IGRT com CBCT: o impacto na precisão em radioterapia

Mestrado em Radiações Aplicadas às Tecnologias da Saúde.

Implementação, validação e análise técnico-económico de alguns parâmetros analíticos no controlo de águas

Mestrado em Engenharia Química

Caracterização do “warpage” e sua variabilidade no processo produtivo de encapsulamento de circuitos integrados

Nos últimos anos a indústria de semicondutores, nomeadamente a produção de memórias, tem sofrido uma grande evolução. A necessidade de baixar custos de produção, assim como de produzir sistemas mais complexos e com maior capacidade, levou à criação da tecnologia WLP (Wafer Level Packaging). Esta tecnologia permite a produção de sistemas mais pequenos, simplificar o fluxo do processo e providenciar uma redução significativa do custo final do produto. A WLP é uma tecnologia de encapsulamento de circuitos integrados quando ainda fazem parte de wafers (bolachas de silício), em contraste com o método tradicional em que os sistemas são individualizados previamente antes de serem encapsulados. Com o desenvolvimento desta tecnologia, surgiu a necessidade de melhor compreender o comportamento mecânico do mold compound (MC - polímero encapsulante) mais especificamente do warpage (empeno) de wafers moldadas. O warpage é uma característica deste produto e deve-se à diferença do coeficiente de expansão térmica entre o silício e o mold compound. Este problema é observável no produto através do arqueamento das wafers moldadas. O warpage de wafers moldadas tem grande impacto na manufatura. Dependendo da quantidade e orientação do warpage, o transporte, manipulação, bem como, a processamento das wafers podem tornar-se complicados ou mesmo impossíveis, o que se traduz numa redução de volume de produção e diminuição da qualidade do produto. Esta dissertação foi desenvolvida na Nanium S.A., empresa portuguesa líder mundial na tecnologia de WLP em wafers de 300mm e aborda a utilização da metodologia Taguchi, no estudo da variabilidade do processo de debond para o produto X. A escolha do processo e produto baseou-se numa análise estatística da variação e do impacto do warpage ao longo doprocesso produtivo. A metodologia Taguchi é uma metodologia de controlo de qualidade e permite uma aproximação sistemática num dado processo, combinando gráficos de controlo, controlo do processo/produto, e desenho do processo para alcançar um processo robusto. Os resultados deste método e a sua correta implementação permitem obter poupanças significativas nos processos com um impacto financeiro significativo. A realização deste projeto permitiu estudar e quantificar o warpage ao longo da linha de produção e minorar o impacto desta característica no processo de debond. Este projecto permitiu ainda a discussão e o alinhamento entre as diferentes áreas de produção no que toca ao controlo e a melhoria de processos. Conseguiu–se demonstrar que o método Taguchi é um método eficiente no que toca ao estudo da variabilidade de um processo e otimização de parâmetros. A sua aplicação ao processo de debond permitiu melhorar ou a fiabilidade do processo em termos de garantia da qualidade do produto, como ao nível do aumento de produção.

Utilization of Quality Tools: does sector and size matter?

This research focuses on the influence of company sector and size on the level of utilization of Basic and Advanced Quality Tools. The paper starts with a literature review and then presents the methodology used for the survey. Based on the responses from 202 managers of Portuguese ISO 9001:2008 Quality Management System certified organizations, statistical tests were performed. Results show, with 95% confidence level, that industry and services have a similar proportion of use of Basic and Advanced Quality Tools. Concerning size, bigger companies show a higher trend to use Advanced Quality Tools than smaller ones. For Basic Quality Tools, there was no statistical significant difference at a 95% confidence level for different company sizes. The three basic Quality tools with higher utilization were Check sheets, Flow charts and Histograms (for Services) or Control Charts/ (for Industry), however 22% of the surveyed organizations reported not using Basic Quality Tools, which highlights a major improvement opportunity for these companies. Additional studies addressing motivations, benefits and barriers for Quality Tools application should be undertaken for further validation and understanding of these results.

Implementation of a lean six sigma project in a production line

Companies from the motorcycles components branch are dealing with a dynamic environment, resulting from the introduction of new products and the increase of market demand. This dynamic environment requires frequent changes in production lines and requires flexibility in the processes, which can cause reductions in the level of quality and productivity. This paper presents a Lean Six Sigma improvement project performed in a production line of the company's machining sector, in order to eliminate losses that cause low productivity, affecting the fulfillment of the production plan and customer satisfaction. The use of Lean methodology following the DMAIC stages allowed analyzing the factors that influence the line productivity loss. The major problems and causes that contribute to a reduction on productivity and that were identified in this study are the lack of standardization in the setup activities and the excessive stoppages for adjustment of the processes that caused an increase of defects. Control charts, Pareto analysis and cause-and-effect diagrams were used to analyze the problem. On the improvement stage, the changes were based on the reconfiguration of the line layout as well as the modernization of the process. Overall, the project justified an investment in new equipment, the defective product units were reduced by 84% and an increase of 29% of line capacity was noticed.

C. difficile surveillance quarterly report: October-December 2010

This quarterly report provides epidemiological data on C. difficile in Northern Ireland, and includes key points, a comprehensiveoverview of all C. diff infections, rates, trends, age-specific informationand statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

S. aureus bacteraemia surveillance quarterly report: October-December 2010

This quarterly report provides epidemiological data onS. aureusin Northern Ireland, including overall infectionfigures as well as those specific to MRSA and MSSA. The report highlights key points, rates, trends and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

C. difficile surveillance quarterly report: January-March 2011

This quarterly report provides epidemiological data on C. difficile in Northern Ireland, and includes key points, a comprehensive�overview of all C. diff infections, rates, trends, age-specific information�and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

S. aureus bacteraemia surveillance quarterly report: January-March 2011

This quarterly report provides epidemiological data on�S. aureus�in Northern Ireland, including overall infection�figures as well as those specific to MRSA and MSSA. The report highlights key points, rates, trends and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

C. difficle surveillance quarterly report: April - June 2011

This quarterly report provides epidemiological data on C. difficile in Northern Ireland, and includes key points, a comprehensive�overview of all C. diff infections, rates, trends, age-specific information�and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

S.aureus bacteraemia surveillance quarterly report

This quarterly report provides epidemiological data on�S. aureus�in Northern Ireland, including overall infection�figures as well as those specific to MRSA and MSSA. The report highlights key points, rates, trends and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland

C. difficile surveillance quarterly report: July - September 2011

This quarterly report provides epidemiological data on C. difficile in Northern Ireland, and includes key points, a comprehensive�overview of all C. diff infections, rates, trends, age-specific information�and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

S.aureus bacteraemia surveillance quarterly report: July - September 2011

This quarterly report provides epidemiological data on�S. aureus�in Northern Ireland, including overall infection�figures as well as those specific to MRSA and MSSA. The report highlights key points, rates, trends and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland

C. difficile surveillance quarterly report: October - December 2011

This quarterly report provides epidemiological data on C. difficile in Northern Ireland, and includes key points, a comprehensive�overview of all C. diff infections, rates, trends, age-specific information�and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland.

S.aureus bacteraemia surveillance quarterly report: October - December 2011

This quarterly report provides epidemiological data on�S. aureus�in Northern Ireland, including overall infection�figures as well as those specific to MRSA and MSSA. The report highlights key points, rates, trends and statistical process control charts. The report also provides information on surveillance methods and data for each hospital and Health and Social Care Trust in Northern Ireland