Location History:
- Hitachi, JA (1977)
- Ibaraki, JP (1991)
- Hitachi-shi, Ibaragi, JP (2003)
- Hitachi, JP (1980 - 2007)
Company Filing History:
29 out of 42,508 
6 out of 3,781 
2 out of 836 
Years Active: 1977-2007
Title: Hiroyoshi Kokaku: A Pioneer in Semiconductor Innovations
Introduction
Hiroyoshi Kokaku, an esteemed inventor based in Hitachi, Japan, holds an impressive portfolio consisting of 38 patents. His contributions to the field of semiconductor technology have significantly advanced the way we approach manufacturing and reliability in devices.
Latest Patents
Among his latest patents are groundbreaking innovations involving semiconductor devices, wafers, and modules. These patents focus on techniques that minimize warp, crack generation, and damage at chip edges during drop tests. Notably, his semiconductor device showcases superior mounting reliability and mass producibility. The design includes a semiconductor chip with a porous stress-relaxing layer that supports circuit layers connected to the electrodes. An organic protecting film is placed strategically on the opposite side of the stress-relaxing layer, with side planes exposed, ensuring optimal functionality.
Another significant patent discusses a semiconductor device characterized by its exceptional connection reliability. This is achieved through a carefully designed buffer body that absorbs thermal expansion differences between the mounting substrate and the semiconductor element. The film material utilized in this design demonstrates a modulus of elasticity that is specifically calibrated for the reflow temperature range, enhancing the overall thermal stress management in semiconductor packages.
Career Highlights
Kokaku’s professional journey includes notable contributions at leading companies such as Hitachi, Ltd. and Renesas Technology Corporation. His work has not only propelled innovations within these organizations but has also fostered advancements in the semiconductor industry at large.
Collaborations
Throughout his career, Kokaku has collaborated with renowned colleagues such as Masanori Segawa and Asao Nishimura. Together, they have worked on various projects that further pushed the boundaries of semiconductor technologies.
Conclusion
Hiroyoshi Kokaku's commitment to innovation in semiconductor technology is reflected in his extensive patent portfolio and collaborative efforts with leading professionals in the field. His advancements not only address the technical challenges faced in the industry but also pave the way for future developments in semiconductor design and manufacturing.