Philipp Hoffmann Untersuchung zur Fixierung von Knorpelgewebe mittels laserinduzierter Koagulation Aus der Chirurgischen Tierklinik der Veterinärmedizinische Fakultät der Universität Leipzig, angefertigt im Forschungszentrum für Medizintechnik und Biotechnologie GmbH, Bad Langensalza Eingereicht im Januar 2012 97 Seiten, 59 Abbildungen, 9 Tabellen, 318 Literaturangaben 10 Seiten Anhang Schlüsselwörter: Laser, Löten, Knorpelgewebe, Zugfestigkeit, thermische Schäden Gelenkerkrankungen zählen zu den häufigsten Ursachen von Bewegungseinschränkungen in der Human- und Veterinärmedizin. Neben der konservativen Therapie gibt es zahlreiche chirurgische Therapieansätze, unter denen die verschiedenen Verfahren der autologen Chondrozytenimplantation (ACI) vermehrt in den Fokus gerückt sind. Als unbefriedigend stellt sich aktuell die Fixierung der Implantate bzw. Transplantate dar. Ziel der vorliegenden Arbeit war es, zunächst in vitro, unter Nutzung von Gelenkknorpelgewebe aus Kadavermaterial (Schwein, Rind), ein Verfahren einzuarbeiten, mit dem es möglich ist, durch laserinduzierte Koagulation eines Lötmittels eine Verbindung zwischen zwei Knorpelfragmenten bei einer möglichst geringen Gewebeschädigung herzustellen. Als Lötmittel war ein geeignetes Chromophoren-Protein-Gemisch (CPG) herzustellen, welches so auf die Wellenlänge des zur Verfügung stehenden Lasers angepasst wurde, dass die Herstellung von Lötverbindungen möglich war. Die mechanische Festigkeit der Lötverbindungen wurde in verschiedenen Studien zur Optimierung der Lötmittelzusammensetzung und der Lasereinstellungen durch die Bestimmung der Zugkraft geprüft. Ebenso wurden Untersuchungen zum Auftreten thermischer Schäden am Gewebe durch das lasergestützte Löten vorgenommen. Ausgehend von der Untersuchung der Absorptionseigenschaften verschiedener Chromophore und Proteine wurden verschiedene, auf die Wellenlänge des Lasers (810 nm Diodenlaser) abgestimmte, CPG unter Verwendung des Farbstoffes Indocyaningrün (ICG), welcher in dem in der Humanmedizin zugelassenen Diagnostikum ICG-Pulsion® (PULSION Medical Systems AG, München) enthalten ist, und bovinem Serumalbumin (BSA) hergestellt. Knorpelgewebe absorbiert die Strahlung des Diodenlasers (810 nm) kaum (μa ≈ 0 bis 0,02 cm-1). Das Lötmittel (ICG + BSA), dessen Absorptionsmaximum mit 790 nm nah an der Emissionswellenlänge des Lasers liegt, absorbiert hingegen in diesem Wellenlängenbereich gut. Dadurch kann eine direkte Schädigung des Knorpelgewebes durch die Absorption der Laserstrahlung vermieden werden. In den Studien wurden drei Lötmittel mit unterschiedlichen Anteilen an ICG (1 %, 0,25 % und 0,025 %) bei einem BSA-Gehalt von 60 % verwendet. Die Lötmittel mit 0,025 % und 0,25 % ICG wurden zur Prüfung der Zugfestigkeit der gelöteten Verbindung in Abhängigkeit von der Leistungsdichte und der Expositionszeit untersucht. Das Lötmittel mit 0,025 % ICG wurde in den Untersuchungen zur Abhängigkeit der Zugfestigkeit von der Tierspezies, der Entnahmestelle des Knorpelgewebes und der Lötmitteldicke genutzt. Einflüsse der Lagerung des Lötmittels und der Anzahl an Lötmittelpunkten auf die Zugfestigkeit wurden mit dem Lötmittel mit 0,25 % ICG untersucht. Zusätzlich war zu prüfen ob durch ein Knorpelgewebefragment hindurch das CPG zu koagulieren ist. Zur Untersuchung thermisch bedingter Schäden wurden zum einen Temperaturmessungen an der Oberfläche des Knorpelgewebes, im Bereich des Lötmittels und in verschiedenen Tiefen unterhalb des Lötmittels durchgeführt. Zum anderen erfolgten histologische Untersuchungen der Knorpelgewebeproben nach Laseranwendung. Es ist möglich, mittels laserinduzierter Koagulation eines CPG eine Verbindung von Knorpelgewebe vom Schwein und Rind herzustellen. Mit Steigerung der Leistungsdichte und Verlängerung der Expositionszeit kommt es zur Erhöhung der Zugfestigkeit. Die Zugfestigkeiten waren bei Koagulation des CPG durch das Knorpelfragment hindurch niedriger als die Zugfestigkeiten mit aufgelegtem Lötmittel. Unter Laseranwendung kommt es zu einem steilen Ansteigen der Temperatur im Lötmittel bis zum Erreichen einer Höchsttemperatur. Die Steilheit des Temperaturanstieges und die sich einstellenden Temperaturen nehmen mit Erhöhung des im Lötmittel enthaltenen ICG-Gehaltes und der am Laser eingestellten Leistung zu. Die Temperaturerhöhung ist jedoch weitgehend auf das Lötmittel und dessen Randbereiche begrenzt. Die histologischen Untersuchungen verdeutlichten, dass die Laserbestrahlung von Knorpelgewebe mittels Diodenlaser (810 nm) nur eine sehr geringe Schädigung verursacht. Unter Verwendung eines Lötmittels kommt es durch die vom Lötmittel absorbierte Energie zu Schäden am umliegenden Knorpelgewebe. Diese Schädigung ist auf Randbereiche des Lötmittels begrenzt und nimmt mit steigender Leistung und Expositionszeit zu. Bei einer Leistungsdichte von (5,09 W/cm2) konnte eine Verbindung zwischen zwei Knorpelfragmenten erzielt werden, die bei einer Zugkraft von 13,3 N/cm2 nachgibt und bei der die Schädigungen des Knorpelgewebes minimal sind. Die vorliegenden Untersuchungen haben gezeigt, dass es möglich ist, Knorpelfragmente mittels laserinduzierter Koagulation eines CPGs miteinander zu fixieren. / Philipp Hoffmann Investigation for the fixation of articular cartilage tissue using laser-induced coagulation From the Large Animal Clinic for Surgery, Faculty of Veterinary Medicine, University of Leipzig, prepared at Research Centre of Medical Technology and Biotechnology GmbH, Bad Langensalza Submitted in January 2012 97 Pages, 59 figures, 9 tables, 318 references, 10 pages appendices Keywords: laser, soldering, cartilage tissue, tensile strength, thermal damage Joint diseases are among the most common causes of restricted movement of patients in the human and veterinary medicine. In addition to the conservative therapy, there are numerous surgical therapies, under which the various methods of autologous chondrocyteimplantation, have moved increasingly into the focus of scientific and clinical interest. As problematic and unsatisfactory is currently the fixation of the implants. The aim of this study was, first in vitro, taking advantage of articular cartilage tissue from cadaver material (pig, cattle) to incorporate a process by which it is possible to produce by laser-induced coagulation of solder a connection between two cartilage fragments with the smallest possible tissue damage. As solder was a suitable chromophore-protein-mixture (CPG) to establish which it was adapted to the wavelength of the laser is available, that the production of solder joints was possible. The mechanical strength of solder joints has been examined in several studies to optimize the laser settings and the solder ingredients by determining the tensile strength. Likewise, studies on the occurrence of thermal damage to the tissues were made by the laser-assisted soldering. Based on the study of the absorption properties of various chromophores and proteins the wavelength of the laser (810 nm diode laser) was tuned, and different CPG using the dye indocyanine green (ICG), which is within the acceptable in human medicine ICG-Pulsion ® (Pulsion Medical Systems AG, Munich) is included, and bovine serum albumin (BSA) were prepared. Articular cartilage tissue absorbs the radiation of the diode laser (810 nm) hardly (uA ≈ 0 to 0.02 cm–1). The solder (ICG + BSA), whose absorption maximum at 790 nm is close to the emission wavelength of the laser is absorbed. This can be avoided direct damage to the cartilage tissue through the absorption of laser radiation. In the studies, three solders were used with different proportions of ICG (1 %, 0.25 % and 0.025 %) at a content of 60 % BSA. The solder with 0.025 % and 0.25 % ICG were studied to test the tensile strength of the soldered connection as a function of power density and exposure time. The solder containing 0.025 % ICG was used in the investigations of the dependence of tensile strength of the animal species, the donor site of the cartilage and the solder thickness. Influences of storage the solder and the number of solder dots on the tensile strength were investigated with the solder with 0.25 % ICG. In addition it was to examine if it is possible to coagulate the CPG through an articular cartilage fragment. To investigate thermally induced damage to temperature measurements were performed on the surface of the cartilage tissue in the area of the solder and at various depths below the solder. Secondly, histological examinations were made of the articular cartilage after laser application. It is possible to produce by laser-induced coagulation of a CPG an articular cartilage bonding of pig and cattle. With increasing power density and lengthening the exposure time leads to the increase in tensile strength. The tensile strengths were measured with coagulation of the CPG passed through the cartilage fragment is lower than the tensile strengths with applied solder. Under laser application leads to a steep rise in temperature in the solder to reach a maximum temperature. The rate of temperature rise increases with increasing the solder contained in ICG content and on the laser power set. The temperature rise is limited largely to the solder and its peripheral areas. The histological examinations showed that the laser irradiation of cartilage tissue using diode laser (810 nm) only a very little damage caused. Using a solder it comes through the energy absorbed by the solder and damage to the surrounding articular cartilage tissue. This damage is limited to border areas and the flux increases with increasing power and exposure time. At a power density of (5.09 W/cm2) was a connection between two cartilage fragments are obtained, which yields at a tensile force of 13.3 N/cm2 and where the damage to the cartilage tissue is minimal. The present studies have shown that it is possible cartilage fragments by laser-inducedcoagulation of a CPG to fix each other.

Environmental stress tests, or accelerated life tests, apply stresses to electronic packages that exceed the stress levels experienced in the field. In theory, these elevated stress levels are used to generate the same failure mechanisms that are seen in the field, only at an accelerated rate. The methods of assessing reliability of electronic packages can be classified into two categories: a statistical failure based approach and a physics of failure based approach. This research uses a statistical based methodology to identify the critical factors in reliability performance of a flip chip on board component level assembly and a physics of failure based approach to develop a low cycle strain based fatigue equation for flip chip component level assemblies. The critical factors in determining reliability performance were established via experimental investigation and their influence quantified via regression analysis. This methodology differs from other strain based fatigue approaches because it is not an empirical fit to experimental data; it utilizes regression analysis and least squares to obtain correction factors, or correction functions, and constants for a strain based fatigue equation, where the total inelastic strain is determined analytically. The end product is a general flip chip on board equation rather than one that is specific to a certain test vehicle or material set.

Optical transceiver module plays an important role in the optical communication system. The packaging quality of the module decides the ability of the communication. Since the light signal is transferred from a laser diode to an optical fiber, the light transfer efficiency between these two components becomes a very important work to be done. The micrometer dimension and the ultra-high performance requirement of these components lead to many problems in module packaging process. Among all the problems, the packaging of the fiber components is the most complicated. In this research, many key technologies are proposed to solve or improve the problems in the packaging of the fiber components. Thus, the performance of the module can be ensured. Two main topics of the fiber component packaging will be introduced here, the fiber-solder-ferrule (FSF) packaging and the machining of the fiber. In the packaging of the FSF, a positioning and a soldering technology are proposed to improve the packaging yield. For the positioning, a novel control strategy is constructed to shorten the positioning time and improve the positioning accuracy. Thus, the position of the fiber can be positioned at the center of the ferrule fast and precisely. The controller successfully completes the positioning command in 0.25sec with 1µm accuracy. And finally, the coupling efficiency can be hold. For the soldering of the FSF, an active soldering mechanism is developed to replace the passive manual operation. The mechanism successfully proofs the stability of the soldering and raises the yield from the 25% to 83%. In machining of the fiber, a fiber end polishing issue and a fiber inspection topic are addressed. For the fiber end polishing, an online force sensing mechanism is implemented. The force sensing mechanism can control the polished fiber tip offset within 1.5µm. So the fiber coupling efficiency can be maintained. A control strategy is designed to solve the polishing problems and reach the polishing requirement. At last, an interference-based fiber inspection method is proposed to find the splicing plane between two spliced fibers. The accuracy of the fiber cleaving in a cascaded fiber fabrication improves from 10µm to 1µm by observing the fiber splicing plane precisely. All the improvements of the above packaging technologies are proposed to raise or keep the performance of the transceiver module. So, the error between theories and experiments can be minimized. Meanwhile, a high stability and repeatability of the packaging can be achieved due to the automation of the positioning, force sensing, and inspection.

Thesis (M.S.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009. / Includes bibliographical references.

Ion contaminants from Printed Circuit Board (PCB) assembly processes pose a high reliability risk because they result in damaged circuits. Therefore, it is essential to understand the level of ionic species on the electronic circuitry as well as the reliability risks caused by these contaminants. There are a number of approaches available in the industry to assess the reliability risks ; for example, the water drop test (WDT) is one of the techniques used to determine the propensity of an ionic contaminant to cause electrical short failures by dendrite formation. The objective of this research is to determine the time to cause the failures, known as electrochemical migration (ECM) failures. A test vehicle was developed for the WDT to obtain the time to cause ECM failure in presence of different anions. The time to form dendritic bridges that cause short circuits was determined as a function of the different anions and the spacings between PCB pads. The experimental method involved dispensing aqueous solutions containing common inorganic and organic acid anions onto test vehicles, applying electrical bias voltages and measuring the time to form dendrites. Specially designed test structures cells were created to contain the test solutions. At each of the test cells, a cavity held the solution and constant current was applied through different metal geometries. To be representative of popular board finishes, test vehicle boards incorporated both Sn-Pb Hot Air Soldering Level (HASL) and Pb free HASL surface finishes.

Darbo tikslas yra, pagaminti ultragarsinį lituoklį laboratorinėmis sąlygomis, skirtą mokymo tikslam. Apžvelgus literatūrą, yra modeliuojama kompaktiškesnė ir mažesnė ultragarsinė pjezomechaninė sistema. Sukonstravus ir pagaminus eksperimentinį pavyzdį, jis yra eksperimentiškai ištiriamas, tai yra, juo bandoma lituoti prie sunkiai lituojamų medžiagų, tokių kaip: aliuminis, stiklas, keramika ir saulės cėlės. Pateikiami bandymų rezultatai. / The aim of this – are CONSTRUCTION AND RESEARCH OF ULTRASONIC SOLDERING IRON. To achieve this, it was raised four challenges: 1) Examine existing ultrasonic soldering iron type, 2) Simulated ultrasonic piezo system, 3) Designed and produced an experimental model, 4) Experimentally investigate constructed ultrasonic soldering iron sample . After literature review is modeled more compact ultrasonic piezo system. Soldering tip is selected from a simple soldering iron, so all system is coordinated to it. Selected wavelength transducer, for the larger sizes, so delaying piezo ceramics from the fusing soldering tip. Designed and built an experimental model, it is experimentally investigated. First performed impedance - frequency and amplitude-frequency characteristics. Then, ultrasonic soldering iron is experimentally tested. Trying to solder, hard solder materials such as aluminum, glass, ceramics and solar cells. Then are presented test results.

Engineering for sustainable development requires prudent utilization of resources under economic, environmental and societal constraints. Resource utilization must follow a holistic approach. This brings in a need for comprehensive metrics which are simple, standard and universal. Thermodynamics may offer a metric that focuses on both quality and quantity of energy resources which may carry information to be combined with other metrics. This metric may be a thermodynamic property called exergy or available energy, which provides a better insight into resource use in both energy and non-energy producing systems. This thesis is devoted to a study of the exergy concept in manufacturing. A high volume PCB assembly, manufactured in a state of the art soldering facility is chosen for the study. Various mass and energy resources flowing through the production line were quantified in terms of exergy. On the basis of exergy content and exergy utilization in the production process, the sustainability in terms of resources use is discussed. An early version of this approach was presented at the International Symposium on Sustainable Systems and Technologies, IEEE, Washington DC, in May 2010.

No description available.

Consumer demands are driving the current trend in the microelectronics industry to make electronic products that are miniature, fast, compact, high-density, reliable and low-cost. The use of surface mount devices (SMDs) has helped to decrease the size of electronic packages through the use of solder bump interconnections between the devices and the substrates/printed wiring boards (PWBs). Solder bumps act as not only mechanical, but also electrical interconnections between the device and the substrate/PWB. Common manufacturing defects ¨C such as open, cracked, missing, and misaligned solder bumps ¨C are difficult to detect because solder bumps are hidden between the device and the substrate/PWB after assembly. The reliability of packaged electronic devices in storage and usage is a major concern in the microelectronics industry. Therefore, quality inspection of solder bumps has become a critical process in the microelectronics industry to help ensure product quality and reliability. In this thesis, a methodology for quality evaluation and reliability study of solder bumps in electronic packages has been developed using the non-destructive and non-contact laser ultrasound-interferometric technique, finite element and statistical methods in this research work. This methodology includes the following aspects: 1) inspection pattern ¨C specific inspection patterns are created according to inspection purpose and package formats, 2) laser pulse energy density calibration ¨C specific laser pulse power and excitation laser spot size are selected in terms of package formats, 3) processing and analysis methods, including integrated analytical, finite element and experimental modal analyses approach, advanced signal processing methods and statistical analysis method, 4) approach combining modal analysis and advanced signal processing to improve measurement sensitivity of laser ultrasound-interferometric inspection technique, and 5) calibration curve using energy based simulation method and laser ultrasound inspection technique to predict thermomechanical reliability of solder bumps in electronic packages. Because of the successful completion of the research objectives, the system has been used to evaluate a broad range of solder bump defects in a variety of packaged electronic devices. The development of this system will help tremendously to improve the quality and reliability of electronic packages.

The objectives of this thesis are to develop and validate laser ultrasonic inspection methods for on-line testing of microelectronic devices. Electronic packaging technologies such as flip chips and BGAs utilize solder bumps as electrical and mechanical connections. Since they are located hidden from view between the device and the substrate, defects such as cracks, voids, misalignments, and missing bumps are difficult to detect using non-destructive methods. Laser ultrasonic inspection is capable of detecting such defects by utilizing a high power laser pulse to induce vibrations in a microelectronic device while measuring the out of plane displacement using an interferometer. Quality can then be assessed by comparing the vibration response of a known-good device to the response of the sample under inspection. The main limitation with the implementation of laser ultrasonic inspection in manufacturing applications is the requirement to establish a known-good reference device utilizing other non-destructive methods. My work will focus on developing a method to inspect flip chip devices without requiring a previously established reference. The method will automatically examine measurement data from a large sample set to identify those devices which are most similar. The selected devices can then be utilized to compose a hybrid reference signal which can be used for comparison and defect detection. Current trends in the electronic packaging industry continue to drive toward increased solder bump density, making it increasingly difficult to generate strong ultrasonic signals in these stiffer devices. To overcome this difficulty, I propose a new excitation method which places the source of ultrasound at the inspection location for each test point on the device surface. This ensures that the same power is available for each inspection location while also increasing the signal to noise ratio. The hardware implementation of this method reduces the system complexity and required automation, which can significantly reduce equipment cost and inspection time. The implementation of the proposed excitation method in conjunction with the use of a hybrid reference signal for defect detection will improve the utility of the laser ultrasonic inspection technique to on-line inspection applications where no other non-destructive methods are currently available.