Clean production in an industrial environment

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Clean production in an industrial environment

  1. 1. Clean productionin an industrial environment Anton de Jong, Anton Duisterwinkel
  2. 2. 1 2011-03-11 Themadag Schoon ProducerenCONTENTS1. Introduction2. Systematic approach of assessing risks3. Contamination control - Prevention - Cleaning - Detection and Qualification
  3. 3. 2 2011-03-11 Themadag Schoon ProducerenWhy bother? Cleanliness becomes more important for the High Tech industry, e.g. Semiconductor (ASML, ASMI, supply chains) Analytical instruments, mass flow controllers of Bronkhorst; FEI Automotive (Nedcar, etc.) Medical Space (ESA, NASA) Solar Lighting (OLED’s), electronics Important: How to produce cleanly in a cost effective way How to check the quality of productsEssential: keep the balance between costs of risks and thecosts that control of the risks will bring
  4. 4. 3 2011-03-11 Themadag Schoon ProducerenClean production of high tech productsProduct Company cleaniliness Remark particles organic outgassing cont. vacuumAnalytical flowmeters Bronkhorst yes yes no oxygen safety(EUV) Lithography ASML yes yes yes optical performanceElectron Microscopy FEI yes yes yes opitcal performanceSpace instruments TNO Space, ESA yes yes yes optical performanceSolar cell prodution OTB,….. yes yes no/yes yield, lifetimeOLED, OPV Holst yes yes no/yes yield, lifetime
  5. 5. 4 2011-03-11 Themadag Schoon ProducerenContaminants: what and where from? Films Oil, grease (production), Food, Biofilms Molecular Water (condensate), Hydrocarbons (air), NH3, silicones (production) Particles Organic particles (pollen, micro-organisms, hairs, fibers, …, > 1 µm) Metallic particles (due to production, abrasion, ageing, > 1 µm) Oxidic: Sand, dirt, asbestos (environment, glass treatment, abrasion) Soot/smoke, salt, (NH4)2SO4 (condensation: < 1 µm) Object surface
  6. 6. 5 2011-03-11 Themadag Schoon ProducerenCleanliness: does it exist?Example 1: Oxygen application; maximum concentration organic material (< 66 mg C/m2)Example 2: Clean surface in food industry, allowed number of colony’s? 2.5 CFU/cm2, or 25000 per square meter!Example 3: Clean assembly: ISO Class 4, allowed number of particles? 10000/m3 (of 0.1 µm or larger); 352/m3 (of 0.5 µm or larger) ‘Dirty’, but fit for purpose !
  7. 7. 6 2011-03-11 Themadag Schoon ProducerenWhat is clean? Clean is dirty … to the extent that functionality is not hindered.Rule 1 ‘Clean must defined’ - Typically: no gross (visual) contamination - Definitions on particles (size, number) and moleculesRule 2 Testing method must be defined - who and when determined - exact description of methodRule 3 Responsibility, liability must be defined
  8. 8. 7 2011-03-11 Themadag Schoon ProducerenCONTENTS1. Introduction2. Systematic approach of assessing risks3. Contamination control - Prevention - Cleaning - Detection and Qualification
  9. 9. 8 2011-03-11 Themadag Schoon ProducerenSystematic approach for contamination control: Example:1. Products and production scheme Supplier: D Supplier: B T = .. T = .. Product : example complex assy 002 002 lfeedthrough Gas hoses Supplier: A s T = .. 001 003 t=.. 004, t=.. t=.. 005 t=.. 004, t=.. t=.. 005 t=.. 008 t=.. 002 Milling Intermediate Transport to Melt in Material for QD1: Intermediate Transport to Weld gas Intermediate fQ Louwers backplate Mat. Cer. Wet clean electrical Wet clean A hoses to Wet clean Supplier: A feedthroughs backplate T = .. 001 003 t=.. 004, t=.. 007 t=.. Material for 002 Milling Intermediate Store QD1: cooler body fQ Wet clean Mat. Cer. 028 t=.. 008 t=.. t=.. Weld water 002 Intermediate Transport to hoses to Press Wet clean T Supplier: B 023 026, t=.. 027 t=.. 024 cooler body Water Hose QD1: Intermediate Store T = .. fQ Mat. Cer. Wet clean 029 041 032, t=.. 044, t=.. 033 t=.. Filament Vac. Bolts QD1: 030 042 QD1: Intermediate Intermediate Store fQ fQMat. Cer. Wet clean Mat. Cer. Wet clean Supplier: C T = .. 035 038, t=.. 039 t=.. Screws 036 QD1: Intermediate Store fQ Wet clean Mat. Cer.2. Assessment of the risks (FMEA)3. Solving of the most important risks
  10. 10. 9 2011-03-11 Themadag Schoon ProducerenWhat kind of product? Simple mono part Simple assembly wet cleanable Assembly not wet cleanable Complex assembly sensitive not wet cleanable and sensitive to heat
  11. 11. 10 2011-03-11 Themadag Schoon ProducerenStep 1: Product /production analysesGoal: Define the how “dirty/clean” the (end)product may be in the different production steps.1. Describe the product and production steps2. Describe the requirements to the end product and the intermediate steps3. Define where contamination is critical for the next step in the process4. Define the contamination sources in the process
  12. 12. 11 2011-03-11 Themadag Schoon ProducerenStrategy for the control of a production process Example: Supplier: D Supplier: B T = .. T = .. Product : example complex assy 002 002 lfeedthrough Gas hoses Supplier: A s T = .. 001 003 t=.. 004, t=.. t=.. 005 t=.. 004, t=.. t=.. 005 t=.. 008 t=.. Material for 002 Milling Intermediate Transport to Melt in QD1: Intermediate Transport to Weld gas Intermediate fQ B Louwers backplate Mat. Cer. Wet clean electrical Wet clean A hoses to Wet clean Supplier: A feedthroughs backplate T = .. 001 003 t=.. 004, t=.. 007 t=.. Material for 002 Milling Intermediate Store QD1: cooler body fQ Wet clean Mat. Cer. 028 t=.. 008 t=.. t=.. Weld water 002 Intermediate Transport to hoses to Press Wet clean T Supplier: B 023 026, t=.. 027 t=.. 024 cooler body Water Hose QD1: Intermediate Store T = .. fQ Wet clean Mat. Cer. 029 041 032, t=.. 044, t=.. 033 t=.. Filament Vac. Bolts QD1: 030 042 QD1: Intermediate Intermediate Store fQ fQMat. Cer. Wet clean Mat. Cer. Wet clean Supplier: C T = .. 035 038, t=.. 039 t=.. Screws 036 QD1: Intermediate Store fQ Wet clean Mat. Cer.• Choice and sequence of the production steps• Detail for the production steps
  13. 13. 12 2011-03-11 Themadag Schoon ProducerenFailure Mode Effect AnalysisStep 2: Make a list of all failure modes1. Severity How big is the negative effect (Higher score if it is more severe)2. Occurrence How often does is happen (Higher score with increasing frequency)3. Detection/prevention How difficult is it to detect the failure (Higher score if it is more difficult to detect)
  14. 14. 13 2011-03-11 Themadag Schoon ProducerenFMEA (2) FMEA score Ernst Voorkomen Detectie 1 1 geen nooit zeker minimale gevolgen voor product zeer 2 (alleen kritische klanten) vrijwel nooit waarschijnlijk 2 minimale gevolgen voor product 3 (50 % van klanten) laag waarschijnlijk 4 gemiddelde gevolgen voor product af en toe boven gemiddeld 3 met 5 grote gevolgen voor product tussenposen gemiddeld kleine schade aan 6 productieapparatuur regelmatig laag 7 4 schade aan productieapparatuur erg regelmatig erg laag grote schade aan 8 productieapparatuur vaak onwaarschijnlijk 5 zeer 9 wettelijke normen erg vaak onwaarschijnlijk 10 mensveiligheid extreem vaak niet mogelijk
  15. 15. 14 2011-03-11 Themadag Schoon ProducerenFMEA (3) Calculate the “Risk Priority Number” for each failure mode RPN = effect x occurrence x Detection Sort on RPNExample: Failure mode severity occurance detection RPN failure in cleaning unit 10 3 8 240 failure in contamination verification 8 2 9 144 delivery of dirty tubing 3 2 9 54 fingerprints on product 2 4 3 24 FM4 FM5
  16. 16. 15 2011-03-11 Themadag Schoon ProducerenCONTENTS1. Introduction2. Systematic approach of assessing risks3. Contamination control - Prevention - Cleaning - Detection and Qualification
  17. 17. 16 2011-03-11 Themadag Schoon ProducerenSolving the risks: Contamination controlIs a systematic effort to control contamination to such a level that it does not disrupt functionality of a process or product by Prevention Clean design some major principles Clean environment this afternoon Clean assembly this lecture Cleaning Overview details this afternoon Detection and Inspection Detection (lab) NOT Inspection (fab) this lecture
  18. 18. 17 2011-03-11 Themadag Schoon ProducerenContamination control: Prevention1. Design rules Source control Clean in (checked!); filtering; easy to clean oils etcetera Design of instruments and processes Accessibility; flow away from critical surfaces; hanging Materials selection and development (electro)polished materials; controlled contacts; non-stick coating Optimization of process conditions Add chemicals that remove dirt; prevent hot spots
  19. 19. 18 2011-03-11 Themadag Schoon ProducerenContamination control: Prevention2. Clean environment Separate from normal production area Closed room where only qualified personnel can enter Cleanroom necessary for very critical parts only For packaging of critical parts: clean bench or flow bench Hang overcoats and gloves near the entrance door. Place extra gloves boxes near baths and clean bench.
  20. 20. 19 2011-03-11 Themadag Schoon ProducerenContamination control: Prevention3. Clean assembly Control the cleanliness of incoming materials and parts: Clean raw materials like bar, rod and profiles before processing Plastics will have oily residues, silicones and plasticizers on the surface from manufacturing All third party components must be qualified, even if they are claimed to be ‘clean’
  21. 21. 20 2011-03-11 Themadag Schoon ProducerenContamination control: Prevention3. Clean assembly Manufacturing of components by machining: Do not use oil based cutting fluids or use vegetable oils Use separate tools for manufacturing especially cleaned for vacuum All surfaces must be machined Last machining step preferably dry or with ethanol or IPA as cutting fluid prevents burial of cutting fluid in surface Clean the parts in the same run Beware of explosion risk and human safety! After machining immediately blow off with nitrogen or dry, pressurized, oil free air for removal of excessive cutting fluid. Wipe parts with lint free cloth soaked with ethanol or IPA Store under clean conditions for future cleaning
  22. 22. 21 2011-03-11 Themadag Schoon ProducerenContamination control: Prevention3. Clean assembly Clean Handling of clean parts Handling of objects only by qualified personnel Always wear overcoat and clean gloves (powder free!) Limit touching of the part to a minimum. After contact with contaminated objects put new gloves on. Do not hesitate to change your gloves if you suspect they got contaminated, it can save you a lot of work! Make sure extra gloves are available Put clean objects in a clean bench on aluminium foil Use a flow bench to briefly store clean objects in Package clean objects ASAP Do not cough or sneeze above (clean) objects
  23. 23. 22 2011-03-11 Themadag Schoon ProducerenContamination control: Cleaning1. Strategy: Step by step cleaning Preclean Removes film, visible dirt, gross contamination Can be manual, industrial dish washer is preferred Particle removal Removes particles and droplets to required level Often involves wet cleaning, ultrasonic Rinsing is critical. Molecular cleaning Removes last molecules, Drives off absorbed contaminants Preferably done shortly before use
  24. 24. 23 2011-03-11 Themadag Schoon ProducerenContamination control: Cleaning1. Strategy: Cleaning strategy per material Metals can tolerate most cleaning methods Alkaline detergents can etch or stain aluminium Glasses are vulnerable for micro-cracking caused by ultrasonic agitation or etching by surfactants Plastics are sensitive to solvents and might change their properties (tacky surface or swelling) Ceramics are often porous and can contain large amounts of water: baking after cleaning necessary!
  25. 25. 24 2011-03-11 Themadag Schoon ProducerenContamination control: Cleaning2. Cleaning methods: precleaningto remove visible dirt and oily residues, prevent clogging Wiping + standard, no investment; - no control, labour intensive Solvent and vapour degreasing + good for high volume - environment, k€ Industrial dish washer + well controlled - (k€) Ultrasonics + standard, well controlled - k€, needs supervision
  26. 26. 25 2011-03-11 Themadag Schoon Produceren Contamination control: Cleaning 2. Cleaning methods: particle removal to remove all particles larger than a specified size Ultrasonics usually good New methods for submicrometer particles Megasonics; CO2-snow; Nano-spray 1,0E-04 1,0E-05 Small = hard to remove 1,0E-06 capillary Binding force is smaller BUTForce [N] 1,0E-07 • Removal force = even smaller VanderWaals 1,0E-08 • Particles hide in roughness 1,0E-09 electrostatic gravity • Boundary layer 1,0E-10 0,01 0,1 1 10 100 1000 Particle diameter [micrometer]
  27. 27. 26 2011-03-11 Themadag Schoon ProducerenContamination control: Cleaning3. Cleaning methods: molecular cleaningTo remove molecules to specified outgassing rate or coverage Baking in/of vacuum system + standard, proven; - high T, low P Plasma + relatively cool; quick - low P, crevices Solvent and vapour degreasing + good for high volume - environment, k€ UV-ozon (optical components) + low T, 1 bar, quick - line of sight, O3
  28. 28. 27 2011-03-11 Themadag Schoon ProducerenContamination control: Cleaning4. After cleaning: packaging Package a part as soon as is has reached room temperature Always check if components are clean Pack the objects in a clean bench or a flow bench Touch the clean objects only with clean, non-powdered gloves Seal the package and mark it with ‘clean parts’. Package in layers Aluminium foil (clean, getter, but may smear) Plastic bags (clean, easy, may outgas) Casing or box for physical protection during shipping
  29. 29. 28 2011-03-11 Themadag Schoon ProducerenContamination control: Inspection1. Pragmatic monitoring methods: non contact Direct inspection Compare to clean surface Use strong and stable lighting and a binocular Also inspect at grazing incidence Black light (purpose built UV-source) Will show up fluorescent contaminants Use protective glasses, aim at surface only Darken the room Fluorescence Will show up fluorescent contaminants, e.g. oils Need to scan the surface
  30. 30. 29 2011-03-11 Themadag Schoon ProducerenContamination control: Inspection2. Pragmatic monitoring methods: contacting methods for particles Wiping (white glove, white towel) Wipe form clean to dirty Compare to non-used glove or towel Use strong and stable lighting, fiber optics Tape test Press transparent tape on object Carefully remove and place on white paper Compare tape to white paper
  31. 31. 30 2011-03-11 Themadag Schoon ProducerenContamination control: Inspection3. Pragmatic monitoring methods: contacting methods for greasiness Water break test (ASTM Method F 22-26) Observes hydrophobic contaminants only Breathing or atomizing is better alternative Use contact angle measurements for qualification Atomizer test Gently spray deionized water over the surface Observe whether droplets are deposited uniformly Non-uniform spots due to hydrophobic contaminants Contact angle measurements Sessile drop technique is preferred. Use DI-water Semi-automized equipment is available (10-20 k€) Sensitive to less than monolayer contamination Water drop test Place drop of 0.2 ml DI-water on surface. Determine surface area (diameter) after standard time Smaller = more hydrophobic = dirtier
  32. 32. 31 2011-03-11 Themadag Schoon ProducerenContamination control: Inspection4. Strategy for qualification of parts and assemblies1. Set clear requirements with client Type of contaminant (gross, particle, grease, …) Method for measurement (suitable for type of contaminant) Maximum acceptable value (that can be determined by that method)2. Develop clean production method (= handling, cleaning, packaging) Test with selected method Optimize production process; document this Train and coach the staff (this is an ongoing activity)3. Ensure clean supply line Parts Assemblies Qualify your suppliers on quality control, Non- Random sampling Random sampling validated procedures, staff training and critical practical test functional test coaching, supply chain, facilities Critical All pieces All assemblies4. Perform regular tests practical test functional test
  33. 33. 32 2011-03-11 Themadag Schoon ProducerenConclusion

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