1 book ‘Cleanroom Technology – Fundamentals of

1 Literature review1.1 MethodologyLiterature review for this master thesis mainly included referring books and research papersfor this topic. Cleanroom technology is a vast topic, therefore, numerous books, researchpapers, journals and other scientific material is widely available. However, the concept of cleanroomfor automotive electronic manufacturing is relatively new. There a few books availableoffer a considerably deep insight on automotive cleanroom technology, which were taken intoconsideration for the scope of this work.1.2 Relevance and significance of the literatureThere are total 3 books which were considered for the literature review, because these bookscould provide information on automotive electronic manufacturing cleanrooms, which is thescope of this work. Further, some additional papers were researched for gaining specific casestudies for automotive cleanrooms. No-Trouble-Found or No-Fault-Found is one of the bigproblems in automotive electronic returned-goods. Unfortunately, after identification of anykind of contamination, these returned goods cannot be every time deeply analysed, becauseof financial and time constraints. Hence research for these papers has been included in thefurther chapters due to its specific relevance for this specific topic.1.3 Cleanroom Technology by William WhyteDr. William Whyte is an honorary research fellow at the University of Glasgow, United Kingdom.He has published numerous articles, papers and scientific material in the area of cleanroomtechnology. His book ‘Cleanroom Technology – Fundamentals of Design, Testing andOperation’ was researched for the relevant information regarding contamination problems andtheir prevention. 111 Literature reviewAuthor has aptly divided the tasks in cleanroom technology in to three broad topics as shownbelow table. Considering the scope of this work, Cleanroom Testing and monitoring and cleanroomoperations will be the topics in focus.Cleanroom design andconstructionCleanroom testing andmonitoringCleanroom operationsStandards and layoutTesting that the newcleanroom performs asdesignedMonitoring and maintenancethe cleanroom performanceFacility Management withwater, air flow, temperatureand humidityTesting to ensure thatcleanroom performsconsistently as per theguidelinesClenaroom disciplines, entryof machines, material andpersonnelTable 1.1: Activities in cleanroom management 2Keeping all the processes contamination-free is rather practically impossible, unless utmostcare has been taken for monitoring and eliminating contaminants. However, this is not a requirementand not possible, keeping in mind financial and technical limitations. Unlike electronicindustry, contamination problem in Pharmaceutical industry is about bio-contamination,for which EU-GMP regulations should be implemented, in order to prevent the generation ofcontamination source. The generation of contaminants is evident of the degree up to whichEU-GMP are implemented. 31.3.1 Sources of ContaminationAuthor has identified the major sources of Contamination as Air, Material and People. Therethree sources has been explained below:Contamination through AirAir is not considered to be an active source of microbiological contaminations, rather isa passive medium through which contaminants nurture. Micro-organisms don’t multiply inair rather they die in air. To eliminate the risk of contamination through air, Pharmaceuticalindustry also deploys Cleanroom technology. There are special filters which are used to filterthe air which is then blown in the manufacturing area. Though these filters are not capable of21 Literature reviewremoving sterilized bacteria however, these can remove a vast majority of micro-organisms. Byusing a cascading effect and deploying several filters for the single air-stream, the number andtype of contaminants can effectively be controlled.Maintaining a positive pressure differential in the production area is relatively easier preventivemeasure for prevention of entry of the contaminants in the clean area. The higherpressure in the clean area ensures a constant air-outflow whenever any opening of the Cleanroomis opened. Additionally, using a laminar air flow in Cleanroom prevents turbulence andmixing, thus influence of micro-organisms. The micro-organisms cannot flow opposite to theair flow, whenever any door of the Cleanroom is opened. Moreover, the microorganisms in thearea can be swept away with implementation of laminar flowContamination through materialsAll the materials which are brought from outside, uncontrolled environment are supposedlypotential sources of contaminants. In Pharma-industry it is impossible to identify the consequencesof the micro-organisms on the products, due to change in chemical and biologicalproperties. Conducting an audit for assessment of cleanliness and manufacturing process tocheck for the potential sources of contaminations. In the case of deviations, the corrective actionsshould be planned at the supplier’s end and cleanliness should be monitored on the basisof incoming batch. This methodical approach is referred to Microbiological Quality Assurance.Contamination through PeopleThe contamination from the people is one of the most unpredictable source of contamination.Skin flakes, face, throat; mouth, genital regions, nose are the areas of human body wheremicroorganisms can be shed. There are also different types of micro-organisms which can betraced back to the specific organ from which it originated. There are two possibilities to preventthe contamination from people:1. Cleanroom attireThe garments used in cleanrooms are usually sterile i.e. free from all viable microorganisms.In intense cleanrooms, stringent garment control is deployed and personnelis covered as much as possible. However, the universal exceptions are made forbreathing, seeing, hearing, wherever necessary touching.2. Education and TrainingPsychologically speaking, whenever people understand the intent behind doing a specific