KR100709171B1 - Laser processing apparatus using beam split - Google Patents

Abstract

The present invention provides a laser processing apparatus using laser beam splitting for dividing an incident laser beam into at least two or more to process an object to improve processing quality of the object and to increase processing efficiency.

The laser processing apparatus according to the present invention comprises beam splitting means for dividing a laser beam emitted from the laser generating means into at least two and entering the mirror, wherein the beam splitting means is a prism, a beam splitter or a combination of a prism and a beam splitter. Can be configured.

According to the present invention, it is possible to obtain an effect of processing an object a plurality of times with a laser beam having a low energy, to ensure a narrow line width, and to ensure a high processing speed because a plurality of divided laser beams are irradiated onto the object at the same time. Can be.

Laser processing, beam splitting

Description

Laser Processing Apparatus Using Beam Split

1 is a structural diagram of a laser processing apparatus according to the present invention;

2A and 2B are a sectional view of a beam splitter and a split beam according to a first embodiment of the present invention;

3A and 3B are a configuration diagram of a beam splitting means and a cross sectional view of a split beam according to a second embodiment of the present invention;

4A and 4B are a configuration diagram of a beam splitting means and a cross-sectional view of a split beam according to a third embodiment of the present invention;

5A and 5B are a schematic view of a beam splitting means and a sectional view of a split beam according to a fourth embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10 mirror 12 optical system

14 object 16: stage

18: stage transfer means 110: control unit

120: laser generating means 130: beam splitting means

140: mirror driving unit 150: input unit

160: output unit 170: storage unit

The present invention relates to a laser processing apparatus, and more particularly, to a laser processing apparatus using laser beam splitting for improving the processing quality and increasing the processing efficiency of an object by dividing an incident laser beam into at least two or more. It is about.

In general, manufacturing an article using various materials such as wafers, metals, plastics, and the like requires processing procedures such as cutting and grooving, which are important because they have a great impact on quality and productivity in subsequent processes. Has meaning.

Recently, a laser has been used for such a processing procedure. The laser processing method focuses a laser beam in a high ultraviolet region (250 to 360 nm) on the surface of an object to induce heating and chemical action so that the focusing region is removed. to be.

Recently, in the semiconductor market, a method of increasing the chip yield per wafer is increasing the number of chips per wafer by reducing the gap between chips on the wafer. As a result, the industry is demanding a very narrow wafer processing line width of about 15 mu m. In order to satisfy such a narrow line width, it is necessary to increase the processing overlap of the laser beam, that is, increase the laser frequency and keep the beam intensity relatively low so as to reduce the breakage around the process line width. However, the current laser is used, the power is reduced as the frequency of the laser beam increases due to its characteristics can improve the processing quality, but there is a problem that can not guarantee the processing time. In addition, when using a laser beam of a low frequency in order to improve the processing speed, the laser beam is overheated into the object to be processed to increase the line width, which makes fine machining impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and there is a technical problem to provide a laser processing apparatus using beam splitting which can improve the processing speed while maintaining the intensity of the laser beam.

Another technical problem of the present invention is to divide the laser beam into at least two or more before entering the object, thereby increasing the power by the number of divided beams while maintaining the intensity of the divided beams the same as before the splitting to increase the processing efficiency. It is to improve.

Laser processing apparatus according to an embodiment of the present invention for achieving the above-described technical problem is provided with a beam dividing means for dividing the laser beam emitted from the laser generating means into at least two or more to enter the mirror.

Here, the beam splitting means may be constituted by a prism, a beam splitter or a combination of a prism and a beam splitter.

In the present invention, when the laser beam incident to the laser processing apparatus is divided into a plurality, the power can be increased by the number of divided beams while maintaining the intensity before the divided beams are divided. It was conceived that it could have the effect of increasing the frequency. For example, processing an object using a laser beam of 200 kHz and 4 W has the same intensity as a laser beam of 100 kHz and 2 W. Therefore, if the object is processed by splitting the laser beam of 100 kHz and 6 W into three parts, a narrower line width can be guaranteed. As the power is 6W, the machining speed can be improved, and the beam overlap effect can be tripled. Likewise, if the object is processed by dividing the laser beam of 100 kHz and 8 W into four parts, the object can be processed at a narrower line width and at a higher speed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a structural diagram of a laser processing apparatus according to the present invention.

As shown, the laser processing apparatus according to the present invention includes a control unit 110 for controlling the overall operation, a laser generating means 120 for outputting a laser beam having a specified aperture, and a laser emitted from the laser generating means 120. Information such as beam splitter 130 for dividing the beam into at least two, a mirror driver 140 for driving the mirror 10, an input unit 150 for inputting control parameters and control commands, an operating state, and the like. An output unit 160 for displaying, a storage unit 170 for storing data, a reflection in the mirror 10 and the mirror 10 for reflecting the laser beam emitted from the beam splitter 130 to the object 14 And an optical system 12 for collecting the converted laser beam or converting the shape of the collected laser beam.

In addition, the object 14 is seated on the stage 16, and the stage 16 moves in the direction designated by the conveying means 18.

Herein, the mirror 10 may be implemented as a reflective mirror or a polygon mirror. When the mirror 10 is implemented as a polygon mirror, the polygon mirror is manufactured by controlling the number of reflecting surfaces so that the aperture of the laser beam covers a plurality of reflecting surfaces of the polygon mirror. It is preferable to use. On the other hand, for a laser processing apparatus using a polygon mirror was filed in the Republic of Korea by the present applicant on March 31, 2004 (application number: 10-2004-0022270), and the polygon mirror manufactured by controlling the number of reflecting surface The laser processing apparatus used was filed in the Republic of Korea on August 18, 2004 by the present applicant (application number: 10-2004-0065066), and a detailed description thereof will be omitted.

In addition, the optical system 12 may be implemented as a condenser lens, or a condenser lens and a cylindrical lens. When the optical system 12 includes a cylindrical lens, the cross-sectional shape of the laser beam becomes an ellipse shape, and if the long axis of the ellipse is controlled to coincide with the processing direction, more excellent processing efficiency can be obtained.

When the object 14 is processed using the laser processing apparatus, first, control parameters are set through the input unit 150. The setting process is performed by registering a preset menu according to the type and processing type of the object to be stored. Stored at 170, it can be easily performed by calling the menu.

When the control parameter setting is completed, the mirror driving unit 140 adjusts the position of the mirror 10. When the mirror 10 is a polygon mirror, the mirror 10 is rotated at a constant speed according to a preset rotation speed. Then, the controller 110 operates the stage transfer means 18 to transfer the object 14 in a specified direction, and controls the laser generating means 120 to generate the laser beam when the laser beam is emitted. ) Is divided into at least two to be incident to the mirror (10).

Thereafter, at least two laser beams reflected from the mirror 10 are irradiated perpendicularly to the object 14 through the optical system 12. At this time, since there are a plurality of beams passing through the optical system 12, the result of irradiating the laser beam to the object 14 can be obtained a plurality of times, and because the plurality of laser beams are incident at the same time, while maintaining the processing speed at the level before beam splitting, Machining is possible with a narrow line width, and post-machining quality can be guaranteed.

2A and 2B are a schematic view of a beam splitting means and a sectional view of a split beam according to a first embodiment of the present invention.

2A and 2B illustrate a case in which a laser beam is divided into two using a prism, and the beam splitter 130 for this purpose includes a first mirror 1311 reflecting an incident laser beam and a laser beam reflected from the first mirror. And a second mirror 1313 reflecting the bi-divided beam from the prism 1312.

Here, the first mirror 1311 serves to inject the laser beam into the prism 1312, and the prism 1312 causes the two beams divided according to their arrangement to be symmetrical. The second mirror 1313 controls the optical axis so that the optical axis of the beam emitted from the prism 1312 is parallel to the optical axis of the laser beam incident on the first mirror 1311, and the laser reflected by the second mirror 1313 The beam is incident on the mirror 10 and irradiated to the object. To this end, of course, the optical axis of the laser beam reflected from the mirror 10 should be controlled to be perpendicular to the object.

An example of the laser beam cross section irradiated to the object by such beam splitting means is as shown in FIG. 2B. The distance between the two semicircular laser beams may be changed according to the degree of beam refraction of the prism 1312. In addition, since two laser beams can be irradiated within the same area as the irradiation area of the laser beam before splitting, that is, the number of laser beams irradiated per unit area can be increased, thereby increasing processing efficiency.

3A and 3B are sectional views of a configuration beam and a split beam of a beam splitting means according to a second embodiment of the present invention.

3A and 3B illustrate a case in which a laser beam is split into two using a beam splitter, and the beam splitter 130 for this is reflected by a beam splitter 1321 and a beam splitter 1321 for dividing an incident laser beam into two. A polarizer 1322 for converting the polarization characteristics of the first laser beam, a first mirror 1324 for reflecting the second laser beam transmitted through the beam splitter 1321, and a second mirror 1324 Polarization for reflecting the first laser beam whose polarization characteristics are switched at the second mirror 1325 and the polarizer 1322 for reflecting the two laser beams, and for transmitting the second laser beam reflected at the second mirror 1325. A beam splitter 1323 is included, and the first and second laser beams reflected and transmitted by the polarization beam splitter 1323 are irradiated perpendicularly to the object through the mirror 10.

An example of the cross section of the first and second laser beams in the beam splitting means is shown in FIG. 3B, and the distance between the two laser beams can be freely controlled by changing the position of the second mirror.

In addition, the optical axis of the laser beam emitted from the polarization beam splitter 1323 should be controlled to be parallel to the optical axis of the laser beam incident to the beam splitter 1321, and the optical axis of the laser beam reflected from the mirror 10 is applied to the object. Of course, it should be controlled to be perpendicular to the.

In addition, the polarizer 1322 may use a polarizer that converts horizontal linearly polarized light (P polarization) into vertical linearly polarized light (S polarization), and the polarizing beam splitter 1323 includes a polarizing beam splitter that transmits P polarized light and reflects S polarized light. Can be used.

4A and 4B are sectional views of a configuration beam and a split beam of a beam splitting means according to a third embodiment of the present invention.

The present embodiment shows beam splitting means for dividing a laser beam through a beam splitter, then splitting one of the two divided laser beams again using a prism, and finally splitting the laser beam into three.

Referring to FIG. 4A, a beam splitter 1331 for dividing an incident laser beam, a polarizer 1332 for converting polarization characteristics of a laser beam reflected by the beam splitter 1331, and a polarizer converted by the polarizer 1332 may be used. A prism 1333 for dividing the laser beam into first and second laser beams, a first mirror 1335 and a first mirror 1335 for reflecting a third laser beam transmitted through the beam splitter 1331. A second mirror 1336 for reflecting the reflected third laser beam, first and second laser beams exiting from the prism 1333, and a third laser beam incident through the second mirror 1336 And a first to third laser beam reflected or transmitted by the polarization beam splitter 1334 is irradiated perpendicularly to the object through the mirror 10.

An example of a cross section of the laser beam divided by the beam splitting means according to the present embodiment is shown in FIG. 4B, and the distance between the first and second laser beams is adjusted by controlling the refractive index of the prism 1333. The arrangement of the 1333 may be controlled so that the two laser beams may be symmetrical, and the position of the second mirror 1336 may be controlled to adjust the position of the third laser beam.

Here, the polarizer 1332 may use a polarizer for converting horizontal linearly polarized light (P polarization) into vertical linearly polarized light (S polarization), and the polarizing beam splitter 1323 transmits P polarized light and reflects S polarized light. Can be used.

5A and 5B are a schematic view of a beam splitting means and a sectional view of a split beam according to a fourth embodiment of the present invention.

This embodiment shows a case in which one laser beam is divided into two using a prism, and then the two divided laser beams are divided into two by a beam splitter and divided into a total of four laser beams.

Referring to FIG. 5A, a prism 1341 for dividing an incident laser beam, a beam splitter 1342 and a beam splitter 1342 for dividing and reflecting a beam divided in two by the prism 1341 respectively. A polarizer 1343 for converting polarization characteristics of the first and second laser beams reflected from the first mirror, a first mirror 1345 and a first mirror for reflecting the third and fourth laser beams transmitted from the beam splitter 1342. The second mirror 1346 for reflecting the laser beam reflected by the mirror 1345, the first and second laser beams whose polarization characteristics are changed by the polarizer 1343 are reflected, and incident through the second mirror 1346. A polarization beam splitter 1344 for transmitting the third and fourth laser beams, wherein the first to fourth laser beams reflected or transmitted by the polarization beam splitter 1344 are irradiated perpendicularly to the object through the mirror 10. do.

An example of a cross section of the laser beam divided by the laser beam splitting means according to the present embodiment is as shown in FIG. 5B, and the interval between the first and fourth laser beams is the refractive index of the prism 1341 or the second mirror 1346. It can be changed by controlling the arrangement of. However, at this time, the optical axis of the laser beam reflected from the second mirror 1346 should be parallel to the optical axis of the laser beam incident to the prism 1321, and the optical axis of the laser beam reflected from the mirror 10 is perpendicular to the object. Of course, the control to achieve.

In the present invention described above, the laser beam is divided into two or more laser beams by a prism, a beam splitter, or a combination of the prism and the beam splitter, and the object is processed using the same. Since the sum of the energy of the divided laser beams is equal to the energy of the laser beam before the division, the processing speed can be maintained, and the narrow line width can be ensured because the intensity of each of the divided laser beams is lower than the intensity of the laser beam before the division. The distance between the divided laser beams can be easily changed according to the arrangement of the optical systems constituting the beam splitting means.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

According to the present invention, by processing the object by dividing the laser beam into two or more, it is possible to obtain the effect of processing the object a plurality of times with a laser beam having a low energy, it is possible to ensure a narrow line width. In addition, since a plurality of divided laser beams are irradiated to the object at the same time, it is possible to ensure a high processing speed.

Claims (11)

A laser processing apparatus for processing an object by reflecting a laser beam emitted from a laser generating means by a mirror, Beam splitting means for dividing the laser beam emitted from the laser generating means into at least two and entering the mirror; The beam splitting means includes: a first mirror reflecting the laser beam emitted from the laser generating means, a prism dividing the laser beam reflected from the first mirror into two, and a second reflecting beam divided into two at the prism; Laser processing apparatus comprising a; mirror. delete A laser processing apparatus for processing an object by reflecting a laser beam emitted from a laser generating means by a mirror, Beam splitting means for dividing the laser beam emitted from the laser generating means into at least two and entering the mirror; The beam splitter may include a beam splitter for dividing an incident laser beam into two, a polarizer for converting polarization characteristics of a first laser beam reflected from the beam splitter, and a second laser beam transmitted through the beam splitter. A first mirror for reflecting, a second mirror for reflecting the second laser beam reflected from the first mirror, a first laser beam whose polarization characteristic is converted in the polarizer, and reflecting the second laser beam reflected from the second mirror 2. A laser processing apparatus comprising a polarizing beam splitter for transmitting a laser beam. A laser processing apparatus for processing an object by reflecting a laser beam emitted from a laser generating means by a mirror, Beam splitting means for dividing the laser beam emitted from the laser generating means into at least two and entering the mirror; And the beam splitting means comprises a beam splitter for dividing the incident laser beam into two and a prism for dividing any one of the laser beam divided into two at the beam splitter. A laser processing apparatus for processing an object by reflecting a laser beam emitted from a laser generating means by a mirror, Beam splitting means for dividing the laser beam emitted from the laser generating means into at least two and entering the mirror; And said beam splitting means comprises a prism for dividing the incident laser beam into two and a beam splitter for dividing the laser beam divided into two in said prism. delete delete The method of claim 3, wherein The beam splitting means further includes a prism between the polarizer and the polarizing beam splitter for dividing the laser beam polarized by the polarizer into two parts, And said polarizing beam splitter respectively reflects a laser beam divided by two in said prism and transmits a second laser beam incident through said second mirror. The method of claim 5, The beam splitter splits the beam divided in two into the prism, respectively, to reflect the first and second laser beams while transmitting the third and fourth laser beams, The beam splitting means may include: a polarizer for converting polarization characteristics of the first and second laser beams reflected by the beam splitter; A first mirror for reflecting third and fourth laser beams transmitted by the beam splitter; A second mirror for reflecting the laser beam reflected from the first mirror; And A polarization beam splitter for reflecting the first and second laser beams whose polarization characteristics are changed in the polarizer and transmitting the third and fourth laser beams incident through the second mirror; Laser processing apparatus comprising a. The method of claim 1, And said mirror is a polygon mirror. The method of claim 1, And the mirror is a polygon mirror manufactured by controlling the number of reflecting surfaces so that the aperture of the laser beam covers the plurality of reflecting surfaces of the polygon mirror.

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