著者

今井 康文 森田 英毅 高瀬 徹 古賀 博之

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.55, no.509, pp.147-151, 1989-01-25

被引用文献数

7 7

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Time-dependent thermal stress singularities at a semi-infinite crack tip associated with a transient temperature field have been analyzed on an infinite plate with a point heat source near the crack tip. As the heating begins, a mode I singularity increases gradually with time, but, after showing its maximum, decreases to be negative. This singularity variation causes a crack to start growing at some instance, but soon after to stop. That is, crack growth may be controlled, which is desirable for a cutting device for brittle materials. Deflection of a heating point from a crack line results in a mode II stress singularity, which also leads a crack to swerve from the original crack line. In an experiment using glass plates, a crack was successfully controlled to grow and also to branch in any angle toward the heat source as long as the heating location was kept appropriately apart from the crack tip.

著者

大村 悦二 小川 健輔 熊谷 正芳 中野 誠 福満 憲志 森田 英毅

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. A編 (ISSN:03875008)

巻号頁・発行日

vol.76, no.764, pp.446-448, 2010-04-25

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In stealth dicing (SD), a permeable nanosecond laser is focused inside a silicon wafer and scanned horizontally. A thermal shock wave is propagated every pulse toward the side to which the laser is irradiated, then a high dislocation density layer is formed inside a wafer after the thermal shock wave propagation. In our previous study, it was supposed that an internal crack whose initiation is a dislocation is propagated when the thermal shock wave by the next pulse over-laps with this layer partially. In this study, a two-dimensional thermal elasticity analysis based on the fracture mechanics was conducted. The internal crack propagation was analyzed by calculating the stress intensity factor at the crack tips and comparing with a threshold of that. As a result, validity of the previous hypothesis was suggested.

著者

大村 悦二 小川 健輔 熊谷 正芳 中野 誠 福満 憲志 森田 英毅

出版者

一般社団法人日本機械学会

雑誌

M&M材料力学カンファレンス

巻号頁・発行日

vol.2009, pp.73-74, 2009-07-24

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In stealth dicing (SD), a permeable nanosecond laser is focused inside a silicon wafer and scanned horizontally. A thermal shock wave is propagated every pulse toward the side to which the laser is irradiated, then a high dislocation density layer is formed inside a wafer after the thermal shock wave propagation. In our previous study, it was supposed that an internal crack whose initiation is a dislocation is propagated when the thermal shock wave by the next pulse overlaps with this layer partially. In this study, a two-dimensional thermal elasticity analysis based on the fracture mechanics was conducted. The internal crack propagation was analyzed by calculating the stress intensity factor at the crack tips and comparing with a threshold of that. As a result, validity of the previous hypothesis was suggested.