Esd prevent and grounding static electricity: esd cause,measurement,norm,and preventive methods



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ESD PREVENT AND GROUNDING


1.Static electricity: ESD cause,measurement,norm,and preventive methods.

  • 1.Static electricity: ESD cause,measurement,norm,and preventive methods.

  • 2.Static electricity compare with usual electrical engineering systems.

  • 3.Static electricity caused damage and effect( discharge phenomena/dynamics phenomena)

  • 4.Surface resistance sorting.

  • 5.Humidity has an effect on ESD.

  • 6.How to make ESD prevent?

  • a. Five kinds of basic ESD eliminations b. Standard prevention of production lines.

  • 7.Conductive wrist band : a. standard use b. inspection c. compare between wire wrist strap and wireless wrist strap.

  • 8.Ground system monitor、ion fan、prevent ESD detergent、surface resistance inspection instruments and surroundings electrostatic voltage using methods and surrounding electrostatic voltage using areas.



ESD PREVENT COURSE(2)

  • 9.The blind point of tradition ESD prevent.

  • 10.Why grounding?

  • 11.”ground“ and “Grounding” related technical terms.( electric ground. circulation area. Ground potential、 logic ground, 、geography ground、grounding、grounding resistance、grounding system)

  • 12.The measurement and defect of tradition grounding resistance.

  • 13.The inspection of production line grounded.

  • 14.How to avoid ESD happening?

  • 15.How to show to customer ESD prevent? a. motionless state b. motion state



Factory location ESD prevent basic rules

  • 1. Adopt which ESD prevent standard: JEDEC JESD625-A, ANSI/ESD S20.20-1999 ,ESD TR 20.20-2000, IEC 61340-5-1, IPC-A-610C, CECC 000 15 (EN 100 015-1), Japanese static electricity safety policy, international standard『 The general guide of prevent ESD incident 』( GB 12158-90 )etc.

  • Suggestion: synthesize the merits of all methods , to create your own method which is suitable for your company and advance quality yield.

  • 2.ESD education training and responsible people.

  • 3.ESD interior investigation and to improve and trace the incomplete investigation.

  • 4.ESD prevent system filing.



PURCHASING PEOPLE

  • Must know-how ESD knowledge, and ESDS( static electricity sensitive devices) data sheets.

  • Basic knowledge and demand for packaging and transportation



FACTORY STAFFS

  • 1. Four kinds of grounding, according to standard, apart, individual grounded.

  • 2. Offer standard and stable power for interior factory.

  • 3. Make sure the temperature, humidity, and floors match the standard of EOS/ESD.

  • 4. All grounding internet and power outfit must be filed and periodic maintenance.



ON PRODUCTION LINES

  • 1.All workers must have strong conscious of ESD, respect the spirit of EPA .

  • 2.In EPA entrance area,whether there is “EPA exist” warning sign or not?

  • 3.Whether there is supervision and record for room temperature and humidity?

  • 4.Before working daily, must test the conductive wrist strap and conductive shoes and record.

  • 5.In EPA area, floors, chairs, tables, operator dresses, handcarts whether or not meet the requests of EOS/ESD , and keep all testing records for point to point and point to grounded.

  • 6.Spare parts saving boxes, packing parts whether or not match the standard of ESD.



On production lines (continuity)

  • 7.The elements of Fixed-frame, transit belt equipment, and test tooling whether or not with prevent ESD?

  • 8.Unless necessary insulated items, not allowed to show up at EPA areas.

  • 9.Whether or not using ion blower correctly, checking whether has collate records of balance, scatter timing..etc.?

  • 10.Make sure equipments grounded correctly, checking whether or not the pole is at right direction?

  • 11.Make sure to separate the ground of ESD from the ground of equipment correctly.

  • 12.Necessary needed test instruments: testing instruments for conductive wrist band and conductive shoes, surface resistance, grounded system monitor.



WAREHOUSE

  • 1.Whether the floors meet the methods of ESD prevent, whether have testing records for point to point and point to grounded?

  • 2.Storage racks set up the preventive ESD mats, and the mats connected with grounded frame is good enough?

  • 3.Every wrist strap or heel strap, conductive shoes checked and recorded daily?

  • 4.Package materials meet requests?

  • 5.Handcart must meet the request of ESD, wheels must be conductive wheels. Is there any record for surface resistance testing?

  • 6.In electric devices inspection workstations, is there met the preventive requests of ESD?

  • 7.Having to invigilate and record the temperature and humidity?



EOS/ESD

  • What is called “ ESD”?

  • The reasons caused ESD: touched separation, damaged separation, induction separation,…etc.

  • ESD = Electro Static Discharge

  • EOS = Electrical Over Stress

  • EPA = ESD Protected Area

  • EMP=electrostatic discharge bring about electromagnetic pulse ,Spectrum width can reach to MHZ~ GHZ。



ELECTROSTATIC PHENOMENON



THREE KINDS OF ESD MODELS



Material rub against generate static electricity



Static electricity damage generation model



Static electricity application and jeopardize

  • Application: dust collecting 、painting、selection、spray、photography and etc。

  • Jeopardize :damage to semiconductor、generate explode in place of inflammables。



Damaged IC caused by electrostatic



Peak value of location temperature and humidity (Taiwan from 1987 to 1988/central weather bureau))



Humidity



Relation of humidity and static voltage



Electronic components to ESD sensitivity



Five kinds of basic ESD eliminations

  • 1.Grounding

  • 2.Increase humidity

  • 3.Use against conductive materials

  • 4.Use ESD elimination instruments

  • 5.Lower chafe speed



Production lines related ESD equipments using

  • 1.Wrist strap and wrist shoes testing instrument

  • 2.Ion fan

  • 3. Surface resistance inspection instrument

  • 4. surroundings electrostatic voltage inspection instrument

  • 5.Grounding system monitor



WRIST STRAP AND WRIST SHOES



ESD prevent wrist strap correct use



Wrist band test instrument



Wrist strap inspecting station



2003 ESD TUTORIALS









How to proceed ESD prevent?

  • 1.All conductive items must be grounding.

  • 2.All insulations must be ionized.

  • 3.All sensitive semiconductor components can only be opened, assembled, repaired at EPA stations.

  • 4.Out of EPA station, must be met ESD prevent request for the materials of transportation and packages of the sensitive semiconductor components



ION FAN

  • Active ion and passive ion neutralization

  • AC/DC ion fan

  • Best choice: set up automatic ion balance sensor,to offer “ just in time “ efficient and stable ion balance liquid, easy to set up and take off when repairing and cleaning.

  • Digitized design can offer data analysis and read, and included automatic ion balance adjuster. User can establish ion balance sensitivity warning value according to their demand and connect with internet monitor to control.







Grounding objects

  • Why grounding?

  • 1). Avoid shocking

  • 2). start prevent equipments、avoid fire affairs and explosion

  • 3). Avoid electroshock

  • 4). Avoid electrostatic

  • 5). Avoid motley messages obstruction



1) Resistance of production lines and grounding 2) grounding rod and soil contact resistance 3) Soil resistance within 20M of half diameter     



Corrective actions for ESD grounding

  • 1.ESD grounding must have the owned connections which can not share with AC power grounding!

  • 2.Separating four kinds of grounding!

  • 3.ESD grounding must be watched at all times.!

  • 4.Neutralize cord (N) and fire cord (H,L) can not be reverse connected!



IPC-A-610C-3-002





Corrective ideals of complete grounding



Underground prevention















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