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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Cell Formation: A Real Life Application

Uyanik, Basar 01 September 2005 (has links) (PDF)
In this study, the plant layout problem of a worldwide Printed Circuit Board (PCB) producer company is analyzed. Machines are grouped into cells using grouping methodologies of Tabular Algorithm, K-means clustering algorithm, and Hierarchical grouping with Levenshtein distances. Production plant layouts, which are formed by using different techniques, are evaluated using technical and economical indicators.
52

Design and construction of a photoplotter : Building a device for rapid prototyping of PCBs

Hajjar, Gabriel January 2018 (has links)
The goal was to build a machine that could rapidly prototype PCBs using a moving light source and photoresist. The project failed, as the UV light did not make it through the lenses used to concentrate it. Better lenses and a laser would allow it to function better.
53

Analise teorica e experimental da tranferencia de calor em placas de circuito impresso formando canais verticais abertos / Theoretical and experimental analysis of the heat transfer in printed circuit boards forming open vertical channels

Avelar, Ana Cristina 22 July 2018 (has links)
Orientador: Marcelo Moreira Ganzarolli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-22T20:18:14Z (GMT). No. of bitstreams: 1 Avelar_AnaCristina_M.pdf: 5757345 bytes, checksum: ab66436b252ec7b8b48d4756dd9e7f42 (MD5) Previous issue date: 1997 / Resumo: Os constantes avanços tecnológicos em eletrônica e informática tem tornado os sistemas eletrônicos cada vez mais compactos, aumentando-se a quantidade de calor a ser removida dos componentes e placas de circuito impresso. Por este motivo, atualmente são exigidos sistemas de dissipação de calor altamente eficientes. Este estudo analisa teórica e experimentalmente a transferência de calor em canais verticais formados por placas de circuito impresso dispostas paralelamente, resfriadas por convecção natural e propõe uma modelagem, baseada em relações existentes na literatura, que busca prever a distribuição de temperaturas em pontos significativos nos canais e placas em função da potência dissipada e da distância entre as placas. Este estudo visa também analisar os efeitos do aquecimento não-uniforme das placas que formam o canal. Na simulação teórica, devido à pequena espessura da placa o gradiente de temperatura ao longo da espessura da mesma foi desprezado e resolveu-se numericamente a equação de transferência de calor em coordenadas cartesianas bidimensionais e em regime permanente. Equacionou-se balanços de energia para os componentes e para o ar no canal e o problema foi resolvido numericamente através de um programa computacional. As placas de circuito impresso utilizadas nos testes experimentais, concebidas exclusivamente para fins de estudos térmicos, possuem uma base de epóxi com 25 resistores discretamente distribuídos sobre sua superfície de 200x164mm. Realizou-se testes com aquecimento uniforme e não-uniforme, variando-se a potência por componentes nas placas. Variou-se também as potências por placas e as distâncias entre as mesmas. Testou-se as potências de 2, 4,6 e 8 W e as distâncias entre placas de 12,24, e 48mm. Verificou-se boa concordância entre os resultados numéricos e experimentais, principalmente para a menor distância entre placas, 12 mm, onde a diferença entre os resultados teóricos e experimentais foi muito pequena / Abstract: The constant technological advances in electronics and computations have made the electronic system increasingly more compact, thus increasing the amount of heat to be removed ITomthe components and printed circuit boards. For this reason, highly efficient system of heat removal are presently required. This study analyses both theoretically and experimentallyheat transfer in an array of vertical parallel printed circuit boards, cooled off by natural convection and proposes a modeling, based on correlation found in literature which tries to predict temperature distribution in significant places in the channels and boards as regards dissipated power and distance among boards. This study also aims at analyzing nonuniform heating effets of the channel made boards. In the theoritical simulation, due to the board' s small thickness, the temperature gradient across the board has been neglected, and the equation of heat transfer in two-dimensional Cartesian was numericallysolved, and on a steady state. Energy balances for the componentes were formulated, and the problem was numerically solved by a computer programo The printed circuit boards used in the experimental tests, manufactured speciallyfor heat trasnfer studies have an epoxy basis with 25 resistors discretely distributed on 200 x 164 mm. Uniform and non-uniform heating tests were performed, thus a variation of power and distance among them had a variation. The 2, 4, 6 and 8 W power and distance among 12, 24 and 48 mm boards were tested. Good agreements between numerical and experimentalresults were observed, mainlyfor the smaller distance among boards, 12 mm, the differencesbetween the theoretical and experimentalresults were small / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
54

The advantages of a printed circuit board over traditional electrical cabinets on an electric boat

Lampa Fjellström, Pontus January 2021 (has links)
This thesis aims to prove the concept of replacing traditional electrical cabinets with PCBs on a fully electric boat. The existing solution with two electrical cabinets is considered expensive and believed to be replacable by PCBs.  Means of protections for PCBs are evaluated with regard to moisture, salt and vibrations. Two PCBs are designed to carry a current up to 60 ampere for a longer period of time. A cost analysis of 1, 10 and 100 PCBs are made to compare the cost of the proposed design to the existing solution. The result is a functioning prototype, a proposed design, cost analysis and suggested means of protections for withstanding the elements that the PCBs are exposed to at sea.Verification of the design is done by PDN Analysis and load testing with thermal imaging to monitor the temperature rise. Soley this is not enough to fully validate the design as further tests are needed and the local juristrictions has to be met before implementing these PCBs in consumer equipment.
55

Monitorování výrobních zařízení / Monitoring of production facilities

Borsuk, Adam January 2020 (has links)
The aim of the diploma thesis is to study the possibilities of creating a monitoring system for older production facilities already in operation. Select the necessary components for the nature of the equipment to create a system that is able to capture and provide information about activities on the equipment. The second goal is to design a suitable communication model for clear information about the operation, sending and storing data. The third goal is to analyze the dual-core ESP32 microprocessor against its predecessors in the role of system control unit.
56

Výroba vícevrstvých desek s plošnými spoji / Production of Multilayer PCB

Janda, Ondřej January 2020 (has links)
This master thesis introduces the problematics of multilayer printed circuit boards. Theoretical part is focused on materials used for production of multilayer PCB and their parameters. At the same time, it focuses on the pressing process of multi-layered PCB, the types of presses used and their advantages and disadvantages. Practical part describes the methodology and testing of the PCB to identify the reliability of chosen electrical parameters. Testing is aimed to simulate thermal stress during machine soldering and during thermal stress in the target environment.
57

Segmentace obrazových dat využitím hlubokých neuronových sítí / Image data segmentation using deep neural networks

Hrdý, Martin January 2021 (has links)
The main aim of this master’s thesis is to get acquainted with the theory of the current segmentation methods, that use deep learning. Segmentation neural network that will be capable of segmenting individual instances of the objects will be proposed and created based on theoretical knowledge. The main focus of the segmentation neural network will be segmentation of electronic components from printed circuit boards.
58

Termomechanická spolehlivost montáže mikroelektronických a elektronických modulů / Modern Assembly for Microelectronic and Electronic Modules

Janík, Pavel January 2010 (has links)
Project is focused on describe modern assembly of microelectronic and electronic modules in electronic devices. Sense of the project is analyse reliability and inadequacies electronic devices assembled by modern technogies. Inadequacies modern technologies are impulse for design, implementation and testing new our way of assembly microelectronic modules. Main kind of materials which are used in this project are ceramics Al2O3 and printed circuit board FR4.
59

Systém řízení slunečních kolektorů / Systme for solar system control

Cseri, Peter January 2011 (has links)
In the first part of my thesis, I was studying materials about using solar energy. Then I write search about all components that are necessary to be used in solar systems. After that I designed the structure of solar system used for heating the hot water for a family house about 4 persons. For this system I designed a regulator and one layer circuit board using Eagle layout editor 4.12r2, which I assembled and tested. This followed creating and debugging program for microprocessor that controls the whole device. This functional regulator for solar collectors connected in a box together with the necessary electronic components is my final product of this project.
60

Automatisering av det interna flödet på ett tillverkande företag : En studie om den interna hanteringen av kretskortställningar och hur det kan effektiviseras i flödet

Kadhim Abed, Ahmed, Rappestad, Erik January 2023 (has links)
Purpose: The purpose of the study was to identify the current transport flow for circuit board racks and to investigate the potential implementation of an automated solution for the transportation of circuit board racks in order to increase efficiency in the flow. The research questions answered during this study were: What does the transport flow for circuit board racks look like today?  What could an automated transport flow for circuit board racks look like?  Is an automated transport flow for circuit board racks a sufficient solution to improve efficiency in the flow? Theoretical framework: The study applied several different theories, with waste being a central part. This, in combination with bottleneck identification, mapping, and automation, has been theories used to study the flow and find improvements. Method: A case study was conducted to analyze the transport flow of circuit board racks and identify potential improvements. The method included a literature review, observations, interviews, brainstorming, Value Stream Mapping, and spaghetti diagrams to collect and analyze data from different perspectives. Results: With a combination of theories and empirical data, an analysis of the current transport flow for the circuit board racks could be made. Furthermore, bottlenecks and waste were identified, and automated transport solutions linked to AMR systems were found as a potential solution for a more efficient transport flow. The result showed that an AMR system is the most advantageous solution. However, the study showed that the automated solution was not sufficient without eliminating the bottlenecks in order to generate maximum efficiency in the automated transport flow. Implications: This study has the implication of highlighting the challenges and opportunities of a more efficient transport flow using AMR systems. This includes an improved working environment, reduced work-related injuries, increased production efficiency by eliminating bottlenecks, and waiting times.

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