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This study aims to investigate the thermal fatigue life of the solder ball.Generally, the fatigue of the solder ball results from thermal cyclic loading in different thermal expansion coefficiency of the material in the IC package. To analyze the equivalent stress and the equivalent strain distributions of the solder ball under loading, an analysis software ANSYS was adopted in this study. To stimulate viscoplastic (creep and plastic) property of the solder ball, the Anand model was adopted. From the modified Coffin-Manson equation and the viscoplastic strain range, the fatigue life of the solder ball was obtained finally. The causes of the fatigue life of the solder ball in this study were attributed to many factors, such as the solider ball¡¦s geometry, substrate thickness, different material properties, change of pad diameter, etc. Finally, the researcher found the increasing solder joint reliability methods and supplied the improving solder joint data for the design engineer.

The behaviors of high temperature corrosion on hot-dip aluminized on 9Cr-1Mo and 310 stainless steels when catalyzed by NaCl and cyclic heating environment were studied experimentally. The corrosion behavior and morphological development were investigated by weight gain kinetics, metallographs, depths of attack, metal losses, and X-ray analyses. The results of 310SS deposited with salt mixtures show that weight gain kinetics in simple oxidation reveals a steady-state parabolic rate law after 3 hr, while the kinetics with salt deposits display multi-stage growth rates. NaCl is the main corrosive specie in high-temperature corrosion involving mixtures of NaCl/Na2SO4 and is responsible for the formation of internal attack. Uniform internal attack is the typical morphology of NaCl-induced hot corrosion, while the extent of intergranular attack is more pronounced as the content of Na2SO4 in the mixture is increased. The thermal-cycling test results of 310SS deposited NaCl and coated 7wt%Si/93wt%Al show that the aluminized layers have good corrosion resistance during the first four cycles of testing, while degradation occurs after testing for five cycles. The reason for degradation of aluminized layers is attributed to the formation of interconnecting voids caused by aluminum inward diffusion, chloridation/oxidation cyclic reactions and the penetration of molten NaCl through the voids into the alloy substrate. The 9Cr-1Mo steels coated with 7wt%Si/93wt%Al oxidized at 750, 850, and 950°C in static air show that oxidation kinetics followed a parabolic rate law at 750 and 850 °C. The cracks propagated through the FexAly layer due to the growth of brittle FeAl2 and Fe2Al5 at 750 and 850°C. The voids condensed in the interface of intermetallics and substrate are attributed to the Kirkendall effect. At 950°C, the fast growing aluminide layer has a different expansion coefficient than oxide scale, leading to scale cracking, oxygen penetration, and internal oxidized, evidenced by a rapid mass gain.

Em determinadas rotas de manufatura de componentes automotivos, principalmente de produtos do segmento rodoviário pesado, são muito comuns processos de desempeno a quente, assim como outros procedimentos como arqueamento e alinhamento de longarinas. O presente trabalho tem por objetivo traçar os principais impactos destes processos sobre os materiais ASTM A570 GR36-C e o aço de alta resistência e baixa liga norma DIN EN 10149 S700MC em uma rota de fabricação de produtos automotivos com interferência de um procedimento a quente. Esses materiais, quando submetidos a determinados ciclos térmicos para alinhamento a quente, através do aquecimento de algumas regiões pontuais e do posterior resfriamento ao ar calmo têm suas propriedades mecânicas alteradas. Para investigar estas modificações, foram reproduzidas as condições do processo atual para mapeamento de dados de temperatura para os subsequentes ensaios de laboratório. Comparando as amostras submetidas ao ciclo térmico, com as produzidas com a mesma matéria prima sem aquecimento, pode-se verificar o impacto causado pelo processo de alinhamento a quente utilizado sobre as propriedades mecânicas do material. Os resultados mostram que o aço ASTM A570 GR36-C não tem suas propriedades alteradas a ponto de inviabilizar o uso do material. Para o aço DIN EN 10149 S700MC as alterações são expressivas em todos os ciclos térmicos realizados. Com isso, ocorrem modificações na microestrutura pelo tratamento térmico ocasionando a diminuição de algumas propriedades mecânicas importantes, como tensão de escoamento, microdureza e limite de resistência à fadiga. Essas últimas variáveis foram correlacionadas e mostraram o mesmo comportamento. / In certain manufacturing routes of automotive components, especially of heavy road segment products are very common straightening processes hot, as well as other procedures such as bending and alignment of rails. This paper aims to draw the main impacts of these processes on ASTM A570 GR36-C materials and high strength low alloy steel DIN EN 10149 S700MC on a route manufacturing of automotive products with interference from a hot procedure. These materials, when subjected to certain thermal cycles to hot alignment by heating of certain individual regions and the subsequent cooling the still air have changed their mechanical properties. In order to investigate this, they were reproduced the conditions of the current process for temperature mapping data for subsequent laboratory tests. Comparing the samples subjected to thermal cycling with produced with the same raw material unheated, one can ascertain the impact caused by hot alignment process used on the mechanical properties of the material. The results show that the steel ASTM A570 GR36-C does not have its properties changed as to make the use of the material. To DIN EN 10149 S700MC Steel changes are significant in all thermal cycles performed. Thus, changes occur in the microstructure by heat treatment causing a reduction of some important mechanical properties such as yield strength, hardness and fatigue strength limit. The latter variables were correlated and showed the same behavior.

Esta tese analisa o ciclo térmico da soldagem por atrito de um aço inoxidável superduplex ASTM A890 - 6A. Esse aço foi unido pelo processo de soldagem com pino consumível em furo cônico não-passante (Friction Tapered Stud Welding - FTSW) e a análise teve como objetivo principal a elaboração de um modelo matemático por meio da definição de alguns elementos do ciclo térmico de soldagem em três diferentes pontos das juntas. Os parâmetros analisados foram a rotação, a força axial e o deslocamento do pino. As equações dos ciclos térmicos foram elaboradas pelas relações existentes entre os parâmetros controlados e as temperaturas de saída medidas durante a execução do processo. Para a coleta dessas temperaturas foi fixada uma geometria para as juntas e elaborado um experimento fatorial com três fatores (deslocamento, rotação e força) e dois níveis. As juntas foram avaliadas e atenderam a todos os requisitos pré-estabelecidos. Os ciclos térmicos foram analisados conforme os valores dos seguintes elementos: temperatura de pico - Tp, tempo de aquecimento da junta entre 500°C e 800°C - ?T5/8, e tempo de resfriamento entre 800°C e 500°C - ?T8/5. Como resultados do trabalho são apresentadas equações que fazem a relação entre as variáveis de entrada (rotação, força e deslocamento) e as respostas ?T5/8, Tpico e ?T8/5. As equações permitem avaliar a importância de cada variável de entrada (e de suas interações) em relação à variável de resposta. Os modelos obtidos podem ser utilizados em simulações numéricas de soldagem por atrito do material estudado. / This work analyzes the thermal cycle of the friction tapered stud welding - FTSW - of a super duplex stainless steel ASTM A890 - 6A. The propose of the analyses was elaborating a mathematical model to define some elements of the welding thermal cycle at three different joint points. The parameters controlled were the rotation, the axial force and the plunge depth of the pin. The thermal cycle equations were elaborated by the relationships between the controlled parameters and the output temperatures measured during the execution of the process. For recording of these temperatures, a joint geometry was fixed, and a factorial design of experiment was developed with three factors (rotation, axial force and plunge depth) and two levels. The joints were evaluated, and they met all established requirements. The thermal cycles were analyzed according to the values of the following elements: peak temperature - Tpeak, joint heating time between 500 °C and 800 °C - ?T5/8, and cooling time between 800 °C and 500 °C - ?T8/5. A list of equations that make the relation between the input variables (rotation, axial force and plunge depth) and the responses ?T5/8, T peak and ?T8/5 is presented. These equations allow evaluating the importance of each input variable (and its interactions) in relation to the response variable. The obtained models can be used in numerical simulations of welding by friction of the studied material.

Em determinadas rotas de manufatura de componentes automotivos, principalmente de produtos do segmento rodoviário pesado, são muito comuns processos de desempeno a quente, assim como outros procedimentos como arqueamento e alinhamento de longarinas. O presente trabalho tem por objetivo traçar os principais impactos destes processos sobre os materiais ASTM A570 GR36-C e o aço de alta resistência e baixa liga norma DIN EN 10149 S700MC em uma rota de fabricação de produtos automotivos com interferência de um procedimento a quente. Esses materiais, quando submetidos a determinados ciclos térmicos para alinhamento a quente, através do aquecimento de algumas regiões pontuais e do posterior resfriamento ao ar calmo têm suas propriedades mecânicas alteradas. Para investigar estas modificações, foram reproduzidas as condições do processo atual para mapeamento de dados de temperatura para os subsequentes ensaios de laboratório. Comparando as amostras submetidas ao ciclo térmico, com as produzidas com a mesma matéria prima sem aquecimento, pode-se verificar o impacto causado pelo processo de alinhamento a quente utilizado sobre as propriedades mecânicas do material. Os resultados mostram que o aço ASTM A570 GR36-C não tem suas propriedades alteradas a ponto de inviabilizar o uso do material. Para o aço DIN EN 10149 S700MC as alterações são expressivas em todos os ciclos térmicos realizados. Com isso, ocorrem modificações na microestrutura pelo tratamento térmico ocasionando a diminuição de algumas propriedades mecânicas importantes, como tensão de escoamento, microdureza e limite de resistência à fadiga. Essas últimas variáveis foram correlacionadas e mostraram o mesmo comportamento. / In certain manufacturing routes of automotive components, especially of heavy road segment products are very common straightening processes hot, as well as other procedures such as bending and alignment of rails. This paper aims to draw the main impacts of these processes on ASTM A570 GR36-C materials and high strength low alloy steel DIN EN 10149 S700MC on a route manufacturing of automotive products with interference from a hot procedure. These materials, when subjected to certain thermal cycles to hot alignment by heating of certain individual regions and the subsequent cooling the still air have changed their mechanical properties. In order to investigate this, they were reproduced the conditions of the current process for temperature mapping data for subsequent laboratory tests. Comparing the samples subjected to thermal cycling with produced with the same raw material unheated, one can ascertain the impact caused by hot alignment process used on the mechanical properties of the material. The results show that the steel ASTM A570 GR36-C does not have its properties changed as to make the use of the material. To DIN EN 10149 S700MC Steel changes are significant in all thermal cycles performed. Thus, changes occur in the microstructure by heat treatment causing a reduction of some important mechanical properties such as yield strength, hardness and fatigue strength limit. The latter variables were correlated and showed the same behavior.

Em determinadas rotas de manufatura de componentes automotivos, principalmente de produtos do segmento rodoviário pesado, são muito comuns processos de desempeno a quente, assim como outros procedimentos como arqueamento e alinhamento de longarinas. O presente trabalho tem por objetivo traçar os principais impactos destes processos sobre os materiais ASTM A570 GR36-C e o aço de alta resistência e baixa liga norma DIN EN 10149 S700MC em uma rota de fabricação de produtos automotivos com interferência de um procedimento a quente. Esses materiais, quando submetidos a determinados ciclos térmicos para alinhamento a quente, através do aquecimento de algumas regiões pontuais e do posterior resfriamento ao ar calmo têm suas propriedades mecânicas alteradas. Para investigar estas modificações, foram reproduzidas as condições do processo atual para mapeamento de dados de temperatura para os subsequentes ensaios de laboratório. Comparando as amostras submetidas ao ciclo térmico, com as produzidas com a mesma matéria prima sem aquecimento, pode-se verificar o impacto causado pelo processo de alinhamento a quente utilizado sobre as propriedades mecânicas do material. Os resultados mostram que o aço ASTM A570 GR36-C não tem suas propriedades alteradas a ponto de inviabilizar o uso do material. Para o aço DIN EN 10149 S700MC as alterações são expressivas em todos os ciclos térmicos realizados. Com isso, ocorrem modificações na microestrutura pelo tratamento térmico ocasionando a diminuição de algumas propriedades mecânicas importantes, como tensão de escoamento, microdureza e limite de resistência à fadiga. Essas últimas variáveis foram correlacionadas e mostraram o mesmo comportamento. / In certain manufacturing routes of automotive components, especially of heavy road segment products are very common straightening processes hot, as well as other procedures such as bending and alignment of rails. This paper aims to draw the main impacts of these processes on ASTM A570 GR36-C materials and high strength low alloy steel DIN EN 10149 S700MC on a route manufacturing of automotive products with interference from a hot procedure. These materials, when subjected to certain thermal cycles to hot alignment by heating of certain individual regions and the subsequent cooling the still air have changed their mechanical properties. In order to investigate this, they were reproduced the conditions of the current process for temperature mapping data for subsequent laboratory tests. Comparing the samples subjected to thermal cycling with produced with the same raw material unheated, one can ascertain the impact caused by hot alignment process used on the mechanical properties of the material. The results show that the steel ASTM A570 GR36-C does not have its properties changed as to make the use of the material. To DIN EN 10149 S700MC Steel changes are significant in all thermal cycles performed. Thus, changes occur in the microstructure by heat treatment causing a reduction of some important mechanical properties such as yield strength, hardness and fatigue strength limit. The latter variables were correlated and showed the same behavior.

Esta tese analisa o ciclo térmico da soldagem por atrito de um aço inoxidável superduplex ASTM A890 - 6A. Esse aço foi unido pelo processo de soldagem com pino consumível em furo cônico não-passante (Friction Tapered Stud Welding - FTSW) e a análise teve como objetivo principal a elaboração de um modelo matemático por meio da definição de alguns elementos do ciclo térmico de soldagem em três diferentes pontos das juntas. Os parâmetros analisados foram a rotação, a força axial e o deslocamento do pino. As equações dos ciclos térmicos foram elaboradas pelas relações existentes entre os parâmetros controlados e as temperaturas de saída medidas durante a execução do processo. Para a coleta dessas temperaturas foi fixada uma geometria para as juntas e elaborado um experimento fatorial com três fatores (deslocamento, rotação e força) e dois níveis. As juntas foram avaliadas e atenderam a todos os requisitos pré-estabelecidos. Os ciclos térmicos foram analisados conforme os valores dos seguintes elementos: temperatura de pico - Tp, tempo de aquecimento da junta entre 500°C e 800°C - ?T5/8, e tempo de resfriamento entre 800°C e 500°C - ?T8/5. Como resultados do trabalho são apresentadas equações que fazem a relação entre as variáveis de entrada (rotação, força e deslocamento) e as respostas ?T5/8, Tpico e ?T8/5. As equações permitem avaliar a importância de cada variável de entrada (e de suas interações) em relação à variável de resposta. Os modelos obtidos podem ser utilizados em simulações numéricas de soldagem por atrito do material estudado. / This work analyzes the thermal cycle of the friction tapered stud welding - FTSW - of a super duplex stainless steel ASTM A890 - 6A. The propose of the analyses was elaborating a mathematical model to define some elements of the welding thermal cycle at three different joint points. The parameters controlled were the rotation, the axial force and the plunge depth of the pin. The thermal cycle equations were elaborated by the relationships between the controlled parameters and the output temperatures measured during the execution of the process. For recording of these temperatures, a joint geometry was fixed, and a factorial design of experiment was developed with three factors (rotation, axial force and plunge depth) and two levels. The joints were evaluated, and they met all established requirements. The thermal cycles were analyzed according to the values of the following elements: peak temperature - Tpeak, joint heating time between 500 °C and 800 °C - ?T5/8, and cooling time between 800 °C and 500 °C - ?T8/5. A list of equations that make the relation between the input variables (rotation, axial force and plunge depth) and the responses ?T5/8, T peak and ?T8/5 is presented. These equations allow evaluating the importance of each input variable (and its interactions) in relation to the response variable. The obtained models can be used in numerical simulations of welding by friction of the studied material.

The diploma thesis is focused on characterization of fine – grained steels, choosing of welding technology and effects of heat transmission on weld joint quality. The effect of transmitted heat on microscopic structure and stiffness of weld have been studied. Based on obtained results the optimal parameters for welding of fine - grained steel have been determined.

Current board technologies are inherently performance-limited (FR-4) or cost-prohibitive (Al2O3/AlN). Next-generation high-density packaging applications would necessitate a new base substrate material to achieve ultra-fine pitch solder-joint reliability and multiple layers of fine-line wiring at low cost. The NEMI 2000 roadmap defines the need for 4-8 layers of 5-10 m wiring for future system boards. The 2003 ITRS roadmap calls for organic substrates with less than 100-m area-array pitch in the package or board by year 2010. Solder-joint reliability at such fine-pitch is a matter of concern for the industry. Use of underfills reduces thermal stresses but increases cost and, in addition, their dispensing becomes increasingly more complicated with the shorter gaps required for future interconnects. Therefore, there is a pronounced need to evaluate board materials with CTE close to that of Si for reliable flip-chip on board without underfill. Recently, a novel manufacturing process (using polymeric precursor) has been demonstrated to yield boards that have the advantages of organic boards in terms of large-area processability and machinability at potentially low-cost while retaining the high stiffness (~250 GPa) and Si-matched CTE (~2.5 ppm/㩠of ceramics. This work reports the evaluation of novel SiC-based ceramic composite board material for ultra-fine pitch solder-joint reliability without underfill and multilayer support. FE models were generated to model the behavior of flip-chips assembled without underfill and subjected to accelerated thermal cycling. These models were used to calculate solder-joint strains which have a strong direct influence on fatigue life of the solder. Multilayer structures were also simulated for thermal shock testing so as to assess via strains for microvia reliability. Via-pad misregistration was derived from the models and compared for different boards. Experiments were done to assemble flip-chips on boards without underfill followed by thermal shock testing so as to get the number of cycles to failure. To assess microvia reliability, 2 layer structures containing vias of different diameters were fabricated and subjected to thermal cycling. Via-pad misalignment was also studied experimentally. Modeling and experimental results were corroborated so as to evaluate thermomechanical suitability of C-SiC for high-density packaging requirements.