Edge detection device and laser processing device

Abstract

The invention provides a laser processing device and an edge detection device for precisely detecting an edge position of a detecting object having any shape and having a high precision and high degree of arranging freedom as a space light filter. The edge detection device is provided with a white light source (101) which is arranged for sending a white light with a plurality of wavelengths to a first light path (109a), a chromatic aberration collector lens (102) which forms a plurality of focal points on a light shaft of a detecting object (1) aiming at the wavelengths of the white light sent by the first light path (109a), a fiber (104) which is guided to a second light path (109b) different from the first light path (109a) by the white light reflected by the detecting object (1), and a detector (103) which is arranged for detecting the strength of the white light guided to the second light path (109b) by the fiber (104).

Description

Technical field [0001] The present invention relates to an edge detection device for detecting the edge of a detection target object, such as a semiconductor wafer, and a laser processing device having the edge detection device. Background technique [0002] In the semiconductor device manufacturing process, on the surface of a substantially disc-shaped semiconductor wafer, a plurality of areas are divided using spacers (cutting lines) arranged in a grid pattern, and ICs are formed in the divided areas ( Semiconductor wafers of circuits such as integrated circuits and LSIs (Large Scale Integrated Circuits) are cut along partitions and divided into individual circuits to manufacture individual semiconductor chips. The cutting of the semiconductor wafer along the spacer lane is generally performed using a cutting device called a cutter, but a processing method of cutting by irradiating a laser beam has also been tried (for example, refer to Patent Document 1). [0003] In order to p...

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Problems solved by technology

There is a problem that the hole for vacuuming formed in the workpiece holding area is blocked due to the attached dicing tape, or the surface accuracy of the workpiece holding area is lowered.

[0010] However, in the technique shown in Patent Document 2, since it is necessary to separately prepare the chuck table according to the shape of the workpiece, the cost is high, and the work of replacing the table is required.

[0011] In addition, in the conventional confocal detection device shown in Patent Document 3 and the like, as a spatial filter for guiding only light of a specific wavelength focused on the detection object out of white light to the spectroscope, A pinhole mask is used, but there is a problem that the accuracy of the spatial filter, the installation work of each optical component and the beam splitter are troublesome, and the degree of freedom of arrangement is limited.

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