Head track width

As the head track width decreases, remanent magnetization of the main pole tip is likely to occur because of stress-induced anisotropy and increased shape anisotropy in the normal direction to the ABS. The field from this remanent magnetization can... 

Deposition and patterning of the bottom magnetic pole follow. The pole is usually electroplated with a through-photoresist window frame mask to a thickness level of 2 to 4 fim. Note that whereas the magnetic pole is made into a pancake shape to increase the head efficiency, it is the narrow p>ole tip s dimension that determines the narrow track width. As stated, the widely used Co-based alloy magnetic poles are elec-trodeposited (wet process). Nanocrystalline FeN-based alloys are sputter-deposited in a vacuum chamber (dry process). 

Table 1. Read head parameters used for a 106 Gb/in2 demonstration. Here w corresponds to the active read track width, h is the sensor height, G the shield to shield separation.

State-of-the-art piezo-based drop-on-demand printers are produced by companies such as Xaar (UK), Konica Minolta (Japan), and Fujifilm Dimatix (US). These print heads have around 180 to 360 nozzles per inch and are designed to print at basic resolutions of up to 360 dpi with drop volumes down to about 40 pi (picoliter). This type of print resolution gives features equivalent to approximately 100 /xm track width on PET or PI substrates. However, Xaar s new generation "gray scale" heads allow variable drop volumes down to around 3 pi to give printed features of around 50 /xm or less. 

Ruigrok, J. J. M., Sillen, C. W. M. P. van Rijn, L. R. M. (1990). High performance metal-in-gap heads with very small track widths. Journal of Magnetism and Magnetic Materials, 83, 41-4. 

The focused aerosol particles are 1 to 5 pm in size and permit microfine conductor structures down to widths of 10 pm and 20 pm spacing. Ink, substrate, and print parameters all have to be closely matched in order to achieve structures as fine as this. On account of the parallel alignment and high exit speed of the aerosol, the contour sharpness of the conductor track geometry remains virtually constant even when the nozzle-to-substrate gap is as wide as 3 mm. Consequently, small irregularities in the substrate surface are easy to print without modification of the print head s z-axis alignment. 

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