A Prototype Tape System Using Multi Channel Stack Heads and Metal Evaporated Tape

2006.05.18

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

) 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

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

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

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

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 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

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 （１５ 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 . S y s t e m AMR - 2 0 System ） B ） - 3 0 ｄ B （ｄ t （ l

u - 4 0 e p v t e u - 5 0 L O - 6 0 - 7 0 - 8 0 0 10 20 30 0 5 1 0 1 5 2 0 Frequency（MHｚ） F re q u e n c y （ M H ｚ）

Can not cover with protective layer. Magnetic layer must be thinner. (Head wear)

Need to improve co rrosion resistance.

NASA/IEEE MSST2006 Sony Corporation 26/29 2006.05.18

Corrosion resistant spin-valve head Ta Ta

PtMn PtMn

CoFe CoNiFe Cu CuAu CoFe CoNiFe NiFe NiFe Ta Ta

Battelle Class 2 test Transfer Curves of the spin-valve head 400 Temperature 30 (degree C) 300 before 200 after

Humidity 70 (%)

) V μ ( t u p t u o d a e 100 H H2S gas 0.01 (ppm) 0

Cl2 gas 0.01 (ppm) -100 -200 NO2 gas 0.2 (ppm) -300 Test time 20 days -400 = 10 years in office -500 -150 -100 -50 0 50 100 150 Magnetic field (Oe)

NASA/IEEE MSST2006 Sony Corporation 27/29 2006.05.18

Ultra-thin ME tape with new lubricant

Test sample Surface image of Tested samples

Magnetic layer 33 (nm) DLC Protective layer 10 (nm)

Lubricant A No carboxyl group SLaumbrpiclea nAt 1A SLaumbrpiclea nCt 1C 20um 20um Lubricant C With 2 carboxyl group

Battelle Class 2 test Error rate of the sample C 1.E+00 Temperature 30 (degree C) Initial Humidity 70 (%)

e After Battelle 2 t 1.E-01 a r

H2S gas 0.01 (ppm) r o r

Cl2 gas 0.01 (ppm) r

E 1.E-02

NO2 gas 0.2 (ppm) Test time 100 days 1.E-03 = 50 years in office 0 1000 2000 3000

Time (sec.)

NASA/IEEE MSST2006 Sony Corporation 28/29 2006.05.18 Conclusion Multi-channel stack heads and NANT were developed for narrow track helical scan tape system.

Corrosion resistant spin-valve element were developed.

New lubricant were developed for ultra-thin metal evaporated tape.

Prototype drive was created with minimum Tp=1.5µm.

NASA/IEEE MSST2006 Sony Corporation 29/29 2006.05.18

Backup •

NASA/IEEE MSST2006 Sony Corporation 30/29 2006.05.18

Azimuth Loss Effect

Wa Wh Wa

E: Signal from an adjacent track to 0 -5 Tp=10um home track ratio, Tw=2Tp (on track) ) -10 Azimuth = +/-25 degrees B d

( -15 Tape Head Relative speed =20m/s Wh: Home track width, ) s s -20 o E(envelop) L

Wa: Head width on the adjacent track,

h -25 t E u

m -30

G: Head gap length, i z

A -35 ( λ : Write/read waveform period, E -40 θ: Azimuth angle -45 -50 0 10 20 30 40 50 60 Frequency (MHz)

NASA/IEEE MSST2006 Sony Corporation 31/29 2006.05.18

NANT Error-rate vs Off-track Characteristics

Most stable case Phase (degrees) Tp 0 degrees -180 -90 0 90 180 180 degrees 1e0

1e-1 Track Error 1e-2 0 Critical case (mechanical error-less) e t

a 0.05μm

Tp R 0.10μm +90 degrees r 1e-3 o

Tw r 0.15μm r

E 0.20μm −90 degrees )

s 1e-4 t i

Td b

0 0

0 1e-5 1

(with mechanical errors) (

Critical case

k Tw=0.7μm

∆ c

Tp- Tp o ∆ l 1e-6

Tw+ Tw B

∆ 1e-7 On the adjacent track Td+ Td Written Track Pitch narrow the Tp 1e-8 Errors widen the Tw -1.125 -0.75 -0.375 0 0.375 0.75 1.125 separate the Td Read Head Off Track (μm)

Track Error = ∆Tp+∆Tw+∆Td (definition)

NASA/IEEE MSST2006 Sony Corporation 32/29 2006.05.18

Abandoning the Azimuth Recording

• We cannot count on the azimuth effect at the target track pitch of 1.5um. • It is difficult to make a thin-film multi-channel write head with azimuth angle. • Multi-channel stack write head has merit to reduce the influence of mechanical accuracy.

Good by and thank you azimuth recording we have employed for many years.

NASA/IEEE MSST2006 Sony Corporation 33/29 2006.05.18

Read Signals and C1 Syndromes

Ch 5 Read Signal Ch 6

No Error Blocks Ch 5 Error Blocks C1 (ECC) Syndrome No Error Blocks Ch 6 Error Blocks

NASA/IEEE MSST2006 Sony Corporation 34/29 2006.05.18

Data Transfer Experiment

1. Recorded a file from PC to tape, 2. Reconstructed the recorded file from tape to PC, 3. Compared the reconstructed file to the original file. same file!

* Recording transfer rate was

20MBps (16 0Mbps).

NASA/IEEE MSST2006 Sony Corporation 35/29 2006.05.18

Contents • Introduction • Writing 1.5um track with multi-channel head • New Reading technology for 1.5um track • Simulations • Prototype drive • Corrosion resistance of spin-valve head and metal evaporated tape • Conclusion

NASA/IEEE MSST2006 Sony Corporation 36/29 Simulations 2006.05.18 NANT Read Tracking Phase (definition) Tp 0 degrees

180 degrees +/−90 degrees

NASA/IEEE MSST2006 Sony Corporation 37/29 Simulations 2006.05.18 Critical Tracking Phase = +/−90 degrees Tp

Tw Mechanical Error-less Td

Tp-∆Tp narrow Tp Tw+∆Tw wide Tw

Td+∆Td separated Td on the adjacent track

Track Error = ∆Tp +∆Tw+∆Td (definition)

NASA/IEEE MSST2006 Sony Corporation 38/29 2006.05.18

Definition of track error

Most stable case Tp 0 degrees 180 degrees

Critical case (mechanical error-less) Tp +90 degrees Tw −90 degrees

Critical case (with mechanical errors)

Tp-∆Tp Tw+∆Tw Errors narrow the Tp ∆ widen the Tw On the adjacent track Td+ Td separate the Td

Track Error = ∆Tp+∆Tw+∆Td

(definition)

NASA/IEEE MSST2006 Sony Corporation 39/29 Simulations 2006.05.18 NANT Error-rate Off-track Characteristics

1e0

1e-1 Most stable case Read Head Width 0 degrees Tp 1e-2 0.5μm e

180 degrees t

a 0.6μm R

r 1e-3 0.7μm o r r 0.8μm E

)

s 1e-4 0.9μm t i b

Critical case (mechanical error-less) 0 0

Tp 0 1e-5 1

+ ( 90 degrees

Tw k c o −90 degrees l 1e-6 B Td 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 40/29 NANT and Multi-channel Head 2006.05.18 Compensation for Error between Scans Recording Track Pattern

Ch 1 Ch 2 Ch 3 Ch 4 Ch 1 Ch 2 Ch 3 Ch 4 1.5µm 1.5µm 1.5µm 2µm 1.5µm 1.5µm 1.5µm 2µm

margin for channel 4

example for 4 channel multi

margin for scan error

Read-head Sca n-area Overlap

NASA/IEEE MSST2006 Sony Corporation 41/29 Narrow Track Reading 2006.05.18 Recording Methods

Tracking reading Non-tracking reading

General NT (audio), Azimuth helical scan DAT walkman, recording systems Micro MV (video)

General magnetic Next generation for Non-azimuth recording systems helical scan systems? recording (except helical scan) (presents in this report)

NASA/IEEE MSST2006 Sony Corporation 42/29 Narrow Track Reading 2006.05.18 Azimuth, Tracking

tape

+azimuth read head −azimuth read head

+azimuth track −azimuth track

NASA/IEEE MSST2006 Sony Corporation 43/29 Simulations 2006.05.18

Worst-Phase Error Rate at SNR* of 20dB

* SNR at center 1e0 tracking using 1e-1 0.7µm head 1e-2 e t

a 1e-3 R r 1e-4 o r r 1e-5 Read Head Width (μm) ) E

s 1e-6 t i

b 0.3

0 1e-7

0 0.4

0 1e-8 0.5

(1 0.6 k 1e-9 0.7 c o l 1e-10 0.8

B 0.9 1e-11 1 EQ:PR4 1e-12 Coding:24/27 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 44/29 Simulations 2006.05.18 Average Error Rate at SNR* of 20dB

* SNR at center 1e0 1e-1 tracking using µ 1e-2 0.7 m head e t

a 1e-3 R r 1e-4 o r r 1e-5 E Read Head Width (μm) )

s 1e-6 t i

b 0.3

0 1e-7

0 0.4

0 1e-8 0.5

(1 0.6 k 1e-9 0.7 c o

l 1e-10 0.8

B 0.9 EQ:PR4 1e-11 1 Coding:24/27 1e-12 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 45/29 Introduction 2006.05.18 Progress of Track Density in Helical Scan

DAT Format DDS2 DV DDS3 AIT-1 AIT-2 DDS4 MMV AIT-3 Prototype unit DDS λ min 0.666 0.666 0.500 0.333 0.350 0.243 0.333 0.286 0.291 0.240 μ m Track Pitch (Tp) 13.6 9.1 10.0 9.1 11.0 11.0 6.8 5.0 5.5 1.6 μ m Tp/λmin Ratio 20 14 20 27 31 45 20 17 19 6.7

Equalize Int Int PR4 PR1 PR1 PR1 PR1 PR4 EPR4 PR4 Coding 8/10 8/10 24/ 25 8/10 8/10 16/ 20 8/10 24/ 27 16/ 18 24/ 27 Azimuth Angle ±20 ±20 ±20 ±20 ±25 ±25 ±20 ±25 ±25 0 degrees

around 10µm around 5µm

NASA/IEEE MSST2006 Sony Corporation 46/29 Narrow Track Reading 2006.05.18 Azimuth, Tracking

1 scan per track, Tp << Tw < 2Tp Maximum Tracking Margin = Tp/2 tape

+azimuth read head −azimuth read head

+azimuth track −azimuth track

NASA/IEEE MSST2006 Sony Corporation 47/29 Narrow Track Reading 2006.05.18 Azimuth, Non-tracking

2 scans per track, Tp << Tw < 2Tp

draw only +azimuth head scans tape 0 and 360 degrees offset: Half scans are just on track.

180 degrees offset

+azimuth track −azimuth track

NASA/IEEE MSST2006 Sony Corporation 48/29 Narrow Track Reading 2006.05.18 Non-azimuth, Tracking

1 scan per track, Tw << Tp Maximum Tracking Margin = Tp/4 tape

NASA/IEEE MSST2006 Sony Corporation 49/29 Narrow Track Reading 2006.05.18 Non-azimuth, Non-tracking

2 scans per track, Tw < Tp/2

tape 0 and 180 degrees offset: Half scans are just on track.

90 degrees offset

NASA/IEEE MSST2006 Sony Corporation 50/29 Simulations 2006.05.18 Output Model of Track on Tape

1.2 1.1 Side Gap Writing Writing Between the tracks, there 1 l

e 0.9 are erase bands written by v m e 0.8

μ 0.28μm L

4 fringing magnetic force t 5

0.7 . u 0 p - t 0.6 from the edge of the write u Overwrited Track 0.10μm Overwriting Track

O 0.5

e head. v

i 0.4 t m a m l 0.3 e μ μ 6 2 R 3 . 0

0.2 . 0 0 These curves were obtained - 0.1 - 0 by analyzing the MFM data -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 of actual tape patterns. Track Width Position （μm）

NASA/IEEE MSST2006 Sony Corporation 51/29 Simulations 2006.05.18 Sensitivity Model of Spin-valve Head

1.1 1 Tw: effective track width Read Head Width 0.9 0.5μm 0.8

y 0.6μm t

i 0.1um

v 0.7 0.7μm i t i 0.8μm s

n 0.6 0.9μm e S

0.5

e Tw v i

t 0.4 a l

e 0.3 50% Height R 0.2 0.1 0 Inferred from track profile data. -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Those were read as recording Track width Position (μm) tracks with width of 0.8µm and 2µm. NASA/IEEE MSST2006 Sony Corporation 52/29 Simulations 2006.05.18

Error-rate Off-track Characteristics

1e0

1e-1 Read Head Width

1e-2 0.5μm e t

a 0.6μm R

r 1e-3 0.7μm o r r 0.8μm E

)

s 1e-4 0.9μm t i b

0 0

0 1e-5 1 (

c EQ:PR4 o l 1e-6 B Coding:24/27

1e-7 SNR:17dB 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 53/29 Simulations 2006.05.18

NANT Error-rate Off-track Characteristics

1e0

1e-1 Read Head Width

1e-2 0.5μm e t

a 0.6μm R

r 1e-3 0.7μm o r r 0.8μm E

)

s 1e-4 0.9μm t i b

0 0

0 1e-5 1 (

c EQ:PR4 o l 1e-6 B Coding:24/27

1e-7 SNR:17dB 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 54/29 Simulations 2006.05.18

NANT Error-rate Track-error Characteristics

1e0

1e-1 Track Error 1e-2 0 e t

a 0.05μm R

0.10μm r 1e-3 o

r 0.15μm r

E 0.20μm

)

s 1e-4 t i b

0 0

0 1e-5 1 (

k Tw=0.7μm c EQ:PR4 o l 1e-6 B Coding:24/27

1e-7 SNR:17dB Written Track Pitch Tw=0.7µm 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 55/29 Simulations 2006.05.18

Worst-Phase Error Rate at SNR* of 18dB

* SNR at center 1e0 tracking using µ 1e-1 0.7 m head e t

a 1e-2 R r o

r 1e-3 r Read Head Width (μm) ) E

s 1e-4 t i

b 0.3 0

0 1e-5 0.4 0 0.5

(1 0.6 k 1e-6 0.7 c o

l 0.8

B 1e-7 0.9 EQ:PR4 1 1e-8 Coding:24/27 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 56/29 Simulations 2006.05.18

Average Error Rate at SNR* of 18dB

* SNR at center 1e0 tracking using µ 1e-1 0.7 m head e t

a 1e-2 R r o

r 1e-3 r

E Read Head Width (μm) )

s 1e-4 t i

b 0.3 0

0 1e-5 0.4 0 0.5

(1 0.6 k 1e-6 0.7 c o l 0.8 EQ:PR4 B 1e-7 0.9 1 Coding:24/27 1e-8 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 57/29 Simulations 2006.05.18

Worst-Phase Error Rate at SNR* of 20dB

* SNR at center 1e0 tracking using 1e-1 0.7µm head 1e-2 e t

a 1e-3 R r 1e-4 o r r 1e-5 Read Head Width (μm) ) E

s 1e-6 t i

b 0.3

0 1e-7

0 0.4

0 1e-8 0.5

(1 0.6 k 1e-9 0.7 c o l 1e-10 0.8

B 0.9 EQ:PR4 1e-11 1 Coding:24/27 1e-12 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 58/29 Simulations 2006.05.18

Average Error Rate at SNR* of 20dB

* SNR at center 1e0 tracking using 1e-1 0.7µm head 1e-2 e t

a 1e-3 R r 1e-4 o r r 1e-5 E Read Head Width (μm) )

s 1e-6 t i

b 0.3

0 1e-7

0 0.4

0 1e-8 0.5

(1 0.6 k 1e-9 0.7 c o

l 1e-10 0.8 B 0.9 EQ:PR4 1e-11 1 1e-12 Coding:24/27 0 0.1 0.2 0.3 0.4 Track Error (μm)

NASA/IEEE MSST2006 Sony Corporation 59/29 2006.05.18

10,000Trend and Prospect of Areal Density

1,000 INSIC

] Hard Disk

2 SRC h Fuji electric ？ c HDD Commercial Read Rite Toshiba n i 100 SeagateR&D s/ R&D Fujitsu t Magnetic tape i b ATP Helical Scan G Tape R&D

[ 11.5Gb/in2 AIT-6 y 10 SAIT-4 t

i 6.5Gb/in2

s AIT-5 SAIT-3 n

e Tape Commercial AIT-4 INSIC D

MMV SAIT-2 l 1 a SAIT- １ e LTO-4 r AIT-3 DVC LTO-3 Linear tape A AIT-2 LTO, DLT AIT-1 LTO-2 0.1 LTO-1

1988 1990 1992 1994 1996 1998 2000 2 002 2004 2006 2008 2010 2012 2014 2016

NASA/IEEE MSST2006 Sony Corporation 60/29 2006.05.18

蒸着テープにおける記録密度向上

• Thinner Magnetic Layer • Finer Magnetic Particle with Under Layer • Smooth Surface

Conventional A-MEⅠ (DVC, AIT1~3) N o is e S p e c tr u m （１５ M H ｚ） 0 A I T - 4 ( A - M E Ⅱ ) - 1 0 A - M E Ⅲ f o r G M R G e n . S y s t e m 100nm - 2 0 Base Film

） - 3 0 B ｄ（

l - 4 0 e v

Ⅲ e - 5 0 A-ME For GMR Generation L - 6 0

Under Layer 30nm - 7 0 Base Film - 8 0 0 5 1 0 1 5 2 0 F r e q u e n c y （ M H ｚ） Co crystallites CoO crystallites

NASA/IEEE MSST2006 Sony Corporation 61/29 2006.05.18

High Sensitivity Read Heads for Tape System

Frequency Response

GMR

AMR High Sensitivity Anti-Corrosion GMR +12.6dB

） AMR 0dB B ｄ（ t u p t u O

0 5 10 15 20 25 30 Frequency（MHｚ） V ＝ 3.5m/s

Difficult to use conventional GMR in Tape Systems Anti-Corrosion GMR Element (Corrosion of GMR Element)

NASA/IEEE MSST2006 Sony Corporation 62/29 2006.05.18

High Performance Magnetic Tapes

-20

Advanced ME for GMR Gen. -25 Advanced MP for Next Gen. LTO-3 Media SNR (EPR4 at=200kFCI) -30 30 -35 ） 25

B 14dB ｄ（ l -40 20 e v ) e B 7.5dB d L -45 ( 15 R N -50 S 10

-55 5

-60 0 0 10 20 30 40 50 LTO-3 Advanced MP Advanced ME Frequency（MHｚ） for Next Gen. for GMR Gen.

Read Head : Tw=0.8µm, Shield to shield=0.18µm, v=13.4m/s

NASA/IEEE MSST2006 Sony Corporation 63/29 2006.05.18 テープの記録密度向上

磁石にならない部分 ( バインダーなど )

磁性粒子サイズ＆充填率 → 蒸着テープの方が高密度化に有利

NASA/IEEE MSST2006 Sony Corporation 64/29 2006.05.18

Demonstration of 4.5Gbit/in2 and 11.5Gbit/in2

Properties of evaporated tapes (ME-1,ME-2) AME ME-1 ME-2 Remnant Magnetism 300 kA/m 221 kA/m Thickness of Magnetic Layer 33 nm 28nm Mrt 10mA 6.2mA 100nm Coercive Force 116kA/m 102kA/m Magnetic Layer Co-CoO AMEⅢ

Properties of spin valve heads (GMR-1, GMR-2) 30nm

GMR-1 GMR-2 Track Width 0.8um 0.45um Distance between Shields 0.18um 0.12um Stripe Height 0.8um 0.5um Element Type Spin Valve

NASA/IEEE MSST2006 Sony Corporation 65/29 2006.05.18

Demonstration of 4.5Gbit/in2 and 11.5Gbit/in2

□4.5Gb/in.2 （磁性層厚： 33nm ） □11.5Gb/in.2 （磁性層厚： 28nm ）磁気記録テープとして、 22.2kTPI ； 203kBPI 39.5kTPI ； 290kBPI 2001/01 新聞発表 2001/08 TMRC 発表世界最高の記録密度を達成！

Isolated pulse of reproduced output signal

0 0

-10 -10 -20 -20 b) ) d b (

l -30 -30 ( Spectra of signal

e l v e tape noise e v l

-40 -40 e l t

and media noise u t p u t

-50 p -50 u t u O tape noise -60 O -60 -70 -70 system noise system noise -80 -80 0 5 10 15 20 0 5 10 15 20 25 30 Frequency (MHz) Frequency (MHz) T.Ozue, M.Kondo, Y.Soda, S.Fukuda, S.Onodera and T.Kawana;” 11.5Gb/in2 Recording Using Spin-Valve Heads in Tape Systems,IEEE Trans. on Magn. Vol.38,No1,pp136-140(2002)

NASA/IEEE MSST2006 Sony Corporation 66/29 2006.05.18

4.5Gbit/in2 、 11.5Gbit/in2 を適用すると．．．

Inductive GMR-1 GMR-2

Areal density(Gbit/in2) 0.7 4.5 11.5

Track Density(kTPI) 4.6 22.2 39.5

Linear density(kBPI) 155 203 290

Mrt of media(mA) 60 10 6

SNR(dB) 18 26 18

Capacity(AIT cassette) 100GB 640GB 1.6TB

Capacity(S-AIT cassette) 500GB 3.2TB 8.2TB

テラバイト巻級の容量が可 / 能

NASA/IEEE MSST2006 Sony Corporation 67/29 2006.05.18

NASA/IEEE MSST2006 Sony Corporation 68/29 2006.05.18

Dynamic Tracking

• To control head position during reading dynamically by using actuator. • To enable to trace narrow track even when the track is not straight.

upper drum

actuator head

Read Head

Dynamic tracking : OFF

Dynamic tracking : ON

NASA/IEEE MSST2006 Sony Corporation 69/29