The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 2013
Filed:
Dec. 12, 2006
Koji Kuno, Hamamatsu, JP;
Kenichi Muramatsu, Hamamatsu, JP;
Kazuhiro Atsumi, Hamamatsu, JP;
Tetsuya Osajima, Hamamatsu, JP;
Koji Kuno, Hamamatsu, JP;
Kenichi Muramatsu, Hamamatsu, JP;
Kazuhiro Atsumi, Hamamatsu, JP;
Tetsuya Osajima, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka, JP;
Abstract
A laser processing apparatus comprises a converging lensfor converging processing laser light and rangefinding laser light Ltoward a wafer, an actuator for actuating the lens, a shaping optical systemfor adding astigmatism to reflected light Lof the rangefinding laser light, a quadrant photodiodefor receiving the reflected light Land outputting voltage values corresponding to its light quantities, and a controller for regulating the actuator, and positions a converging point Pof the rangefinding laser light Lbetween a focal point Pof the lens and the lens, so as to make it possible to form a modified region at a position deeper from the front face, thereby suppressing adverse effects due to the reflected light L. The control is based on an arithmetic value subjected to a division by a sum of the voltage values, so as to prevent the arithmetic value from being changed by the quantity of reflected light.