addressed correctly. Moreover, the external in-plane magnet extension unit allow analyzing the magnetic vortex rotational sense which is extremely practical for magnetic coupling investigations of magnetic coupling phenomena