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Re-examination of PQ Standards, Mark Stephens – EPRI. NYSDPS Power Quality Technical Conference December 12, 2013. Original EPRI R&D Project (1996-2000). In 1996 EPRI Began “ Task 24: Power Quality in the Semiconductor Industry ” Original Participants:. Original Task 24 Testing.
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Re-examination of PQ Standards, Mark Stephens – EPRI NYSDPS Power Quality Technical Conference December 12, 2013
Original EPRI R&D Project (1996-2000) • In 1996 EPRI Began “Task 24: Power Quality in the Semiconductor Industry” • Original Participants: Original Task 24 Testing
Original R&D Project Timeline Task 24 Research and Testing 33 Tools Tested By EPRI PEAC Nov 1998 June 97 April 99Workshop 4Tempe Mid 1996 April 97Workshop 1Dallas June 98Workshop 3Dallas Sept 99SEMI F47Published Feb 1999T24 FinalReport Sept 97Workshop 2Tempe June 2000SEMI F42AndSEMI F47 Revisions SEMI Task Force Standards Work Oct 97 Oct 97Approval forTask Force By SEMI June 99Test MethodologySEMI F42Published
SEMI F47-0706 Test Levels Relevant for Single and Two Phase Voltage Sags Only – does not address Three-Phase Events.
The Question Remains… • Previous EPRI studies have shown that SEMI F47 has made an impact on reducing fab downtime. • However, there are still PQ events above the SEMI F47 requirements that are causing downtime in semiconductor fabs. • WHY?
New EPRI Research Projectto Re-Examine SEMI F47 • Understand electric service quality requirements. • Identify post SEMI F47 mechanisms for continued semiconductor processing equipment downtime through industry collaboration. • Determine key strategies and methodologies to further harden semiconductor equipment to power quality events. • Inform development of revised standards, equipment designs, power system requirements, and PQ testing methodologies for current and next generation semiconductor tools. • Improve productivity through minimizing production downtime.
Example Utility PQ Data at Semiconductor Plant • 72 Sag Events • 38 Diff. Days • 16 Events affected production, • Only 1 clearly below SEMI F47! SEMI F47 VoltageSag
Objectives • The key objectives of this project are: • Determine the characteristics of power quality events still causing semiconductor plant process downtime • Take a new look at the sensitivities in the process equipment • Determine any required adjustments to equipment design or standards to further reduce voltage sag induced losses by the semiconductor industry.
Benefits (1) • Utility Collaborators will gain information about the characterization of a broad spectrum of equipment and fabrication tools, which will enable them to evaluate industry expectations in the context of the service capabilities of electric power systems. • Utility Host-Collaborators will work closely with partnering Semiconductor Site-Hosts to gain specific understanding of the needs and expectations of their customer.
Benefits (2) • Semiconductor Site-Hosts will gain an in-depth understanding of why their equipment is still sensitive to specific power quality events and learn specific measures that can be taken to further harden their current and future process systems. • Equipment and Tool Manufacturers will gain a better understanding of why their equipment may still be vulnerable to power quality issues and methods for improving their power quality robustness.
Stakeholder Collaboration • Collaboration between stakeholders will be required. • Project approach is to carefully examine the cause of PQ related downtime • The outcome of basic R&D will inform processes and standards to further improve system compatibility *Utilities can participate as Collaborators or Host-Collaborators.
Project Approach and Summary (1) • This project will methodically investigate the potential factors that continue to cause semiconductor plant downtime in a post-SEMI F47 environment. • These factors may include: • (1) three-phase voltage sag events • (2) repeated voltage sag events due to recloser operations • (3) events outside SEMI F47 scope of magnitude, duration, phase-shift or point-on-wave • (4) voltage sag testing methods utilized during certification, tool software, design, or configuration differences • (5) electrical system differences between the certification environment and the actual fab environment. • (6) Equipment not certified to SEMI F47
Project Approach and Summary (2) • Working through EPRI, Utility Host-Collaborators will partner with a specific Semiconductor Site-Hosts to investigate SEMI F47 requirements against specific site electrical environments and identify potential gaps against tool shutdown data. • SEMI F47 certification documents will be reviewed for the sensitive tool sets and characterization of this equipment will be accomplished through additional analysis and testing. • Specific design and mitigation strategies including cost-benefit will be determined and documented.
Project Approach and Summary (3) • The general, non-confidential findings from these partnerships will help inform the overall collaborative effort through workshops, white papers, and the final report. • Utility Collaborators will participate in the overall effort through participation in project web-meeting and workshops, inclusion in engagement with SEMI and SEMATECH, and involvement in any proposed standards modifications.
Research Project Tasks Specific R&D Activities at each Host-Site Collaborative Activities
Potential Causes for Downtime (1) Three-Phase voltage sag events. • SEMI F47 does not require the OEM to test their equipment against three phase voltage sags events • CIGRE study (C4.110) has shown that three-phase (Type III) events can make up to 20 percent of the events that occur
Potential Causes for Downtime (2) Repeat voltage sag events • Reclosing to restore operations. • SEMI F47 does not require testing for back to back events • Sag events can be multiple events in close intervals based on fault clearing
Potential Causes for Downtime (3) Event magnitude, duration, phase-shift, and point-on-wave are outside of SEMI F47 scope • SEMI F47 calls for testing at 0 degree point-on-wave. • Actual events can occur at various points-on-wave • Possible Phase-shifts are based on set of test vectors. • Actual events can be different • Minimum magnitudes and durations are: • 50% Vnom, 200ms • 70% Vnom, 500ms • 80% Vnom, 1 Second
Potential Causes for Downtime (4) Voltage sag testing methods utilized during certification. • There are three types of phase-to-phase voltage sag test vectors that are allowed for SEMI F47 testing. • These three types of vectors result in various voltage magnitudes and phase shifts.
Potential Causes for Downtime (5) Tool Software, design, or configuration differences • The tool configuration and software during SEMI F47 testing may have been slightly different than the equipment that is installed at the semiconductor fab’s facility. Graphic Ref: SEMI F49 “Guide for Semiconductor Factory Voltage Sag Immunity””
Potential Causes for Downtime (6) Electrical System Differences • During SEMI F47 certification testing, the equipment is tested against the nominal voltage available at the site. • The available nominal and peak voltage at the point of connection at the semiconductor fab can change due to changes to the system configuration. The Lower the Pre-Sag Voltage, the Less Energy (and ride-through time)Is Available in the Components with Capacitors
Potential Causes for Downtime (7) Installed Equipment In the Fab is not Compliant to SEMI F47 • Equipment in the factory may not actually be compliant to power quality standards such as SEMI F47. • In procurement, tool capabilities and delivery schedule may trump testing for SEMI F47 compliance REF: Impact of SEMI F47 on Utilities and Their Customers, EPRI, Palo Alto, CA: 2004. 1002284.