2006.05.18 A Prototype Tape System Using Multi Channel Stack Heads and Metal Evaporated Tape Hiroaki Ono Shinichi Fukuda Yusuke Tamakawa Masaaki Sekine Tomoe Iwano Seiichi Onodera Sony Corporation NASA/IEEE MSST2006 Sony Corporation 1/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Prototype drive • Corrosion resistance of spin-valve head and ultra-thin metal evaporated tape • Conclusion NASA/IEEE MSST2006 Sony Corporation 2/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Corrosion resistance of spin-valve head and metal evaporated tape • Prototype drive • Conclusion NASA/IEEE MSST2006 Sony Corporation 3/29 2006.05.18 Previous Works An SNR of 26dB was obtained using a spin-valve head with a width of 0.8µm, and a metal evaporated tape with a contact tape/head interface. --- reported in TMRC-2001 Possibility of a high track-density tape-drive However, these were laboratory works using a spin-stand tape tester, not a drive. NASA/IEEE MSST2006 Sony Corporation 4/29 2006.05.18 Target To create a helical-scan tape drive with a track pitch of 1.5µm using a spin-valve head. NASA/IEEE MSST2006 Sony Corporation 5/29 2006.05.18 Progress of Track Density in Helical Scan 100 ) m 1 ktpi μ DAT ( DV AIT-1 h AIT-2 c 10 t i DDS-2 DDS-3 P AIT-3 DDS-4 k AIT-4 c a MicroMV r T with AMR Head 10 ktpi Our Prototype with GMR Head 1 1985 1990 1995 2000 2005 2010 Released Year Track pitch should be reduced dras tically from around 5um to 1.5um. NASA/IEEE MSST2006 Sony Corporation 6/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel stack head • New Reading technology for 1.5um track • Prototype drive • Corrosion resistance of spin-valve head and metal evaporated tape • Conclusion NASA/IEEE MSST2006 Sony Corporation 7/29 2006.05.18 Azimuth Recording Linear (Serpentine) System Helical Scan System BOT BOT EOT EOT Tape Length Tape Length tape +azimuth read head −azimuth read head +azimuth track −azimuth track NASA/IEEE MSST2006 Sony Corporation 8/29 2006.05.18 Signal to Crosstalk Noise Ratio 40 ) Micro MV EQ: PR4 B d 35 ( Code: 24/27 o i t a 30 Azimuth: R +/− e 25 degrees s i 25 o λ µ Tw=1.5 Tp N min. ( m) k 20 l 0.15 a t s 0.20 s o 15 r 0.25 C 0.30 o If our prototype t 10 0.35 l a drive used an 0.40 n g 5 i azimuth recording; S 0 0 1 2 3 4 5 6 7 8 9 10 Track Pitch (um) NASA/IEEE MSST2006 Sony Corporation 9/29 2006.05.18 Influence of Mechanical Accuracy Ideal Track Pattern Stability of Drum Rotation tape Head 2 Track width Head 1 With Mechanical Inaccuracy tape Stability of Tape Run Accuracy of Head Mount Head 1 Head 3 Head 2 Head 4 NASA/IEEE MSST2006 Sony Corporation 10/29 2006.05.18 Multi-channel stack write head Write Gaps ch1 ch1 ch2 1.5 1.5um ch2 ch3 ch3 ch4 ch4 3.5um Cross Section Recording Direction 1.5um NASA/IEEE MSST2006 Sony Corporation 11/29 2006.05.18 Track Pattern of Multi-channel Stack Head Stability of Drum Rotation (i) AN +1) SC N (i SCA tape Ch1 Ch2 Ch3 Ch4 Ch1 Ch2 Ch3 Ch4 w i t c c c h c c c o o o o o o fl n n n n n n s s s uc s s s t t t t t t a a a t a a a nt nt n ua nt nt nt t t i o n s MFM Image of Tracks Stability of Tape Run 4ch Stack head Accuracy of Head Mount ch4 ch4 ch4 NASA/IEEE MSST2006 Sony Corporation 12/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Prototype drive • Corrosion resistance of spin-valve head and metal evaporated tape • Conclusion NASA/IEEE MSST2006 Sony Corporation 13/29 2006.05.18 NANT (Non-azimuth, Non-tracking) tape tracking Tracking phase is controlled to the center of the track. non-tracking Double density scan Tracking phase is free. NASA/IEEE MSST2006 Sony Corporation 14/29 2006.05.18 Multi-channel Read Head and NANT Reading Recorded Tracks O n e D t B C r A a Read Heads c head D k i s r e a head C d b y se v e r a head B l r e a d h head A e a d s H . T e r a a c d this track is read by k Example of 4 channel multi head NASA/IEEE MSST2006 Sony Corporation 15/29 2006.05.18 Multi-channel stack read head Read Gaps 8ch Read Elements ch1 ch5 ch2 ch6 ch3 ch7 ch4 ch8 Spin Valve Element Hard Magnet / Electrode 0.75um 1.5um 9um NASA/IEEE MSST2006 Sony Corporation 16/29 2006.05.18 NANT Error Rate Off-track Characteristics Read Elements Read element width ; 0.7um 1e0 1e-1 Total Error Read ch1 Read ch2 e 1e-2 t Read ch3 a R r o 1e-3 Read Head Off Track r r E ) s t - + i 1e-4 b 0 0 0 1 ( 1e-5 k c o l B 1e-6 Recorded Track 1e-7 Written Track Pitch 1e-8 -1.125 -0.75 -0.375 0 0.375 0.75 1.125 Read Head Off Track (μm) NASA/IEEE MSST2006 Sony Corporation 17/29 2006.05.18 Worst-Phase Error Rate at SNR* of 20dB 1e0 1e-1 1e-2 Critical case (with mechanical errors) e t ∆ a 1e-3 Tp- Tp R Tw+∆Tw r 1e-4 o r r 1e-5 ∆ E Read Head Width (μm) On the adjacent track Td+ Td ) s 1e-6 t i narrow the Tp b 0.3 0 1e-7 Errors widen the Tw 0 0.4 0 1e-8 0.5 separate the Td (1 0.6 k 1e-9 0.7 c o l 1e-10 0.8 B 0.9 1e-11 1 1e-12 0 0.1 0.2 0.3 0.4 Track Error (μm) Track Error = ∆Tp+∆Tw+∆Td (definition) * SNR at center tracking using 0.7µm head EQ: PR4 Coding: 24/27 Tp: 1.5µm NASA/IEEE MSST2006 Sony Corporation 18/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Prototype drive • Corrosion resistance of spin-valve head and metal evaporated tape • Conclusion NASA/IEEE MSST2006 Sony Corporation 19/29 2006.05.18 Prototype Drive Prototype Drive Specifications Drum Diameter 40mm Track Width of Ch1 to Ch3 1.5um 1.625µm Average Track Width of Ch4 2um Tape Width 8mm Write Channel 4ch One head with 4 channels Read Channel 8ch One head with 8 channels Coding Rate 8/9 Channel PR4ML Write Data Transfer Rate 20MBps Channel Clock 148MHz Minimum Wavelength 0.24um Linear Density 188kbpi Track Density 15.6ktpi Areal Density 2.94Gbpi2 Head Placement Read Channel Block Diagram ADC PLL EQ DET C1 Ch 1 4ch write head Ch 2 8ch read head Ch 3 NT USB Ch 4 C2 I/F Ch 5 Ch 6 Ch 7 Ch 8 NASA/IEEE MSST2006 Sony Corporation 20/29 2006.05.18 Recorded Pattern Tape running Ch1 Ch2 Ch3 Ch4 Ch1 Ch2 Ch3 Ch4 Head running write N write N+1 NASA/IEEE MSST2006 Sony Corporation 21/29 2006.05.18 Recorded Pattern (enlargement) Ch 4 Ch 4 Ch 4 Ch 4 Ch 4 Ch 3 Ch 2 Ch 4 Ch 1 Ch 4 Ch 4 Ch 3 Ch 3 Ch 2 Ch 4 Ch 1 Ch 2 Ch 4 Ch 3 He Ch 2 ad Ch 1 Ch 4 Ch 1 Ch 4 Ch4: 2µm Ch 4 Ch3: 1.5µm Ch 4 Ch2: 1.5µm Ch1: 1.5µm NASA/IEEE MSST2006 Sony Corporation 22/29 2006.05.18 1 block NANT -- Two Head Scans Analysis Symbol Error Map Write Write Ch1 Write Ch2 Read A Ch2 Read B Write Ch1 Write Ch2 Ch4 Estimated Scanning trail s Ch3 k c a Ch2 r Read A T Ch1 Read B e t i r Ch4 W Ch3 NASA/IEEE MSST2006 Sony Corporation 23/29 2006.05.18 Track Composed of Read Heads Write 1 Write 2 Write 3 Read 5 Write 4 Read 6 Read 7 Read 8 Read 1 Read 2 Read 3 Read 5 Read 4 Read 6 Read 7 Read 8 Read 1 Read 2 Read 3 Read 5 Read 4 Read 6 Read 7 Read 8 beginning of track head scan end of track NASA/IEEE MSST2006 Sony Corporation 24/29 2006.05.18 Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Prototype drive • Corrosion resistance of spin-valve head and metal evaporated tape • Conclusion NASA/IEEE MSST2006 Sony Corporation 25/29 2006.05.18 Key Devices for High Recording Density High Sensitivity Head Low Noise Media Frequency Response N o is e S p e c t ru m （ １ ５ M H ｚ ） 0 A I T - 4 ( A - M E Ⅱ ) - 1 0 Conventional ME GMR AU-lMtrEa-Ⅲth ifno MEr G M R G e n .