TY - JOUR

T1 - Evaluation of Machining Characteristics of Aluminum Nitride by Harmonics of Nd:YAG Laser - Effects of Laser Beam Wavelength on Machining Characteristics -

AU - Okamoto, Yasuhiro

AU - Kataoka, Norio

AU - Uno, Yoshiyuki

AU - Nakashiba, Shin ichi

AU - Tanino, Itaru

PY - 2006

Y1 - 2006

N2 - Machining characteristics of aluminum nitride by various kinds of the harmonics of Nd:YAG laser, that is the fundamental harmonic (λ1 = 1064nm), the second harmonic (λ2 = 532nm), the third harmonic (λ3 = 355nm) and the forth harmonic (λ4 = 266nm), were experimentally investigated. Since the material removal is mainly performed by thermal processing in the case of long wavelength such as fundamental wavelength, the removal rate greatly decreases with increasing the distance from the focusing point to the tip of removal. Thus, the limit of removal depth was shallow, since the material removal was sensitive to the energy density of laser beam. On the other hand, when the photon energy of laser beam is larger than the bonding energy of material, the material is mainly removed by the photochemical reaction. Thus, the decrease of removal rate was small for shorter wavelength. Therefore, the removal rate increases with decreasing the wavelength of laser beam for long term irradiation under the same energy condition. In the case of deep hole drilling, the drilled depth increases proportionally with the number of laser shot at the beginning region. Therefore, the removal depth could be controlled by the number of laser shot in this region.

AB - Machining characteristics of aluminum nitride by various kinds of the harmonics of Nd:YAG laser, that is the fundamental harmonic (λ1 = 1064nm), the second harmonic (λ2 = 532nm), the third harmonic (λ3 = 355nm) and the forth harmonic (λ4 = 266nm), were experimentally investigated. Since the material removal is mainly performed by thermal processing in the case of long wavelength such as fundamental wavelength, the removal rate greatly decreases with increasing the distance from the focusing point to the tip of removal. Thus, the limit of removal depth was shallow, since the material removal was sensitive to the energy density of laser beam. On the other hand, when the photon energy of laser beam is larger than the bonding energy of material, the material is mainly removed by the photochemical reaction. Thus, the decrease of removal rate was small for shorter wavelength. Therefore, the removal rate increases with decreasing the wavelength of laser beam for long term irradiation under the same energy condition. In the case of deep hole drilling, the drilled depth increases proportionally with the number of laser shot at the beginning region. Therefore, the removal depth could be controlled by the number of laser shot in this region.

KW - Nd:YAG laser

KW - aluminum nitride

KW - drilling

KW - harmonics

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U2 - 10.2493/jjspe.72.694

DO - 10.2493/jjspe.72.694

M3 - Article

AN - SCOPUS:85024746005

VL - 72

SP - 694

EP - 698

JO - Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering

JF - Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering

SN - 0912-0289

IS - 6

ER -