Requirements for Handling Electrostatic-Discharge-Sensitive (ESDS) Devices JESD625-A
(Revision of EIA-625)
ELECTRONIC INDUSTRIES ALLIANCE
JEDEC Solid State Technology Association
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JEDEC Standard No. 625-A
REQUIREMENTS FOR HANDLING ELECTROSTATIC-DISCHARGE-SENSITIVE (ESDS) DEVICES
CONTENTS Page 1 1 1 1 2 2 3 5 5 5 6 6 9 9 11 11 11 11 11 11 11 11 12 12 12 12 12 13 13 13 13 13 13 13 14 14
1 Purpose 2 Scope 2.1 Applicable users 2.2 Applicable part types 3 Related documents 3.1 Applicable documents 4 Terms and definitions 5 Inspection, measuring and test equipment 5.1 Calibration system 5.2 Recommended inspection, measuring and test equipment types 6 Facilities for ESD protected areas and workstations 6.1 Minimum acceptable requirements 6.2 ESD item check records 6.3 Personnel grounding 6.4 Wrist strap and ESD protective footwear resistance path checks 6.4.1 Wrist strap resistance measurement path 6.4.2 Heel/toe strap and conductive shoe resistance measurement paths 6.4.3 Wrist strap monitor 6.5 Electrostatic potential measurements 6.6 ESD signs and labels 6.6.1 Sign content and posting 6.6.2 ESD caution labels for packing and shipping 6.6.3 Package ESD caution label content 6.6.4 Commercial device package ESD caution label 6.6.5 Military device package ESD caution label 7 Grounding for protection of ESDS devices 7.1 ESD ground 7.1.1 Earth and equipment ESD grounds 7.1.2 Equipment grounding receptacle and conductor testing 7.2 ESD ground system safety review 7.3 ESD protected workstation ESD ground 7.4 ESD protected worksurfaces 7.4.1 Static dissipative ESD protective worksurfaces 7.4.2 Conductive ESD protective worksurfaces 7.5 ESD protective flooring/mats 7.6 ESD ground connections
JEDEC Standard No. 625-A
REQUIREMENTS FOR HANDLING ELECTROSTATIC-DISCHARGE-SENSITIVE (ESDS) DEVICES
CONTENTS (continued) Page 7.7 Ground wire mechanical considerations 7.8 Storage areas 7.9 Mobile ESD protected workstation 8 ESD packaging requirements for ESDS devices 8.1 ESD device protective packaging requirement 8.2 Packing and filler materials 8.3 Antistatic tubes, trays, magazines and carriers 8.4 Individual Finished device carrier materials 8.5 ESDS device wafer and die packing 8.6 ESDS device shipping and receiving operations 9 Compliance verification 9.1 ESD coordinator
9.2 Auditing 9.3 Noncompliance 9.3.1 Noncompliant ESD protected areas and workstations 9.3.2 Mishandled ESDS device 9.3.3 Returning rejected ESDS devices to suppliers 9.4 Records 10 ESD handling training 10.1 Training program 10.2 Training records 11 Methods for minimizing static charging 11.1 Antistatic solution 11.2 Relative humidity control 11.3 Air ionizers 11.4 ESD protective smocks 11.5 Gloves/finger cots ESD handling audit checklist Annex A - Informational reference documents Figure 1 - ESD protected workstation Figure 2 - Example of ESD protected package caution label 14 14 14 14 14 14 15 15 15 15 15 15 15 15 16 16 16 16 16 16 16 17 17 17 17 18 18 19 22 8 12
Table 1 - Minimum requirements for ESD protected areas , workstations, and tools Table 2 - ESD protective item checks
JEDEC Standard No. 625-A
Foreword This standard was prepared to standardize the requirements for a comprehensive Electrostatic Discharge (ESD) control program for handling ESD-Sensitive (ESDS) devices. The requirements within this standard were derived from existing industry standards, specifications, test methods, and input from various industry reviews. The intent of this document is for users to incorporate these minimal requirements into their ESD control program to provide a consistent ESD protection level for their products. This standard replaces JEDEC Standard No. 42 (formerly JEDEC Publication 108-B, Distributor Requirements for Handling Electrostatic-Discharge Sensitive (ESDS) Devices).
JEDEC Standard No. 625-A
JEDEC Standard No. 625-A Page 1
REQUIREMENTS FOR HANDLING ELECTROSTATIC-DISCHARGE-SENSITIVE (ESDS) DEVICES (From JEDEC Board ballot JCB-98-134, formulated under the cognizance of JEDEC JC-14.1 Committee on Reliability Test Methods for Packaged Devices and the JC-13 Committee on Government Liaison.)
1 Purpose This standard establishes the minimum requirements for Electrostatic Discharge (ESD) control methods and materials used to protect electronic devices that are susceptible to damage or degradation from electrostatic discharge (ESD). The passage of a static charge through an electrostatic-discharge-sensitive (ESDS) device can result in catastrophic failure or performance degradation of the part. Device sensitivity to ESD is determined by test methods such as JESD22-A114. ESDS devices with human body model sensitivities of less than ?À200 volts may need additional protective measures beyond those specified in this standard.
2 Scope 2.1 Applicable users a) Semiconductor Manufacturers - from
wafer electrical probe through shipment of finished devices except for in-process operations when all leads are shorted together. NOTE ?ª The requirements of this standard are not imposed prior to probe. Prior to probe, the manufacturer should take appropriate ESD precautions to minimize damage to devices. b) Semiconductor Distributors - from receipt through shipment of finished devices. c) Semiconductor Processing/Testing Facilities - from receipt through shipment of finished devices. d) ESDS Device Users ?C from receipt to installation in a higher assembly/card 2.2 Applicable device types The device types for which these requirements are applicable include, but are not limited to, ESDsensitive discrete and integrated circuit semiconductors, hybrid microcircuits, and thin film passive devices. NOTE ?ª ESD susceptibility/sensitivity may be determined and specified by the manufacturer or user.
JEDEC Standard No. 625-A Page 2
3 Related documents Unless otherwise specified, the following documents of the latest issue, revision or amendment, form a part of this standard to the extent specified herein. 3.1 Applicable documents ANSI/ASQC-Q9001 Quality Systems - Model for Quality Assurance in Design/Development, Production, Installation and Servicing (US version of ISO-9001) Quality Systems - Model for Quality Assurance in Production and Installation (US version of ISO-9002) Symbol and Label for Electrostatic Sensitive Devices (Formulated by JEDEC JC-10 Committee) Packaging Materials Standards for ESD sensitive Items Standard for Protection of Electrostatic Discharge Susceptible Items Ionization Standard for Protection of Electrostatic Discharge Susceptible Items Worksurfaces - Resistive Characterization Standard for Protection of Electrostatic Discharge Susceptible Items Grounding - Recommended Practice Standard for Protection of Electrostatic Discharge Susceptible Items - Floor Materials - Resistive Characterization of Materials Calibration Laboratories and Measuring and Test Equipment - General Requirements Human Body Model (HBM) Electrostatic Discharge (ESD) Sensitivity Testing Standard Electrostatic Discharge (ESD) Sensitivity Testing - Human Body Model (HBM) Electrostatic Discharge (ESD) Sensitivity Testing - Machine Model (MM) Field Induced Charged Device Model Test Method for Electrostatic Discharge Withstand Threshold for Microelectronic Modules Specification for the Protection of Electronic Devices from Electrostatic Phenomena - Section 1: General Requirements. Specification for the Protection of Electronic Devices from Electrostatic Phenomena - Section 2: User Guide.
JEDEC Standard No. 625-A Page 3
3 Related documents (cont??d) MIL-HDBK-263 Electrostatic Discharge Control Handbook for Protection of Electrical and Electronic Parts, Assemblies and Equipment (Excluding Electrically Initiated Explosive Devices) Marking for Shipment and Storage
4 Terms and definitions For the purpose of this standard the following definitions apply. air ionizer: A source of charged air molecules (ions). antistatic material: Referring to the property of material that inhibits triboelectric charging. Antistatic materials shall not triboelectric charge to greater than ?À1,000 volts under normal/ intended usage. NOTE ?ª A material's antistatic property is not necessarily correlatable with its resistivity or resistance. conductive material: A material that has a surface resistivity less than 1x105 ohms per square or a volume resistivity less than 1x104 ohm centimeter. NOTE ?ª A conductive material is not necessarily antistatic. electrostatic charge: see ??static electricity??. electrostatic discharge (ESD): The transfer of electrostatic charge between bodies or surfaces that are at different electrostatic potentials. electrostatic-discharge susceptibility [sensitivity] (ESDS): The lowest level of ESD that produces changes in device characteristics such that the device fails to meet its specified characteristics. electrostatic field: Lines of force surrounding an electrically charged object. electrostatic shielding: A barrier or enclosure that limits the penetration of an electrostatic field so that its effects do not reach the stored or contained devices and produce damage. equipment ground: The entire low-impedance path from a piece of electrical equipment to a hardground electrode (e.g., the third wire (green) terminal of a receptacle). ESD ground: The point, electrodes, bus bar, metal strips, or other system of conductors that form a path from a statically charged person or object to ground. ESD-protected area: potential. A work environment with materials and equipment that limit electrostatic
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4 Terms and definitions (cont??d) ESD-protected workstation: A work position with materials and equipment that limit electrostatic
potential. ESD-protective packaging: A packaging system that provides electrostatic protection and limits triboelectric charging to levels that do not result in device damage. ESD-protective worksurface: A table top or other surface on which to work that has a resistance to ground of less than 109 ohms ground: (1) A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth or some conducting body that serves in place of earth. (2) The portion of an electrical circuit at zero potential with respect to the earth. (3) A conducting body, such as the earth or the hull of a steel ship, used as a return path for electric currents and as an arbitrary zero reference point. groundable point: A designated connection, location, or assembly used on an ESD protective material or device that is intended to accommodate electrical connection from the device to ESD ground. insulative material: A material having a surface resistivity of at least 1 x 1012 ohms per square or volume resistivity of at least 1 x 1011 ohm centimeter. static: A short form of electrostatic. static dissipative material: A material having a surface resistance between 1 x 105 ohms and 1 x 1011 ohms or a volume resistivity between 1 x 105 ohm centimeters and 1 x 1011 ohm centimeters. static electricity: Electrical charge at rest. NOTE ?ª The electrical charge is due to the transfer of electrons within a body (polarization) or from one body to another. surface resistance: The dc voltage divided by the current passing between two electrodes of specified configuration that contact the same side of a insulative material or item. NOTE ?ª Surface resistance is expressed in ohms. triboelectric charging: The generation of electrostatic charges when two pieces of material in intimate contact are separated (where one or both is an insulator). NOTE ?ª Substantial generation of static electricity can be caused by contact and separation of two materials or by rubbing two substances together. unprotected ESDS device: An ESDS device that is not in an ESD protective package. NOTE ?ª See ??ESD-protective packaging??
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4 Terms and definitions (cont??d) volume resistivity (?Ñv): The dc voltage per unit thickness, applied across two electrodes in contact with ?Ñ a specimen, divided by the current per unit area passing through the system. NOTE 1 Volume resistivity is generally expressed in ohm centimeters. 2 When concentric ring electrodes are used as described in ASTM-D991, volume resistivity is calculated from the following equation:
volume resistivity (?Ñv) = where D1 = diameter of inner electrode or disk R = measured resistance in ohms T = thickness of specimen
?Ð ?Á (D1 )2 ?Á R
5 Inspection, measuring and test equipment 5.1 Calibration system The calibration system for all inspection, measuring and test equipment used to perform required ESD Item Checks listed in table 2 shall be compliant with the requirements of ANSI/NCSL Z540-1 and
ANSI/ASQC-Q9001/Q9002. 5.2 Recommended inspection, measuring and test equipment types The recommended test equipment types and capabilities are listed below: a) A Go/No-go tester, a meter, an in-line monitor, or equivalent resistance path measuring equipment shall be capable of measuring the resistance of each connection path (e.g., wrist strap, heel strap or ESD protective footwear) (see 6.4.1 and 6.4.2) within the table 2 limits. b) When wrist strap monitoring equipment is used, it shall alarm (audio and/or visual) when a wrist strap exceeds the limits specified in table 2 and when there is a broken or missing connection to the user or to ground.
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5 Inspection, measuring and test equipment (cont??d) 5.2 Recommended inspection, measuring and test equipment types (cont??d) c) Electrostatic fieldmeters shall be capable of verifying the presence of electrostatic fields in the work environment. NOTES 1 Electrostatic fieldmeters used in ionized air streams shall be constructed (e.g., chopperstabilized) to operate in that environment. 2 In this standard, items with measured potential greater than +/- 1000 volts are to be kept at least 12 inches from unprotected ESDS devices. This refers to Measurements of +/- 1000 volts using a fieldmeter per the manufacturer??s instructions, typically +/-1000 volts at one inch. d) Meters used to verify ESD ground continuity shall be capable of verifying resistance values less than one ohm. e) Meters use to measure resistance to ground and resistance point to point shall be capable of verifying resistance values within the table 2 limits. f) Electrostatic charged plate monitors shall be capable of measuring the charge neutralization properties of ionization equipment within the table 2 limits.
6 Facilities for ESD protected areas and workstations 6.1 Minimum requirements The minimum requirements for ESD protected areas and workstations are listed in table 1 and illustrated in figure 1. The required and recommended ESD item checks are listed in table 2.
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6 Facilities for ESD protected areas and workstations (cont??d) 6.1 Minimum requirements (cont??d) Table 1 ?ª Minimum requirements for ESD protected areas, workstations, and tools ITEM 1. ESD Protective Worksurface 2. ESD Protective Flooring or Floor Mats 3. Personnel Grounding MINIMUM REQUIREMENTS Where unprotected ESDS devices are handled, a grounded static protective worksurface with a resistance to ground of less than 109 shall be used. Grounded flooring or floor mats are only required when personnel or mobile ESD protective
workstations utilize floor grounding methods. Each person handling or within twelve (12) inches of unprotected ESDS devices shall be grounded using EITHER: a) Wrist straps that shall: 1) Provide a continuous electrical path from the user directly to ESD ground. 2) Have an integral resistance at the wrist band end of the grounding wire that will limit current to less than 0.5 mA through that specific path to ground at the highest power supply voltage that may be encountered. 3) Be worn by operators handling unprotected ESDS devices when seated. b) ESD protective footwear (heel straps, toe straps or shoes) that shall: 1) Provide a continuous electrical path from the user directly to the ESD protective flooring or floor mat. 2) Be worn on both feet. 3) Limit current to less than 0.5 mA through that specific path to ground at the highest power supply voltage that may be encountered. 4) NOT be relied upon for grounding of seated personnel. a) Nonessential and personal items shall not be placed on ESD protective worksurfaces that are in use. b) No item with an electrostatic potential greater than +/- 1000 volts (as measured with a fieldmeter) shall be closer than 12 inches from unprotected ESDS devices. c) Operations, equipment or clothing generating electrostatic potential greater than ?À1,000 volts within twelve (12) inches of unprotected ESDS devices shall be neutralized or reduced to less than ?À1,000 volts. d) Charged items must not contact ESDS devices. When ESD protective smocks are worn, they shall cover all personal garments above the waist except at the neck area. Air ionizers may be used to reduce electrostatic potentials to less than ?À1,000 volts within twelve (12) inches of unprotected ESDS devices if those voltages are not controlled by other means. ESD caution signs shall be posted at each ESD protected workstation or at the entrances of defined ESD protected areas.
4. Static Generating Sources and Charged Surfaces
5. ESD Protective Smocks 6. Air Ionizers
7. ESD Protected Area and Workstation Identification
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6 Facilities for ESD protected areas and workstations (cont??d) 6.1 Minimum requirements (cont??d)
NOTES 1 G1 (equipment ground) or G2 (earth ground) is acceptable for ESD ground. Where both grounds are used, they shall be connected (bonded) together. 2 R1 is mandatory for all wrist straps. Its value shall be within the limits specified in table 2, 1.a. 3 R2 (for static dissipative worksurfaces) and R3 (for ESD protective floor mats) are optional. When R2 or R3 are used, the resistor values shall be as recommended by the ESD protective equipment manufacturer. ESD protective flooring shall be connected directly to the ESD ground without R3. 4 See paragraph 7 of this standard for grounding details (Reference EOS/ESD-S6.1). Figure 1 ?ª ESD protected workstation (Side
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6 Facilities for ESD protected areas and workstations (cont??d) 6.1 Minimum requirements (cont??d) Table 2 ?ª ESD protective item checks ITEMS ACCEPTANCE LIMITS a) Wrist straps (see Note 3). ?Ý500 k to ?Ü10 M b) ESD protective footwear (see Note 4). c) Personnel ESD protective smock (e.g., buttoned smocks) on personnel required to wear them. ?Ý500 k to ?Ü109 Visual check
FREQUENCY (see Notes 1&2) 1. Required Daily
REF. PARA. 6.4/6.4.1 6.4/6.4.2 11.4
d) Wrist straps or ESD protective footwear Visual check on personnel required to wear them. 2. Recommended Weekly a) ESD protected workstation. (e.g., ground connections) b) ESD protective floor mat (e.g., cleanliness and freedom from tears). c) ESD ground connections (e.g., wrist straps, mat ground wires). 3. Recommended Monthly 4. Recommended Quarterly ESD protected area and workstation static voltage surveys. a) ESD protective static dissipative worksurface to ESD ground resistance (See Note 5). b) ESD conductive worksurface to ESD ground resistance. (see Note 5) c) ESD protective floor to ESD ground resistance using EOS/ ESD S7.1. d) Wrist strap monitor check. e) ESD ground continuity from the groundable point (e.g., shelving ground wires, mobile equipment ground wires, cord ground wires) using EOS/ESDS6.1. (see Note 6) 5. Recommended Semiannually a) Ionizer balance using EOS/ ESD-S3.1. (see Note 7) b) Ionizer charge decay performance using EOS/ESD-S3.1. (See Note 9) Visual check Visual check Visual check ?Ü?À1,000 volts within 12 inches of unprotected ESDS devices ?Ý105 to <109
6.3 7.3/7.4.1/ 7.4.2 7.3/7.5 7.3/7.6 6.5
<100 k (with no series 4.3/7.3/ 7.4.2 resistor) ?Ý104 to <109 (see Note 8) ?Ý500 k to ?Ü10 M <1.0 7.5 6.4.3 4.10/7.6/ 7.7/7.8/7.9
Balance < ?À35 V Charge decay performance per manufacturer's specification.
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6 Facilities for ESD protected areas and workstations (cont??d) 6.1 Minimum requirements (cont??d) Table 2 ?ª ESD protective item checks (cont??d) ITEMS ACCEPTANCE LIMITS ESD system compliance to the requirements Using the ESD Audit of this standard Checklist or equivalent.
FREQUENCY REF. (see Notes 1&2) PARA. 6. Recommended 9.2 Annually NOTES 1 The ESD Item check frequencies should be established to ensure that the items remain compliant between checks. 2 The ESD item checks shall be performed more frequently than listed when compliance is not
continuously maintained. 3 Wrist straps in use shall be checked at least once a day when continuous wrist strap monitors are not used. 4 ESD protective footwear is available in a wide range of resistance values. Those with mid-to-lower resistance values provide shorter charge dissipation times. 5 Use EOS/ESD-S4.1 except make a single measurement using the limits specified in this standard at a high wear point relative to the ground connection on the worksurface to the ESD ground (instead of several points to the groundable point). All ESDS devices shall be removed from the worksurface while making these measurements. 6 If a resistor is used in the circuit, the resistance limit shall include the value of the resistor. 7 Use EOS/ESD-S3.1, except a single measurement point can be used for benchtop ionizing systems. Air velocity measurements are not required. 8 100K ohms is a suggested lower limit. However a lower value may be used if local safety requirements can still be met. 9 Use EOS/ESD-S3.1 except the number of measurement points and locations may be selected based on the application. 6.2 ESD item check records Records of the table 2 ESD item checks shall be maintained for a minimum of one year except for continuously monitored items and visual checks that do not require written records. a) Compliant resistance and electrical potential measurements may be recorded either as variables (the measured values) or attributes (pass). b) Noncompliant measurements must be recorded using variables (the measured values) when the measuring equipment is capable of providing variables. Otherwise, the attribute (fail) must be recorded. 6.3 Personnel grounding Personnel handling or within twelve (12) inches of unprotected ESDS devices shall be grounded per table 1.
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6 Facilities for ESD protected areas and workstations (cont??d) 6.4 Wrist strap and ESD protective footwear resistance path checks While being worn, the resistance paths of wrist straps, heel/toe straps and conductive shoes shall be independently checked to the table 2 limits for minimum resistance (to provide current limiting characteristics) and maximum resistance (to ensure that adequate body contact is maintained). 6.4.1 Wrist strap resistance measurement path The wrist strap resistance path is measured from the user's hand, through the user's body, the body-tostrap contact, the integral resistor, the strap wire, to the strap ground connector. 6.4.2 Heel/toe straps and conductive shoes resistance measurement paths Each heel/toe strap and conductive shoe resistance path shall be individually measured from the user's hand, through the user's body, the body-to-strap/shoe contact, the strap/shoe to the conductive plate. 6.4.3 Wrist strap monitor When continuous wrist strap monitoring equipment is used, daily wrist strap checks and logs are not required. Corrective actions resulting from monitor alarms shall be documented. 6.5 Electrostatic