Laser processing apparatus and laser processing method using the same, which enable various processing patterns.

Abstract

The present invention provides a laser processing apparatus and a laser processing method, including an optical unit configured to achieve various processing patterns. [Solution] An optical unit including a first optical group containing multiple first diffractive optical elements that transform the shape of a laser beam in order to realize various processing patterns with a single optical unit, a second optical group containing multiple second diffractive optical elements that split the laser beam into multiple beams, an optical element holder that selects diffractive optical elements from the first optical group and the second optical group respectively, and combines the selected diffractive optical elements by arranging them in series with respect to the optical axis of the laser beam, and a lens unit that focuses the laser beam onto the surface of the workpiece, and a controller that receives processing pattern data, determines processing parameters according to the input processing pattern data, and controls the optical element holder to select a combination of first and second diffractive optical elements corresponding to the determined processing parameters.

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus used for semiconductor or display processing, and a laser processing method using the same.

Background Art

[0002] When processing a semiconductor substrate or a display element, laser patterning can be performed to precisely form a desired pattern by selectively removing material from the surface of the workpiece using laser ablation. Also, in the processes of semiconductor chip dicing, chip packaging, or the separation process of a display substrate, laser grooving can be performed to form precise grooves in the workpiece.

[0003] The laser beam pattern irradiated on the workpiece must change according to the type of the workpiece to be laser processed, the standards and shapes of the processing shapes, the process method, etc. For this purpose, both the type and size of the optical unit included in the laser processing apparatus must also change.

[0004] However, changing the optical unit according to various processing specifications has not only technical limitations but also problems such as a decrease in yield, a decrease in processing quality, an increase in processing defects, and cost issues. The configuration of the optical unit is very complex. However, when changing and operating a plurality of elements included in the optical unit to meet various processing specifications, problems such as a decrease in processing quality and processing defects occur due to aberrations generated by the plurality of elements included in the optical unit, resulting in a drawback of low yield.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a laser processing apparatus including an optical unit configured to realize various processing patterns, and a laser processing method using the same. The technical problems that this embodiment aims to solve are not limited to the technical problems described above, and other technical problems can be inferred from the following embodiments. [Means for solving the problem]

[0006] According to one aspect of the present invention, a laser processing apparatus is provided, comprising: a laser oscillator for generating a laser beam; a first optical group including a plurality of first diffractive optical elements for adjusting the laser beam and irradiating the adjusted laser beam onto the surface of a workpiece; b) a second optical group including a plurality of second diffractive optical elements for splitting the laser beam into multiple beams; c) an optical element holder for selecting diffractive optical elements from the first optical group and the second optical group, and arranging the selected diffractive optical elements in series with respect to the optical axis of the laser beam; and d) an optical unit including a lens unit for focusing the laser beam onto the surface of a workpiece; a processing table for moving the workpiece in the processing direction; and a controller for which processing pattern data is input, which determines processing parameters according to the input processing pattern data, and which controls the optical element holder to select a combination of the first diffractive optical elements and the second diffractive optical elements corresponding to the determined processing parameters.

[0007] This further includes a laser attenuator for adjusting the output intensity of the laser beam.

[0008] Here, the first optical group further includes a blank through which the laser beam passes, and the plurality of first diffractive optical elements include top-hat diffractive optical elements that convert the laser beam into at least one of a line shape, a rectangle shape, and a square shape.

[0009] Here, the second optical group further includes a blank through which the laser beam passes, and the plurality of second diffractive optical elements include multi-spot diffractive optical elements that split the laser beam into multiple beams and realize a different number of multiple beams.

[0010] Here, the optical element holder includes a rotary turret or sliding mechanism that can selectively position the diffractive optical elements of the first optical group and the second optical group.

[0011] Here, the lens unit includes a plurality of objective lenses, each with a different magnification, and the device further includes a lens holder that combines the objective lenses selected in the lens unit with a selected diffractive optical element in series with respect to the optical axis, and the controller controls the lens holder to select an objective lens corresponding to a determined machining parameter.

[0012] Here, the plurality of objective lenses include an objective lens having at least 5x magnification and an objective lens having 10x magnification.

[0013] Here, the processing pattern data includes the processing line width and processing depth, and the processing parameters include at least the shape of the laser beam and the number of multiple beams.

[0014] Here, the controller determines the rotation angle of the first diffractive optical element selected according to the input processing pattern data, and controls the first diffractive optical element to rotate with respect to a rotation axis parallel to the normal of the plane of the workpiece, according to the determined rotation angle.

[0015] The present invention further includes a beam limiting element positioned between the first optical group and the lens unit, which blocks a portion of the laser beam, wherein the beam limiting element is a slit or aperture, and the controller determines the blocking range of the laser beam based on the rotation angle and controls the beam limiting element based on the determined blocking range of the laser beam.

[0016] This further includes a camera that acquires real-time video via the same path through which the laser beam is irradiated.

[0017] According to another aspect of the present invention, a laser processing method using a laser processing apparatus is provided, comprising the steps of: a) inputting processing pattern data to the controller and determining processing parameters; b) the controller controlling a combination of a first diffractive optical element and a second diffractive optical element in accordance with the processing parameters; and c) the controller controlling the laser oscillator to output a laser beam and irradiating the surface of the workpiece with a laser beam adjusted via the selected first diffractive optical element and the selected second diffractive optical element, thereby forming a processing pattern on the workpiece.

[0018] Here, in step a), if first processing pattern data for processing a first processing pattern with a first processing line width and a first processing depth is input to the controller, in step b), the controller controls the optical element holder to select a first top-hat diffractive optical element that converts the laser beam into a line beam of a first length with the first diffractive optical element, and a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams with the second diffractive optical element, so that the multiple beams are arranged in parallel in the processing direction.

[0019] Here, in step a), if the controller is input second processing pattern data for processing a second processing pattern having a first processing line width and a second processing depth different from the first processing depth (for example, greater than the first processing depth), in step b), the controller controls the optical element holder to select and combine a first top-hat diffractive optical element that converts the laser beam into a line beam of a first length with the first diffractive optical element, and a second multi-spot diffractive optical element that splits the line beam into a second number of multiple beams with the second diffractive optical element, the second number being different from the first number (for example, greater than the first number).

[0020] Here, in step a), if the controller is input third processing pattern data for processing a third processing pattern having a second processing line width and a first processing depth that is different from (e.g., smaller than) the first processing line width, then in step b), the controller controls the optical element holder to combine the first diffractive optical element with a second top-hat diffractive optical element that converts the laser beam into a line beam of a second length, and the second diffractive optical element with a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams, wherein the second length is different from (e.g., smaller than) the first length.

[0021] Here, in step a), if the controller receives fourth processing pattern data for processing a fourth processing pattern having a third processing line width smaller than the first processing line width and a third processing depth greater than the first processing depth, in step b), the controller selects a blank in the first optical group through which the laser beam passes directly, and the second diffractive optical element controls the optical element holder to select and combine a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams.

[0022] Here, the lens unit includes a plurality of objective lenses, each having a different magnification, and the laser processing apparatus further includes a lens holder that combines the objective lenses selected in the lens unit with a selected diffractive optical element in series with respect to the optical axis, and in step b), the controller further includes controlling the selection of an objective lens according to the processing parameters.

[0023] The controller further includes the steps of determining the rotation angle of a first diffractive optical element selected according to the input processing pattern data, and controlling the first diffractive optical element to rotate with respect to a rotation axis parallel to the normal of the plane of the workpiece, according to the determined rotation angle.

[0024] Here, the laser processing apparatus further includes a beam limiting element disposed between the first optical group and the lens unit for blocking a part of the laser beam, and the controller further includes a step of determining a blocking range of the laser beam based on the rotation angle and controlling the beam limiting element based on the determined blocking range of the laser beam.

[0025] Here, the laser processing apparatus further includes a camera for acquiring real-time video through the same path as the path through which the laser beam is irradiated, and the controller further includes a step of confirming the alignment of the first diffractive optical element and the second diffractive optical element in real time.

Advantages of the Invention

[0026] According to the problem-solving means of the present invention described above, various processing steps can be performed by adjusting the processing line width and the processing depth without changing the optical unit included in the laser processing apparatus.

[0027] Specifically, by selectively combining diffractive optical elements (DOEs) in a single optical unit, the shape of the laser beam irradiated on the workpiece and the number of branched beams are changed, and thereby the processing line width and the processing depth of the processing pattern can be realized in various ways.

[0028] In addition, since various processing specifications can be satisfied without changing the optical unit, it can contribute to the simplification and stabilization of the process conditions.

[0029]

Brief Description of the Drawings

[0030] FIG. 1 is a diagram showing a laser processing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing an optical unit according to an embodiment of the present invention. FIG. 3 is a flowchart for explaining a laser processing method using the laser processing apparatus of FIG. 1. Figure 4 illustrates one embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus shown in Figure 1. Figure 5 illustrates another embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus shown in Figure 1. Figure 6 illustrates another embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus shown in Figure 1. Figure 7 shows a laser processing apparatus according to another embodiment of the present invention. Figure 8 is a flowchart illustrating the laser processing method using the laser processing apparatus shown in Figure 7. Figure 9 illustrates one embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus shown in Figure 7. Figure 10 is an image showing the rotation of the laser beam produced by the laser processing apparatus shown in Figure 7. Figure 11 shows a laser processing apparatus according to another embodiment of the present invention. Figure 12 is a flowchart illustrating the laser processing method using the laser processing apparatus shown in Figure 11. Figure 13 illustrates one embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus shown in Figure 11. [Modes for carrying out the invention]

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings, so that those with ordinary skill in the art to which the present invention pertains can easily implement it. However, the present invention can be realized in a variety of different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention in the drawings, parts unrelated to the description have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0032] In the following embodiments, terms such as "first," "second," etc., are used not in a restrictive sense, but to distinguish one component from another.

[0033] In the following embodiments, a singular expression includes plural expressions unless the context clearly indicates otherwise.

[0034] In the following embodiments, terms such as "includes" or "has" mean that the features or components described herein are present, and do not preclude the possibility of the addition of one or more other features or components.

[0035] In the following embodiments, when we say that a part such as a membrane, region, or component is on or above another part, this includes not only cases where it is directly above the other part, but also cases where another membrane, region, component, etc. is interposed between them.

[0036] In drawings, for illustrative purposes, the size of components may be exaggerated or reduced. For example, the dimensions and thicknesses of each component shown in the drawings are arbitrarily shown for illustrative purposes, and therefore the present invention is not necessarily limited to those shown.

[0037] In the following embodiments, DR1, DR2, and DR3 are not limited to the three axes on the Cartesian coordinate system, but can be interpreted in a broader sense that includes them. For example, DR1, DR2, and DR3 may be orthogonal to each other, or they may each point in different directions that are not orthogonal to each other.

[0038] The sequence of the processing method may differ from the sequence described if other embodiments are feasible. For example, two steps described consecutively may be performed substantially simultaneously, or they may proceed in the reverse order of the description.

[0039] The present invention will be described in detail below with reference to the attached drawings.

[0040] Figure 1 shows a laser processing apparatus 100 according to one embodiment of the present invention. Figure 2 shows an optical unit 120 according to one embodiment of the present invention.

[0041] Referring to Figure 1, the laser processing apparatus 100 includes a laser oscillator 110, a laser attenuator 115, an optical unit 120, a processing table 130, a coaxial optical system 140, and a controller 150.

[0042] The laser oscillator 110 generates a laser beam La. The laser beam La generated by the laser oscillator 110 may be a single-spot laser beam having a Gaussian profile. In Figure 1, the laser beam generated by the laser oscillator 110 is labeled as La.

[0043] The laser oscillator 110 may include a laser source capable of generating and outputting a laser beam having a specific wavelength. The type of laser beam output from the laser oscillator 110 is not particularly limited and can be appropriately selected according to the type of workpiece W and processing method. For example, the laser beam output from the laser oscillator 110 may be any of the following: a solid-state laser beam including a ruby ​​laser beam, Nd:YAG laser beam, Ti:sapphire laser beam, etc.; a liquid laser beam including a dye laser beam, etc.; a gas laser beam including a CO2 laser beam, He-Ne laser beam, Ar+ laser beam, excimer laser beam, etc.; or a UV (Ultraviolet) laser beam. The laser oscillator 110 is connected to the controller 150. The characteristics of the laser beam output from the laser oscillator 110, such as the wavelength and mode (continuous wave or pulsed wave) of the laser beam, can be controlled by signals generated by the controller 150.

[0044] The laser attenuator 115 adjusts the output intensity of the laser beam La generated by the laser oscillator 110. Here, the output intensity of the laser beam is expressed as the total amount of laser energy emitted from the laser oscillator 110 per unit time, and is in units of W (watts) or mW (milliwatts). In Figure 1, the laser beam whose output intensity has been adjusted by the laser attenuator 115 is indicated as Lb. The laser attenuator 115 prevents excessive laser beam output during processing, which could damage the workpiece, and precisely controls the laser beam intensity to optimize processing quality. The laser attenuator 115 can be controlled by a signal generated by the controller 150.

[0045] The optical unit 120 may include a first optical group 121, a second optical group 122, an optical element holder 125, and a lens unit 124. The optical unit 120 can adjust the laser beam Lb from the laser attenuator 115 to irradiate the laser beam L onto a desired position on the surface of the workpiece W. The operation of the optical unit 120 can be controlled by the controller 150.

[0046] The first optical group 121 is positioned between the laser oscillator 110 and the second optical group 122, with respect to the optical axis. The first optical group 121 provides a laser beam Lc whose shape has been changed by the laser attenuator 115, which adjusts the output intensity of the laser beam Lb. For this purpose, the first optical group 121 includes multiple first diffractive optical elements that change the shape of the laser beam. Each first diffractive optical element may be a top-hat diffractive optical element (TH DOE), which converts the laser beam into laser beams of different shapes. For example, the first top-hat diffractive optical element TH1 is an element that converts a laser beam into a line-shaped line beam, the second top-hat diffractive optical element TH2 is an element that converts a laser beam into a rectangular shape, and the third top-hat diffractive optical element (not shown) may be an element that converts a laser beam into a square shape. Therefore, the first optical group 121 is equipped with various top-hat diffracting optical elements, allowing for the selective use of desired beam shapes depending on the processing conditions.

[0047] Furthermore, the first optical group 121 can include a blank BLK through which the laser beam passes directly, in addition to the top-hat diffractive optical elements. A blank BLK is a flat, transparent element without a pattern, which allows a laser beam to pass through in a straight line without scattering or diffracting it.

[0048] The second optical group 122 is positioned between the first optical group 121 and the lens unit 124, with respect to the optical axis. The second optical group 122 provides the branched laser beam Ld by branching the laser beam Lc that has passed through the first optical group 121. The second optical group 122 includes multiple second diffractive optical elements that change the number of branching points of the laser beam. Each second diffractive optical element may be a multi-spot diffractive optical element (MS DOE) that converts the laser beam into multiple beams with different numbers of branched beams. For example, the first multi-spot diffractive optical element MS1 is an element that converts a laser beam into five multiple beams with a predetermined pitch (interval) in a one-dimensional beam array (1 × (by) N, where N is a natural number), the second multi-spot diffractive optical element MS2 is an element that converts a laser beam into eight multiple beams with a predetermined pitch in a one-dimensional beam array 1 × N, and the third multi-spot diffractive optical element (not shown) may be an element that converts a laser beam into eleven multiple beams with a predetermined pitch in a one-dimensional beam array 1 × N. In this invention, the number of beams branched by the multi-spot diffractive optical element can be 2, 3, tens, hundreds, or tens of thousands in a one-dimensional beam array of 1 × N. Furthermore, in this invention, the beam branched by the multi-spot diffractive optical element may be not only a one-dimensional beam array 1×N, but also a two-dimensional beam matrix M×N (where M and N are natural numbers). Thus, the second optical group 122 is equipped with a variety of multi-spot diffractive optical elements, allowing for the selective use of desired multiple beams depending on the processing conditions.

[0049] Furthermore, the second optical group 122 may include, in addition to the multi-spot diffractive optical elements, a blank BLK through which the laser beam passes directly.

[0050] The optical element holder 125 selects and combines diffractive optical elements from the first optical group 121 and the second optical group 122, respectively. Specifically, the optical element holder 125 selects one first diffractive optical element (or blank BLK) from the first optical group 121 and one second diffractive optical element (or blank BLK) from the second optical group 122. The optical element holder 125 combines two selected diffractive optical elements by arranging them in series based on the optical axis of the laser beam. The optical element holder 125 can be controlled by signals from the controller 150.

[0051] Referring to Figure 2, the optical element holder 125 may include a first optical element holder 1251 and a second optical element holder 1252. The first optical element holder 1251 can select one first diffractive optical element (or blank BLK) in the first optical group 121 and position it along the optical axis of the laser beam. The first optical element holder 1251 may include a rotary turret as shown in Figure 2(a) or a sliding mechanism as shown in Figure 2(b). The second optical element holder 1252 can select one second diffractive optical element (or blank BLK) in the second optical group 122 and position it along the optical axis of the laser beam. The second optical element holder 1252 may include a rotary turret as shown in Figure 2(a) or a sliding mechanism as shown in Figure 2(b). In other embodiments, the first optical element holder 1251 and the second optical element holder 1252 may be configured integrally. In yet another embodiment, the first optical element holder 1251 may include a rotary turret, and the second optical element holder 1252 may include a sliding mechanism, or vice versa.

[0052] In the embodiment, the laser processing apparatus 100 allows for combinations of different types of diffractive optical elements (or blank BLKs) within a single optical unit 120 via the optical element holder 125, enabling the realization of various processing pattern line widths and depths with a single optical unit 120.

[0053] The lens unit 124 may be positioned between the second optical group 122 and the processing table 130 with respect to the optical axis. The lens unit 124 adjusts the size of the branched laser beam Ld to provide a laser beam L of adjusted size. The lens unit 124 includes an objective lens 124L, which adjusts the size of the laser beam and focuses it onto the surface of the workpiece W. The objective lens 124L adjusts the size of the laser beam at a predetermined magnification. The magnification of the objective lens 124L may be 5x, which reduces the laser beam to 1 / 5 of its original size; 10x, which reduces the laser beam to 1 / 10 of its original size; 20x, which reduces the laser beam to 1 / 20 of its original size; and so on.

[0054] The processing table 130 may be positioned in the direction from which the laser beam is irradiated. Then, the workpiece W is placed on the processing table 130. Furthermore, the machining table 130 can move the workpiece W in the machining direction PD (Figure 4). For example, the machining table 130 can move the workpiece W in each of the following directions: DR1, DR2, or DR3. The operation of the processing table 130 can be controlled by the controller 150.

[0055] The coaxial optical system 140 aligns the optical path of the laser beam and the vision path, enabling the camera 141 to acquire images via the same path through which the laser beam is emitted. Furthermore, since the laser irradiation position and the position observed by the camera 141 coincide in this coaxial optical system 140, precise alignment monitoring of the optical unit 120 and real-time processing observation are possible. Specifically, the coaxial optical system 140 enables precise alignment monitoring when diffractive optical elements selected from the first optical group 121 and the second optical group 122 are arranged in series with reference to the optical axis of the laser beam. Furthermore, the coaxial optical system 140 eliminates travel time due to the offset between the machining process and the vision, allowing for real-time observation of the machining process.

[0056] The coaxial optical system 140 may include a coaxial illumination system 142, at least one or more mirrors 141m, 142m, 120m, and a camera 141.

[0057] The coaxial illumination 142 provides the light necessary for the camera 141 to acquire images or video. The coaxial lighting 142 may include an LED light source. The coaxial illumination 142 converges the illumination on the optical axis via at least one mirror 141m, 142m, and 120m, so that the light enters through the same path as the field of view of the camera 141.

[0058] At least one of the mirrors 141m, 142m, and 120m may include a coaxial illumination mirror 142m that directs the coaxial illumination 142 to the optical axis, an optical mirror 120m that directs the light reflected from the workpiece W into the optical unit 120 and directs it to the optical axis, and a camera mirror 141m that directs the light that has been directed to the optical axis into the camera 141. The type and number of mirrors can be increased or decreased by the laser processing equipment. Here, unlike the coaxial illumination mirror 142m, the optical mirror 120m and the camera mirror 141m may be half-mirrors (beam splitters) that reflect some of the incident light and transmit some of it.

[0059] Camera 141 monitors the processing location to which the laser beam is irradiated. The camera 141 then acquires real-time images via the same path through which the laser beam is emitted. For this purpose, light irradiated by the coaxial illumination 142 is reflected from the surface of the workpiece W and incident on the optical unit 120, and through a mirror or the like, reaches the camera 141, which then generates images or videos. Before processing the workpiece W, the camera 141 generates images and video information to align the diffractive optical elements selected from the first optical group 121 and the second optical group 122. Furthermore, during the processing of the workpiece W, the camera 141 generates image and video information including the trajectory of the laser beam, the irradiation position, and the processing results.

[0060] Specifically, the camera 141 confirms that the diffractive optical elements selected in the first optical group 121 and the second optical group 122 are arranged in series with reference to the optical axis of the laser beam and aligned accordingly. Camera 141 can be controlled by controller 150, and information such as images and videos acquired from camera 141 is transmitted to controller 150. The controller 150 can control the optical element holder 125 based on the transmitted information to precisely control the position of the selected diffractive optical element. Furthermore, camera 141 monitors the surface of the workpiece W being irradiated with the laser beam in real time. Camera 141 can be controlled by controller 150, and information such as images and videos acquired from camera 141 is transmitted to controller 150. The controller 150 can then verify, based on the transmitted information, whether the machining line width and machining depth of the machining pattern match the input machining pattern data.

[0061] Generally, laser processing equipment employs a "separated optical system" in which processing and observation are separated. However, in the case of such a separated optical system, it is difficult to accurately confirm whether the diffractive optical elements selected in the first optical group 121 and the second optical group 122 are correctly aligned, making real-time observation of the processing impossible. However, according to embodiments of the present invention, the inclusion of a coaxial optical system 140 in the laser processing apparatus 100 has the effect of enabling accurate alignment of multiple diffractive optical element combinations and real-time observation of the processing.

[0062] The controller 150 can control each component of the laser processing apparatus 100. Furthermore, this controller 150 can be implemented by including at least one of the following as a processor: ASICs (application-specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), controllers, microcontrollers, microprocessors, or other electrical units for performing functions.

[0063] According to one embodiment of the present invention, the controller 150 can receive processing pattern data, determine processing parameters according to the input processing pattern data, and control the optical element holder 125 to select a combination of a first diffractive optical element and a second diffractive optical element corresponding to the determined processing parameters. The specific operation of controller 150 will be described later.

[0064] Figure 3 is a flowchart illustrating the laser processing method using the laser processing apparatus 100 shown in Figure 1. Figure 4 illustrates one embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus 100 shown in Figure 1. Figure 5 illustrates another embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus 100 shown in Figure 1. Figure 6 illustrates another embodiment of a laser processing method that uses the laser processing apparatus 100 of Figure 1 to achieve various processing patterns.

[0065] Figures 4 to 6 show (a) a conceptual representation of the combination of the first and second diffractive optical elements, (b) a conceptual representation of the laser beam irradiated onto the workpiece W, (c) a top view of the workpiece W processed by the laser beam in (b), and (d) a side view of the workpiece W processed by the laser beam in (b), which corresponds to the plane in (c).

[0066] Referring to Figure 3, in step 110 (S110), the controller 150 receives the machining pattern data and determines the machining parameters.

[0067] Here, machining pattern data refers to information about the machining pattern, and may include information on the machining line width (represented in the diagram as a combination of D and a number) and machining depth (represented in the diagram as a combination of t and a number). Here, "machining pattern" refers to the shape of grooves, trenches, holes, etc., formed in the workpiece W by the laser beam. The machining pattern can be defined as the machining line width and machining depth.

[0068] Here, the machining line width refers to the width of the machining pattern, and it represents the length of the machining pattern in the direction that intersects the machining direction PD with respect to the surface of the workpiece W as the reference plane. Here, the machining direction PD is the direction in which the laser beam and the workpiece W move relative to each other as the machining progresses. In this invention, the machining direction PD is the DR3 direction (Figure 3). Therefore, the machining line width can be the length of the machining pattern in the DR1 direction (Figure 3) that intersects the DR3 direction.

[0069] Here, machining depth refers to the depth of the machining pattern, and in the thickness direction of the workpiece W, it refers to the length of the machining pattern. In this invention, the machining depth may be the length of the machining pattern in the negative DR2 direction.

[0070] Here, processing parameters refer to the parameters of the beam irradiated to form the processing pattern. Processing parameters may include the shape of the laser beam and the number of branched beams. Other processing parameters may include the size of the laser beam, the pitch (spacing) of the branched beams, and the output intensity of the laser beam.

[0071] The controller 150 can determine machining parameters based on machining pattern data. For example, the controller 150 can determine machining parameters via a table in which machining parameters are mapped according to the machining line width and machining depth included in the machining pattern data. In this embodiment, the processing line width can be determined based on the shape of the laser beam among the processing parameters. Furthermore, the machining depth can be determined by the number of laser beams branched within the machining parameters. If multiple beams branching from a single light source maintain the same output, the depth that each beam can illuminate can increase as the number of branching beams increases. Machining parameters can be determined by considering not only the machining pattern data, but also the material and thickness of the workpiece W. However, the processing parameters may be determined according to user input, although this is not limited to the above.

[0072] In step 120 (S120), the controller 150 controls the combination of the first diffractive optical element and the second diffractive optical element in accordance with the determined machining parameters. In detail, the controller 150 selects one first diffractive optical element (or blank BLK) from the first optical group 121 corresponding to the shape of the laser beam of the processing parameter, and selects one second diffractive optical element (or blank BLK) from the second optical group 122 corresponding to the number of branched beams of the processing parameter. The controller then controls the optical element holder 125 to align and combine the selected diffractive optical elements (or blank BLKs) in series with respect to the optical axis of the laser beam.

[0073] Furthermore, in step 120 (S120), the controller 150 monitors the alignment of the selected first diffractive optical element and the selected second diffractive optical element in real time based on the video transmitted from the camera 141 of the coaxial optical system 140, and if an alignment error occurs, it can control the optical element holder 125 to correct the alignment.

[0074] In step 130 (S130), the controller 150 controls the laser oscillator 110 to output a laser beam and controls the laser beam, which has been adjusted via the selected first diffractive optical element and the selected second diffractive optical element, to irradiate the surface of the workpiece W. This creates a processing pattern on the workpiece W.

[0075] In step 141 (S141), the controller 150 checks whether multiple machining parameters have been determined. If multiple machining parameters have been determined, the process proceeds to step 142 (S142) to determine if there are any remaining machining operations. If there are any remaining machining operations, the process returns to step 120 (S120) to perform the remaining operations. However, if multiple machining parameters have not been determined in step 141 (S141), the controller 150 terminates the machining process. Furthermore, if multiple machining parameters have been determined in step 141 (S141), but there are no remaining machining operations in step 142 (S142), the controller 150 will terminate the machining process.

[0076] Referring to Figure 4, a specific processing method using the laser processing device 100 will be explained.

[0077] Referring to Figures 3 and 4, in step 120 (S120) of Figure 3, the controller 150 selects one optical element from the first optical group 121 and one optical element from the second optical group 122, and combines them to start a method of machining U-shaped machining patterns P1 and P2, which have different machining depths.

[0078] First, referring to Figure 4(i), the controller 150 is configured to handle the case in step 110 (S110) of Figure 3 where first machining pattern data is input for machining a first machining pattern P1 with a first machining line width D1 and a first machining depth t1.

[0079] In step 110 (S110) of Figure 3, the controller 150 receives the first machining pattern data and determines a single first machining parameter corresponding to the input first machining pattern data.

[0080] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select a first top-hat diffracting optical element TH1 in the first optical group 121 that converts the laser beam into a line beam of a first length using a first diffracting optical element, and a first multi-spot diffracting optical element MS1 in the second optical group 122 that splits the line beam into a first number of multiple beams using a second diffracting optical element, according to the determined first processing parameters.

[0081] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam generated by the laser oscillator 110 may be a Gaussian laser beam and may be point-shaped. The laser beam passes through the first top-hat diffractometer TH1 and is converted into a line beam of first length. Here, the shape of a line beam is defined by its length Len and width Wid. Here, the line beam length Len may be the length of the laser beam in the direction intersecting the processing direction PD. For example, the length Len of the line beam in Figure 4(i) may be the length in the DR1 direction. Here, the line beam width Wid may be the length of the laser beam in a direction parallel to the processing direction PD. For example, the width Wid of the line beam in Figure 4(i) may be the length in the DR3 direction. On the other hand, the profile of a line beam has a uniform intensity above the ablation threshold, i.e., a flat top-hat shape. Here, beam intensity is the amount of energy per unit area of ​​the laser beam, expressed in W / cm². 2 It has units of .

[0082] Next, the line beam of the first length passes through the first multi-spot diffracting optical element MS1 and is split into a first number of multiple beams. For example, the number of multiple beams (first number) in Figure 4(i) is shown as 5, but it could be 2, 3, or 4. The first multi-spot diffractive optical element MS1 can split the laser beam that has passed through the first top-hat diffractive optical element TH1 into a one-dimensional beam array 1 × N (where N is the first number) arranged in parallel in the processing direction PD. In this case, each beam constituting the multiple beams has the same shape, size, and intensity.

[0083] Next, the adjusted laser beam passes through the lens unit 124 and is irradiated onto the surface of the workpiece W, forming a U-shaped first processing pattern P1 on the workpiece W that corresponds to the first processing pattern data.

[0084] Generally, laser processing equipment employs a low-power, multi-pass processing method in which a low-power single beam processes the workpiece W multiple times to minimize thermal damage to the workpiece W and improve processing quality. However, the low-power, multi-pass machining method using a single beam has the problem of increased machining time and reduced production volume because the workpiece W must be moved and the machining process performed several times. However, according to an embodiment of the present invention, the second diffractive optical element splits the laser beam into multiple beams arranged in parallel in the processing direction PD, thereby achieving a low-power, multiple-pass processing effect with just one irradiation. Therefore, according to one embodiment of the laser processing apparatus 100, the processing time is shortened while minimizing damage to the workpiece W.

[0085] Since only a single machining parameter was determined in step 141 (S141) of Figure 3, the machining process is terminated.

[0086] Referring to Figure 4(ii), the controller 150 is configured to handle the case in step 110 (S110) of Figure 3 where second machining pattern data is input for machining a second machining pattern P2 with a first machining line width D1 and a second machining depth t2. Compared to the first machining pattern P1 in Figure 4(i), the second machining pattern P2 in Figure 4(ii) has a deeper machining depth. In other words, the second machining depth t2 is greater (deeper) than the first machining depth t1. <t2)。

[0087] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select a first top-hat diffracting optical element TH1 in the first optical group 121 that converts the laser beam into a line beam of a first length using a first diffracting optical element, and a second multi-spot diffracting optical element MS2 in the second optical group 122 that splits the line beam into a second number of multiple beams using a second diffracting optical element, according to the determined second processing parameters. Here, the second multispot diffractive optical element MS2 splits the laser beam into more parts than the first multispot diffractive optical element MS1.

[0088] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. Then, this laser beam passes through the first top-hat diffractometer TH1 and is converted into a line beam of first length. Next, the line beam of the first length passes through the second multispot diffracting optical element MS2 and is converted into a second number of multiple beams, which is greater than the first number. For example, the number of multiple beams (second number) in Figure 4(ii) is shown as 8, but it could be 6, 7, 9, or 10. Here, each individual beam constituting the multiple beam can maintain the same output. The second set of multiple beams that have passed through the second multi-spot diffractive optical element MS2 can be arranged in parallel with the processing direction PD. The adjusted laser beam passes through the lens unit 124 and is irradiated onto the surface of the workpiece W, forming a second processing pattern P2 on the workpiece W that corresponds to the second processing pattern data.

[0089] Since only a single machining parameter was determined in step 141 (S141) of Figure 3, the controller 150 terminates the machining process.

[0090] As shown in Figure 4, the controller 150 can adjust the processing depth by changing the combination of diffractive optical elements selected in the first optical group 121 and the second optical group 122.

[0091] Next, a specific processing method using the laser processing device 100 will be explained, with reference to Figure 5.

[0092] Referring to Figures 3 and 5, in step 120 (S120) of Figure 3, the controller 150 selects one optical element from the first optical group 121 and one optical element from the second optical group 122, and combines them to start a method of processing a processing pattern with different processing line widths.

[0093] Figure 5(i) is the same as Figure 4(i), so please refer to the explanation above.

[0094] Referring to Figure 5(iii), the controller 150 is concerned with the case in step 110(S110) of Figure 3 in which third machining pattern data is input for machining a third machining pattern P3 having a second machining line width D2 smaller than the first machining line width D1 and a first machining depth t1. Compared to the first machining pattern P1 in Figure 5(i), the third machining pattern P3 in Figure 5(iii) has a smaller machining line width. In other words, the second processing line width D2 is smaller (shorter) than the first processing line width D1 (D1 > D2).

[0095] In step 110 (S110) of Figure 3, the controller 150 receives the third machining pattern data and determines the third machining parameters corresponding to the input third machining pattern data.

[0096] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select and combine, according to the determined third processing parameter, a second top-hat diffracting optical element TH2 in the first optical group 121 that converts the laser beam into a line beam of a second length shorter than the first length using a first diffracting optical element, and a first multi-spot diffracting optical element MS1 in the second optical group 122 that splits the line beam into a first number of multiple beams using a second diffracting optical element. Here, the second top-hat diffracting optical element TH2 generates a line beam that is shorter in length than the first top-hat diffracting optical element TH1.

[0097] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the second top-hat diffractometer TH2 and is converted into a line beam of the second length. Next, the line beam of the second length passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. The adjusted laser beam passes through the lens unit 124 and is irradiated onto the surface of the workpiece W, forming a third processing pattern P3 on the workpiece W that corresponds to the third processing pattern data.

[0098] Since only a single machining parameter was determined in step 141 (S141) of Figure 3, the machining process is terminated.

[0099] Referring to Figure 5(iv), the controller 150 is configured to process a fourth machining pattern data in step 110(S110) of Figure 3, which has a third machining line width D3 smaller than the first machining line width D1 and the second machining line width D2, and a third machining depth t3 deeper than the first machining depth t1 and the second machining depth t2. Compared to the first machining pattern P1 and the second machining pattern P2 in Figure 5(i) and (iii), the fourth machining pattern P4 in Figure 5(iv) has a smaller machining line width. In other words, the third processing line width D3 is smaller (shorter) than the first processing line width D1 and the second processing line width D2. (D1, D2 > D3)

[0100] In step 110 (S110) of Figure 3, the controller 150 receives the fourth machining pattern data and determines the fourth machining parameters corresponding to the input fourth machining pattern data.

[0101] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select a blank BLK in the first optical group 121 that allows the laser beam to pass through directly, according to the determined fourth processing parameter, and to select and combine a first multi-spot diffracting optical element MS1 in the second optical group 122 that splits the line beam into a first number of multiple beams using a second diffracting optical element.

[0102] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. The output laser beam could be a Gaussian laser beam. After passing through the blank BLK, the laser beam passes through the first multi-spot diffractive optical element MS1 and is converted into a spot beam arranged in parallel in the first processing direction PD. The adjusted laser beam passes through the lens unit 124 and is irradiated onto the surface of the workpiece W, forming a fourth processing pattern P4 on the workpiece W that corresponds to the fourth processing pattern data.

[0103] Since only a single machining parameter was determined in step 141 (S141) of Figure 3, the controller 150 terminates the machining process.

[0104] As shown in Figure 5, the controller 150 can adjust the processing line width by changing the combination of diffractive optical elements selected in the first optical group 121 and the second optical group 122.

[0105] Next, a specific processing method using the laser processing device 100 will be explained, with reference to Figure 6.

[0106] Referring to Figures 3 and 6, we begin the process of manufacturing the combined form of the processing pattern. The device can form machining patterns with various machining line widths and depths, and can also machine machining patterns in combined forms. Figure 6 shows an example where multiple machining parameters are determined.

[0107] Referring to Figure 6(v), in step 110 (S110) of Figure 3, the controller 150 receives data for a fifth machining pattern, which is a combination of the third machining pattern P3 and the fourth machining pattern P4.

[0108] In step 110 (S110) of Figure 3, the controller 150 analyzes the fifth machining pattern data to separate the third machining pattern data and the fourth machining pattern data, and determines the third machining parameters for machining the third machining pattern P3 and the fourth machining parameters for machining the fourth machining pattern P4.

[0109] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select the second top-hat diffractive optical element TH2 in the first optical group 121 and the first multi-spot diffractive optical element MS1 in the second optical group 122, according to the determined third processing parameter.

[0110] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the second top-hat diffractometer TH2 and is converted into a line beam of the second length. Next, the line beam of the second length passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. The adjusted laser beam passes through the lens unit 124 and is irradiated onto the surface of the workpiece W, forming a third processing pattern P3 on the workpiece W.

[0111] In step 141 (S141) of Figure 3, multiple machining parameters are determined, and in step 142 (S142), machining corresponding to the fourth machining parameter is not performed, so the controller 150 repeats step 120 (S120) of Figure 3.

[0112] In step 120 (S120) of Figure 3, the controller 150 controls the optical element holder 125 to select a blank BLK in the first optical group 121 that allows the laser beam to pass through directly, according to the determined fourth processing parameter, and to select and combine a first multi-spot diffracting optical element MS1 in the second optical group 122 that splits the line beam into a first number of multiple beams using a second diffracting optical element.

[0113] In step 130 (S130) of Figure 3, the controller 150 controls the laser oscillator 110 to output a laser beam. The output laser beam could be a Gaussian laser beam. After passing through the blank BLK, the laser beam passes through the first multi-spot diffractive optical element MS1 and is converted into a spot beam arranged in parallel in the first processing direction PD. The adjusted laser beam passes through the lens unit 124 and irradiates the surface of the workpiece W, further forming a fourth processing pattern P4 in the portion of the workpiece W where the third processing pattern P3 has already been formed. Therefore, a fifth processing pattern P5, which is a combination of the third processing pattern P3 and the fourth processing pattern P4, is formed on the workpiece W.

[0114] In step 141 (S141) of Figure 3, only several machining parameters were determined, but in step 142 (S142), all machining was performed, so the controller 150 terminates the machining.

[0115] As shown in Figure 6, the controller 150 changes the combination of diffractive optical elements selected in the first optical group 121 and the second optical group 122 for each processing time, and by performing processing multiple times, various processing patterns can be realized using the laser processing apparatus 100 which includes a single optical unit 120.

[0116] Figure 7 shows a laser processing apparatus 100a according to another embodiment of the present invention.

[0117] The laser processing apparatus 100a in Figure 7 differs from the laser processing apparatus 100 in Figure 1 in its lens unit 124. The following explanation will focus on the lens unit 124, and for the remaining components, please refer to the explanation of the laser processing apparatus in Figure 1.

[0118] The lens unit 124 may include multiple objective lenses 124L1, 124L2 and a lens holder 127.

[0119] Furthermore, this lens unit 124 includes multiple objective lenses 124L1, 124L2, each with a different magnification. Figure 7 shows two objective lenses, 124L1 and 124L2, but the objective lens can contain more than three, four, or any number of lenses. For example, the first objective lens 124L1 may have a 5x magnification that reduces the laser beam to 1 / 5 of its original size, and the second objective lens 124L2 may have a 10x magnification that reduces the laser beam to 1 / 10 of its original size. Thus, the lens unit 124 is equipped with objective lenses of various magnifications, and the laser processing apparatus 100a can selectively achieve a desired beam size according to the processing conditions.

[0120] The lens holder 127 selects one of several objective lenses 124L1 and 124L2. Specifically, the lens holder 127 selects one of several objective lenses 124L1 and 124L2, and combines the selected objective lens with the diffractive optical element by arranging them in series with respect to the optical axis. The lens holder 127 can be controlled by signals from the controller 150. The lens holder 127 may include a rotating turret or a sliding mechanism, similar to the optical element holder 125 shown in Figure 1.

[0121] The laser processing apparatus 100a, via the lens holder 127, allows for combinations of objective lenses in addition to different types of diffractive optical elements within a single optical unit 120. Therefore, the laser processing apparatus 100a according to this embodiment can achieve various processing pattern line widths and depths with a single optical unit 120.

[0122] Next, the laser processing apparatus in Figure 7 differs from the laser processing apparatus in Figure 1 in that the first diffractive optical element selected in the first optical group 121 can be rotated. The following explanation will focus on the rotational operation of the first diffractive optical element; for other components, please refer to the description of the laser processing apparatus in Figure 1 above.

[0123] Referring to Figure 7, the controller 150 can determine the rotation angle θ (Figure 9) of the first diffractive optical element selected according to the input processing pattern data, and control the optical element holder 125 to rotate the first diffractive optical element with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined rotation angle θ. Here, the axis of rotation can coincide with the optical axis.

[0124] In this case, the optical element holder 125 may further include a mechanism for rotating the diffractive optical element, such as a hollow motor.

[0125] Figure 8 is a flowchart illustrating the laser processing method using the laser processing apparatus 100a shown in Figure 7. Figure 9 illustrates one embodiment of a laser processing method that achieves various processing patterns using the laser processing apparatus 100a shown in Figure 7.

[0126] Figure 9(a) conceptually shows a combination of the first and second diffractive optical elements, (b) conceptually shows the laser beam irradiated onto the workpiece W, (c) shows a top view of the workpiece W processed by the laser beam in (b), and (d) shows a side view of the workpiece W processed by the laser beam in (b), which is the cross-section corresponding to the plane in (c).

[0127] Referring to Figures 8 and 9, in step 110 (S110), the controller 150 receives the machining pattern data and determines the machining parameters.

[0128] In step 120 (S120), the controller 150 controls the combination of the first diffractive optical element and the second diffractive optical element in accordance with the determined machining parameters. Furthermore, the controller 150 selects the objective lens in the lens unit 124 according to the determined processing parameters. In detail, the controller 150 selects one first diffractive optical element in the first optical group 121 corresponding to the shape of the laser beam of the processing parameter, selects one second diffractive optical element in the second optical group 122 corresponding to the number of branched beams of the processing parameter, selects an objective lens according to the size of the laser beam of the processing parameter, and controls the optical element holder 125 and lens holder 127 to align and combine the selected diffractive optical elements and the selected objective lens in series with respect to the optical axis of the laser beam.

[0129] Furthermore, in step 120 (S120), the controller 150 checks the alignment of the selected first diffractive optical element, the selected second diffractive optical element, and the selected objective lens in real time based on the image transmitted from the camera 141 of the coaxial optical system 140. If an alignment error occurs, the controller can control the optical element holder 125 and the lens holder 127 to correct the alignment.

[0130] In step 125 (S125), the controller 150 determines the rotation angle θ of the first diffractive optical element selected according to the determined machining parameters, and controls the first diffractive optical element to rotate with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined rotation angle θ.

[0131] Here, the rotation angle θ represents the angle at which the first diffractive optical element, positioned opposite the surface of the workpiece W, rotates relative to the workpiece W. The rotation angle θ is defined based on the positional relationship between the laser beam irradiated onto the workpiece W and the workpiece W.

[0132] Referring to Figure 9 in the embodiment, the rotation angle θ may mean the angle that a parallel axis Lt parallel to the line beam has with respect to a reference axis (As) parallel to the machining direction PD (third direction, DR3) that intersects the machining line width when the laser beam irradiated onto the workpiece W has the narrowest machining line width relative to the workpiece W. In other words, as shown in Figure 9(iv'), when the parallel axis Lt and the reference axis As are parallel, the rotation angle θ can be defined as approximately 0 degrees, and as shown in Figure 9(i), when the parallel axis Lt is perpendicular to the reference axis As, the rotation angle θ can be defined as approximately 90 degrees. According to one embodiment, the rotation angle θ can be selected from approximately 0 degrees, defined as the case when the parallel axis Lt and the reference axis As are parallel, to approximately 90 degrees, defined as the case when the parallel axis Lt and the reference axis As are perpendicular.

[0133] The rotation angle θ can be defined using methods other than those shown in the embodiment of Figure 9. The following explanation will be based on the definition of the rotation angle θ in the embodiment shown in Figure 9.

[0134] On the other hand, by rotating the first diffractive optical element, the linear arrangement direction of the laser beam irradiated onto the workpiece W can be changed. The rotation angle θ can be defined as follows: the first angle is defined as the case when the laser beam's linear arrangement direction processes the narrowest machining line width, and the second angle is defined as the case when the widest machining line width is processed. Here, the first angle may be approximately 0 degrees, and the second angle may be approximately 90 degrees, but is not limited to these values.

[0135] The controller 150 determines a smaller rotation angle θ (a rotation angle close to approximately 0 degrees) when the machining line width is narrow and the machining depth is deep, and a larger rotation angle θ (a rotation angle close to approximately 90 degrees) when the machining line width is wide and the machining depth is shallow. This is because the linear alignment direction of the laser beam changes according to the rotation angle, which in turn changes the processing line width, and the energy density of the laser beam irradiated onto the workpiece W changes due to the change in the linear alignment direction of the laser beam, thus changing the processing depth.

[0136] Steps 130 (S130), 141 (S141), and 142 (S142) will be described later with reference to Figure 9.

[0137] Here, with reference to Figure 9, a specific processing method using the laser processing device 100a will be described.

[0138] Referring to Figures 8 and 9, in step 125 (S125) of Figure 8, the controller 150 rotates the first diffractive optical element around the rotation axis according to the determined rotation angle θ, and starts a method for processing machining patterns in which the machining line width and machining depth differ depending on the rotation angle θ of the first diffractive optical element, even when using the same combination of first and second diffractive optical elements.

[0139] In the case of (i) in Figure 9, the first diffractive optical element is rotated according to the first rotation angle θ1 (approximately 90 degrees). The first processing pattern P1 has a first processing line width D1 and a first processing depth t1. Figure 9(i) is similar to Figure 5(i), so please refer to the explanation above.

[0140] In the case of (iii') in Figure 9, the first diffractive optical element is rotated according to the second rotation angle θ2 (between approximately 0 degrees and approximately 90 degrees).

[0141] Referring to Figure 9, in step 110 (S110) of Figure 8, the controller 150 receives the 3' machining pattern data and determines the 3' machining parameters in accordance with the input 3' machining pattern data.

[0142] In step 120 (S120) of Figure 8, the controller 150 controls the optical element holder 125 to select the first top-hat diffracting optical element TH1 as the first diffracting optical element in the first optical group 121 and the first multi-spot diffracting optical element MS1 as the second diffracting optical element in the second optical group 122, according to the determined third' processing parameters.

[0143] In step 125 (S125) of Figure 8, the controller 150 determines the rotation angle θ of the first top-hat diffractive optical element TH1 to be a second rotation angle θ2 which is smaller than the first rotation angle θ1, according to the determined third' machining parameter, and controls the optical element holder 125 to rotate the first top-hat diffractive optical element TH1 with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined second rotation angle θ2.

[0144] In step 130 (S130) of Figure 8, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the first top-hat diffractometer TH1, which has been rotated by a second rotation angle θ2, and is converted into a line beam of first length. However, the line beam is a line beam whose direction has been adjusted by a second rotation angle θ2. Next, the line beam passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. Here, the direction of the multiple beams is also adjusted by the second rotation angle θ2. The adjusted laser beam passes through a selected objective lens, is resized, and irradiates the surface of the workpiece W, forming a third' processing pattern P3' on the workpiece W that corresponds to the third' processing pattern data. The third' machining pattern P1 has a second machining line width D2 that is smaller than the first machining line width D1, and a second' machining depth t2' that is larger (deeper) than the first machining depth.

[0145] Since only a single machining parameter was determined in step 141 (S141) of Figure 3, the machining process is terminated.

[0146] The first machining pattern P1 and the third machining pattern P3' in Figure 9 have the same machining parameters except for the rotation angle θ. When comparing a first machining pattern P1 using a beam with a first rotation angle θ1 with a third machining pattern P3' using a beam with a second rotation angle θ2, the machining line width is larger when the rotation angle θ is larger, and the machining depth is smaller (shallower) when the rotation angle θ is larger.

[0147] In the case of (iv') in Figure 9, the first diffracting optical element is rotated according to the third rotation angle θ3 (approximately 0 degrees).

[0148] Referring to Figure 9, in step 110 (S110) of Figure 8, the controller 150 receives the 4' machining pattern data and determines the 4' machining parameters in accordance with the input 4' machining pattern data.

[0149] In step 120 (S120) of Figure 8, the controller 150 controls the optical element holder 125 to select the first top-hat diffracting optical element TH1 as the first diffracting optical element in the first optical group 121 and the first multi-spot diffracting optical element MS1 as the second diffracting optical element in the second optical group 122, according to the determined 4' processing parameters.

[0150] In step 125 (S125) of Figure 8, the controller 150 determines the rotation angle of the first top-hat diffractive optical element TH1 to be a third rotation angle θ3 which is smaller than the second rotation angle θ2, according to the determined fourth' machining parameter, and controls the optical element holder 125 to rotate the first top-hat diffractive optical element TH1 with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined third rotation angle θ3.

[0151] In step 130 (S130) of Figure 8, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the first top-hat diffractometer HT1 and is converted into a line beam of first length. However, the line beam is a line beam whose direction has been adjusted by a third rotation angle θ3. Next, the line beam passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. Here, the direction of the multiple beams is also adjusted by the third rotation angle θ3. The adjusted laser beam passes through a selected objective lens, is resized, and irradiates the surface of the workpiece W, forming a fourth' processing pattern P4' on the workpiece W that corresponds to the fourth' processing pattern data. The fourth machining pattern P4' has a fourth machining line width D4 that is smaller than the second machining line width D2, and a fourth machining depth t4' that is larger (deeper) than the second machining depth.

[0152] Since only a single machining parameter was determined in step 141 (S141) of Figure 8, the machining process is terminated.

[0153] The third machining pattern P3' and the fourth machining pattern P4' in Figure 9 have the same machining parameters except for the rotation angle θ. When comparing the third machining pattern P3' using a beam with a second rotation angle θ2 with the fourth machining pattern P4' using a beam with a third rotation angle θ3, the machining line width is larger when the rotation angle θ is larger, and the machining depth is smaller (shallower) when the rotation angle θ is larger.

[0154] Figure 10 is an image showing the rotation of the laser beam produced by the laser processing device 100a in Figure 7.

[0155] Referring to Figure 10, it can be seen that the pitch (spacing) of the multiple laser beams decreases as the rotation angle decreases. Figure 10(a) shows a rotation angle close to approximately 90 degrees, Figure 10(b) shows a rotation angle between approximately 90 degrees and approximately 0 degrees, and Figure 10(c) shows a case where the rotation angle is close to approximately 0 degrees. Therefore, when the rotation angle θ is approximately 0 degrees, the beam pitch becomes the minimum value, and the multiple beams completely overlap as shown in Figure 9 (iv').

[0156] As shown in Figure 9, the controller 150 can adjust the machining depth and machining line width by changing the combination of diffractive optical elements selected in the first optical group 121 and the second optical group 122, as well as by rotating the first diffractive optical element.

[0157] Figure 11 shows a laser processing apparatus 100b according to another embodiment of the present invention.

[0158] The laser processing apparatus 100b in Figure 11 differs from the laser processing apparatus 100a in Figure 7 in that it further includes a beam limiting element 123. The following explanation will focus on the beam limiting element 123, and for other components, please refer to the explanation of the laser processing apparatus 100a in Figure 7 above.

[0159] The beam limiting element 123 is positioned between the selected second diffractive optical element and the selected objective lens. The beam limiting element 123 blocks a portion of the laser beam, which has been adjusted by the selected combination of the first and second diffractive optical elements, thereby generating a partially blocked laser beam. The beam limiting element 123 may be a slit or a aperture, but is not limited to these; any element capable of blocking a portion of the laser beam can be used.

[0160] The controller 150 can control the beam limiting element 123 to adjust the laser beam blocking ratio of the beam limiting element 123 based on the rotation angle θ, in order to machine the workpiece W to a constant machining depth, regardless of the rotation angle θ of the first diffractive optical element. In other words, the controller 150 can control the beam limiting element 123 in synchronization with the rotation angle θ.

[0161] Specifically, the controller 150 can control the beam limiting element 123 so that the smaller the rotation angle θ (closer to approximately 0 degrees), the higher the laser beam blocking rate, and the larger the rotation angle θ (closer to approximately 90 degrees), the lower the laser beam blocking rate. In other words, the controller 150 increases the laser beam blocking rate as the processing line width of the processing pattern narrows, and decreases the laser beam blocking rate as the processing line width of the processing pattern widens, thereby enabling the workpiece W to be processed to a uniform depth.

[0162] Figure 12 is a flowchart illustrating the laser processing method using the laser processing apparatus 100b shown in Figure 11. Figure 13 illustrates one embodiment of a laser processing method that realizes various processing patterns using the laser processing apparatus 100b shown in Figure 11.

[0163] Figure 13(a) conceptually shows a combination of the first and second diffractive optical elements, (b) conceptually shows the laser beam irradiated onto the workpiece W, (c) shows the plane of the workpiece W processed by the laser beam in (b), and (d) shows the cross-section of the workpiece W processed by the laser beam in (b), which corresponds to the plane in (c).

[0164] Referring to Figures 12 and 13, in step 110 (S110), the controller 150 receives the machining pattern data and determines the machining parameters.

[0165] In step 120 (S120), the controller 150 selects one first diffractive optical element from the first optical group 121 corresponding to the shape of the laser beam of the processing parameter, selects one second diffractive optical element from the second optical group 122 corresponding to the number of branched beams of the processing parameter, selects an objective lens according to the size of the laser beam of the processing parameter, and controls the optical element holder 125 and the lens holder 127 to align and combine the selected diffractive optical element and the selected objective lens in series with respect to the optical axis of the laser beam.

[0166] Furthermore, in step 120 (S120), the controller 150 can check the alignment of the selected first diffractive optical element, the selected second diffractive optical element, and the selected objective lens in real time based on the image transmitted from the camera 141 of the coaxial optical system 140, and can control the optical element holder 125 and the lens holder 127 to correct the alignment if an alignment error occurs.

[0167] In step 125 (S125), the controller 150 determines the rotation angle θ of the first diffractive optical element selected according to the determined machining parameters, and controls the first diffractive optical element to rotate with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined rotation angle θ.

[0168] In step 127 (S127), the controller 150 can determine the cutoff range of the laser beam based on the determined rotation angle θ and control the beam limiting element 123 based on the determined cutoff range of the laser beam.

[0169] Referring again to Figures 9(i) and (iii'), the workpiece W is machined to a second machining line width D2, which is narrower than the first machining line width D1, at a second rotation angle θ2 that is smaller than the first rotation angle θ1, and to a second machining depth t2' that is deeper than the first machining depth t1. The output (power) and processing speed of the laser beam remain constant, but when the direction of the laser beam changes, the processing line width narrows, and the energy density per unit area of ​​the laser beam transmitted to the narrowed processing line width increases.

[0170] Furthermore, in another embodiment of the laser processing apparatus 100b, the controller 150 can maintain a constant energy density per unit area transmitted to the workpiece W by adjusting the laser beam blocking ratio of the beam limiting element 123 in synchronization with the rotation angle θ of the first optical diffraction element. As a result, the laser processing device 100b can maintain a constant processing depth even when processing the workpiece W with various processing line widths. In detail, Figure 13 shows that the first machining depth t1 is the same for the first rotation angle θ1, the second rotation angle θ2, and the third rotation angle θ3, but the machining line widths are different for each rotation angle, being the first machining line width D1, the second machining line width D2, and the fourth machining line width D4, respectively.

[0171] Steps 130 (S130), 141 (S141), and 142 (S142) will be described later with reference to Figure 13.

[0172] Here, we will explain a specific processing method using the laser processing device 100b, referring to Figure 13 as well.

[0173] Referring to Figures 12 and 13, in step 127 (S127) of Figure 12, the controller 150 rotates the first diffractive optical element around the rotation axis according to the determined rotation angle θ. The beam limiting element 123 blocks the beam in conjunction with the rotation angle θ, and even when using the same combination of first and second diffractive optical elements, the processing line width differs depending on the rotation angle θ of the first diffractive optical element, but the processing depth remains constant.

[0174] In the case of (i) in Figure 13, the first diffractive optical element is rotated according to the first rotation angle θ1 (approximately 90 degrees). The first processing pattern P1 has a first processing line width D1 and a first processing depth t1. Figure 13(i) is the same as Figure 9(i), so please refer to the explanation above.

[0175] In the case of (iii') in Figure 13, the first diffracting optical element is rotated according to the second rotation angle θ2 (between approximately 0 degrees and approximately 90 degrees), and the beam is limited in accordance with the second rotation angle θ2.

[0176] Referring to Figure 13, in step 110 (S110) of Figure 12, the controller 150 receives the third machining pattern data and determines the third machining parameters corresponding to the input third machining pattern data.

[0177] In step 120 (S120) of Figure 12, the controller 150 controls the optical element holder 125 to select the first top-hat diffracting optical element TH1 as the first diffracting optical element in the first optical group 121 and the first multi-spot diffracting optical element MS1 as the second diffracting optical element in the second optical group 122, according to the determined third processing parameter.

[0178] In step 125 (S125) of Figure 12, the controller 150 determines the rotation angle θ of the first top-hat diffractive optical element TH1 to be a second rotation angle θ2 which is smaller than the first rotation angle θ1, according to the determined third machining parameter, and controls the optical element holder 125 to rotate the first top-hat diffractive optical element TH1 with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined second rotation angle θ2.

[0179] In step 127 (S127) of Figure 12, the controller 150 determines the laser beam cutoff range as the second cutoff range according to the determined second rotation angle θ2, and controls the beam limiting element 123 based on the second cutoff range.

[0180] In step 130 (S130) of Figure 12, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the first top-hat diffractometer TH1 and is converted into a line beam of first length. However, the line beam is a line beam whose direction has been adjusted by a second rotation angle θ2. Next, the line beam passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. Here, the direction of the multiple beams is also adjusted by the second rotation angle θ2. On the other hand, the adjusted multiple beams are blocked according to the second blocking range. Therefore, the number of multiple beams can be smaller than the first number, depending on the second cutoff range. The adjusted laser beam passes through the selected objective lens, is resized, and irradiates the surface of the workpiece W, forming a third "processing pattern P3" on the workpiece W that corresponds to the third "processing pattern data". The third "processing pattern P3" has a second processing line width D2 that is smaller than the first processing line width D1, but has the same processing depth t1 as the first processing depth t1.

[0181] Since only a single machining parameter was determined in step 141 (S141) of Figure 12, the machining process is terminated.

[0182] The third "processing pattern P3" in Figure 12 has the same processing parameters as the third "processing pattern P3" in Figure 9, except for the beam cutoff range. The third "machining pattern P3" in Figure 12 and the third "machining pattern P3" in Figure 9 have the same machining line width, but their machining depths are different. In other words, the third "machining pattern P3" in Figure 12, which is machined based on the second cutoff range corresponding to the second rotation angle θ2, has a smaller (shallower) machining depth compared to the third "machining pattern P3" in Figure 9.

[0183] In the case of (iv) in Figure 13, the first diffracting optical element is rotated according to the third rotation angle θ3 (approximately 0 degrees), and the beam is limited in accordance with the third rotation angle θ3.

[0184] Referring to Figure 13, in step 110 (S110) of Figure 12, the controller 150 receives the fourth machining pattern data and determines the fourth machining parameters corresponding to the input fourth machining pattern data.

[0185] In step 120 (S120) of Figure 12, the controller 150 controls the optical element holder 125 to select the first top-hat diffracting optical element TH1 as the first diffracting optical element in the first optical group 121 and the first multi-spot diffracting optical element MS1 as the second diffracting optical element in the second optical group 122, according to the determined fourth processing parameter.

[0186] In step 125 (S125) of Figure 12, the controller 150 determines the rotation angle of the first top-hat diffractive optical element TH1 to be a third rotation angle θ3 which is smaller than the second rotation angle θ2, according to the determined fourth machining parameter, and controls the optical element holder 125 to rotate the first top-hat diffractive optical element TH1 with respect to a rotation axis parallel to the normal of the plane of the workpiece W according to the determined third rotation angle θ3.

[0187] In step 127 (S127) of Figure 12, the controller 150 determines the laser beam cutoff range as the third cutoff range according to the determined third rotation angle θ3, and controls the beam limiting element 123 based on the third cutoff range.

[0188] In step 130 (S130) of Figure 12, the controller 150 controls the laser oscillator 110 to output a laser beam. The laser beam passes through the first top-hat diffractometer HT1 and is converted into a line beam of first length. However, the line beam is a line beam whose direction has been adjusted by a third rotation angle θ3. Next, the line beam passes through the first multi-spot diffracting optical element MS1 and is converted into multiple beams arranged in parallel in the first processing direction PD. Here, the direction of the multiple beams is also adjusted by the third rotation angle θ3. On the other hand, the adjusted multiple beams are blocked according to the third blocking range. Therefore, the number of multiple beams can be smaller than the first number, depending on the third cutoff range. The adjusted laser beam passes through the selected objective lens, is resized, and irradiates the surface of the workpiece W, forming a fourth "processing pattern P4" on the workpiece W that corresponds to the fourth "processing pattern data". The fourth "processing pattern P4" has a fourth processing line width D4 that is smaller than the second processing line width D2, but has the same first processing depth t1 as the first processing depth t1.

[0189] Since only a single machining parameter was determined in step 141 (S141) of Figure 12, the machining process is terminated.

[0190] The fourth "processing pattern P4" in Figure 12 has the same processing parameters as the fourth "processing pattern P4" in Figure 9, except for the beam cutoff range. The 4th "machining pattern P4" in Figure 12 and the 4th "machining pattern P4" in Figure 9 have the same machining line width, but their machining depths are different. In other words, the fourth "machining pattern P4" in Figure 12, which is machined to have a third cutoff range corresponding to the third rotation angle θ3, has a smaller (shallower) machining depth compared to the fourth "machining pattern P4" in Figure 9.

[0191] According to the laser processing apparatus and laser processing method using the embodiment, various processing steps can be performed by adjusting the processing line width and processing depth without changing the optical unit included in the laser processing apparatus. Furthermore, since various processing specifications can be met without changing the optical unit, it can contribute to the simplification and stabilization of process conditions.

[0192] Embodiments of the present invention can be realized in the form of a computer program that can be executed on a computer via various components, and such a computer program can be recorded on a computer-readable medium. In this case, the medium may include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical recording media such as floptical disks; and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, and flash memory.

[0193] On the other hand, the computer program may be specifically designed and configured for the present invention, or it may be publicly known and available to those skilled in the field of computer software. Examples of computer programs can include not only machine code, such as that created by a compiler, but also high-level language code that can be executed by a computer using an interpreter or similar tool.

[0194] According to one embodiment, methods according to various embodiments of the present invention can be provided in a computer program product. Computer program products can be traded as goods between sellers and buyers. Computer program products may be distributed in the form of a device-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or online (e.g., by download or upload) via an application store (e.g., Play Store®), or directly between two user devices. In the case of online distribution, at least a portion of a computer program product can be temporarily stored or temporarily generated on a storage medium that can be read by devices such as the memory of the manufacturer's server, the application store's server, or an intermediary server.

[0195] In the present invention, the use of all examples or exemplary terms (e.g., etc.) is solely for the purpose of illustrating the invention in detail, and the scope of the invention is not limited by such examples or exemplary terms unless otherwise defined by the claims. Furthermore, those skilled in the art will understand that design conditions and factors can be comprised within the scope of the claims or their equivalents, with various modifications, combinations, and changes added.

[0196] Therefore, the spirit of the present invention should not be limited to the embodiments described above, and it can be said that not only the claims described later, but also all scopes equivalent to or modified from these claims, fall within the scope of the spirit of the present invention. [Explanation of symbols]

[0197] 100, 100a, 100b... Laser processing equipment 110... Laser oscillator 120... Optical Unit 123... Beam limiting element 130... Processing Table 140...Coaxial optical system 150... Controller

Claims

1. In a laser processing apparatus configured to achieve various processing patterns with a single optical unit, A laser oscillator that generates a laser beam, The laser beam is adjusted, and the adjusted laser beam is irradiated onto the surface of the workpiece. A first optical group including a plurality of first diffractive optical elements that change the shape of the laser beam, A second optical group including multiple second diffractive optical elements that split the aforementioned laser beam into multiple beams, An optical element holder for selecting diffractive optical elements from the first optical group and the second optical group, and arranging the selected diffractive optical elements in series with respect to the optical axis of the laser beam, and Lens unit for focusing the laser beam onto the surface of the workpiece An optical unit including, A processing table for moving the workpiece in the processing direction, A controller that receives processing pattern data, determines processing parameters according to the input processing pattern data, and controls the optical element holder to select a combination of the first diffractive optical element and the second diffractive optical element corresponding to the determined processing parameters, Laser processing equipment, including...

2. The laser processing apparatus according to claim 1, further comprising a laser attenuator for adjusting the output intensity of the laser beam.

3. The first optical group further includes a blank through which the laser beam passes directly, The laser processing apparatus according to claim 1, wherein the plurality of first diffractive optical elements include top-hat diffractive optical elements that convert the laser beam into at least one shape from a line shape, a rectangular shape, and a square shape.

4. The second optical group further includes a blank through which the laser beam passes directly, The laser processing apparatus according to claim 1, wherein the plurality of second diffractive optical elements include multi-spot diffractive optical elements that split the laser beam into multiple beams and realize a different number of multiple beams.

5. The laser processing apparatus according to claim 1, wherein the optical element holder includes a rotary turret or sliding mechanism capable of selectively positioning the diffractive optical elements of the first optical group and the second optical group.

6. The aforementioned lens unit includes a plurality of objective lenses, each with a different magnification. The laser processing apparatus further includes a lens holder that arranges and combines the objective lens selected by the lens unit with the selected diffractive optical element in series with respect to the optical axis, The laser processing apparatus according to claim 1, wherein the controller controls the lens holder to select an objective lens corresponding to the determined processing parameters.

7. The laser processing apparatus according to claim 6, wherein the plurality of objective lenses include an objective lens having at least 5x magnification and an objective lens having 10x magnification.

8. The aforementioned processing pattern data includes the processing line width and processing depth. The laser processing apparatus according to claim 1, wherein the processing parameters include at least the shape of the laser beam and the number of multiple beams.

9. The laser processing apparatus according to claim 1, wherein the controller determines the rotation angle of a first diffractive optical element selected according to input processing pattern data, and controls the first diffractive optical element to rotate with respect to a rotation axis parallel to the normal of the plane of the workpiece according to the determined rotation angle.

10. The system further includes a beam limiting element disposed between the first optical group and the lens unit, which blocks a portion of the laser beam. The beam limiting element is a slit or aperture. The laser processing apparatus according to claim 9, wherein the controller determines the cutoff range of the laser beam based on the rotation angle and controls the beam limiting element based on the determined cutoff range of the laser beam.

11. The laser processing apparatus according to claim 1, further comprising a camera that acquires real-time images via the same path through which the laser beam is irradiated.

12. In a laser processing method using the laser processing apparatus described in claim 1, a) A step in which processing pattern data is input to the controller and processing parameters are determined, b) The controller controls the combination of the first diffractive optical element and the second diffractive optical element according to the processing parameters. c) The controller controls the laser oscillator to output a laser beam, and the laser beam, adjusted via a selected first diffractive optical element and a selected second diffractive optical element, to irradiate the surface of the workpiece, thereby forming a processing pattern on the workpiece. A laser processing method, including the following.

13. In step a), if first machining pattern data for machining a first machining pattern with a first machining line width and a first machining depth is input to the controller, The laser processing method according to claim 12, wherein in step b), the controller controls the optical element holder to combine a first top-hat diffractive optical element that converts a laser beam into a line beam of a first length as the first diffractive optical element, and a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams as the second diffractive optical element, and the multiple beams are arranged in parallel in the processing direction.

14. In step a), if second machining pattern data for machining a second machining pattern having a first machining line width and a second machining depth different from the first machining depth is input to the controller, In step b), the controller controls the optical element holder to combine a first top-hat diffractive optical element that converts a laser beam into a line beam of a first length as the first diffractive optical element, and a second multi-spot diffractive optical element that splits the line beam into a second number of multiple beams as the second diffractive optical element, wherein the second number is different from the first number, the laser processing method according to claim 13.

15. In step a), if third machining pattern data for machining a third machining pattern having a second machining line width and a first machining depth different from the first machining line width is input to the controller, In step b), the controller controls the optical element holder so that the first diffractive optical element selects a second top-hat diffractive optical element that converts the laser beam into a line beam of a second length, and the second diffractive optical element selects a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams, wherein the second length is different from the first length, the laser processing method according to claim 13.

16. In step a), if the controller receives fourth machining pattern data for machining a fourth machining pattern having a third machining line width smaller than the first machining line width and a third machining depth greater than the first machining depth, The laser processing method according to claim 13, in step b), the controller selects a blank in the first optical group through which the laser beam passes directly, and the second diffractive optical element controls the optical element holder to select and combine with a first multi-spot diffractive optical element that splits the line beam into a first number of multiple beams.

17. The lens unit includes multiple objective lenses, each with a different magnification. The aforementioned laser processing apparatus is The lens unit further includes a lens holder that arranges the objective lens selected in the aforementioned lens unit in series with the selected diffractive optical element with respect to the optical axis, The method according to claim 12, further comprising controlling the controller to select an objective lens in accordance with the processing parameters in step b).

18. The controller determines the rotation angle of the first diffractive optical element selected according to the input processing pattern data, and controls the first diffractive optical element to rotate according to the determined rotation angle with respect to a rotation axis parallel to the normal of the plane of the workpiece. The laser processing method according to claim 12, further comprising:

19. The laser processing apparatus further includes a beam limiting element positioned between the first optical group and the lens unit, which blocks a portion of the laser beam. The controller determines the cutoff range of the laser beam based on the rotation angle, and controls the beam limiting element based on the determined cutoff range of the laser beam. The laser processing method according to claim 18, further comprising:

20. The laser processing apparatus further includes a camera that acquires real-time images via the same path through which the laser beam is irradiated. The laser processing method according to claim 12, further comprising the step of the controller confirming the alignment of the first diffractive optical element and the second diffractive optical element in real time.

Images