JPH0919781A - Method and device for spliting substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To split precisely in following the irradiation locus of laser beam and not to generate a microcrack on the edge surface, rear surface and side surface of substrate to be split in cutting a substrate. SOLUTION: In a substrate splitting method to split from one end of a substrate 1 to the other end by traveling the substrate l while irradiating on the surface of substrate to be worked made of non-metallic material with laser beam by causing assist gas to flow along the transfer direction of a carbon dioxide gas laser beam 3, by closely adhering dummy substrates 2-1, 2-2 made of non-metallic material on one end and the other end of the substrate 1 to be worked, the substrate l to be worked is cut together with the dummy substrates 2-1, 2-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a surface of a non-metallic material with carbon dioxide laser light while flowing an assist gas along the direction of propagation of carbon dioxide laser light, and moves the non-metal material to remove the non-metal material. The present invention relates to a method of processing a non-metallic material to be processed and a processing apparatus therefor.

[0002]

2. Description of the Related Art In recent years, on and in substrates of non-metal materials such as glass materials, magnetic materials, semiconductor materials and dielectric materials,
Product development of integrated circuits, optical integrated circuits having optical circuits mounted therein, or electric / optical integrated circuits in which electric circuits and optical circuits are integrated has become active.

This type of integrated circuit is densely integrated in a range of several tens to several tens of thousands on a circular or square substrate having a size of 3 inches to 10 and several inches. For example, as shown in FIG. 4, the substrate 701 is cut and separated into n × m integrated circuit 702 chips. As a method of cutting and separating the substrate 701, the substrate 701 is defined by alternate long and short dash lines 703a to 703.
n, 704a to 704m, diamond blade dicing is performed or scribing is performed by irradiating a laser beam.

FIG. 5 is a block diagram of a glass cutting device by irradiation of carbon dioxide gas laser light previously proposed by the present inventor (Japanese Patent Application No. 6-247436).

[0005] This is on the base 803 while blowing the assist gas G through the assist gas introduction pipe 802 around the laser light L which is emitted from the carbon dioxide gas (CO ₂ ) laser 801 and then condensed by the condenser lens Le. The glass substrate 804 fixed by vacuum suction is irradiated and cut into two pieces A and B. Reference numeral 805 is a through hole.

[0006]

By the way, it has been found that when the brittle material such as a ceramic substrate or a glass substrate is cleaved by using the apparatus shown in FIG. 5, the following problems occur.

(1) FIG. 6 (a) is a plan view of a non-metallic material cleaved by using the carbon dioxide gas laser irradiation device previously proposed by the present inventor, and FIG. 6 (b) is a side view thereof. . FIG.
As shown in (a), the thickness is 0.5 mm, 1.0 mm,
1.5 mm ceramic substrate (size: 50 mm x 5
(0 mm) 901 is moved in the direction of arrow 902 at a constant speed, the surface of the ceramic substrate 901 is irradiated with carbon dioxide laser light, and the ceramic substrate 901 is moved in the direction of arrow A.
It was found that when cleaved, the defect portions 904 and 905 due to discontinuous and non-linear cracks were generated at the start portion on one end face side and the end portion on the other end face side of the ceramic substrate 901. It has been found that these defective portions 904 and 905 are always generated on one end face side where the carbon dioxide laser light is first irradiated and the other end face side where the carbon dioxide gas laser beam is finally irradiated.
Such non-linear cracks have to treat the defective portions 904 and 905 as defective products, resulting in impeding effective use of the ceramic substrate. Moreover, it has been found that the area of such a defective portion extends from several mm ² to several tens of mm ² .

Further, as shown in FIGS. 6 (a) and 6 (b), the manner of cracking at the defective portions 904 and 905 is not constant, and the target cutting position 906 to 0. It was found that cracking occurred at a position 907 displaced by several mm to several mm.

(2) The generation of the defective portions 904 and 905 could not be easily suppressed even if the moving speed of the ceramic substrate 901 or the power of the carbon dioxide laser light was changed. However, it tended to decrease when the beam spot diameter of the carbon dioxide laser light was reduced. However, when the spot diameter was reduced, the cutting condition was deviated from the cutting condition, and the cutting could not be performed.

[0010]

In order to achieve the above object, the present invention provides a laser beam on the surface of a processing substrate made of a non-metallic material while flowing an assist gas along the propagation direction of carbon dioxide laser beam. In the method of cutting a substrate by moving the substrate while irradiating and cutting the substrate from one end to the other end, a dummy substrate made of a non-metal material is adhered to one end and the other end of the substrate for processing to make a dummy. The substrate for processing is cut together with the substrate.

In addition to the above structure, the present invention forcibly adheres and fixes both substrates on the moving stage so that the dummy substrate and the processing substrate are not separated during processing.

In addition to the above structure, according to the present invention, the moving stage for adhering and fixing the dummy substrate and the processing substrate is made of a metal material.

The present invention includes a carbon dioxide gas laser device, an optical system for collecting laser light emitted from the carbon dioxide gas laser device with a lens and guiding the laser light to a substrate for processing, and a dummy substrate made of a non-metallic material. A stage for moving a processing substrate made of a metal material in at least one direction and a contact fixing mechanism for forcibly contacting and fixing the dummy substrate and the processing substrate on the stage are provided.

According to the above construction, when the carbon dioxide laser light is irradiated while the dummy substrate is in close contact with the start portion on one end face side and the end portion on the other end face side of the substrate, the start portion of the cleavage and Discontinuous and non-linear cracks are generated at the end portion, but discontinuous and non-linear cracks are not generated in the processing substrate. Therefore, the substrate for processing can be faithfully cut according to the irradiation trajectory of the laser beam, and microcracks do not occur on the edge surface, back surface and side surface of the cut substrate.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION When the present invention is applied to the cutting of a substrate, carbon dioxide laser light is applied while the dummy substrate is in close contact with the start portion on one end face side of the substrate and the end portion on the other end face side. The substrate is cut by the irradiation. Discontinuous and non-linear cracks occur only at the start and end of the fracture. Therefore, the substrate for processing can be faithfully cut according to the irradiation trajectory of the laser beam, and microcracks do not occur on the edge surface, back surface and side surface of the cut substrate.

Ceramics, glass or the like is used as the substrate for processing. The same dummy substrate is used as the dummy substrate. As the assist gas, N ₂ , Ar,
O ₂ , air or a mixed gas thereof is used.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an explanatory view for explaining the principle of the substrate cutting method of the present invention.

Dummy ceramic substrates 2-1 and 2-2 are arranged in close contact with each other on both sides of the processing ceramic substrate 1 so as to be cut. It is fixed on an XY moving stage (not shown) like a single integrated substrate. Each board 1, 2-1,
The contact surface 2-2 is in close contact with almost no space. X
Substrates 1, 2-1, 2-2 fixed on the Y moving stage
Is moved in the direction of arrow B at a constant speed. Substrate 1, 2-
Carbon dioxide laser light (hereinafter referred to as “laser beam”) 3 is irradiated onto the surfaces 1 and 2-2. Assist gas is blown concentrically along the propagation direction of the laser beam 3 in the direction of arrow C so as to cover the laser beam 3.

Here, the laser beam 3 is focused at a position of 6 mm to 12 mm above the substrate, and the spot diameter of the beam is slightly expanded on the substrate 1 (beam spot diameter: 200 to 700 μmφ). Is illuminated by. In this way, the spot diameter of the laser beam 3 is expanded, and the pressure of the assist gas (N ₂ , Ar, O ₂ , air, etc.) is selected from 2.5 Kg / cm ² to 5 Kg / cm ² , and the power of the laser beam 3 is set. 50-80 W, if the moving speed in the direction of arrow B is selected in the range of 4 mm / sec to 10 mm / sec, a crack 4 due to thermal stress is generated on the substrate 1 as shown in the figure, and this crack causes a movement locus of the laser beam 3. It was found that the substrate 1 was cleaved and consequently the substrate 1 was cleaved. The cutting margin width W by this cutting was "0". Then, the defective portion 5 was formed at the start portion on one end surface side of the dummy substrates 2-1 and 2-2. Although not shown in the figure, a defect portion was also generated in the end portion on the other end surface side of the substrate 1.
However, the substrate 1 to be originally processed could be cleaved according to the movement trajectory of the laser beam 3 (the movement trajectory of the laser beam 3 in this case is a straight line, and the substrate 1 can be cleaved linearly. did it).

FIG. 2 shows an embodiment of a cleaving apparatus to which the substrate cleaving method of the present invention is applied.

In the figure, reference numeral 20 is a carbon dioxide laser device, and an external grating portion 2 is provided in a box 21.
2 and a carbon dioxide laser tube 23 are provided. An internal mirror 24 and a Brewster window 25 are provided at both ends of the carbon dioxide laser tube 23, respectively. Carbon dioxide laser tube 2
3 is a mixed gas (CO ₂ , N ₂ and He at a mixing ratio of 8: 1).
Gas mixed in a ratio of 8:74) 26 is enclosed. A pair of electrodes 2 is provided near the end of the carbon dioxide laser tube 23.
7-1, 27-2 are provided, and both electrodes 27-1,
27-2 are connected to the drive power supply 28, respectively.

At the emission port (on the side of the internal mirror 24) of the carbon dioxide laser device 20, there is provided a monitor light detecting mirror 29 consisting of a half mirror for taking out a part L2 of the emitted laser light L1. The laser light L2 reflected by the monitor light detecting mirror 29 is monitored by a monitor light detector 30 and is taken out as a monitor signal 31. A feedback signal 32 based on the monitor signal 31 is fed back to the drive power source 28, and the laser light L
The output of 1 is kept constant.

The laser light L3 transmitted through the monitor light detecting mirror 29 is reflected by the total reflection mirror 34 to the processing substrate 35 side (lower side in the figure) through the optical shutter opening / closing adjusting section 33. The laser light L3 reflected by the total reflection mirror 34 is condensed by the condenser lens 36 to be a laser beam.

These total reflection mirror 34 and condenser lens 36
An optical system 37 is formed by the optical system 37, and the optical system 37 includes a monitor light detection mirror 29, an optical shutter 38 of the optical shutter opening / closing adjustment unit 33, and a housing 3 formed of a tubular body having an L-shaped cross section.
9.

A gas introduction system 42 including a gas supply port 40 and a gas nozzle 41 for blowing the assist gas G1 along the propagation direction of the laser beam L3 is provided at the laser beam emission port of the casing 39 of the optical system 37. ing. Gas introduction system 4
A substrate holding / moving device 43 is arranged below 2.

The substrate holding and moving device 43 is used for processing the substrate 3
5 and the dummy substrates 44-1 and 44-2 at least X
Substrate fixing base 45 as a stage that can be moved in the direction (or Y direction), and a stopper 45 for forcibly and closely fixing the substrates 35, 44-1 and 44-2 on the substrate fixing base 45. -1,45-2 and vacuum suction device 46
And the close contact fixing mechanism 47. 4
Reference numeral 8 denotes an XY moving device that moves the substrate fixing base 45.

In order to cut a substrate made of ceramics, glass or the like using such a processing apparatus, the substrate 35
Must be installed a distance S below the focal length F of the condenser lens 36. Here, S is preferably in the range of 6 mm to 12 mm. Further, the power of the laser beam, the moving speed of the XY moving device 48, the assist gas pressure and the like are preferably the above-mentioned values.

Next, the operation of the embodiment will be described.

The substrate 35 is mounted on the substrate fixing base 45 so that the dummy substrates 44-1 and 44-2 are arranged at the start portion on one end surface side and the end portion on the other end surface side of the processing substrate 35, respectively. And dummy substrates 44-1 and 44-2
And put. The dummy substrates 44-1 and 35 are sandwiched from both sides by the stoppers 45-1 and 45-2 so as to be in close contact with each other,
The substrates 35, 44-1 and 44-2 are fixed on the substrate fixing base 45 by the vacuum suction device 46.

When the assist gas G1 is blown to the substrate 35 and the dummy substrate 44-1 on the start portion side is irradiated with the laser beam to be cleaved, discontinuous and non-linear cracks are generated at the cleaved start and end portions. However, the substrate 35 does not have discontinuous and non-linear cracks. Therefore, the substrate 35 can be faithfully cut according to the irradiation trajectory of the laser beam, and no microcracks are generated on the edge surface, back surface, and side surface of the cut substrate 35.

In the above, by adhering the dummy substrate made of a non-metal material to one end and the other end of the processing substrate, and cutting the processing substrate together with the dummy substrate, the laser light irradiation locus is followed. It can be faithfully cleaved, and micro-cracks do not occur on the edge surface, back surface and side surfaces of the cleaved substrate.

Next, FIG. 3 shows a schematic view of a cleaving method for cleaving a square non-metal material substrate in a matrix.

This is because cracks 51-1, 51-2, 51- are formed in the rectangular ceramic substrate for processing 50 by cleaving.
3, 51-4, 51-5, 51-6 are generated and processed in a matrix. In this case, dummy ceramic substrates 52-1, 52-2, 52-3, 52- are provided on the outer periphery of the processing ceramic substrate 50.
4 are arranged in close contact with each other and fixed, and the ceramic substrate 50 for processing including the dummy ceramic substrates 52-1, 52-2, 52-3 and 52-4 is cut. By cleaving with such a configuration, the ceramic substrate 50 for processing could be cleaved uniformly.

The unevenness of the front and back surfaces of the edge of the cut substrate 50 was within several μm. Further, the side surface of the cleaved substrate 50 was also a flat surface which was substantially a mirror surface. No microcracks were generated under the above-mentioned conditions.

In the above, while irradiating the laser beam onto the surface of the processing substrate made of a non-metallic material while flowing the assist gas along the propagation direction of the carbon dioxide gas laser beam, the substrate is moved to move from one end of the substrate to the other. In the method of cleaving the substrate to cleave up to the edge, the dummy substrate made of a non-metal material is closely adhered to one end and the other end of the substrate for processing, so that the substrate for processing is cleaved together with the dummy substrate. Only a few μm unevenness was produced on the front and back surfaces of the edge of the substrate for processing which was cleaved by the laser beam irradiation. No microcracks were found on the fractured surface.

[0037]

In summary, according to the present invention, the following excellent effects are exhibited.

Since the dummy substrate made of a non-metallic material is adhered to one end and the other end of the processing substrate and the processing substrate is cut together with the dummy substrate, it is faithful to the laser light irradiation trajectory. The substrate can be cleaved, and microcracks do not occur on the edge surface, back surface and side surface of the cleaved substrate.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining the principle of a substrate cleaving method of the present invention.

FIG. 2 shows an embodiment of a cleaving apparatus to which the substrate cleaving method of the present invention is applied.

FIG. 3 shows a case where a rectangular-shaped non-metal material substrate is cut into a matrix by applying the substrate cutting method of the present invention.

FIG. 4 is a plan view of a substrate material for explaining a method of cutting and separating an integrated circuit.

FIG. 5 shows a configuration diagram of a glass cutting device by irradiation of carbon dioxide laser light previously proposed by the present inventor.

FIG. 6 shows a non-metallic material cleaved by using the carbon dioxide gas laser irradiation device previously proposed by the present inventor.

[Explanation of symbols]

 1 Substrate for processing 2-1, 2-2 Dummy substrate 3 Carbon dioxide laser light (laser beam)

Claims (4)

[Claims] 1. The one end of the substrate is moved by irradiating the surface of a substrate for processing made of a non-metallic material with the laser beam while flowing an assist gas along the propagation direction of the carbon dioxide laser beam and moving the substrate. In the method of cleaving a substrate from the other end to the other end, a dummy substrate made of a non-metal material is brought into close contact with one end and the other end of the working substrate, and the working substrate is cleaved together with the dummy substrate. A method for cutting a substrate, characterized in that 2. The substrate cutting method according to claim 1, wherein both the dummy substrate and the processing substrate are forcibly brought into close contact with each other and fixed on a moving stage so that they are not separated during processing. 3. The method of cleaving a substrate according to claim 1, wherein the moving stage for adhering and fixing the dummy substrate and the processing substrate is made of a metal material. 4. A carbon dioxide gas laser device, an optical system that collects laser light emitted from the carbon dioxide gas laser device with a lens and guides the laser light to a substrate for processing, and a non-metal sandwiched by a dummy substrate made of a non-metal material. A stage for moving a processing substrate made of a material in at least one direction, and a contact fixing mechanism for forcibly contacting and fixing the dummy substrate and the processing substrate on the stage. Substrate cleaving device.