The Head-Disk Interface Roadmap to an Areal Density of 4Tbit/in²

Table 2

HMS breakdown scenarios for 4 Tb/in².

HMS Budget	1 Tb/in²			4 Tb/in²			HMS adder
Components	INSIC 2010	Target HMS by ~2014		INSIC 2010	Target HMS by ~2020-21		(effect of HAMR, BPM)
Component		Hi	Lo		Medium risk	High risk	BPM	HAMR
TDH	1.8	2.0	1.0	1.4	1.1	0.6	0.3	0.5
Disc overcoat	0.9	2.5	2.0	0.6	1.8	1.5	0.3	0.6
Disk lubricant	0.9	1.2	1.0	0.8	1.0	0.8
Clearance	1.3	1.2	1.0	0.6	0.6	0.5	0.2	0.3
Head overcoat	1.0	2.0	1.5	0.7	1.1	0.9
Total	5.8	8.9	6.5	4.0	5.6	4.3	0.8	1.4

The HMS adder columns corresponding to HAMR and BPM will be discussed in Section 4.