Yoshio Umayahara
Nippon Electric Glass
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Publication
Featured researches published by Yoshio Umayahara.
Key Engineering Materials | 2006
Masaru Iwao; Yoshio Umayahara; Kazuyoshi Shindo
For high frequency packaging applications, LTCC materials are required to have a low loss tangent to reduce the total microwave loss. For multi-layered ceramic devices with embedded passive components, besides a loss tangent, a small temperature coefficient of resonance frequency (TCF) is an important factor. To meet these demands, we developed a new LTCC material with a smaller TCF, less than +/-3ppm/oC, and a low loss tangent, 0.0012 at 15GHz. We designed the glass composition to precipitate two low-loss crystal phases during firing at 900 oC. One phase has a plus TCF and the other phase has a minus TCF. We also controlled the amount of the two crystal phases, so these crystal phases and the fixed amount of alumina filler make the sum of TCF for the LTCC material close to zero.
Journal of The Ceramic Society of Japan | 2010
Shunsuke Fujita; Yoshio Umayahara; Setsuhisa Tanabe
Archive | 2007
Masaaki Kadomi; Yoshio Umayahara; Tadahito Furuyama; Masaru Iwao; Atsutomo Hama; Takafumi Sugiyama; Yukihiro Hayashi; Naoto Morizumi
Archive | 2007
Shunsuke Fujita; Yoshio Umayahara; Masaru Iwao; Takemi Kikutani
Archive | 2009
Shunsuke Fujita; Yoshio Umayahara; Akihiko Sakamoto
Archive | 2008
Yoshio Umayahara; Ryota Suzuki; Yoshikatsu Nishikawa; Masaru Ikebe; Hiroki Mori; Yoshinori Hasegawa
Archive | 2007
Masaru Iwao; Yoshio Umayahara
Archive | 2002
Yoshio Umayahara; Yoshikatsu Nishikawa; Kazuyoshi Shindo
Archive | 2003
Yoshikatsu Nishikawa; Yoshio Umayahara
Archive | 2011
Yoshio Umayahara; 芳夫 馬屋原; Shunsuke Fujita; 俊輔 藤田; Masaru Iwao; 克 岩尾
