EJA January abab Dust Level Control in Phototooling Basics Eric JanssensJanuary 2002

EJA January abab What is dust ? Any material particles that may have a negative effect on their environment

EJA January abab Sources of dust Natural dust Cosmic dust from outer space Eruption of volcano’s Sand, stone... due to erosion by wind and water Seeds, pollen Humans Man generated dust Exhaust by industry and traffic Generated by any friction Human body tissue: hair, skin particle, sweat, ….

EJA January abab Dust generated by the human body Calling generates 20,000 particles Coughing generates 600,000 particles Sneezing generates 1,200,000 particles A man looses 1 hair every 15 minutes A man looses 15 grams of skin tissue every day

EJA January abab Dust generated by peoples action Writing on paper30µm particles Folding paper60µm particles Rubbing on a painted surface90µm particles Rubbing metal on metal100µm particles Putting on a screw100µm particles ….. By moving man make dust particles air born

EJA January abab Dust particles - Size distribution Air born dust particles range in size from 0 to +/- 50  m There are many small particles and fewer larger ones Remark: dust particles may conglomerate

EJA January abab Dust particles - Size distribution

EJA January abab Definition Clean Room Class Clean room class x means: one cubic feet of air contains x particles of 0,5  m or smaller

EJA January abab

EJA January abab The importance of clean room conditions As long as dust particles are relative small compared to the lines and spaces they don’t cause much trouble Stricter demands for PCB fabrication Ever decreasing line and space widths Stricter tolerances for lines and spaces and pads More layers Higher yield Today the size of an average dust particles is ¼ to ½ of an average L/S Today dust particles cause more defects and the defects are more expensive

EJA January abab Dust particles in PCB production Dust particles jeopardise image formation: Phototool generation Dust on the film while plotting Dust in the light path while plotting Dust on the plotter drum (fly off, out focus) Dust on the film while processing Primary imaging Secondary imaging Dust particles scratch phototools and resist

EJA January abab Dust measurement Measuring/counting tools Particle sizeMeasuring device µm Filter > 20 µm Petri dish

EJA January abab Petri dish

EJA January abab Pert dish

EJA January abab Pert dish

EJA January abab Dust measurement Measuring/counting tools Particle sizeMeasuring device µm Filter > 20 µm Petri dish µm Particle counters with light* µm Particle counter with laser light* * does not measure the heavier dust particles Remark The naked human eye can see: 50 µm particles under normal conditions 25 µm particles under ideal conditions

EJA January abab Dust measurement: take care We are fighting an invisible enemy

EJA January abab PCB production anno 2000 To remain competitive in the PCB industry production is to be done in clean room conditions where the dust level is well controlled

EJA January abab Clean room: the compromise A clean room has to be build correctly and used correctly Find a compromise Quality of the installationversusinstallation cost Discipline appliedversuscomfort

EJA January abab Clean room: how to organise No paper or card board (paper is compressed dust) Limit access of people Limit access of materials Avoid transportation from one compartment to another (install hatch) No cutting or punching of film in the clean room No knifes,no scissors, nail files, no pencils No posters, no photos, no radio Use clean room certified tools and equipment discipline discipline discipline discipline discipline discipline discipline

EJA January abab Clean room: how to act No paper or card board (paper is compressed dust) Clean feet Dress correctly (overall, hair cap, over shoes, gloves) Never ever enter in “out side” clothing, not even for just a second Never ever leave the clean room in clean room clothing No brief cases, no handbags No food, no drinks, no smoking Move slowly and as little as possible Keep films in vertical position, use (humidity tide) envelopes Clean the film as often as needed discipline discipline discipline discipline discipline discipline discipline

EJA January abab Clean room: maintain dust level Golden rule Prevent dust generation (people, production process, environment) Prevent dust from entering the clean room Remove dust

EJA January abab Clean room: maintain dust level Implement cleaning programme per batch, shift, day, week, month what to clean, how to clean Remark: after cleaning the dust level is higher as before vacuum cleaner out of the clean room Replace mats Replace filters Wash clean room clothing in special washing machine discipline discipline discipline discipline discipline discipline discipline

EJA January abab Clean room: SPC programme Dust level at all relevant locations Cleaning Pressure over the filters Air flows.… discipline discipline discipline discipline discipline discipline discipline

EJA January abab The ideal phototool lab Shoeshine Hatch Film stock Changing room Overalls Haircap Glovers Over shoes Check Retouch Label Measure Copy onto diazo Laminate Climitise film Chemistry supply   Plotter Dust retaining mat Hatch Lock Package ++   Processor

EJA January abab Dust level control at Agfa Agfa’s commitment Production in class 1,000 Cutting and packaging in class 5,000 Special PCB packaging Film safe

EJA January abab Dust level control at Agfa

EJA January abab Dust level control at Agfa

EJA January abab Dust level control at Agfa

EJA January abab Dust level control at Agfa

EJA January abab Dust level control at Agfa

EJA January abab PCB packaging

EJA January abab Film safe 790 mm x 680 mm: FROJN 1179 mm x 870 mm: FROFG 1690 mm x 1480 mm: FPMM3

EJA January abab Conclusion Working in clean room conditions is producing with well-focused discipline in a well-monitored environment in order to control defects

EJA January abab Conclusion Dust level control in the PCB industry is a question of common sense and discipline! but it makes the difference between making or loosing money