Optimisation of a surface mount technology process using a SnAgCu lead-free alloy

The impending introduction of lead-free solder in the manufacture of electrical and electronic products has presented the electronics industry with many challenges. European manufacturers must transfer from a tin-lead process to a lead-free process by July 2006 as a result of the publication of two directives from the European Parliament. Tin-lead solders have been used for mechanical and electrical connections on printed circuit boards for over fifty years and considerable process knowledge has been accumulated. Extensive literature reviews were conducted on the topic and as a result it was found there are many implications to be considered with the introduction of lead-free solder. One particular question that requires answering is; can lead-free solder be used in existing manufacturing processes? The purpose of this research is to conduct a comparative study of a tin-lead solder and a lead-free solder in two key surface mount technology (SMT) processes. The two SMT processes in question were the stencil printing process and the reflow soldering process. Unreplicated fractional factorial experimental designs were used to carry out the studies. The quality of paste deposition in terms of height and volume were the characteristics of interest in the stencil printing process. The quality of solder joints produced in the reflow soldering experiment was assessed using x-ray and cross sectional analysis. This provided qualitative data that was then uniquely scored and weighted using a method developed during the research. Nested experimental design techniques were then used to analyse the resulting quantitative data. Predictive models were developed that allowed for the optimisation of both processes. Results from both experiments show that solder joints of comparable quality to those produced using tin-lead solder can be produced using lead-free solder in current SMT processes.

Aspects on Process Engineering in the Finnish Pulp and Paper Industry : Thesis for the Degree of Licentiate in Science of Technology

Process development will be largely driven by the main equipment suppliers. The reason for this development is their ambition to supply complete plants or process systems instead of single pieces of equipment. The pulp and paper companies' interest lies in product development, as their main goal is to create winning brands and effective brand management. Design engineering companies will find their niche in detail engineering based on approved process solutions. Their development work will focus on increasing the efficiency of engineering work. Process design is a content-producing profession, which requires certain special characteristics: creativity, carefulness, the ability to work as a member of a design team according to time schedules and fluency in oral as well as written presentation. In the future, process engineers will increasingly need knowledge of chemistry as well as information and automation technology. Process engineering tools are developing rapidly. At the moment, these tools are good enough for static sizing and balancing, but dynamic simulation tools are not yet good enough for the complicated chemical reactions of pulp and paper chemistry. Dynamic simulation and virtual mill models are used as tools for training the operators. Computational fluid dynamics will certainlygain ground in process design.

Assessing the capability to acquire and absorb technology within the public sector in developing countries : the case of Kuwait

The aim of this research is to assess the acquisition and absorption technology capabilities of the public sector in developing countries, with specific focus on the State of Kuwait. The assessment process of these two capabilities was conducted using a model originally designed for the private sector. In addition, the research aims to propose a framework to enhance the technological capability of developing countries, as well as the performance of the public sector. To achieve these aims, an investigation of the technology process to three public ministries in Kuwait was conducted. The prime interest of this investigation was to evaluate the role of the transferred technology in enhancing the indigenous technological capability of the public sector. The research is based on a case study approach, comprising a main case study (Ministry of Electricity and Water) and three minor case studies. Based on the outcomes from an extensive literature review and the preliminary sectoral visits, the research question and four hypotheses were formulated. These hypotheses were then tested using interview-based survey and documentation. The findings of the research revealed the weakness of the acquisition and absorption technological capabilities of the public sector. Consequently, the public sector relies extensively on foreign contractors and expatriates to compensate for this weakness. Also, it was found that Kuwait Government has not taken the necessary measures to develop its technological capability. This research has proposed a framework which could lead, if properly managed, to the enhancement of indigenous capability. It has also proposed how to improve performance and productivity in the public sector. Finally, the findings suggest that the assessment model, with minor adjustment, is applicable to the public sector.

Química Analítica de Processos

Process Analytical Chemistry (PAC) is an important and growing area in analytical chemistry, that has received little attention in academic centers devoted to the gathering of knowledge and to optimization of chemical processes. PAC is an area devoted to optimization and knowledge acquisition of chemical processes, to reducing costs and wastes and to making an important contribution to sustainable development. The main aim of this review is to present to the Brazilian community the development and state of the art of PAC, discussing concepts, analytical techniques currently employed in the industry and some applications.

Yrityksen sähköistysprojektoinnin tiedonhallinnan tehostaminen

Diplomityössä on käsitelty kolmea kokonaisuutta. Työssä on tutkittu RFID- teknologian hyödyntämistä kattilalaitostyömaan asennusvalvonnassa, prosessisähköistyksen osa-alueiden automatisoimista sekä edellä mainittujen asiakokonaisuuksien yhdistämistä. Prosessisähköistyksen osa-alueista työssä on käsitelty sähköpääkaavioita, sähköasennustyyppejä, toimitusrajakaavioita sekä potentiaalintasausta. Tutkittavienasiakokonaisuuksien yhdistävänä tekijänä on projektitietokanta, joka yrityksellä on käytössä. RFID- teknologiaa tutkitaan MOVER- hankkeen yhteydessä. Työssä yritetään selvittää mahdollisia tulevaisuuden hyötyjä, jos asennusraportointi suoritettaisiin mobiililla ratkaisulla. Prosessisähköistyksen osa-alueista sähköpääkaavioiden laatimista on pyritty automatisoimaan. Sähkö- asennustyyppien ja potentiaalintasauksen kohdalla tarkoituksena oli tuottaa esimerkkiratkaisuja, joita voitaisiin jatkokehittää tulevaisuudessa. Toimitusrajakaavioiden korvaajaksi kehitettiin uutta menetelmää, joka tulisi sisältämään automatiikkaa toimiakseen.

Coolant Flow and Heat Transfer in Pebble-Bed Reactor Core

This thesis gathers knowledge about ongoing high-temperature reactor projects around the world. Methods for calculating coolant flow and heat transfer inside a pebble-bed reactor core are also developed. The thesis begins with the introduction of high-temperature reactors including the current state of the technology. Process heat applications that could use the heat from a high-temperature reactor are also introduced. A suitable reactor design with data available in literature is selected for the calculation part of the thesis. Commercial computational fluid dynamics software Fluent is used for the calculations. The pebble-bed is approximated as a packed-bed, which causes sink terms to the momentum equations of the gas flowing through it. A position dependent value is used for the packing fraction. Two different models are used to calculate heat transfer. First a local thermal equilibrium is assumed between the gas and solid phases and a single energy equation is used. In the second approach, separate energy equations are used for the phases. Information about steady state flow behavior, pressure loss, and temperature distribution in the core is obtained as results of the calculations. The effect of inlet mass flow rate to pressure loss is also investigated. Data found in literature and the results correspond each other quite well, considered the amount of simplifications in the calculations. The models developed in this thesis can be used to solve coolant flow and heat transfer in a pebble-bed reactor, although additional development and model validation is needed for better accuracy and reliability.

Química Analítica de Processos

Process Analytical Chemistry (PAC) is an important and growing area in analytical chemistry, that has received little attention in academic centers devoted to the gathering of knowledge and to optimization of chemical processes. PAC is an area devoted to optimization and knowledge acquisition of chemical processes, to reducing costs and wastes and to making an important contribution to sustainable development. The main aim of this review is to present to the Brazilian community the development and state of the art of PAC, discussing concepts, analytical techniques currently employed in the industry and some applications.

Investointilaskennan kehittäminen elintarviketeollisuuden yrityksessä

Tämän työn tavoitteena on kehittää elintarvikealan yrityksen investointilaskentaa osana teknologiaprosessia. Työssä kehitetään investointien laskennallista mallintamista ja analysoidaan investointeja elintarviketeollisuuden näkökulmasta. Investointilaskennan kehittäminen toteutetaan tapaus-tutkimuksena ottaen huomioon case yrityksen tarpeet. Tässä työssä empiriaosa pohjautuu teoriaan, joka koostuu pääasiassa investointiprosessista, investointilaskennan komponenteista ja investointi-laskentamenetelmistä sekä riskianalyysistä. Työssä käsitellään kohdeyrityksen investointiprosessia ja analysoidaan laskelmien muuttujia kohdeyrityksen kannalta. Investointilaskennan kehittämisellä pyritään analysoimaan investointeja monipuolisemmin pidemmällä aikajänteellä sekä tekemään laskelmia enemmän investointiteorian mukaisella tavalla. Empiriaosan taustalla vaikuttaa kuitenkin vahvasti myös kohdeyrityksessä tehdyt haastattelut sekä osallistuvan havainnoin kautta saadut tiedot. Vaikka investointilaskentaa kehitetään monipuolisemmaksi, kannattaa investointiin liittyviin epävarmuuksiin kiinnittää huomiota. Työn tuloksena yrityksessä otetaankin käyttöön investointeihin liittyvä riskianalyysi.