Armand Usher Electrical Engineer Intel Electronics Kiriat Gat Israel Voltage sags-solutions in semiconductor industry Armand Usher Electrical Engineer Intel Electronics Kiriat Gat Israel

Voltage sags in semiconductor industry In the semiconductor industry facilities (FABs) the “voltage sags” or “voltage dips” (in British English) are the most common power problem and cause downtime, scrap and M$ losses. SAG – voltage drop below 90% of the Un ,but not interruption Causes - Weather conditions ,equipment failure, operation errors https://www.youtube.com/watch?v=SeGqCl3YAaQ

Voltage sags in semiconductor industry ΔU=35.8%Un Phase Start Time Duration (s) Value (V) Deviation Voltage Sag 2 15/09/2014 5:17:32.441AM 0.079 59600 35.83% 64.12% Interpretation 161 KV 1Ph sag 35% → 22 KV 2 Ph sag 20% → 0.4 KV 3Ph sag 12%

Voltage sags in semiconductor industry 3 Ph Sc

Voltage sags in semiconductor industry Source Intel Fab 28A XFMR 522 45MVA 161/22KV Dec 2012 –Dec 2013

Voltage sags in semiconductor industry Affected systems: •Instrument and controller power supplies •VFD –variable frequency drives •Voltage monitoring relays •Circuit breakers open due to increased current on phases without sags •Sensor faults or errors •Robot failure •Internal communication errors •Computer re-boots

Voltage sags in semiconductor industry SOLUTIONS 1 IEC performance improvement 2 Increase the voltage sags immunity for equipment's and tools 3 Install DVR (Dynamic Voltage Restorer) 4 SEMI F47 standard

Voltage sags in semiconductor industry SOLUTIONS 1 IEC performance improvement In 1999 were registered about 200 events from IEC supply grid In 2013 were registered about 100 events

Voltage sags in semiconductor industry 2 Increase the voltage sags immunity for equipment's and tools Switch power supply settings Increase the rating of power supply unit (PSU) Reduce the load in the power supply unit(PSU) Use 2 Phase PSU instead of one phase Use 3 phase PSU Change the voltage relays settings (threshold and trip delay) Use contactors instead of relays were possible VFD calibration instead of scalar to set DFC (direct fly start) were flying start is automatic

Voltage sags in semiconductor industry 3 Install DVR (Dynamic Voltage Restorer) The DVR purpose to compensate loss of power during voltage sags The energy is provided by a capacitors bank Intel DVR statistic Two DVRs –rated power of one DVR 15/22MVA Concept : DVR at Off line mode Vs UPS at On line mode 15 years in service DVR availability 99.9% Average voltage compensation /year 120 DVR external/internal compensation rate 99.5% Compensation for 1Ph sags– 50% , for 500msec Compensation for 3Ph sags– 35% , for 500msec

Voltage sags in semiconductor industry

Voltage sags in semiconductor industry DVR

After DVR compensation on 22KV Voltage sags upstream DVR on 161KV 161/93KV ΔUn=35% 22/12.7KV ΔUn=2.9% After DVR compensation on 22KV

After DVR compensation Voltage sags in semiconductor industry Voltage sags upstream DVR on 161KV After DVR compensation

Voltage sags in semiconductor industry 4 SEMI F47- Specification for Semiconductor Process Equipment Voltage Sag Immunity SCOPE SEMI F47-0706 defines the required voltage sag tolerance for a semiconductor tool that must operate without interruption For sags Phase to N and two Phases (not 3 Ph) SEMI= Semiconductor Equipment and Materials International The standard has been implemented by semiconductor tool vendors

Voltage sags in semiconductor industry The primary focus for tools: Lito, Dif, Etch etc The secondary focus for utilities subsystems and components –Power supplies units –Ultrasonic generators –Computers and communication systems –Robots and factory interfaces –AC Contactor coils and AC relay coils –Chillers pumps and blowers –Variable frequency drives (VFD)

Voltage sags in semiconductor industry SEMI F47 requires that tools tolerate the following voltage sags: •50% remaining voltage, 50% missing voltage, for 200 milliseconds •70% remaining voltage, 30% missing voltage, for 500 milliseconds •80% remaining voltage, 20% missing voltage for 1 second. In addition, SEMI F47 recommends, but does not require, that tools tolerate: •0% remaining voltage, 100% missing voltage, for 1 cycle •80% remaining voltage, 20% missing voltage, for 10 seconds

Voltage sags in semiconductor industry SEMI F47-0706 Equipment will continue to operate Equipment not required to operate

Voltage sags in semiconductor industry F28A 2012-2013 VOLTAGE SAGS vs SEMI -F47 STANDARD

Voltage sags in semiconductor industry Bibliography: -Intel F28 DVR ABB Switzerland-Maintenance manual -Intel F28 Elspec- Investigator manual -SEMI F47-0706 and IEC Voltage Sag Standards -Differences, overlaps, and similarities - Alex Mc Eachern Power Standards Lab (PSL) -Sag immunity - Inexpensive, simple ways to increase sag immunity -Power Standards Lab (PSL) -Voltage sag immunity standards –Pacific Gas and Electric Company –Power quality bulletin 3 -www.semi.org