KR20100089530A - Laser beam machining apparatus and method thereof - Google Patents

Abstract

PURPOSE: A laser machining device and a method thereof are provided to deliver minute energy of laser beam stably and improve machining accuracy by controlling the propagation of laser beam. CONSTITUTION: A laser machining device comprises a laser generator(110), an optical modulator(120), an objective lens(160), a stage part(170), and a beam blocking unit(180). The laser generator generates laser beam. The optical modulator divides the laser beam into a first path and a second path. The object lens condenses the laser beam separated into the first path to be irradiated to a target position. The stage part in which a work piece is placed is able to control the distance to the object lens. The beam blocking unit is arranged in the first path and allows laser beam to propagate along the first path for an irradiation time corresponding to the target position.

Description

Laser beam machining apparatus and method thereof

The present invention relates to a laser processing apparatus and method for use in micromachining.

Mechanical working refers to an operation that imparts a certain shape and properties to an article. Conventional machining uses machine tools, rolling mills, presses, and the like. However, the precision machining of a large number of products is required these days, the conventional machining technology alone has reached the limit and it is difficult to cope. Laser processing technology is expected as a means of realizing such industrial needs, and its use is expanding in a wide range of industries.

The processing apparatus using a laser irradiates a laser beam at a very local place in a non-contact manner with respect to a workpiece to remove, destroy, mark, or surface a desired target without surrounding damage.

For example, when the semiconductor wafer process is changed from the original design in the patterning of the semiconductor wafer process, or when defects appear due to small impurities, the linkage can be connected to a surplus circuit that can be replaced by a replacement. Alternatively, the defect can be corrected by removing the projection or darkening the pixel where the bright spot is generated when a defect due to the projection defect or the bright spot defect appears for a specific pixel in the color filter substrate for the liquid crystal display device.

In order to remove a desired target by irradiating a laser beam to a target region such as a link of a semiconductor device, a projection in a liquid crystal display, or a bright point generating pixel, the quality of processing depends on the material of the object / target. The size, the energy intensity distribution of the laser beam to be irradiated, the size of the laser beam spot and the accuracy of the irradiation position are affected. In particular, when the energy intensity of the laser beam becomes unstable, there is a problem in that a precise work effect cannot be obtained in a fine machining operation.

The present invention is to provide a laser processing apparatus and method for stably transmitting the fine energy of the laser beam by arranging a beam blocker to allow or block the progress of the laser beam when processing the object to be processed using the laser. .

According to an aspect of the present invention, an apparatus for processing a target position of a workpiece by using a laser beam, comprising: a laser generator for generating a laser beam; An optical modulator for separating the laser beam into a first path and a second path; An objective lens unit focusing the laser beam separated by the first path to irradiate the target position; A stage unit on which the object to be processed is mounted and distance adjustable with respect to the objective lens unit; A laser processing apparatus is provided that includes a beam blocker disposed on a first path and allowing the laser beam to travel along the first path for an irradiation time corresponding to a target position.

The beam blocker may be a shutter that mechanically blocks or allows the progress of the laser beam.

Alternatively, the beam blocker may be a mirror that allows the laser beam to travel in the first path during the irradiation time and in the third path for other times.

The optical modulator may be kept ON during the machining operation of the workpiece.

The amount of laser beam split into the first path by the optical modulator may be greater than or equal to a certain threshold than the amount of laser beam allowed to travel during the irradiation time by the beam blocker.

The beam blocking unit may allow the laser beam to progress after a predetermined time passes after the laser beam is separated into the first path by the optical modulator.

The irradiation condition may be preset or correspond to the size of the target position.

According to another aspect of the present invention, a method for processing a target position of a workpiece by using a laser beam, the method comprising the steps of: (a) generating a laser beam; (b) separating the laser beam into a first path and a second path; (c) allowing the laser beam separated by the first path to proceed for a time corresponding to the irradiation condition, wherein the time corresponding to the irradiation condition is preset or set in accordance with the size of the target position; (D) there is provided a laser processing method comprising condensing the laser beam separated by the first path to be irradiated to the target position.

Step (c) may be performed by a shutter that mechanically blocks or allows the progress of the laser beam.

Alternatively, step (c) may be performed by a mirror that causes the laser beam to travel in the first path during the irradiation time and in the third path for other times.

Here, the laser beam may have a wavelength of 400 nm, an average output power of 100 mW, a beam diameter of 2 mm or less, and a pulse duration of 300 fs or less.

In addition, the laser beam may have a pulse frequency of 1 kHz or more and 150 MHz or less.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to a preferred embodiment of the present invention, when the processing of the object to be processed using a laser to arrange the beam blocker to allow or block the progress of the laser beam to enable a stable transmission to the fine energy of the laser beam.

In addition, when processing the object to be processed using a laser, a laser pulse having the same size of energy to the corresponding portion of the object to be processed is stably and continuously transmitted to enable a desired level of precision processing.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and redundant description thereof will be omitted. Shall be.

In the present invention, for convenience and understanding of the description will be described assuming a substrate as a processing object for the laser processing apparatus, this embodiment is not limited to this, the fine filter by a laser beam such as a color filter substrate, a semiconductor wafer for a liquid crystal display device If the product requires processing, it may be a processing target of the laser processing apparatus according to the present embodiment. Here, the projection defect pixel, the bright defect pixel or the link of the semiconductor memory of the color filter substrate may be a target to be corrected or removed by irradiating a laser beam.

1 is a schematic diagram of a laser processing apparatus according to an embodiment of the present invention. Referring to FIG. 1, a laser generator 110, an optical modulator 120, a beam dump 125, a reflection mirror 130, a beam expander 140, a scanner 150, an objective lens unit 160, a stage The unit 170, the beam blocking unit 180, the substrate 100, and the path 115 of the laser beam are shown.

The present invention is characterized by performing fine precision machining using ultra-short laser pulses. The laser beam having the ultra short laser pulse is oscillated by the laser generator 110, modulated by the optical modulator 120, and directed to the beam dump 125 or the reflection mirror 130. The laser beam that has traveled to the reflective mirror 130 is enlarged through the beam expander 140, and is scanned on the scanner 150 to be mounted on the stage 170 through the objective lens unit 160. In 100, the target to be corrected or removed by laser processing is irradiated. Here, the beam blocking unit 180 is interposed between the optical modulator 120 and the objective lens unit 160 to block the progress of the laser beam in the corresponding path depending on whether the predetermined condition is satisfied. This will be described in detail for each part as follows.

The laser generator 110 includes a laser medium, a pumping unit, a switching unit, and the like to output a laser beam having a predetermined pulse width. The laser beam oscillated by the laser generator 110 may be an ultra-short laser pulse having a pulse width in femto-second or pico-second units.

By using a laser beam with an extremely short pulse, the pulse duration is shorter than the thermal diffusion time, so there is no energy transfer between the electrons and the lattice, and the target exposed to the laser beam with high energy intensity is removed in an instant.

As a result, a melting zone or a heat affected zone is hardly observed in the portion to which the laser beam is irradiated. In addition, the length of the laser pulse absorbed and diffused in any material is proportional to the width of the laser pulse. The ultra short laser pulse has a short duration and a diffusion length in which the laser pulse is absorbed and diffused into the processing part. It also shortens, enabling precision machining.

In this embodiment, the target may be irradiated with one or more ultra-short laser pulses so that the target may be modified or removed. The target is a link of a semiconductor memory, a part of a defective pixel (projection, etc.) of a color filter substrate of a liquid crystal display device, etc., and its size is very small and requires minute precision processing. For efficient and stable correction or removal of such targets, the energy intensity of each ultrashort laser pulse to be irradiated is required to be the same or within a predetermined error range.

In this embodiment, a laser having a wavelength of approximately 400 nm, an average output power of 100 mW, a beam diameter of 2 mm or less, and a pulse duration of 300 fs or less may be used. In addition, the pulse frequency of the laser beam may be 1 kHz or more and 150 MHz or less.

The optical modulator 120 modulates the laser beam so that a part thereof is directed toward the objective lens unit 160 (first path), and the other part is adjusted to be irradiated to the beam dump 125 (second path). It plays a role. The scheme may be an Acoustic Optic Modulator (AOM) or an Electro Optic Modulator (EOM).

Since the optical modulator 120 may have a faster response than a shutter or a motor driving mirror generally used, the optical modulator 120 may be suitable for controlling the laser processing time at a high speed. In this embodiment, the response time of the optical modulator 120 is within 110 ns / mm, and can be closed after opening only for a desired processing time in conjunction with the position of the target measured by the position measuring unit, which will be described later. The time can vary from a few microseconds to a few seconds depending on the target.

Here, the amount of the laser beam to be adjusted may be one or more of the number of laser pulses, irradiation time, and the like. In the case of adjusting the number of laser pulses, the pulses of the laser beam generated from the laser generation unit 110 are routed to the objective lens unit 160 as much or more pulses necessary for the processing of the substrate 100, and the remaining pulses are The amount of pulse is controlled by branching to another path, such as the bypass path (in this embodiment, the path to the beam dump 125). When the number of pulses of the laser beam generated from the laser generator 110 is a natural number unit, the optical modulator 120 may adjust the amount of pulses by separating the number of pulses, that is, the quantity. When the irradiation time is adjusted, the laser beam is in the continuous wave mode, and the path is set so that the laser beam travels to the objective lens unit 160 only for a predetermined irradiation time or additionally a predetermined time or more. do.

The optical modulator 120 calculates the amount of laser pulses required to process the target according to the size of the target, and controls the operation of the optical modulator 120 to direct the laser pulse corresponding to the calculated amount to the objective lens unit 160. Modulation control unit (not shown) may be added. The modulation control unit may be integrated with the optical modulator 120, may be connected to a separate device, or may be integrated into a processing unit control unit (not shown) for controlling the entire laser processing apparatus.

That is, the optical modulator 120 may determine the path of travel of the laser beam according to the on / off signal from the modulation controller corresponding to the irradiation time. That is, the path of the laser beam is deflected by deflecting the laser beam from the laser generating unit 110 to the objective lens unit 160 when the on signal is applied, and deflecting the laser beam to the beam dump 125 when the off signal is applied. Can be separated.

The scanner 150 corresponds to a focus adjusting unit, and finely horizontally moves the focus of the laser beam on the processing surface. The scanner 150 may be a galvano mirror installed with two mirrors facing each other.

The first galvano mirror receives and reflects the laser beam and rotates about the first axis. The second galvano mirror receives and reflects a laser beam reflected from the first galvano mirror while rotating about a second axis different from the first axis. Therefore, the laser beam can be irradiated to a desired point on the stage unit 170 by adjusting the angle between the first and second axes, the degree of rotation of the first galvano mirror, and the degree of rotation of the second galvano mirror. Do.

After the scanner 150 positions the laser beam at a specific point, the objective lens unit 160 collects the laser beam with finely adjusted focus and irradiates a target to be processed. Here, the objective lens unit 160 may be composed of a single objective lens, a plurality of lens groups such as a convex lens, a concave lens may be composed of, or may be composed of a combination of one or more lenses and other optical systems. .

The scanner 150 may be provided with a scanner controller (not shown) for controlling the operation of the scanner 150 so that the laser beam can be irradiated to the corresponding position according to the position of the target. The scanner controller may be integrally formed with the scanner 150, may be connected to a separate device, or may be integrated with a processing unit controller for controlling the entire laser processing apparatus.

In this embodiment, in order to remove or destroy the target of the substrate 100, the position, shape, size, height, etc. of the target should be measured, and the objective of the objective lens unit 160 may be accurately irradiated to the target portion of the laser beam. It should be in focus.

To this end, a position measuring unit (not shown) capable of capturing a target by using an image pickup camera and receiving the photographed information to determine the position of the target may be added. Like the above-described modulation control unit or scanner control unit, the position measuring unit may be formed integrally with or separately from other devices, and may be integrated with the processing unit control unit. In this embodiment, the position measuring unit may include all the devices for measuring the position using the imaging camera, a detailed description thereof will be omitted. In addition, an auto focus system for receiving a signal from the imaging camera and focusing the objective lens unit 160 may be added.

The stage unit 170 is a portion for placing the substrate 100 to be processed, and the distance and / or position with respect to the objective lens unit 160 may be adjusted to adjust the exact position and focus. To this end, the stage unit 170 may be added a mechanical component that allows movement, rotation, and the like.

The path of the laser beam is directed from the laser generator 110 to the substrate 100 on the stage 170 through the optical modulator 120, the beam expander 140, the scanner 150, and the objective lens unit 160. The path is changed according to the configuration of the laser processing apparatus, and the reflection mirror 130 is used for this purpose.

The beam blocking unit 180 is disposed at an arbitrary position between the optical modulator 120 and the objective lens unit 160 on the path of the laser beam to block or allow the progress of the laser beam depending on whether a predetermined condition is satisfied. The beam blocking unit 180 may be a shutter or a mirror driven by a motor having a fast response time with a simple mechanical configuration. The shutter is a device that allows or blocks the progress of the laser beam traveling on the path, and the mirror adjusts the traveling direction with respect to the laser beam so as to proceed in the desired path or proceed in another path.

As described above, the optical modulator 120 has a fast response time, but is required to have a predetermined operating time in order to maintain the efficiency required for the response time. That is, the optical modulator 120 has a predetermined warm-up time for adjusting the amount of the laser beam at the time when the control signal is applied from the modulation controller. During this warm-up time, each pulse of the laser beam directed to the objective lens unit 160 through the optical modulator 120 has an energy intensity of a transition state rather than a steady state energy intensity. For this reason, when adjusting the amount of the laser beam in the optical modulator 120, the laser beam irradiated to the target for a predetermined irradiation time does not have a constant energy intensity may not be easy to fine energy control. That is, the energy intensity of the laser pulse irradiated at the beginning of the irradiation time and the energy intensity of the laser pulse irradiated in the middle or late stage may be different, and thus may not be stable in the micro machining.

In addition, since it takes a certain time to return to the initial unstabilized state after the state is stabilized so that the operation efficiency is maintained, in the present invention, in order to allow processing to be performed during the time that stabilization can be maintained, By using the unit 180, finer energy control can be made to the laser beam that has passed through the optical modulator 120.

The AOM efficiency of the optical modulator 120 according to the operating time of the optical modulator 120 before using the preheating function in relation to the predetermined warm-up time is shown in Table 1. Here, the AOM efficiency refers to the ratio of first order light to incident light. Referring to Table 1 below, the initial operation state stabilization introduction time of the optical modulator 120 is possible within about 120 seconds.

Time after AOM ON AOM efficiency 0.5 sec 79% 20 sec 82% 40 sec 84% 60 sec 86% 120 sec 88%

Table 2 shows the AOM efficiency of the optical modulator 120 according to the operating time of the optical modulator 120 after the optical modulator 120 uses the preheating function. Unlike before the preheating function, it can be seen that the optical modulator 120 can obtain the desired AOM efficiency within a very short time.

Time after AOM ON AOM efficiency 0.5 sec 87% 20 sec 88% 40 sec 88% 60 sec 88% 120 sec 88%

In addition, the AOM efficiency immediately after applying the on-signal to the optical modulator 120 when the optical modulator 120 is sufficiently warmed in the on state of the optical modulator 120 and then the optical modulator 120 is maintained in the off state for a predetermined time is shown in the table. It is shown in 3. It can be seen that the longer the holding time in the off state, the lower the AOM efficiency immediately after applying the on signal. That is, it can be seen that the preheating effect of the previous optical modulator 120 disappears when the holding time of the off state is long.

AOM Off State Hold Time Efficiency at AOM ON Startup 2 sec 88% 5 sec 87% 10 sec 85% 30 sec 82% 60 sec 80% 300 sec 79%

Therefore, after the optical modulator 120 enters the stabilization state in the initial operating state, a preheating function is used to maintain the on state without turning off the optical modulator 120 and the beam block unit 180 may be used to By controlling the progress, stable operating efficiency can be obtained in a short time.

To this end, the optical modulator 120 adjusts the amount of the laser beam so that the laser beam more than a predetermined threshold is directed to the objective lens unit 160 than the amount of the laser beam corresponding to the irradiation time required for correcting or removing the target. . Alternatively, the optical modulator 120 may be in the ON state during laser processing of the processing object so that the laser beam oscillated from the laser generator 110 may be directed to the objective lens unit 160.

The beam blocking unit 180 is disposed on a laser beam propagation path between the optical modulator 120 and the objective lens unit 160 to block the progress of the laser beam. After the scanner 150 is operated according to the position of the target to be corrected or removed and controlled so that the laser beam can be irradiated to the target, the beam blocking unit 180 may perform the irradiation time required for correcting or removing the target. Only allow the laser beam to travel in the original path and block the laser beam from traveling in the original path for any other time.

The beam blocking unit 180 has a simple mechanical configuration such as a shutter or a mirror, and thus does not require a stabilization introduction time, that is, a warm-up time, such as the optical modulator 120. Therefore, the laser beam only has a very short transition state at the time of interruption and allowance of the laser beam propagation, and accordingly, the laser beam is allowed to travel between the allowable time and the interruption time as much as necessary. ) Can be irradiated to the target to achieve the desired level of precision machining effect.

The beam blocking unit 180 calculates an amount of laser pulses necessary for processing the same according to the size of the target, and operates the beam blocking unit 180 to direct only the calculated amount of laser pulses to the objective lens unit 160. A blocking control unit (not shown) for controlling may be added. The blocking control unit may be integrally formed with the beam blocking unit 180, may be connected by a separate device, or may be integrated with the processing unit control unit that controls the entire laser processing apparatus.

In this embodiment, the processing unit controller for controlling the overall driving of the laser generator 110, the optical modulator 120, the scanner 150, the stage unit 170, the beam blocking unit 180, etc. may be provided. have. The processing unit controller may be a conventional computer including a CPU, a ROM, and a RAM, and checks a target to be processed through an imaging camera and a position measuring unit, and generates a laser beam, modulates a laser beam, and outputs a control signal. It is possible to control irradiation position selection, focal length movement, movement and rotation of the stage portion, blocking of the laser beam, and blocking / permitting timing.

In addition, according to the present embodiment, it is preferable to use a laser beam in a wavelength region with good absorption depending on the material of the substrate 100 to be processed in the laser processing apparatus. To this end, a wavelength converter for converting the wavelength of the laser beam before the laser beam generated by the laser generator 110 is modulated by the optical modulator 120 or separated by a necessary amount through the fine adjustment by the beam blocker 180. (Not shown) may be interposed. In this embodiment, the wavelength converter may include any device for converting the wavelength of the laser beam, and a detailed description thereof will be omitted.

The wavelength converter receives the laser beam generated from the laser generator 110 and converts the laser beam into a laser beam having an appropriate wavelength.

In the present embodiment, the laser generator 110, the optical modulator 120, the reflection mirror 130, the beam expander 140, the scanner 150, the objective lens unit 160, and the beam blocking unit 180 are optically It is connected. Optical phenomena include various phenomena such as reflection, diffraction, and refraction of light. Here, 'optically connected' means that light emitted from one component by various optical phenomena is received by the other component. it means.

A laser processing method using the above laser processing apparatus will be described in detail with reference to FIG. 2.

2 is a flow chart of a laser processing method according to an embodiment of the present invention.

In operation 200, the laser generator 110 generates a laser beam having a predetermined pulse width. Here, the laser beam may have an ultra-short laser pulse for fine precision processing as described above.

In operation 210, the optical modulator 120 separates the laser beam oscillated from the laser generator 110 into the first path through a modulation process. The first path means a path from the optical modulator 120 to the object to be mounted on the stage unit 170.

In step 220, the position of the target to be processed by the laser beam is measured.

The scanner 150 is adjusted to correspond to the position of the target measured in step 230 so that the laser beam is irradiated to the corresponding position. The scanner 150 may be finely driven so that the laser beam is uniformly irradiated to the entire target during the irradiation time.

The beam blocking unit 180 is basically disposed on the first path to block the progress of the laser beam. If the position of the target has been measured and the scanner 150 has been adjusted to irradiate the laser beam to the target, then allowing the laser beam to continue along the first path for a time in accordance with the predetermined irradiation condition in step 240. do. Here, the time according to the irradiation condition is set in advance or is determined by the size of the target object from the time point at which the laser beam is allowed to proceed to the blocking time, and the time when the laser beam is irradiated to the target or the number of laser pulses corresponding thereto. to be.

In operation 250, the objective lens unit 160 proceeds to the first path to collect the laser beam allowed to proceed by the beam blocking unit 180 to irradiate the target object. The target is corrected or removed by laser beam irradiation for a predetermined time.

There may be a plurality of targets for one substrate 100, in which case steps 220 to 250 may be repeated.

In another embodiment, the step 220 may be performed once to measure the positions of multiple targets simultaneously. In this case, after laser processing is completed for one target, the laser processing may be performed on the target at the next position without measuring the position of the target.

According to the present invention, substrate defects can be corrected by darkening the point pixels when correcting the point defects of the liquid crystal display using a laser processing apparatus.

3 is a diagram illustrating a laser beam irradiated onto a pixel area of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 4 is a pixel type of a color filter of a liquid crystal display according to an exemplary embodiment. It is a figure shown separately.

Referring to FIG. 3, the LCD includes an upper substrate 300, a lower substrate 302, a liquid crystal layer 304, a black matrix 312, and a color filter 315.

The laser beam irradiation on the color filter 315 may be performed in various ways. Preferably, the laser beam is sequentially irradiated onto the color filter 315 at predetermined point intervals.

For example, the above-described processing unit controller moves the focus of the laser beam to a point of the color filter through the scanner 150. Thereafter, the beam blocking unit 120 is controlled to irradiate a laser beam for a predetermined irradiation time or a predetermined number of pulses at a corresponding point. When the irradiation of the laser beam at the corresponding point is completed, the OFF signal is applied to the optical modulator 120 to stay for a predetermined time, and then, the scanner 150 moves the focus of the laser beam to the next point and irradiates the laser beam.

In this case, the scanner 150 may irradiate the laser beam in a direction parallel to the short side of the color filter corresponding to the defective pixel, a direction parallel to the long side, and a direction from the center to the outside. Depending on the shape of the pixel or in the direction of less influence on the surrounding pixels, the laser beam may be irradiated as if the water droplets are dropped.

Referring to FIG. 4, a darkened green color filter 410, a darkened blue color filter 420, a darkened red color filter 430, and a darkened color filter peripheral pixel 435 are illustrated. . Color filters darkened by color can correct spot defects without causing the surrounding pixels to brighten.

In addition, the present invention can be used to correct the substrate defect by removing the projection when the projection defect correction of the liquid crystal display device using a laser processing apparatus. In the liquid crystal display device, foreign matters in the air and the like are mixed with the respective materials during the manufacturing process of the color filter substrate, and in the subsequent process, a photoresist, an overcoat, and the like are applied onto the foreign matters, thereby causing protrusion defects. Measure the position, shape, size, etc. of the protrusion using the position measuring unit. The size of the protrusion can be measured by various methods such as three-dimensional non-contact height measurement, and the amount of laser beam is calculated based on the measured value. According to the calculated result, the beam blocking unit 180 is mechanically driven to allow the propagation only for the required amount of laser beams, and the others block the propagation. In this case, the optical modulator 120 allows the laser beam more than necessary to travel to the beam blocking unit 180 along the corresponding path. The scanner 150 is driven based on the position measured by the position measuring unit so that the laser beam passing through the objective lens unit 160 is irradiated to the projection. The mechanical driving of the beam blocking unit 180 prevents unstable energy transfer due to the warm-up time in the optical modulator 120 and enables precision machining operation.

In addition, the present invention is reproducible by connecting to a redundant circuit that can be replaced by removing a connection portion of a circuit that acts like a fuse when the pattern is changed from the original design in a semiconductor wafer process using a laser processing apparatus. can do. Here, the size of the link is varied, the shape of the link is long, and the link and the link maintain a very close distance. The laser beam is irradiated to the link to be removed using the laser processing apparatus according to the present embodiment only for the time allowed by the beam blocking unit 180, so that the effect of precision machining to efficiently remove the link can be obtained. have.

Although the present invention has been described only in the case of the modification of the color filter substrate for the liquid crystal display device and the removal of the link during the semiconductor wafer process, the present invention is not limited thereto, as well as other types of substrates, ultra-short pulse lasers are used. It can be applied to 3D micromachining which minimizes damage of the object and demands finer and more precise structures, patterns and shapes.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a schematic view of a laser processing apparatus according to an embodiment of the present invention.

2 is a flow chart of a laser processing method according to an embodiment of the present invention.

3 is a diagram illustrating a laser beam radiated to a pixel region of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 4 is a diagram illustrating color filters for pixel types of a liquid crystal display device in which defects are corrected according to an exemplary embodiment of the present invention. FIG.

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

100: substrate 110: laser generation unit

120: optical modulator 130: reflective mirror

140: beam expander 150: scanner

160: objective lens unit 170: stage unit

180: beam blocking unit

Claims (14)

In the apparatus for processing the target position of the object to be processed using a laser beam, A laser generator for generating the laser beam; An optical modulator separating the laser beam into a first path and a second path; An objective lens unit focusing the laser beam separated by the first path to irradiate the target position; A stage unit on which the object to be processed is mounted and distance adjustable with respect to the objective lens unit; And a beam blocker disposed on the first path and allowing the laser beam to travel along the first path for an irradiation time corresponding to the target position. The method of claim 1, And the beam blocking unit is a shutter which mechanically blocks or permits the progress of the laser beam. The method of claim 1, And the beam blocking unit is a mirror to allow the laser beam to travel in the first path during the irradiation time and in the third path for other times. The method of claim 1, And the optical modulator is maintained in an ON state during a machining operation of the object. The method of claim 1, And the amount of laser beam split into the first path by the optical modulator is greater than or equal to a predetermined threshold than the amount of laser beam allowed to travel during the irradiation time by the beam blocking unit. The method of claim 1, And the beam blocking unit allows the laser beam to progress after a predetermined time has passed after the laser beam is separated into the first path by the optical modulator. The method of claim 1, And said irradiation condition is predetermined or corresponds to the size of said target position. The method of claim 1, And said laser beam has a wavelength of 400 nm, an average output power of 100 mW, a beam diameter of 2 mm or less, and a pulse duration of 300 fs or less. The method of claim 8, And said laser beam has a pulse frequency of 1 kHz or more and 150 MHz or less. In the method for processing the target position of the object to be processed using a laser beam, (a) generating a laser beam; (b) separating the laser beam into a first path and a second path; (c) allowing the laser beam separated by the first path to proceed for a time corresponding to an irradiation condition, wherein the time corresponding to the irradiation condition is set in advance or corresponding to the size of the target position. -Wow; (d) concentrating the laser beam separated by the first path to irradiate the target position. The method of claim 10, And said step (c) is performed by a shutter which mechanically blocks or permits the progress of said laser beam. The method of claim 10, And said step (c) is performed by a mirror that causes said laser beam to travel in said first path during said irradiation time and in a third path for other times. The method of claim 10, The laser beam has a wavelength of 400 nm, an average output power of 100 mW, a beam diameter of 2 mm or less, and a pulse duration of 300 fs or less. The method of claim 13, And said laser beam has a pulse frequency of 1 kHz or more and 150 MHz or less.

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