AREMA C&S Manual Part Recommendations for an Electrostatic Discharge (ESD) Control Program New Revised (156 Pages)

Transcription

1 Part Recommendations for an Electrostatic Discharge (ESD) Control Program New Revised (156 Pages) A. Purpose The purpose of an ESD control program is to provide electronic assemblies and components with continuous protection from ESD during handling and testing. B. General 1. Static damage can result in destruction or catastrophic failure when high voltage and instantaneous current flow cause the melting of metallic oxide and other components. 2. Static damage can cause life degradation or which may lead to latent defects. 3. Intermittent failures can occur when transient induced current and polarization cause a device to fail intermittently. This type of damage is very difficult to detect. 43. In order to prevent static damage to electronic parts and assemblies, a railroad should establish and enforce an ESD control policy that includes the following six five steps: a. Insure that vendors provide ESD protection is provided during manufacture and handling or shipment of electronic modules and components. b. Insure that all ESD sensitive items are marked with an ESD caution label. cb. Provide appropriate instructions for personnel who will be handling ESD sensitive items. dc. ed. fe. Transport ESD sensitive items only in appropriate packaging. Open ESD protective packaging only in ESD protected conditions Insure that the ESD protection is functioning properly. 54. Definition of Terms - 1

2 Part ESD: Electrostatic Discharge, a sudden redistribution of static charge that is can stress or damaging damage to sensitive electronic components. ESD-Sensitive (ESDS): A part, assembly or product that can be degraded or damaged by ESD. There are ESDS parts in nearly every family of electronic components containing thin films or insulators, including resistors, capacitors and semiconductor devices. All unmarked components or assemblies and all Class 0, Class 1, and Class 2 devices should be considered as ESDS parts. See Part Classification Table ESD Controlled Area: A specifically designated area that has been properly marked and equipped for handling ESD-Sensitive assemblies and components. ESDS parts should only be removed from ESD packaging in an ESD Controlled Area. Triboelectricity: A charge of electricity generated by friction (as by rubbing glass with silk). The transfer of charge by contact and separation of two surfaces. This charging by "rubbing or separating" is a common source of static charges. Antistatic: Reducing, removing, or preventing the buildup of static electricity. A material that used resists to protect sensitive electronic components and modules from ESD. triboelectric charging and produces a static voltage of less than 100 volts when rubbed against itself or another material. A material's antistatic property is not necessarily correlated with its resistivity, and can be degraded by factors such as age, wear, contamination, solvents and climate. Conductive: A material with surface resistivity less than 100,000 ohms per square cm and volume resistivity less than 10,000 ohm-cm ( Per MILmil- HDBK-263A263B ), generally achieved by means of coating or impregnating with carbon or metal. Conductive materials are not necessarily antistatic. A static-shielding enclosure ("Faraday Cage") requires conductive materials. Dissipative: A material with surface resistivity from 100,000 ohms to 1,000,000,000,000 ohms per square cm and volume resistivity between 10,000 ohm-cm and 100,000,000,000 ohm-cm ( Per MILmil- HDBK- 263A263B). Static Shield: Material that attenuates an ESD. ( Per MILmil- HDBK- 263B ). A conductive surface that terminates all the static field lines that intersect it. A Faraday Cage is a static shield formed into a closed - 2

3 Part container. This is the best form of protection for ESDS items that may be transported or stored in static-unsafe areas. Reuse: To use a product more than one time without altering its physical construction. Inspecting, and relabeling are permitted within the definition of reuse. C. Part Classification (ESD) D. Responsibility The part supplier shall establish, and furnish upon request, the level of susceptibility to ESD for each individual part, family or assembly per the following classes (per MIL-STD-1686C) based on Human Body Model: Table CLASS V CLASS V CLASS V CLASS ,999 V Unless otherwise stated all ESDS Parts should be treated as Class 1 for the level of susceptibility to ESD damage. 1. An individual should be designated who is responsible for the implementation and administration of the ESD control program. ESD coordinators should be designated in each work area where the guidelines are to be enforced. The ESD coordinator is responsible for yearly and monthly ESD Audits. Appendix A provides a sample ESD Audit Form. 2. All employees should join in the enforcement of these policies by bringing any deficiencies to the attention of their manager or the ESD coordinator. 3. Employees are responsible for escorting and assuring that ALL VISITORS adhere to the ESD guidelines, and should report when visitors are coming into ESD protected areas to the ESD Coordinator. E. Training All personnel who come in contact, or may come in contact with static sensitive parts, shall have instruction in the safe handling of those items. These - 3

4 Part instructions should enable personnel to meet the requirements of this policy. Approved ESD protection instructions will be provided by the ESD coordinator. F. Labeling Recommendations 1. ESD Symbols a. Recommended Symbol: The recommended symbol for ESDS devices is defined by EIA-471 (Figure ). It consists of a triangle enclosing a hand, crossed by a diagonal slash, and the words "ATTENTION, OBSERVE PRECAUTIONS FOR HANDLING ELECTROSTATIC SENSITIVE DEVICES". The colors are not specified, but a black symbol on a yellow background is recommended. b. Acceptable Symbol: The MIL-STD-1285 is acceptable for use but must be accompanied by the EIA symbol when used for ESD control. All packages containing Class 1 or 2 ESDS items shall display an approved static attention label on the outside of the static container. c. Yellow or fluorescent orange-red are the preferred colors for caution signs and labels. Thus, ESD control labels and signs should preferably be black on yellow, in triangular or rectangular shapes. Figure Figure

5 Part EIA-471 MIL-STD-1285 RECOMMENDED LABEL ACCEPTABLE LABEL G. Handling Requirements 1. Packaging a. All electrostatic sensitive parts shall be protected from electrostatic discharge by protective packaging. -i. -ii. All electrostatic packages containing electrostatic sensitive parts must be labeled with an appropriate ESD Caution label. Circuit assemblies and components are only protected when completely enclosed inside an antistatic protective environment such translucent static shielded bag, pink or blue poly antistatic bag, or black conductive container. b. Sensitive parts shall be shipped from the manufacturer in electrostatic protective packaging and labeled with an ESD label. These parts shall remain in that packaging continuously except when actually at a static free workstation. c. Circuit assemblies shall be placed in static shielded bags or conductive containers for transportation or storage. 2. Workstations a. Workstations used for handling sensitive parts must be equipped with static free work surfaces and floor mats. These surfaces and mats must be static dissipative and grounded to a true earth ground. b. All electrical equipment used at static free workstations must be grounded. Soldering irons shall be of an approved ESD protected design. c. Workstation chairs or stools must be grounded in one of two ways: carbon filled conductive casters or brass drag chains attached to the center of the chair base. These chairs or stools must be used in conjunction with static free floor mats. - 5

6 Part d. No plastic materials shall be allowed within three feet of static free workstations. This includes candy wrappers, tape, cigarette packages, cellophane wrappers, foam cups, foam packaging (peanuts), bubble wrap, plastic bins, plastic folders, etc. - 6

7 Part EDS Figure e. Temperature and humidity monitors should be installed in ESD safe areas and are to be monitored by personnel in each area for humidity levels. Humidity levels that reach 25% or less should be reported to the ESD coordinator, as these levels present possible ESD problems. 3. Personnel a. The wrist strap must be worn in direct contact with the bare skin. Personnel shall not be attached directly to an earth ground. There must be a safety 250k Ohm to 1 Meg Ohm resistance between the operator and the ground (these resistors have been molded into the ground cords of some ESD mats). b. All personnel within three feet of a static free work station must be grounded with a wrist strap and ground cord attached to the grounded work surface. c. The wrist strap shall be functionally checked by the user daily. Testers should be placed in all ESD protected areas for this purpose. Equipment is also available to continuously monitor the wrist strap. d. Improperly grounded or ungrounded personnel shall never touch static sensitive parts, assemblies, or other operators at a static free work station. 4. Equipment locations a. A railroad may elect to place properly grounded floor mats on floors where access is made to any system using plug in cards with ESDS components. This should include microwave equipment, electronic switchboards, packet switches, rack mounted data modems or multiplexers, radio base stations, and other electronic equipment. b. A properly grounded wrist strap should be attached to the equipment rack. c. Alternatively, a portable service kit containing ESD mat and wrist strap can be used when servicing installed equipment. - 7

8 Part AREMA C&S Manual H. Maintenance of Static Protective Equipment 1. Workstation Mats The surface of mats must be cleaned with an antistatic cleaner, monthly, or more often as required, to prevent contamination from dirt, grime, solder, body oils, dust particles, etc. 2. Wrist Bands Wrist bands may be laundered, using a mild detergent - no bleach, as required to prevent body oils from compromising the electrical functionality of the material. Care must be taken to place the band in a pocket to keep it from becoming entangled in the agitator of the washing machine. 3. Smocks (Lab Coats) a. All personnel are to wear conductive smocks while working on Static Sensitive components or assemblies. b. All other personnel including visitors are to wear conductive smocks while working in or touring the ESD Protected Area. c. Smocks may be laundered, using a mild detergent - no bleach, by the user at home, or by an approved garment laundering agency. I. Maintenance Shop Area, Warehouse, and Staging Areas 1. The ESD Protected Area floor should have an anti-static surface applied to it. Facility maintenance will maintain the floor on the following schedule: - weekly - anti-static wax to be applied to surfaces where required. - yearly - floor to be stripped and retreated. 2. Areas designated as a Static Safeguarded Work Area are marked by ESD signs informing personnel of the ESD Policy and by a yellow band on the floor defining the perimeter of the area. J. Electrical Tests - 8

9 Part Specialized test equipment can be used to routinely verify proper electrical performance of the wrist strap. Follow the manufacturer's instructions to verify wrist strap performance. 2. Equipment is available to continuously monitor the performance of the wrist strap and grounding. Follow the manufacturer's instructions to continuously verify wrist strap performance. 3. The bench/table and floor mats should be tested by a qualified ESD auditor. K. Frequency of Testing Wrist Straps - Daily - (personnel not required to use wrist straps daily, must test them before each use) Table/Floor Mats - Monthly by ESD Coordinator, Yearly by Quality Assurance Mat Ground Cords - Ground/Connection - Daily by Operators, Monthly by ESD Coordinator, Yearly by Quality Assurance Daily by Operators Static Shielded - As Required. At the minimum Bags Yearly Ionizers - Yearly or as determined by the Calibration Dept. L. ESD Program Supplies This section provides a listing of items that may be needed for a successful ESD control program. Antistatic Cleaner Antistatic Storage Cabinet Conductive Storage Drawers Conductive Smock (Lab Coat) Conductive Tool Box ESD Floor Mat ESD Video Tapes ESD Packaging ESD Heel Strap Field Service Ground Kit Ground Cords - 9

10 Part Ionizer Outlet Tester Portable Static Meter Static Shielding Work Surfaces Static Shielding Work Surface Tester Static Shielding Floor Finish (Antistatic Wax) Static Shielding Floor Surfaces Warning Labels Wrist Strap Wrist Strap Tester M. Sources This section provides a partial listing of possible sources for the ESD program supplies identified in Section J. Baxter Healthcare Corp., Scientific Products Division, 1210 Waukegan Road, McGraw Park, IL Phone (708) Charles Walters, 93 Border Street, West Newton, MA Phone (617) Contact East, 335 Willow Street South, North Andover, MA Phone (508) HYMAR Meters, 6647 Blossom Acres Drive, San Jose, CA Phone (408) JULIE Associates, P.O. Box 141, Billerica, MA Phone (508) Motorola C&E Inc., Communications Parts Division, 1313 E. Algonquin Road, Schaumburg, IL Phone (708) Static Control Components, Inc., P.O. Box 152, Stanford, NC Phone (800) Static Control Systems Division/3M, P.O. Box 2963, Austin, TX Phone (800) Westcorp, 144 S. Whisman Road, Mountain View, CA Phone (800) N. References - 10

11 Part MIL-STD-1686A 1686C - Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment 2. MIL-HDBK-263B, Electrostatic Discharge Control Handbook. 3. AMCI Electrostatic Discharge Control Policy, M07093, Revision C, October 14, 1993, Automated Monitoring and Control International, Miami, Omaha, NE A sample of a more detailed Packaging and Handling Specification, ESD control policy is available from 3M Company, Electrical Specialties Division, P.O. Box 33211, St. Paul, MN A videotape (F.A.S.T. #5) on electrostatic discharge is available from Motorola National Service Training. - 11

12 Part AREMA C&S Manual APPENDIX A ELECTROSTATIC DISCHARGE CONTROL STANDARDS AUDIT CHECKLIST A. PURCHASING 1. Appropriate ESD requirements on purchase orders. 2. Procurement only buys ESDS parts from suppliers that have been ESDapproved by the Purchasing Department or Engineering Department. 3. Procurement maintains a list of ESD-approved suppliers. 4. Restrictions on packaging, labeling, and proper invoices/packing slips are imposed on vendors. 5. Procurement maintains a list of approved suppliers, the list need not be segregated into ESD and Non-ESD suppliers, but if ESD approval is needed for a new supplier, the vendor is audited for ESD. B. RECEIVING 1. ESDS devices are identifiable by their outside packaging and/or invoices. 2. ESDS devices are checked for proper packaging and marking. 3. Areas where ESDS packages are opened are equipped with proper ESD control measures, (i.e., mats, wrist straps, proper grounding). C. INCOMING INSPECTION 1. Packages containing ESDS devices are opened only is in ESD areas by trained, grounded personnel. 2. ESDS items are stored in protective packaging for transfer to storage and work areas. - 12

13 Part Incoming Inspection personnel write trouble tickets on any improperly marked or packaged devices and report deficiencies to the proper ESD Coordinator, Purchasing, and Engineering. D. SHIPPING 1. ESDS items are only handled at ESD protective workstations by trained, grounded ESD Certified personnel. 2. Items are labeled and packaged using appropriate labels and protective packaging. E. STOCKROOMS, STORAGE AREAS, KITTING AND STAGING AREAS 1. ESDS items are maintained and issued in ESD-protective packaging. 2. Bin boxes or shelves storing ESDS devices are so labeled. 3. ESD procedures are implemented during kitting and in staging areas. F. ENGINEERING 1. ESD procedures are implemented in all engineering laboratories. 2. Engineering Assembly drawings involving ESDS components contain references to ESD Policies and Procedures. G. PRODUCT INTEGRATION AND MANUFACTURING AREAS 1. ESD designated areas and workstations are established throughout these areas. 2. Personnel in these areas are properly trained in the use of ESD workstations and implementation of precautionary handling procedures for ESDS devices. - 13

14 Part All processing equipment is properly grounded. 4. ESD protective materials (i.e., bags, foams, totes) are available at every workstation and ESDS devices are transferred between areas in protective containers or packaging. 5. Special ESD control measures that are necessary (e.g., conductive flooring, personnel apparel, humidity control, ionization) are implemented as appropriate. 6. ESD areas are clearly identified by signs/placards/caution warnings and personnel entering these areas are alerted to ESDS handing and visitor requirements. H. PRODUCTION TEST AND ENGINEERING TEST 1. ESD workstation implemented in test and burn-in areas. 2. There is an absence of prime sources of static in test areas. 3. ESD control measures are implemented. 4. ESDS items are transferred to the next work area in protective containers. 5. Operators are not grounded while operating voltages are applied. I. QUALITY ASSURANCE 1. Compliance to ESD control procedures. 2. Suppliers' and Vendors' ESD compliance. 3. Workstations ESD certification. 4. ESD training programs. 5. Engineering drawings containing references to ESD Policies and Procedures. - 14

15 Part STEP DAILY SELF-CHECK PROCEDURES [ ] 1. Visually check your work area to see that there are no Static-Generating materials in or around your area, (such as carpet or plastic or other insulating materials), check to see that there are no static-generating tools being used such as plastic solder suckers. [ ] 2. Visually check to see that all ground wiring to your work station has not been disconnected or damaged. Be especially suspicious if equipment or furniture has been moved. If you have a Continuous Monitor at your station, test it to see if it is working before using. [ ] 3. If you are using an air ionizer, turn it on and aim it properly. [ ] 4. Clear your work area of static charge generators, such as untreated plastic bags, boxes, foam, tape, paper, or personal items, for a distance of at least one meter (3 feet). [ ] 5. Visually check that all ESD-sensitive parts, assemblies or products are completely inside their static-shielding bags or conductive containers, with nothing sticking out. Both at the beginning and end of your shift. [ ] 6. Make sure that there are no static generators inside the static-shielding bags or conductive containers with or without ESD sensitive parts or assemblies. [ ] 7. Make sure that all static-shielding bags and conductive containers have the correct static attention label on the outside of the container. Visually check static-shielding bags for tears or excessive wear. [ ] 8. All cleaners, solvents, coatings, sprays used at your work station must be the types approved by your ESD control static coordinator. [ ] 9. Never allow anyone who is not grounded closer than one meter (3 feet) to your static-safe work area. Ask them to comply with grounding and garment requirements of your area before coming into the area, touching anything, or coming closer to your work. Report all violators that fail to comply. [ ] 10. Put on your wrist strap and any special garments required to do your job in your area, such as smocks and conductive footwear. Test your wrist strap according to manufacturer's instructions and sign the check-off sheet as demonstrated by your ESD coordinator. Check your smocks to see that there are no holes, rips or tears, and that they are clean. Wrist straps are - 15

16 Part required to be checked once a day at the beginning of your shift, but should be checked after each break and before beginning work after lunch or supper. ESD AUDIT FORM Area Audited: Responsibility: 1. Table Mats, Qty Grounds: Pass Fail/Problem Aesthetics (surface is clean, no static-generating materials) Pass Fail/Problem 2. Floor Mats, Qty Grounds: Pass Fail/Problem Aesthetics (surface is clean, no static-generating materials) Pass Fail/Problem 3. Personal (Wrist Straps, Ground Cords, Smocks, etc.) Comments: 4. Handing/Storage of Static Sensitive Components and Assemblies Pass Fail/Problem Additional Comments: Auditor: Audit Date: - 16

17 Part CORRECTIVE ACTION Corrective Action Required: Corrective Action Completed: - 17

18 2015 Part Recommendations for an Electrostatic Discharge (ESD) Control Program Revised 2015 (15 Pages) A. Purpose The purpose of an ESD control program is to provide electronic assemblies and components with protection from ESD during handling and testing. B. General 1. Static damage can result in destruction or catastrophic failure when high voltage and instantaneous current flow cause the melting of metallic oxide and other components. 2. Static damage can cause degradation which may lead to latent defects.. 3. In order to prevent static damage to electronic parts and assemblies, a railroad should establish and enforce an ESD control policy that includes the following five steps: a. Insure that ESD protection is provided during handling or shipment of electronic modules and components.. b. Provide appropriate instructions for personnel who will be handling ESD sensitive items. c. Transport ESD sensitive items only in appropriate packaging. d. Open ESD protective packaging only in ESD protected conditions e. Insure that the ESD protection is functioning properly. 4. Definition of Terms ESD: Electrostatic Discharge, a sudden redistribution of static charge that can stress or damage sensitive electronic components. ESD-Sensitive (ESDS): A part, assembly or product that can be degraded or damaged by ESD. There are ESDS parts in nearly every family of electronic components containing thin films or insulators, including resistors, capacitors and semiconductor devices. All unmarked - 1

19 Part components or assemblies and all Class 0, Class 1, and Class 2 devices should be considered as ESDS parts. See Part Classification Table ESD Controlled Area: A specifically designated area that has been properly marked and equipped for handling ESD-Sensitive assemblies and components. ESDS parts should only be removed from ESD packaging in an ESD Controlled Area. Triboelectricity: A charge of electricity generated by friction (as by rubbing glass with silk). This charging by "rubbing " is a common source of static charges. Antistatic: Reducing, removing, or preventing the buildup of static electricity. A material used to protect sensitive electronic components and modules from ESD. A material's antistatic property is not necessarily correlated with its resistivity, and can be degraded by factors such as age, wear, contamination, solvents and climate. Conductive: A material with surface resistivity less than 100,000 ohms per square cm and volume resistivity less than 10,000 ohm-cm ( Per MIL- HDBK-263B ), generally achieved by means of coating or impregnating with carbon or metal. Conductive materials are not necessarily antistatic. Dissipative: A material with surface resistivity from 100,000 ohms to 1,000,000,000,000 ohms per square cm and volume resistivity between 10,000 ohm-cm and 100,000,000,000 ohm-cm ( Per MIL-HDBK-263B). Static Shield: Material that attenuates an ESD. ( Per MIL-HDBK- 263B ). Reuse: To use a product more than one time without altering its physical construction. Inspecting, and relabeling are permitted within the definition of reuse. C. Part Classification (ESD) The part supplier shall establish, and furnish upon request, the level of susceptibility to ESD for each individual part, family or assembly per the following classes (per MIL-STD-1686C) based on Human Body Model: Table

20 2015 Part CLASS V CLASS V CLASS ,999 V D. Responsibility Unless otherwise stated all ESDS Parts should be treated as Class 1 for the level of susceptibility to ESD damage. 1. An individual should be designated who is responsible for the implementation and administration of the ESD control program. ESD coordinators should be designated in each work area where the guidelines are to be enforced. The ESD coordinator is responsible for yearly and monthly ESD Audits. Appendix A provides a sample ESD Audit Form. 2. All employees should join in the enforcement of these policies by bringing any deficiencies to the attention of their manager or the ESD coordinator. 3. Employees are responsible for escorting and assuring that ALL VISITORS adhere to the ESD guidelines, and should report when visitors are coming into ESD protected areas to the ESD Coordinator. E. Training All personnel who come in contact, or may come in contact with static sensitive parts, shall have instruction in the safe handling of those items. These instructions should enable personnel to meet the requirements of this policy. Approved ESD protection instructions will be provided by the ESD coordinator. F. Labeling Recommendations 1. ESD Symbols a. Recommended Symbol: The recommended symbol for ESDS devices is defined by EIA-471 (Figure ). It consists of a triangle enclosing a hand, crossed by a diagonal slash, and the words "ATTENTION, OBSERVE PRECAUTIONS FOR HANDLING ELECTROSTATIC SENSITIVE DEVICES". The colors are not specified, but a black symbol on a yellow background is recommended. b. Acceptable Symbol: The MIL-STD-1285 is acceptable for use but must be accompanied by the EIA symbol when used for ESD control. All packages containing Class 1 or 2 ESDS items shall - 3

21 Part display an approved static attention label on the outside of the static container. c. Yellow or fluorescent orange-red are the preferred colors for caution signs and labels. Thus, ESD control labels and signs should preferably be black on yellow, in triangular or rectangular shapes. Figure Figure EIA-471 MIL-STD-1285 RECOMMENDED LABEL ACCEPTABLE LABEL G. Handling Requirements 1. Packaging a. All electrostatic sensitive parts shall be protected from electrostatic discharge by protective packaging. i. All electrostatic packages containing electrostatic sensitive parts must be labeled with an appropriate ESD Caution label. ii. Circuit assemblies and components are only protected when completely enclosed inside an antistatic protective environment such translucent static shielded bag, pink or blue poly antistatic bag, or black conductive container. - 4

22 2015 Part b. Sensitive parts shall be shipped from the manufacturer in electrostatic protective packaging and labeled with an ESD label. These parts shall remain in that packaging continuously except when actually at a static free workstation. c. Circuit assemblies shall be placed in static shielded bags or conductive containers for transportation or storage. 2. Workstations a. Workstations used for handling sensitive parts must be equipped with static free work surfaces and floor mats. These surfaces and mats must be static dissipative and grounded to a true earth ground. b. All electrical equipment used at static free workstations must be grounded. Soldering irons shall be of an approved ESD protected design. c. Workstation chairs or stools must be grounded in one of two ways: carbon filled conductive casters or brass drag chains attached to the center of the chair base. These chairs or stools must be used in conjunction with static free floor mats. d. No plastic materials shall be allowed within three feet of static free workstations. This includes candy wrappers, tape, cigarette packages, cellophane wrappers, foam cups, foam packaging (peanuts), bubble wrap, plastic bins, plastic folders, etc. - 5

23 Part EDS Figure e. Temperature and humidity monitors should be installed in ESD safe areas and are to be monitored by personnel in each area for humidity levels. Humidity levels that reach 25% or less should be reported to the ESD coordinator, as these levels present possible ESD problems. 3. Personnel a. The wrist strap must be worn in direct contact with the bare skin. Personnel shall not be attached directly to an earth ground. There must be a safety 250k Ohm to 1 Meg Ohm resistance - 6

24 2015 Part between the operator and the ground (these resistors have been molded into the ground cords of some ESD mats). b. All personnel within three feet of a static free work station must be grounded with a wrist strap and ground cord attached to the grounded work surface. c. The wrist strap shall be functionally checked by the user daily. Testers should be placed in all ESD protected areas for this purpose. Equipment is also available to continuously monitor the wrist strap. d. Improperly grounded or ungrounded personnel shall never touch static sensitive parts, assemblies, or other operators at a static free work station. 4. Equipment locations a. A railroad may elect to place properly grounded floor mats on floors where access is made to any system using plug in cards with ESDS components. This should include microwave equipment, electronic switchboards, packet switches, rack mounted data modems or multiplexers, radio base stations, and other electronic equipment. b. A properly grounded wrist strap should be attached to the equipment rack. c. Alternatively, a portable service kit containing ESD mat and wrist strap can be used when servicing installed equipment. H. Maintenance of Static Protective Equipment 1. Workstation Mats The surface of mats must be cleaned with an antistatic cleaner, monthly, or more often as required, to prevent contamination from dirt, grime, solder, body oils, dust particles, etc. 2. Wrist Bands Wrist bands may be laundered, using a mild detergent - no bleach, as required to prevent body oils from compromising the electrical functionality of the material. Care must be taken to place the band in a pocket to keep it from becoming entangled in the agitator of the washing machine. - 7

25 Part Smocks (Lab Coats) a. All personnel are to wear conductive smocks while working on Static Sensitive components or assemblies. b. All other personnel including visitors are to wear conductive smocks while working in or touring the ESD Protected Area. c. Smocks may be laundered, using a mild detergent - no bleach, by the user at home, or by an approved garment laundering agency. I. Maintenance Shop Area, Warehouse, and Staging Areas 1. The ESD Protected Area floor should have an anti-static surface applied to it. Facility maintenance will maintain the floor on the following schedule: - weekly - anti-static wax to be applied to surfaces where required. - yearly - floor to be stripped and retreated. 2. Areas designated as a Static Safeguarded Work Area are marked by ESD signs informing personnel of the ESD Policy and by a yellow band on the floor defining the perimeter of the area. J. Electrical Tests 1. Specialized test equipment can be used to routinely verify proper electrical performance of the wrist strap. Follow the manufacturer's instructions to verify wrist strap performance. 2. Equipment is available to continuously monitor the performance of the wrist strap and grounding. Follow the manufacturer's instructions to continuously verify wrist strap performance. 3. The bench/table and floor mats should be tested by a qualified ESD auditor. K. Frequency of Testing Wrist Straps - Daily - (personnel not required to use wrist straps daily, must test them before each use) Table/Floor Mats - Monthly by ESD Coordinator, Yearly by Quality Assurance - 8

26 2015 Part Mat Ground Cords - Ground/Connection - Daily by Operators, Monthly by ESD Coordinator, Yearly by Quality Assurance Daily by Operators Static Shielded - As Required. At the minimum Bags Yearly Ionizers - Yearly or as determined by the Calibration Dept. L. ESD Program Supplies M. This section provides a listing of items that may be needed for a successful ESD control program. Antistatic Cleaner Antistatic Storage Cabinet Conductive Storage Drawers Conductive Smock (Lab Coat) Conductive Tool Box ESD Floor Mat ESD Video Tapes ESD Packaging ESD Heel Strap Field Service Ground Kit Ground Cords Ionizer Outlet Tester Portable Static Meter Static Shielding Work Surfaces Static Shielding Work Surface Tester Static Shielding Floor Finish (Antistatic Wax) Static Shielding Floor Surfaces Warning Labels Wrist Strap Wrist Strap Tester. - 9

27 Part References 1. MIL-STD-1686C - Electrostatic Discharge Control Program for Protection of Electrical and Electronic Parts, Assemblies and Equipment 2. MIL-HDBK-263B, Electrostatic Discharge Control Handbook

28 2015 Part APPENDIX A ELECTROSTATIC DISCHARGE CONTROL STANDARDS AUDIT CHECKLIST A. PURCHASING 1. Appropriate ESD requirements on purchase orders. 2. Procurement only buys ESDS parts from suppliers that have been ESDapproved by the Purchasing Department or Engineering Department. 3. Procurement maintains a list of ESD-approved suppliers. 4. Restrictions on packaging, labeling, and proper invoices/packing slips are imposed on vendors. 5. Procurement maintains a list of approved suppliers, the list need not be segregated into ESD and Non-ESD suppliers, but if ESD approval is needed for a new supplier, the vendor is audited for ESD. B. RECEIVING 1. ESDS devices are identifiable by their outside packaging and/or invoices. 2. ESDS devices are checked for proper packaging and marking. 3. Areas where ESDS packages are opened are equipped with proper ESD control measures, (i.e., mats, wrist straps, proper grounding). C. INCOMING INSPECTION 1. Packages containing ESDS devices are opened only in ESD areas by trained, grounded personnel. 2. ESDS items are stored in protective packaging for transfer to storage and work areas. - 11

29 Part Incoming Inspection personnel write trouble tickets on any improperly marked or packaged devices and report deficiencies to the proper ESD Coordinator, Purchasing, and Engineering. D. SHIPPING 1. ESDS items are only handled at ESD protective workstations by trained, grounded ESD Certified personnel. 2. Items are labeled and packaged using appropriate labels and protective packaging. E. STOCKROOMS, STORAGE AREAS, KITTING AND STAGING AREAS 1. ESDS items are maintained and issued in ESD-protective packaging. 2. Bin boxes or shelves storing ESDS devices are so labeled. 3. ESD procedures are implemented during kitting and in staging areas. F. ENGINEERING 1. ESD procedures are implemented in all engineering laboratories. 2. Engineering Assembly drawings involving ESDS components contain references to ESD Policies and Procedures. G. PRODUCT INTEGRATION AND MANUFACTURING AREAS 1. ESD designated areas and workstations are established throughout these areas. 2. Personnel in these areas are properly trained in the use of ESD workstations and implementation of precautionary handling procedures for ESDS devices. 3. All processing equipment is properly grounded. - 12

30 2015 Part ESD protective materials (i.e., bags, foams, totes) are available at every workstation and ESDS devices are transferred between areas in protective containers or packaging. 5. Special ESD control measures that are necessary (e.g., conductive flooring, personnel apparel, humidity control, ionization) are implemented as appropriate. 6. ESD areas are clearly identified by signs/placards/caution warnings and personnel entering these areas are alerted to ESDS handing and visitor requirements. H. PRODUCTION TEST AND ENGINEERING TEST 1. ESD workstation implemented in test and burn-in areas. 2. There is an absence of prime sources of static in test areas. 3. ESD control measures are implemented. 4. ESDS items are transferred to the next work area in protective containers. 5. Operators are not grounded while operating voltages are applied. I. QUALITY ASSURANCE 1. Compliance to ESD control procedures. 2. Suppliers' and Vendors' ESD compliance. 3. Workstations ESD certification. 4. ESD training programs. 5. Engineering drawings containing references to ESD Policies and Procedures. - 13

31 Part STEP DAILY SELF-CHECK PROCEDURES [ ] 1. Visually check your work area to see that there are no Static-Generating materials in or around your area, (such as carpet or plastic or other insulating materials), check to see that there are no static-generating tools being used such as plastic solder suckers. [ ] 2. Visually check to see that all ground wiring to your work station has not been disconnected or damaged. Be especially suspicious if equipment or furniture has been moved. If you have a Continuous Monitor at your station, test it to see if it is working before using. [ ] 3. If you are using an air ionizer, turn it on and aim it properly. [ ] 4. Clear your work area of static charge generators, such as untreated plastic bags, boxes, foam, tape, paper, or personal items, for a distance of at least one meter (3 feet). [ ] 5. Visually check that all ESD-sensitive parts, assemblies or products are completely inside their static-shielding bags or conductive containers, with nothing sticking out. [ ] 6. Make sure that there are no static generators inside the static-shielding bags or conductive containers with or without ESD sensitive parts or assemblies. [ ] 7. Make sure that all static-shielding bags and conductive containers have the correct static attention label on the outside of the container. Visually check static-shielding bags for tears or excessive wear. [ ] 8. All cleaners, solvents, coatings, sprays used at your work station must be the types approved by your ESD control static coordinator. [ ] 9. Never allow anyone who is not grounded closer than one meter (3 feet) to your static-safe work area. Ask them to comply with grounding and garment requirements of your area before coming into the area, touching anything, or coming closer to your work. Report all violators that fail to comply. [ ] 10. Put on your wrist strap and any special garments required to do your job in your area, such as smocks and conductive footwear. Test your wrist strap according to manufacturer's instructions and sign the check-off sheet as demonstrated by your ESD coordinator. Check your smocks to see that there are no holes, rips or tears, and that they are clean. Wrist straps are required to be checked once a day at the beginning of your shift, but - 14

32 2015 Part should be checked after each break and before beginning work after lunch or supper. ESD AUDIT FORM Area Audited: Responsibility: 1. Table Mats, Qty Grounds: Pass Fail/Problem Aesthetics (surface is clean, no static-generating materials) Pass Fail/Problem 2. Floor Mats, Qty Grounds: Pass Fail/Problem Aesthetics (surface is clean, no static-generating materials) Pass Fail/Problem 3. Personal (Wrist Straps, Ground Cords, Smocks, etc.) Comments: 4. Handing/Storage of Static Sensitive Components and Assemblies Pass Fail/Problem Additional Comments: Auditor: Audit Date: - 15

33 Part CORRECTIVE ACTION Corrective Action Required: Corrective Action Completed: - 16