Kiyoharu Fujita

Title: Kiyoharu Fujita: Innovator in Thin Film Magnetic Head Technology

Introduction

Kiyoharu Fujita is a prominent inventor based in Mohka, Japan. He has made significant contributions to the field of magnetic head technology, holding a total of 3 patents. His work focuses on enhancing the performance of thin film magnetic heads, which are crucial components in various electronic devices.

Latest Patents

Fujita's latest patents include a manufacturing method for a thin film magnetic head that features a fine crystal grain coil. This innovative design incorporates a lower magnetic core, an upper magnetic core, and a thin film copper coil. The method aims to reduce the time constant by lowering the specific resistance of the thin film coil and minimizing insulating resin layers. This advancement allows for writing information at higher frequencies. Additionally, the average crystal grain size of the thin film copper coil is optimized to be no more than 0.5 µm, with a preference for 0.2 µm. Furthermore, the surface roughness of the thin film copper coil is reduced to not more than 15 nm.

Another notable patent involves a thin film magnetic head with a reduced magnetic gap achieved by incorporating coil conductors with convex surfaces. This design maintains insulation between layers while reducing the distances between thin film coils. The lowermost-layer thin film conductors are designed with a rectangular cross-section and are placed on insulating resin layers. The second lowermost-layer thin film coil features conductors with a downward convex bottom surface, enhancing the magnetic path efficiency.

Career Highlights

Kiyoharu Fujita is currently employed at Hitachi Metals, Ltd., where he continues to innovate in the field of magnetic technology. His work has significantly impacted the development of high-performance magnetic heads used in various applications.

Collaborations

Fujita has collaborated with notable colleagues, including Shinji Furuichi and Takeo Sasaki. Their combined expertise has contributed to the advancement of thin film magnetic head technology.

Conclusion

Kiyoharu Fujita's contributions to the field of thin film magnetic heads demonstrate his commitment to innovation and excellence. His patents reflect a deep understanding of material science and engineering, paving the way for future advancements in this critical technology.