SSL Cleanroom Training September 6, - PowerPoint Presentation

Slide1

SSL Cleanroom Training

September 6,

2011

Jeremy McCauley, PFP CCE & PPE

Mars Atmosphere and Volatile

EvolutioN

(MAVEN) Mission

Slide2

Training Objectives

Provide Understanding of:

Need for cleanroomsCleanroom ClassificationsSources of Contamination

Human ContaminationCleanroom GowningEmergency ProceduresCleanroom Work Habits

Slide3

Need for Cleanrooms

Failure to control contamination may lead to:Out of control processes

Electronic components that don’t functionParts that corrodeOptics that don’t transmit radiation correctlyCostly rework (with increased risk to hardware)

Loss of time (schedule)Unreliable performanceBiocontamination of MarsLOSS OF SCIENCE DATA!

Slide4

Definitions:

Contamination: any foreign material that has a detrimental effect on a product or process.Particles (dust, metal flakes, droplets)

Biological contaminates (organisms, viruses, bacteria)Molecular Residue (Oils, chemicals)MoistureRadiation (Ionic and Electromagnetic)

Cleanroom: any space constructed and maintained to control forms of contamination.Typical controls: temperature, humidity, particle filtering, pressurization, protective garments, work habits

Slide5

Particle Sizes

Visible to the Naked Eye

Diameter (microns)

Slide6

Certification: Airborne vs. Surface

Class (or Classification) – Measure of Airborne particulate contamination by volume per ISO 14644

Cleanliness Level – Measure of Surface particle and molecular contamination by area per IEST-STD-CC1246D

In the cleanroom, we measure Class regularly. Your Flight Hardware is accepted based upon Cleanliness Level.Air exchange rate, activity levels, gowning requirements, and housekeeping all affect both measures.

Slide7

Cleanroom Classifications

PROTOCOLS

GARMENT REQUIREMENTS

FED-STD-209 CLASSESISO 14644 CLASSESLOCATIONLooserNone1,000,0009133, SSL160Smock300,000 *

8.5

SSL 165

Smock

100,000

8

Smock or Suit

10,000

7

Addition

125

Bunny Suit

1,000

6

Bunny Suit

100

5Flow BenchBunny Suit104Stricter“Space” Suit13

*Controlled Environment

Slide8

Cleanroom Classifications

Laboratory Cleanrooms – Class 10,000 (ISO Class 7)HEPA filters, increased airflow, positive pressure system.

Smock or Bunny Suit by project.Cleanroom paper only. No paper, cardboard or wood.Controlled Environments – Class 300,000 (ISO Class 8.5)

May or may not have HEPA filters.Smocks worn when working on Flight Hardware.For use with subassemblies and projects that are not contamination sensitive or easily cleaned.Paper OK. Cardboard and Wood must be encased.

Slide9

Cleanroom Design Basics

HEPA filters remove >99.999% of airborne particles from supply air.Air is continually supplied to flush room and minimize particle settling

Pressurization decreases particle entry through joints, feedthrus, and doorways.Careful material selection minimizes particle shedding, outgassing and corrosion.Housekeeping maintains surface cleanliness and minimizes shedding from walls

Gowning areas and cleaning areas permit preparation of personnel and hardware before entry.

Slide10

Cleanroom Airflow

UNIDIRECTIONAL FLOW ROOM

LAMINAR FLOW BENCH

TURBULENT FLOW ROOM

Slide11

Clean Tents

Vertical airflow.

HEPA filtered.No positive pressure.

No gowning or staging area.Dirty and clean air meet at the curtain.Turbulent flow draws dirty air into room.

Slide12

Hardware and Equipment Entry

All hardware, equipment and tooling must be either cleaned and inspected before entering the cleanroom or sealed within bagging material.Double bag all hardware for movement between cleanrooms.

Use only approved packaging materials.

Slide13

Human Body Contamination

Skin flakesHairSpittle droplets

Fingerprint residueBacteria and virusesClothing fibersCosmetic chemicalsDirt, especially from footwear

Slide14

Human Body Contamination

Huge Quantities!Millions of particles released each minuteSkin oils, fats, and salts

Lose 50 to 100 hairs per day5 pounds of dead skin flakes per yearA column of warm air around the body

carries these particles upwardMany other emissions and excretions

Slide15

Human Body Contamination

Bathing with thorough hair washingRemoves contaminants from the body

Skin, hair, chemicalsNot all removedTemporary benefitsCutting fingernailsLong and sharp fingernails can rip gloves.

Slide16

Street Clothing

Wear clothing that is clean and in good condition.Denim is acceptable as long as it is not worn or frayed.

No wool, cotton flannel, frayed or badly worn clothing.No shorts, skirts or tank tops in cleanrooms.No sandals or open-toed shoes allowed. (Safety)

Slide17

Makeup

Cosmetics produce huge quantities of particulate and chemical residue and should not be worn in the cleanroom.Perfume and Cologne are

designed to outgas and shouldnot be worn in the cleanroom.Billions of particles can be found

on face and gloves of test subjects.

Slide18

Food Items, Gum and Candy

No drinks, food, candy or gum allowed in cleanroom.Not in pockets either.Gum and candy stimulate salivation, which increases spitting when talking or sneezing.

Face masks are not 100% effective filters.

Slide19

Why Cleanroom Garments?

The human body generates millions of particles every minute.Fabrics constantly generate, trap and shed millions of particles.

Skin, skin oils and body hair are a significant source of contamination.In short, you are a contamination risk!

Slide20

Cleanroom Garments

A properly work cleanroom garment will reduce particle shedding by 300X.

Thousands of particles are still being shed.

Slide21

Gowning Procedure

Slip on disposable shoe covers.

Use clean side – dirty side protocol.Face maskBouffant head cover

Cover all your hair.SmockCut open bags (don’t rip).Zip or snap all snaps.ESD strap to bare skinGloves – NitrileDo not handle at fingers.Tape the cuffs to smock to keep the wrist from being exposed.

Slide22

Ungowning

ProcedureRemove tape at wrists.

Remove and hang smock.Do not allow to touch the floor.Remove ESD strap.

Remove and trash bouffant head cover and facemask.Step out of cleanroom.Use clean side – dirty side protocol.Dispose of shoe covers.Dispose of gloves.

Slide23

Unplanned Garment Situations

Torn or Damaged Glove“Glove over” immediately or go to the gowning area and replace.

Do not remove gloves in cleanroom.Do not continue work.Contaminated GarmentsGo to the gowning area and replace immediately.

Slide24

Alarms and Emergencies

Just leave.Walk out in your gowns. Cycle out for cleaning and switch to new before coming back.

Call Jeremy McCauley or Steve Marker from a safe location.FIRE ALARM

BLACKOUTOXYGEN SENSOR

Slide25

Tacky Mats

Step on six (6) times whenever you encounter them.

To refresh:Pull slowly starting at numbered corner pull tab.Work around the edges and gather to middle.

Fold together to capture loose particles.Dispose in closest trash receptacle toward the outside of the room.

Slide26

Work Habits

Maintain deliberate actions and behavior.No unnecessary movement, rubbing, pacing, etc.

Try to stand downwind.Don’t touch exposed skin.Face and glasses, leg, hair, etc.Particle generating practices need special planning and provision.

Soldering, drilling, abrading, wire stripping, etc.If it can be done outside, do it there.Ask me for help!Vacuums, protective covers, etc.Work areas must be neat and orderly.Tools should be wiped down and put away.Never reach under your garments.Go out to the gowning area for cell phones, pens, cameras, etc.

Slide27

Work Habits

Particles Generated

(0.3 micrometers/minute/activity)

Motionless, sitting or standing100,000Head, arm, neck, leg motion300,000All above with foot motion1,000,000Standing to sitting or v.v.2,500,000Walking at 2 mph5,000,000

Walking at 3.5 mph

7,500,000

Walking at 5 mph

10,000,000

Slide28

Work Habits

Walk slowly.Minimize movements.Avoid congregating in the cleanroom and near workstations.

Lift your feet when walking (don’t shuffle).Gloves are required.Do not lean against walls, support hardware, etc.Not all areas of the cleanroom

are as clean as others.Floors, walls, plastic curtains.Work on tables.Cover hardware.Store extras elsewhere.

Slide29

Restricted Items

Do not bring the following into the cleanroom:Food, candy, gum, tobacco products

Unapproved pens and markersBallpoint pens and Sharpies are OK. Cleanroom pens are preferred.Pencils and erasersUnsealed wood

Lighters or matchesCardboard or paper productsCorroded toolsAerosols of any kindAny particle-generating materialAny high-outgassing material

Slide30

Contamination Control

Assembled in Class 100,000 cleanroom (or flowbench).Subassemblies in 165 are OK.

Final cleaning and closeout of any cavity must occur in cleanroom.Final cleaning and closeout.Wipe all internal surfaces with IPA.Inspect to VC-HS+UV

From 6 to 18 inches away.Illuminate with >100 foot-candles of white light, remove any visible particulates.Illuminate with >100 foot-candles of black light, remove any visible fibers.BakeoutMaximum flight temperature for 48 hours.TQCM data for >2 hours at end of bakeout.

Slide31

Planetary Protection

Assembled in Class 100,000 or better cleanroom.Log of exposure to worse environments. Keep it bagged!

Enhanced protections:Face masksGloves taped at wristsBiological assay:each box or boom

a representative PWB just prior to closeout (PFDPU, SWIA, SEP, SWEA electronics, STATIC)500 spores/m^2 or lessDry Heat Microbial Reduction for harnesses.125C at <1 torr for 20 hoursHope it will burn up.

Slide32

165 Specifics

This is a controlled space, not a cleanroom.Wear your smock and gloves.Don’t hang your head over the hardware.

No final closeout of hardware spaces.Don’t be upwind of air currents from building supply or air ionizers.Keep it bagged!

Slide33

Who to Contact

Jeremy McCauleyCCE and PPE, 3-9857Cell: 510-282-1115

Steve MarkerFacilities and Supplies, 3-7388Jorg Fischer

Safety and Mission Assurance Manager, 3-4415Thanks to JPL Cleanroom Certification Course for baseline materials from which this presentation was created.