Background Statement for SEMI Draft Document 4316C
Revision to SEMI S2-0706, Environmental, Safety and Health Guideline for Semiconductor Manufacturing Equipment, and SEMI S22-0706, Safety Guideline for the Electrical Design of Semiconductor Manufacturing Equipment
Note: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this document.
Note: Recipients of this document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, “patented technology” is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided.
Background Statement
This ballot consists of 10 line items. The purpose is to align the interlock, EMO and electrical criteria in SEMI S2 and S22 and improve on them where determined to be necessary.
Following the safety checklist, the next section of the background statement is provided to make the 10 line items easier to understand, review and comment against if necessary. As the purpose of the line items is to align the criteria, there will be changes to both documents, but not necessarily on the same line items.
If any discrepancies are found between the explanatory section that immediately follows and the sample pages from the document that follow (assuming that all line items pass), the last section (the simulated pages of the document) are the balloted material. The items marked with change bars in the sample pages of the document are the items from the previous delayed revision sections for the two documents as this is how they will appear in the new document. The items marked with boxes around them and including the underlined and struck through text are the items that are proposed to be changed by this ballot.
This ballot will be adjudicated at the NA “Spring” Standards meetings during the week of March 30th with the NA EHS Committee meeting scheduled on April 2nd, 2009.
Please forward a courtesy copy of any comments or negatives against the ballot to Chris Evanston at and Chuck Mello at . As this is a technical ballot, all votes of reject must be accompanied by reasons (negatives) and also be sent to SEMI staff before the balloting deadline or they will be considered abstention votes. If you have any comments on the ballot (suggestions or questions that you do not believe are technical negatives, please clearly indicate them as COMMENTS to assist us with reducing the administrative overhead in handling them during the task force and committee meetings.
Review and Adjudication Information for 4316C
Group: / S2-S22 Working Group / NA EHS Committee
Date: / Monday, March 30, 2009 / Thursday, April 2, 2009
Time & Timezone: / 1600-1730 PDT / 0800-2200 PDT
Location: / To be determined / To be determined
City, State/Country: / San Jose, CA (metro) / San Jose, CA (metro)
Leader(s): / Chris Evanston (Earth Tech | AECOM)
Chuck Mello (UL)
/ James Beasley (ISMI)
Chris Evanston (Earth Tech | AECOM)
Sean Larsen (AMEC)
Eric Sklar (Safety Guru, LLC)
Standards Staff: / Ian McLeod (SEMI NA)
408.943.6996
/ Ian McLeod (SEMI NA)
408.943.6996
Meeting Type(s): / X / Face-to-Face / X / Face-to-Face
X / Telephone / Telephone
X / Web / Web
Meeting Notes: / This meeting’s details are subject to change, and additional review sessions may be scheduled if necessary. Contact the task force leaders or Standards staff for confirmation.
Telephone and web information will be distributed to interested parties as the meeting date approaches. If you will not be able to physically attend these meetings but would like to participate by telephone/web, please contact Standards staff. / Only participants attending committee meetings in person are allowed to vote. Participants attending by telephone/web are not allowed to vote at this time.
Safety Checklist for SEMI Draft Document #4316C
Title: Revision to SEMI S2-0706, Environmental, Safety and Health Guideline for Semiconductor Manufacturing Equipment, and SEMI S22-0706, Safety Guideline for the Electrical Design of Semiconductor Manufacturing Equipment
Developing/Revising Body
Name/Type: / S2-S22 Working GroupTechnical Committee: / Environmental Health and Safety
Region: / North America
Leadership
Position / Last / First / AffiliationLeader / Evanston / Chris / Earth Tech | AECOM
Leader / Mello / Chuck / UL
Author/Editor* / Larsen / Sean / AMEC
Checklist Author* / Larsen / Sean / AMEC
* Only necessary if different from leaders
Documents, Conflicts, and Consideration
Safety related codes, standards, and practices used in developing the safety guideline, and the manner in which each item was considered by the technical committee
# and Title / Manner of ConsiderationSEMI S2
SEMI S22
Known inconsistencies between the safety guideline and any other safety related codes, standards, and practices cited in the safety guideline
# and Title / Inconsistency with This Safety GuidelineNone identified
Other conflicts with known codes, standards, and practices or with commonly accepted safety and health principles to the extent practical
# and Title / Nature of Conflict with This Safety GuidelineNone identified
Participants and Contributors
Last / First / Affiliation /Evanston / Chris / EarthTech | AECOM
Mello / Chuck / UL
Beasley / James / Intel / ISMI
Bernardin / David / Cymer
Brody / Steve / Thermo / Brooks
Crane / Lauren / Applied Materials
Crockett / Alan / KLA-Tencor
Deboer / Dave / ASML
Endow / Keith / KLA-Tencor
Epstein / Brian / Veeco
Freudenberg / John / Teradyne / Hypertherm
Guild / Ed / IBM
Hamilton / Jeff / EarthTech / AMAT
Heinz / Udo / TUV
Hoertig / Thomas / Pilz Automation
Hom / Jeff / UL
Hoover / Charles / Rockwell
Johnson / Larry / Estec / Intertek
Karl / Edward / Applied Materials
Krauss / Mark / EHS2
Kryska / Paul / Novellus
Larsen / Sean / AMEC
Mashiro / Supika / Canon Anelva
Nishihara / T. / DNS
Oi / Nobuo / Ulvac
Oswalt / James / Mattson
Pilz / Thomas / Pilz Automation
Planting / Bert / ASML
Rai / Sunny / Intertek
Rehder / Alan / UL
Roberge / Steve / Axcelis
Sherman / Mike / FSI
Shilt / Marv / Rockwell
Sklar / Eric / Safety Guru
Sugihara / Kenji / Panasonic
Sugita / Yoshiro / TUV
Vang / Tou / Asyst Technologies
Wong / Carl / AMAT / AKT
Wright / Jim / Intertek / Axcellis
The content requirements of this checklist are documented in Section 14.2 of the Regulations Governing SEMI Standards Committees.
Summary of Ballot 4316C
Additions are indicated in Underline, deletions indicated with strikethrough.
# / Section / # / Section /S22 / S2 /
S2-S22 LI1
Rationale: Clean-up previous reformatting errors in SEMI S22 and clearly call out Appendix criteria in main text of document.
10.2.1.1 / Refer to Finger Probe Test, §22.15, and IEC61010-1 Annex B for the test finger. In addition to enclosures, physical barriers at the point of hazard should be included where inadvertent contact is likely.
NOTE 28: IEC 60529 “Degrees of Protection Provided by Enclosures” may be used as a reference.
10.2.1.2 / Any openings in the enclosure should meet the criteria of either Table A31-1 in Appendix 3 or the Finger Probe Test in §22.15.
NOTE 28: IEC 60529 “Degrees of Protection Provided by Enclosures” may be used as a reference.
15.1.5 / Top covers of electrical enclosures should be designed and constructed in accordance with Appendix 3. / 13.4.8 / Top covers of electrical enclosures should be designed and constructed to prevent objects from falling into the enclosures (refer to Appendix 1 for examples of acceptable top enclosure openings). in accordance with Appendix 1.
App 3 / Add Appendix 1 from S2
S2-S22 LI2
Rationale: Align criteria in S22 with S2.
13.7.2 / Safety interlock Function ¾ Safety interlocks should be designed such that the equipment is automatically brought to a safe condition before personnel can access the point of hazard. Safety interlock systems should be designed such that, upon activation of the interlock, the equipment, or relevant parts of the equipment, is automatically brought to a safe condition. Each safety interlock, when activated, should alert the operator immediately.
EXCEPTION: If a safety interlock triggers the emergency off (EMO) circuit, or otherwise removes power to the user interface, notification to the operator is not needed.
S2-S22 LI3
Rationale: Clarify intent and grammar of exception in S2 and provide matching criteria in S22.
13.7.10 / Safety interlock systems should be fault-tolerant and designed so that the functions or set points of the system components cannot be altered without disassembling, physically modifying, or damaging the device or component.
EXCEPTION: Safety interlock systems having adjustable set points or trip functions may be used if access is limited by requiring a deliberate action, such as using a tool or special keypad sequences, to access the adjustable devices or to adjust the devices. The intent is to limit access to the adjustable setpoints to properly trained maintenance and service personnel. / 11.5 / Safety interlock systems should be fault-tolerant and designed so that the functions or set points of the system components cannot be altered without disassembling, physically modifying, or damaging the device or component.
EXCEPTION: When safety interlock systems having adjustable set points or trip functions are used, access should be limited to maintenance or service personnel by requiring a deliberate action, such as using a tool or special keypad sequences, to access the adjustable devices or to adjust the devices. Safety interlock systems having adjustable set points or trip functions may be used if access is limited by requiring a deliberate action, such as using a tool or special keypad sequences, to access the adjustable devices or to adjust the devices. The intent is to limit access to the adjustable setpoints to properly trained maintenance and service personnel.
S2-S22 LI4
Rationale: Clarify requirement in S22 and move shunt trip exclusion to normative text in S2 to align criteria.
13.7.9 / Shunt Trip Circuits ¾ Shunt trips that require power to trip (actuate) should not be used as safety interlocks because they are not fail-safe. / 11.5.1 / Shunt Trip Circuits — Shunt trips that require power to trip (actuate) should not be used as safety interlocks because they are not fail-safe.
Note 44 / 13.4.3 Where failure of components and assemblies could result in a risk of electric shock, fire, or personal injury, those components and assemblies should be certified by an accredited testing laboratory and used in accordance with the manufacturer’s specifications, or otherwise evaluated to the applicable standard(s).
NOTE 44: With the exception of implementation of ground fault protection, shunt trip units that require power to trip (actuate) are not recommended to be used in a safety control circuit, because they are not fail-safe.
S2-S22 LI5
Rationale: Port over remaining criteria into SEMI S22 that appears to have been left out by a formatting error, and modify exception 3 in both documents to indicate protection of all personnel, not just maintenance personnel.
13.3.3 / EMO Function ¾ Activation of the emergency off circuit should de-energize all hazardous voltage and all power greater than 240 volt-amperes in the equipment beyond the main power enclosure.
EXCEPTION 1: A non-hazardous voltage EMO circuit (typically 24 Volts) may remain energized.
EXCEPTION 2: Safety related devices (e.g., smoke detectors, gas/water leak detectors, pressure measurement devices, etc.) may remain energized from a non-hazardous power source.
EXCEPTION 3: A computer system or PLC performing data/alarm logging and error recovery functions may remain energized, provided that the breaker and receptacle supplying the power to the computer system are clearly labeled as remaining energized after EMO activation. Hazardous energized parts that remain energized after EMO activation should be insulated or guarded to prevent inadvertent contact by personnel.
EXCEPTION 4: Multiple units mounted separately with no shared hazards and without interconnecting circuits with hazardous voltages, energy levels or other potentially hazardous conditions may have:
· separate sources of power and separate supply circuit disconnect means if clearly identified, or
· separate EMO circuits, if they are clearly identified. / 12.2 / Activation of the emergency off circuit should de-energize all hazardous voltage and all power greater than 240 volt-amps in the equipment beyond the main power enclosure.
EXCEPTION 1: A non-hazardous voltage EMO circuit (typically 24 volts) and its supply may remain energized.
EXCEPTION 2: Safety related devices (e.g., smoke detectors, gas/water leak detectors, pressure measurement devices, etc.) may remain energized from a non-hazardous power source.
EXCEPTION 3: A computer system performing data/alarm logging and error recovery functions may remain energized, provided that the energized breaker(s), receptacle(s), and each energized conductor termination are clearly labeled as remaining energized after EMO activation. Hazardous energized parts that remain energized after EMO activation should be insulated or guarded to prevent inadvertent contact by maintenance personnel.
EXCEPTION 4: Multiple units mounted separately with no shared hazards and without interconnecting circuits with hazardous voltages, energy levels or other potentially hazardous conditions may have:
· separate sources of power and separate supply circuit disconnect means if clearly identified, or
· separate EMO circuits, if they are clearly identified.
S2-S22 LI6
Rationale: Add remaining text of exception into S22 that appears to have been left off as a cut and paste error.
13.3.4 / EMO Design ¾ The design of the EMO circuit should include all the following:
a) the EMO circuit should not include controls that enable it to be defeated or bypassed;
b) the EMO circuit should consist of electro-mechanical components;
c) resetting the EMO switch should not re-energize circuits, equipment, or subassemblies that create a hazard to personnel or the facility;
d) the EMO circuit should shut down the equipment by de-energizing rather than energizing control components; and
e) the EMO actuator should be self-latching.
EXCEPTION 1: Solid-state devices and components may be used, provided the system or relevant parts of the system are evaluated and found suitable for use. The components should be evaluated and found suitable considering abnormal conditions such as over voltage, under voltage, power supply interruption, transient over voltage, ramp voltage, electromagnetic susceptibility, electrostatic discharge, thermal cycling, humidity, dust, vibration and jarring. The final removal of power should be accomplished by means of electromechanical components.
S2-S22 LI7
Rationale: Align S2 criteria with industry practice and S22 criteria.
12.3 / The emergency off button should be red, and mushroom shaped and self-latching. A yellow background for the EMO should be provided.
NOTE 40: Non-lockable self-latching (i.e., twist- or pull-to-release) EMO buttons may be required by regulations.
S2-S22 LI8
Rationale: Delete the incomplete list of potential hazards and align the criteria in the two documents.
13.3.8 / The person actuating or inspecting the EMO button should not be exposed to hazards that could cause significant injury. / 12.5.3 / The person actuating or inspecting the EMO button should not be exposed to serious risks of tripping or falling or of coming in contact with energized electrical parts, moving machinery, surfaces or objects operating at high temperatures, or other hazardous equipment. hazards that could cause significant injury.
S2-S22 LI9
Rationale: Add the apparently forgotten criteria into SEMI S22.
13.3.9 / EMO circuits should be fault-tolerant.
S2-S22 LI10
Rationale: Delete the ambiguous and difficult to translate concept of maintenance mode. Break out the criteria in S22 so that they do not get combined in strange ways.
13.7.5 / When maintenance access to areas protected by safety interlocks is necessary, safety interlocks that can be defeated may be used, provided that they require an intentional operation to bypass. Safety interlocks that safeguard operator tasks should not be able to be defeated without the use of a tool. Upon exiting or completing the maintenance mode, all safety interlocks should be automatically restored.
13.7.5 Defeat of Interlocks
13.7.5.1 Safety interlocks that safeguard operator tasks should not be able to be defeated without the use of a tool.
13.7.5.2 When maintenance access to areas protected by safety interlocks is necessary, safety interlocks that can be defeated may be used, provided that they require an intentional operation to bypass.
13.7.5.3 All safety interlocks shall be designed such that the equipment cannot be returned to normal operation before the interlocks are restored. / 11.7.2.1 / Upon exiting or completing the maintenance mode, all safety interlocks should be automatically restored. All safety interlocks shall be designed such that the equipment cannot be returned to normal operation before the interlocks are restored.
End of Background Statement