Thin Film Head Division
203 Matsunokijima, Toyooka-mura, Iwata-gun
Shizuoka 438-0192, Japan
Date Visited: 10 March 1998
Yamaha is widely known for the manufacture of musical instruments from pianos to synthesizers but less well known for its electronic components, which were developed to support electronic instruments. In 1997 revenue was ~$4 billion, generated by 8,800 employees at several sites worldwide. Yamaha surprised the industry in 1991 by bringing TFH and, later, MR and GMR heads to the market before many other companies. In 1997, Yamaha produced 80 million MR heads. Although Yamaha has extensive experience in LSI, and previously, in 1984, made an aborted attempt at perpendicular heads, the company was not known to have competence in magnetic materials and recording systems. It is possible that a major Japanese customer such as NTT is collaborating with Yamaha. Head fabrication is done at the Shizuoka plant.
Yamaha has a clear focus to maintain its leadership and be the major non-captive supplier of advanced GMR sensors. Yamaha managers are well aware of the approaching supraparamagnetic limit and have developed a clear technology roadmap that includes two generations of SIL followed by near-field optical recording. Because they also manufacture CD optical heads, they are confident about their ability to manufacture future optical heads. For now, however, the focus is production of TFHs.
Yamaha's technology roadmap includes GMR heads, advanced GMR heads, dual stage actuators, and sliders shrinking to the "femtoslider" level and beyond. The superparamagnetic effect in media has not affected the company's plans as yet, since it does not make media. In anticipation of higher coercivities and narrower track widths in the future, Yamaha researchers have experimented with sputtered high moment pole tip materials, but did not have them in production at the time of this visit.
Although a market leader, Yamaha hosts indicated that they felt squeezed by system integrators to lower prices unrealistically.
Three-inch square Al2O3-TiC substrates are obtained from two sources, and the heads are fabricated using a relatively conventional process. Magnetic pole materials are plated, and the GMR is sputtered. Nikon I-line steppers are used to define features with critical dimensions, and focused ion beam etching is used for pole trimming. The wafer size is quite small by industry standards, which now can be up to 6", but Yamaha managers do not believe this is as important as achieving high yield. Re-tooling for larger wafers would require substantial new capital investments. Smaller sliders allowing many more heads per wafer have improved productivity.
Yamaha makes its own integrated suspensions, which allows it to produce advanced prototypes. Yamaha researchers have considered silicon chips placed on the suspension and the possibility of their producing SIL flying optical heads, but have no projects to report as yet.
Yamaha managers indicated that they did not believe it is necessary for them to establish collaborations with any Japanese university. Yamaha does not participate in ASET.
The highlight of this visit was the extensive, informative tour led by Mr. Ito of the wafer fabrication area. Most of the equipment, astonishingly, was custom designed and is maintained by Yamaha. Although this was common in the IC industry 25 years ago, most manufacturers of ICs and TFHs use commercially available equipment, often supported by service contracts. The equipment was obviously carefully designed for maximum automation, efficient integration and maximum use of space. The fab area is one large Class 1000 clean room (ceiling filters and floor exhausts) estimated to be 40,000-50,000 ft2. All operations, including substrate polishing, are carried out in long parallel rows. Overall, it appeared comparable in size to those of major U.S. manufacturers, such as Seagate Technology.
Yamaha is primarily focused on GMR TFHs for longitudinal recording. No interest was expressed in heads for perpendicular recording, partially due to the memory of the earlier failure of the market to develop in 1984. It would appear that Yamaha will depend on obtaining new technologies from more research-oriented customers. No evidence of a significant R&D effort was obtained in this visit.