The Laser Irradiating Apparatus consisting of Beam Rearrangement Part which control the Irradiation Area of the light

Abstract

The present invention provides a laser irradiation device comprising: a beam irradiation unit for irradiating a laser beam; and a beam repositioning unit for repositioning the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam, wherein the laser beam is incident on a first area on the upper surface of the beam repositioning unit, refracted while passing through the beam repositioning unit, and irradiated on a second area of ​​a target member located below the beam repositioning unit, and wherein the energy intensity of the laser beam irradiated on the second area comprises a first section in which it rises from a reference value to a first target value, a second section in which it decreases from the first target value to a second target value, and a third section in which it rises from the second target value to the first target value.

Description

Technology Field

[0001] The present invention relates to a laser irradiation device comprising a beam repositioning unit that repositions the irradiation area of ​​a beam. Background Technology

[0002] Optical systems utilizing lasers as light sources are employed in a wide range of fields, including space communications, precision manufacturing, medicine, materials research, and the military, because they possess the characteristic of being able to emit high-energy beams with excellent properties over long distances.

[0003] An electronic device includes various electronic components, such as semiconductor chips or semiconductor packages. These electronic components are mounted on a printed circuit board by soldering. Therefore, a soldering process is required to connect the electrode pads of the electronic components to the electrode pads of the printed circuit board.

[0004] In order to mount electronic components of various sizes on a printed circuit board, solder of various sizes is required, and laser soldering technology can be used to melt the solder of various sizes simultaneously.

[0005] Laser soldering refers to the process of using a laser beam to melt solder, positioning electronic components on the molten solder, and connecting them to a printed circuit board.

[0006] In the laser soldering process, the laser beam is homogenized and irradiated onto the target component. However, because the heat loss rate differs between the center and edge regions of the target component, the temperature of the center region becomes higher than that of the edge region. If the temperature of the center region rises too high, the electronic component cannot be used due to the burning phenomenon. If the temperature of the center region is controlled to an appropriate temperature, the edge region may not reach the target temperature, and the electronic component may not be connected to the printed circuit board. The problem to be solved

[0007] The present invention is designed to solve the aforementioned conventional problems and aims to provide a laser irradiation device that uniformly raises the temperature of a target member by controlling the intensity distribution of the laser beam using a beam redistribution unit. means of solving the problem

[0008] To achieve the above objective, the present invention provides a laser irradiation device comprising: a beam irradiation unit for irradiating a laser beam; and a beam repositioning unit for repositioning the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam, wherein the laser beam is incident on a first area on the upper surface of the beam repositioning unit, refracted while passing through the beam repositioning unit, and irradiated on a second area of ​​a target member located below the beam repositioning unit, and wherein the energy intensity of the laser beam irradiated on the second area comprises a first section in which it rises from a reference value to a first target value, a second section in which it decreases from the first target value to a second target value, and a third section in which it rises from the second target value to the first target value.

[0009] Furthermore, the present invention provides a laser irradiation device in which the second target value is greater than the reference value.

[0010] Furthermore, the present invention provides a laser irradiation device in which the second section includes a fifth section decreasing from the first target value to the third target value and a sixth section increasing from the third target value to the second target value, and the third section includes a seventh section decreasing from the second target value to the third target value and an eighth section increasing from the third target value to the first target value.

[0011] Furthermore, the present invention provides a laser irradiation device in which the second section includes a ninth section decreasing from the first target value to the third target value and a tenth section decreasing from the third target value to the second target value, and the third section includes a eleventh section increasing from the second target value to the third target value and a twelveth section increasing from the third target value to the first target value.

[0012] Furthermore, the present invention provides a laser irradiation device comprising a 13th section in which at least one of the 9th section and the 10th section is maintained at the 3rd target value, and a 14th section in which at least one of the 11th section and the 12th section is maintained at the 3rd target value.

[0013] Furthermore, the present invention provides a laser irradiation device in which the 9th section further includes a 15th section decreasing from the 1st target value to the 4th target value and a 16th section increasing from the 4th target value to the 3rd target value, and the 12th section includes a 17th section decreasing from the 3rd target value to the 4th target value and an 18th section increasing from the 4th target value to the 1st target value.

[0014] Furthermore, the present invention provides a laser irradiation device comprising a beam redistribution unit that redistributes a portion of the laser beam irradiated in the first region while passing it through, a second core that surrounds the first core and redistributes a portion of the laser beam irradiated in the first region while passing it through, and a cladding provided between the first core and the second core.

[0015] Furthermore, the present invention provides a laser irradiation device in which the beam redeployment unit comprises a first lens array and a second lens array that overlaps with the first lens array.

[0016] Furthermore, the present invention provides a laser irradiation device wherein the beam repositioning unit comprises a third lens array that repositions a portion of the laser beam irradiated in the first region and a fourth lens array that overlaps with the third lens array and collects the repositioned laser beam from the third laser, and the third lens array comprises a first uneven portion and a second uneven portion having a different size from the first uneven portion. Effects of the invention

[0017] According to the present invention as described above, the following effects are achieved.

[0018] According to one embodiment of the present invention, by using an optical system, the laser beam can be repositioned to have various sizes, shapes, and intensity distributions, thereby optimizing the laser beam to suit the size and shape of the target member.

[0019] According to one embodiment of the present invention, the intensity distribution of the laser beam can be freely adjusted using a beam redistribution unit, thereby allowing the temperature of the central region and the edge region of the target member to be uniformly raised, thus minimizing errors during the process of mounting electronic components.

[0020] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0021] FIGS. 1a and FIGS. 1b are schematic diagrams of a laser irradiation device according to one embodiment of the present invention. FIG. 2 is a schematic diagram showing a laser beam being repositioned by a beam repositioning unit according to one embodiment of the present invention. FIGS. 3a and 3b are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to an embodiment of the present invention. In this case, FIG. 3b is a perspective view specifically showing a beam repositioning unit according to an embodiment of the present invention. FIGS. 4a and 4b are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to another embodiment of the present invention. In this case, FIG. 4b is a cross-sectional view specifically showing a beam repositioning unit according to another embodiment of the present invention. FIGS. 5A and 5B are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to another embodiment of the present invention. In this case, FIG. 5B is a cross-sectional view specifically showing a beam repositioning unit according to an embodiment of the present invention. FIG. 6a is a diagram showing the energy distribution on the plane of a second region formed by a laser irradiation device according to one embodiment of the present invention. FIG. 6b is a graph showing the energy distribution according to the position of the laser beam irradiated in the second region of FIG. 6a. In this case, FIG. 6b shows the energy distribution according to the position at cross-section I-I' of FIG. 6a. FIG. 7a is a diagram showing the energy distribution on the plane of a second region formed by a laser irradiation device according to another embodiment of the present invention. FIG. 7b is a graph showing the energy distribution according to the position of the laser beam irradiated in the second region of FIG. 7a. In this case, FIG. 7b shows the energy distribution according to the position at cross-section II-II' of FIG. 7a. FIG. 8a is a diagram showing the energy distribution on the plane of a second region formed by a laser irradiation device according to another embodiment of the present invention. FIG. 8b is a graph showing the energy distribution according to the position of the laser beam irradiated in the second region of FIG. 8a. In this case, FIG. 8b shows the energy distribution according to the position at cross-section III-III' of FIG. 8a. FIG. 9a is a diagram showing the energy distribution on the plane of a second region formed by a laser irradiation device according to another embodiment of the present invention. FIG. 9b is a graph showing the energy distribution according to the position of the laser beam irradiated in the second region of FIG. 9a. In this case, FIG. 9b shows the energy distribution according to the position at cross-section IV-IV' of FIG. 9a. FIG. 10a is a diagram showing the energy distribution on the plane of a second region formed by a laser irradiation device according to another embodiment of the present invention. FIG. 10b is a graph showing the energy distribution according to the position of the laser beam irradiated in the second region of FIG. 10a. In this case, FIG. 10b shows the energy distribution according to the position at cross-section V-VI' of FIG. 10a. Specific details for implementing the invention

[0022] Embodiments of the present invention will be described in detail below with reference to the attached drawings. However, the embodiments described below are presented for illustrative purposes only to aid in a clear understanding of the present invention and do not limit the scope of the present invention.

[0023] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters shown in the drawings. Throughout the specification, identical components may be referred to by the same reference numerals. In describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted.

[0024] Where terms such as "includes," "has," or "consists of" are used in this specification, other parts may be added unless the expression "only" is used. Where a component is expressed in the singular, it includes the plural unless specifically stated otherwise. Furthermore, in interpreting a component, it is interpreted to include a margin of error even without separate explicit description.

[0025] In the case of describing a positional relationship, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless expressions such as 'immediately' or 'directly' are used.

[0026] Spatially relative terms such as "below" or "beneath," "lower," "above," and "upper" may be used to facilitate the description of the relationships between components as illustrated in the drawings. Spatially relative terms should be understood as terms that include different directions of a component during use or operation, in addition to the directions illustrated in the drawings. For example, if a component illustrated in the drawings is flipped, a component described as "below" or "beneath" another component may be placed "above" of that other component. Therefore, the exemplary term "below" may include both the lower and upper directions. Similarly, the exemplary terms "above" or "upper" may include both the upper and lower directions.

[0027] In the case of an explanation of a temporal relationship, for example, when the temporal sequence is explained using expressions such as 'after', 'following', 'next', or 'before', it may include cases where the sequence is not continuous unless expressions such as 'immediately' or 'directly' are used.

[0028] Although terms such as "first," "second," etc. are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the technical scope of the present invention.

[0029] The term “at least one” should be understood to include all combinations that can be presented from one or more related items. For example, the meaning of “at least one of the first item, the second item, and the third item” may mean not only the first item, the second item, or the third item individually, but also all combinations of items that can be presented from two or more of the first item, the second item, and the third item.

[0030] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and driving mechanisms. Each embodiment may be implemented independently of one another or may be implemented together in an interlocking relationship.

[0031] FIGS. 1a and FIGS. 2 are schematic diagrams of a laser irradiation device according to one embodiment of the present invention.

[0032] As can be seen in FIG. 1a and FIG. 2, a laser irradiation device (100) according to one embodiment of the present invention comprises a beam irradiation unit (110) and a beam redistribution unit (120), and the laser irradiation device (100) according to one embodiment irradiates a laser beam onto a target member (200).

[0033] A laser irradiation device (100) according to one embodiment of the present invention comprises the beam redeployment unit (120), thereby enabling the irradiation of laser beams of various shapes or sizes according to the shape and size of the target member (200).

[0034] The beam irradiation unit (110) can emit a laser beam after forming it. For example, the energy intensity of the laser beam irradiated by the beam irradiation unit (110) may follow, for example, a Gaussian distribution. In this case, the laser beam may have an energy distribution in which the energy intensity is high at the center and decreases as it moves toward the surrounding region relative to the center.

[0035] As another example, the energy intensity of the laser beam irradiated from the beam irradiation unit (110) may have the form of, for example, a flat-top distribution. In this case, the laser beam can homogenize the total energy intensity by making the energy intensity of the center region and the edge region similar.

[0036] As another example, the energy intensity of the laser beam irradiated by the beam irradiation unit (110) may have a ring-shaped distribution, for example. In this case, the laser beam may have a distribution in which the energy intensity is low in the central region and high in the edge region. Meanwhile, the energy intensity of the laser beam irradiated by the beam irradiation unit (110) is not limited thereto, and according to the technical common sense of the art, the beam irradiation unit (110) may irradiate laser beams of various intensity distributions and various shapes.

[0037] A beam homogenizer may be optionally added between the beam irradiation unit (110) and the beam redistribution unit (120). The beam homogenizer may homogenize the laser beam emitted from the beam irradiation unit (110). For example, if the laser beam passing through the beam irradiation unit (110) follows a Gaussian distribution, for example, the laser beam following the Gaussian distribution may be homogenized by passing through the beam homogenizer, thereby allowing the energy intensity of the laser beam to follow a flat-top distribution. The beam homogenizer may include, for example, a beam homogenizer or a collimator, but is not limited thereto, and may be composed of various configurations capable of uniformly controlling the energy intensity distribution of the laser beam.

[0038] The beam redistribution unit (120) can redistribute the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam irradiated from the beam irradiation unit (110), thereby irradiating the target member (200) with a laser beam of various intensities, shapes, or sizes. In this case, the laser beam redistributed by the beam redistribution unit (120) may be formed in a circular shape where the laser beam is not irradiated in the central area, as shown in FIG. 2. However, the laser beam redistributed by the beam redistribution unit (120) is not limited to this and may be formed in various shapes. The energy distribution of the laser beam redistributed by the beam redistribution unit (120) will be explained in more detail later through FIG. 7a to FIG. 10a.

[0039] The beam repositioning unit (120) may comprise any one of the first sub-beam repositioning unit (300) of FIG. 3a, the second sub-beam repositioning unit (400) of FIG. 4a, and the third sub-beam repositioning unit (500) of FIG. 5a, but is not limited thereto. Meanwhile, the first sub-beam repositioning unit (300) to the third sub-beam repositioning unit (500) will be described in more detail through FIG. 3a to FIG. 5a.

[0040] The above target member (200) may be a target of the laser irradiation device (100) according to an embodiment of the present invention. The above target member (200) may be, for example, a solder, a solder bump, or a solder ball located on a PCB (Printed Circuit Board). Alternatively, the above target member (200) may be, for example, a wafer substrate. Meanwhile, the above target member (200) is not limited thereto and may be a target object to which a laser beam can be irradiated, to the knowledge of a person skilled in the art.

[0041] FIG. 1b is a schematic diagram of a laser irradiation device according to another embodiment of the present invention. In this case, FIG. 1b is identical to FIG. 1a except for the configuration of the first beam redistribution unit and the second beam redistribution unit, so the following description will focus on the different configuration.

[0042] As can be seen in FIG. 1b, a laser irradiation device (100) according to another embodiment of the present invention may comprise a beam irradiation unit (110), a first beam repositioning unit (120a), and a second beam repositioning unit (120b). The first beam repositioning unit (120a) and the second beam repositioning unit (120b) may each comprise any one of the first sub-beam repositioning unit (300) of FIG. 3a, the second sub-beam repositioning unit (400) of FIG. 4a, and the third sub-beam repositioning unit (500) of FIG. 5a, but are not limited thereto. Meanwhile, the first sub-beam repositioning unit (300) to the third sub-beam repositioning unit (500) will be described in more detail through FIG. 3a to FIG. 5a.

[0043] The first beam repositioning unit (120a) can reposition the irradiation area of ​​the laser beam by adjusting the movement path of at least some of the laser beams irradiated from the beam irradiation unit (110), thereby irradiating the second beam repositioning unit (120b) with laser beams of various intensities, shapes, or sizes.

[0044] The second beam repositioning unit (120b) can reposition the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam repositioned from the first beam repositioning unit (120a). In this case, the repositioned laser beam can be irradiated on the target member (200) that is the target of the laser irradiation device (100) with various intensities, shapes, or sizes.

[0045] In this case, the laser beam repositioned by the first beam repositioning unit (120a) and the second beam repositioning unit (120b) may be formed in a circular shape such that the laser beam is not irradiated in the central region, as shown in FIG. 2. However, the laser beam repositioned by the first beam repositioning unit (120a) and the second beam repositioning unit (120b) is not limited thereto.

[0046] FIGS. 3a and 3b are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to an embodiment of the present invention. In this case, FIG. 3b is a perspective view specifically showing a beam repositioning unit according to an embodiment of the present invention.

[0047] FIGS. 3a and 3b relate to a laser irradiation device in which the beam repositioning unit (see 120 in FIG. 1) is formed as a first sub-beam repositioning unit (300), wherein a first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1) is repositioned while passing through the first sub-beam repositioning unit (300), and the repositioned second laser beam (130b) can be irradiated onto the target member (200).

[0048] As can be seen in FIG. 3a, the first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1) is irradiated to a first region (A1) on the first sub-beam repositioning unit (300), and the first laser beam (130a) can be repositioned by the first sub-beam repositioning unit (300) to be irradiated to a second region (A2) on the target member (200). In this case, the second laser beam (130b) repositioned by the first sub-beam repositioning unit (300) may, for example, have an energy intensity in the center region that is lower than the energy intensity in the edge region. Accordingly, the first sub-region (LA1) of the second laser beam (130b) can be irradiated onto the target member (200) with a lower intensity compared to the second sub-region (LA2) of the second laser beam (130b). Meanwhile, the distribution of the second laser beam (130b) is not limited thereto, and the second laser beam (130b) can be adjusted as in the embodiments of FIG. 6a to 10a, which will be described later, by adjusting the first sub-beam redistribution unit (300). In this regard, it will be explained in more detail through the drawings according to each embodiment.

[0049] As can be seen in FIG. 3b, the first sub-beam repositioning unit (300) comprises a first core (310), a second core (320), a first cladding (330), and a second cladding (340).

[0050] The first core (310) and the second core (320) correspond to the area through which the first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1a) passes. The first core (310) and the second core (320) may be extended vertically in the form of a pipe with a circular cross-section, for example, but are not limited thereto. As another example, the first core (310) and the second core (320) may have a polygonal cross-section such as a square or triangle, or may have a shape other than a polygon.

[0051] The first core (310) may be located in the central part of the first sub-beam repositioning unit (300), for example, in the central region, and the second core (320) may be provided in a form that surrounds the first core (310). The first core (310) and the second core (320) may be made of a material with a high refractive index, and through this, the laser beam (130a) passing through the first core (310) and the second core (320) may be totally reflected and proceed toward the outside of the first sub-beam repositioning unit (300), for example, toward the target member (200).

[0052] The first cladding (330) is provided between the first core (310) and the second core (320), and may be extended vertically in the form of a pipe with a circular cross-section, for example, but is not limited thereto. The first cladding (330) may prevent any part of the first laser beam (130a) passing through the first core (310) from moving to the second core (320), and may prevent any other part of the first laser beam (130a) passing through the second core (320) from moving to the first core (310).

[0053] The second cladding (340) wraps around the second core (320) and can be extended vertically in the form of a pipe with a circular cross-section. The second cladding (340) can prevent other parts of the first laser beam (130a) passing through the second core (320) from being exposed to the outside.

[0054] According to one embodiment of the present invention, some of the first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1a) may travel through the first core (310), and other parts of the first laser beam (130a) may travel through the second core (320).

[0055] The first core (310) may have a first diameter (d1) in the horizontal direction, and the second core (320) may have a second diameter (d2) in the horizontal direction. In this case, the second diameter (d2) of the second core (320) is larger than the first diameter (d1) of the first core (310).

[0056] By adjusting the first diameter (d1) of the first core (310) and the second diameter (d2) of the second core (320), the path of some of the first laser beam (130a) passing through the first core (310) and the path of other parts of the first laser beam (130a) passing through the second core (320) can be adjusted. Accordingly, by varying and combining the first diameter (d1) of the first core (310) and the second diameter (d2) of the second core (320), the degree to which the second laser beam (130b) is repositioned can be varied. For example, as can be seen again in FIG. 3a, by adjusting the first diameter (d1) of the first core (310) and the second diameter (d2) of the second core (320), the intensity of the first sub-region (LA1) of the second laser beam (130b) can be formed to be lower than the intensity of the second sub-region (LA2). However, the intensity distribution according to the position of the second laser beam (130b) is not limited thereto.

[0057] FIGS. 4a and 4b are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to another embodiment of the present invention. In this case, FIG. 4b is a cross-sectional view specifically showing a beam repositioning unit according to another embodiment of the present invention.

[0058] FIGS. 4a and 4b relate to a laser irradiation device in which the beam repositioning unit (see 120 in FIG. 1) is formed into a second sub-beam repositioning unit (400), wherein a first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1) is repositioned while passing through the first sub-beam repositioning unit (300), and the repositioned second laser beam (130b) can be irradiated onto the target member (200).

[0059] As can be seen in FIG. 4a, the second sub-beam repositioning unit (400) comprises at least one lens array (410). At this time, the at least one lens array (410) comprises a first lens array (410a), a second lens array (410b), ..., and an nth lens array (410n). At this time, each of the lens arrays (410a, 410b, ..., 410n) may comprise at least one convex portion (v) and at least one planar portion (f), or may comprise at least one concave portion (c) and at least one planar portion (f). This will be explained in detail in FIG. 4b, which is an enlarged view of FIG. 4a.

[0060] Each of the above lens arrays (410a, 410b, …, 410n) is formed by overlapping each other, so that the path of the first laser beam (130a) passing through the first lens array (410a) is repositioned to pass through the second lens array (410b), and the path of the laser beam passing through the second lens array (410b) is repositioned again, and the process is repeated, and finally, the second laser beam (130b) with its path finally repositioned can be formed by passing through the nth lens array (410n).

[0061] By adjusting the size, curvature of the lens, and distance between the lens arrays provided in each of the at least one lens array (410), the travel path of the first laser beam (130a) can be repositioned to freely form the second laser beam (130b) with a desired shape and intensity. Accordingly, the second sub-beam repositioning unit (400) can form the second laser beam (130b) by repositioning the travel path of the first laser beam (130a), even if, for example, it comprises only the first lens array (410a).

[0062] Below, with reference to FIG. 4b, which is an enlarged view of FIG. 4a, the principle of the laser beam repositioning of the at least one lens array (410) will be explained. Meanwhile, for convenience of explanation, the principle of the laser beam repositioning will be explained using parts of the first lens array (410a) and the second lens array (410b).

[0063] FIG. 4b is an enlarged view of a portion of the second sub-beam repositioning section (400) of FIG. 4a.

[0064] As can be seen in FIG. 4b, the first lens array (410a) may be formed by including at least one convex portion (v) and at least one planar portion (fa), and the second lens array (410b) may be formed by including at least one concave portion (c) and at least one planar portion (fb). Meanwhile, as previously described, the first lens array (410a) and the second lens array (410b) are not limited thereto and may be manufactured according to the knowledge of those skilled in the art through various combinations such as the size of the lenses, the curvature of the lenses, and the distance between each array.

[0065] The first lens array (410a) and the second lens array (410b) may be formed by overlapping each other. At this time, as can be seen in FIG. 4b, the first lens array (410a) includes a first convex portion (v1), a second convex portion (v2), and a first planar portion (fa1), and the second lens array (410b) includes a first concave portion (c1), a second concave portion (c2), and a first planar portion (fb1).

[0066] The first lens array (410a) may, for example, have the first convex portion (v1) provided on the left side of the drawing and the second convex portion (v2) provided on the right side of the drawing, and the first planar portion (fa1) provided between the first convex portion (v1) and the second convex portion (v2). According to an embodiment of the present invention, the first convex portion (v1) and the second convex portion (v2) may have the same size and shape and may have the same curvature. However, they are not limited thereto and may have different sizes, different shapes, and different curvatures.

[0067] The second lens array (410b) may, for example, have the first concave portion (c1) provided on the left side of the drawing and the second concave portion (c2) provided on the right side of the drawing, and the first planar portion (fb1) provided between the first concave portion (c1) and the second concave portion (c2). According to an embodiment of the present invention, the first concave portion (c1) and the second concave portion (c2) may have the same size and shape and may have the same curvature. However, they are not limited thereto and may have different sizes, different shapes, and different curvatures.

[0068] According to an embodiment of the present invention, the first convex portion (v1) overlaps with the first concave portion (c1), the second convex portion (v2) overlaps with the second concave portion (c2), and the first planar portion (fa1) overlaps with the second planar portion (fa2). Accordingly, the first laser beam (140a) that passes through the first convex portion (v1) is gathered towards the center of the first convex portion (v1), and the laser beam gathered after passing through the first convex portion (v1) then passes through the first concave portion (c1) and spreads out with respect to the center of the first concave portion (c1). The laser beam that passes through the first planar portion (fa1) of the first lens array (410a) is not redeployed but passes through as is and passes through the first planar portion (fb1) of the second lens array (410b). Furthermore, the laser beam passing through the second convex portion (v2) and the second concave portion (c2) can be rerouted to pass through the same path as the laser beam passing through the first convex portion (v1) and the first concave portion (c1).

[0069] Ultimately, according to one embodiment of the present invention, the laser beam passing through the first convex portion (v1) and the first concave portion (c1) and the laser beam passing through the second convex portion (v2) and the second concave portion (c2) have their travel paths repositioned by the second sub-beam repositioning unit (400), and the laser beam passing through the first planar portion (fa1) of the first lens array (410a) and the first planar portion (fb1) of the second lens array (410b) may not have their travel paths repositioned.

[0070] Meanwhile, the method of overlapping the first lens array (410a) and the second lens array (410b) is not limited thereto, and the first convex portion (v1) may overlap with the first planar portion (fb1) of the second lens array (410b), and the first planar portion (fa1) of the first lens array (410a) may overlap with the first concave portion (c1). Additionally, although not illustrated, it may be designed so that a part of the first convex portion (v1) provided in the first lens array (410a) overlaps with the first concave portion (c1), while the remaining part of the first convex portion (v1) overlaps with the first planar portion (fb1) of the second lens array (410b).

[0071] In this way, the path along which the second laser beam (130b) is repositioned can be freely adjusted by combining each lens array (410) provided in the second sub-beam repositioning unit (400).

[0072] Furthermore, the intensity distribution of the second region (A2) can be controlled by adjusting the path along which the second laser beam (130b) is repositioned. For example, the intensity distribution of the second region (A2) can be controlled by adjusting the at least one lens array (410) to adjust the path so that a larger amount of laser beam is repositioned on one side of the second region (A2) and a smaller amount of laser beam is repositioned on the other side of the second region (A2).

[0073] Additionally, the shape of the second area (A2) can be adjusted by controlling the path along which the second laser beam (130b) is repositioned. For example, if the shape of the first area (A1) is a square, the shape of the second area (A2) can be formed as a rectangle by repositioning the path of a portion of the first laser beam (130a) irradiated on one side and the other side of the first area (A1) so that it is directed toward the center of the square.

[0074] Accordingly, according to an embodiment of the present invention, the movement path, intensity distribution, size, and shape of the second region (A2) formed by the second laser beam (130b) can be varied by the second sub-beam repositioning unit (400).

[0075] FIGS. 5A and 5B are schematic diagrams showing a laser beam being repositioned by a beam repositioning unit according to another embodiment of the present invention. In this case, FIG. 5B is a cross-sectional view specifically showing a beam repositioning unit according to an embodiment of the present invention.

[0076] FIGS. 5a and 5b relate to a laser irradiation device in which the beam repositioning unit (see 120 in FIG. 1) is formed into a third sub-beam repositioning unit (500), wherein a first laser beam (130a) irradiated from the beam irradiation unit (see 110 in FIG. 1) is repositioned while passing through the first sub-beam repositioning unit (300), and the repositioned second laser beam (130b) can be irradiated onto the target member (200).

[0077] As can be seen in FIG. 5a, the third sub-beam repositioning unit (500) comprises a second-1 lens array (510) and a second-2 lens array (520). The first laser beam (130a) passing through the second-1 lens array (510) can be repositioned to become the second laser beam (130b). The second-1 lens array (510) comprises a plurality of uneven and flat sections, and by arranging these plurality of uneven and flat sections, the first laser beam (130a) can be repositioned into the second laser beam (130b).

[0078] The second-2 lens array (520) serves to focus the laser beam repositioned by the second-1 lens array (510) toward the target member (200). Through the second-2 lens array (520), the second laser beam (130b) can be prevented from spreading to areas other than the target member (200). Meanwhile, the second-2 lens array (520) may be omitted depending on the circumstances.

[0079] As can be seen in FIG. 5b, the second-1 lens array (510) may comprise a plurality of flat portions (511), a plurality of first uneven portions (512), and a plurality of second uneven portions (513). The plurality of flat portions (511) can pass the first laser beam (130a) without significant refraction, and the plurality of first uneven portions (512) and the plurality of second uneven portions (513) can refract the first laser beam (130a).

[0080] The plurality of first uneven portions (512) and the plurality of second uneven portions (513) may be formed with different numbers, different sizes, different angles, different pitches, and different shapes. In this case, the pitch may be defined as the length of repetition of the plurality of first uneven portions (512, or the plurality of second uneven portions (513)). Accordingly, by adjusting the position, number, size, and respective pitch of the plurality of first uneven portions (512), the plurality of second uneven portions (513), and the plurality of flat portions (511), the degree to which the first laser beam (130a) is repositioned can be varied. For example, as can be seen again in FIG. 5a, by adjusting the position, number, size, and respective pitch of the plurality of flat portions (511), the plurality of first uneven portions (512), and the plurality of second uneven portions (513), the intensity of the first sub-region (LA1) of the second laser beam (130b) can be formed to be lower than the intensity of the second sub-region (LA2). However, the intensity distribution according to the position of the second laser beam (130b) is not limited thereto.

[0081] According to another embodiment of the present invention, as can be seen again in FIG. 5b, the plurality of second uneven portions (513) may have a larger size in the horizontal direction than the plurality of first uneven portions (512). In this case, the degree to which a portion of the first laser beam (130a) passing through the plurality of second uneven portions (513) is refracted and the degree to which another portion of the first laser beam (130a) passing through the plurality of first uneven portions (512) is refracted are different, and as a result, the second laser beam (130b) may form the second region (see A2 in FIG. 5a) by gathering laser beams with repositioned travel paths.

[0082] FIG. 6a is a diagram showing the energy distribution on a plane of a second region (see A2 in FIG. 3a, FIG. 4a and FIG. 5a) formed by a laser irradiation device according to one embodiment of the present invention, and FIG. 6b is a graph showing the energy distribution according to the position of a laser beam irradiated in the second region of FIG. 6a. In this case, FIG. 6b shows the energy distribution according to the position at cross-section I-I' of FIG. 6a. Meanwhile, f shows the energy distribution on a plane of a laser beam of a comparative example, and relates to the energy distribution of a laser beam irradiated by a beam irradiation unit without a beam redistribution unit.

[0083] As can be seen in FIG. 6a, a second region formed by a laser irradiation device according to one embodiment of the present invention may be formed to have a relatively high energy distribution in a circular shape (red part in FIG. 6a) from the center in the drawing. In this case, the area of ​​the second region may be adjusted by the beam redistribution unit (see 120 in FIG. 1a). When compared to comparative example (b), the second region according to one embodiment of the present invention may be formed with a relatively narrow area compared to comparative example (b), where a laser beam is irradiated by a beam irradiation unit without a beam redistribution unit. Meanwhile, the second region may be formed with a wider area than comparative example (b) by adjusting the beam redistribution unit (see 120 in FIG. 1a).

[0084] Furthermore, as can be seen in FIG. 6b, the energy distribution of the laser beam irradiated by the laser irradiation device according to one embodiment of the present invention, i.e., the second region, comprises a first section (I-1) rising from a reference value (R) to a first target value (T11), a second section (I-2) maintained at the first target value (T11), and a third section (I-3) decreasing from the first target value (T11) to the reference value (R). In this case, it can be seen that the energy distribution of the second region according to one embodiment of the present invention is formed with a narrower length compared to the comparative example, and the first target value (T11) of the second region may be formed higher than the first comparative value (T10), which is the maximum energy intensity of the comparative example (b).

[0085] FIG. 7a is a diagram showing the energy distribution on a plane of a second region (see A2 in FIG. 3a, FIG. 4a and FIG. 5a) formed by a laser irradiation device according to another embodiment of the present invention, and FIG. 7b is a graph showing the energy distribution according to the position of a laser beam irradiated in the second region of FIG. 7a. In this case, FIG. 7b shows the energy distribution according to the position at cross-section II-II' of FIG. 7a.

[0086] As can be seen in FIG. 7a, a second region formed by a laser irradiation device according to another embodiment of the present invention may be formed to have a relatively high energy distribution in a ring or ring shape (red part in FIG. 7a) from the center in the drawing. By being formed in this way, when a laser beam irradiated from a laser irradiation device according to an embodiment of the present invention (see 100 in FIG. 1a) reaches a target member (see 200 in FIG. 1a), the temperature of the central region of the target member (see 200 in FIG. 1a) rises more slowly than the edge region, thereby preventing the problem of the central region of the target member (see 200 in FIG. 1a) burning up or the edge region failing to rise to a sufficient temperature. Conventionally, for example, when performing a laser soldering process, a laser with a uniform energy distribution, such as a flat-top beam, was used. In this case, the rate of heat emission differed between the center region of the target component and the edge region. Consequently, if the temperature of the center region was heated to a target temperature (e.g., by irradiating with a laser beam), the edge region failed to reach the target temperature, resulting in a problem where the solder could not melt. Conversely, if the temperature of the edge region was heated to the target temperature, the temperature of the center region would exceed the target temperature, causing the solder to burn.

[0087] According to one embodiment of the present invention, by forming the energy intensity of the central region lower than the energy intensity of the edge region using the beam redistribution unit (see 120 in FIG. 1a), a uniform heat distribution can be achieved in the central region and the edge region of the target member (see 200 in FIG. 1a). In this case, since the central region and the edge region of the target member (see 200 in FIG. 1a) have a uniform heat distribution, the target member (see 200 in FIG. 1a), for example, solder, can rise to the same target temperature in the central region and the edge region, thereby enabling uniform soldering depending on the location.

[0088] Furthermore, as can be seen in FIG. 7b, the energy distribution of the laser beam irradiated by the laser irradiation device according to another embodiment of the present invention, i.e., the second region, may comprise a first section (II-1) rising from a reference value (R) to a first target value (T21), a second section (II-2) falling from the first target value (T21) to a second target value (T22), a third section (II-3) rising from the second target value (T22) to the first target value (T21), and a fourth section (II-4) falling from the first target value (T21) to the reference value (R). In this case, the first target value (T21) may have a higher energy intensity than the second target value (T22). By being formed in this way, a uniform heat distribution can be achieved in the center region and the edge region of the target member (see 200 in FIG. 1a), as previously described.

[0089] FIG. 8a is a diagram showing the energy distribution on a plane of a second region (see A2 in FIG. 3a, 4a and 5a) formed by a laser irradiation device according to another embodiment of the present invention, and FIG. 8b is a graph showing the energy distribution according to the position of a laser beam irradiated in the second region of FIG. 8a. In this case, FIG. 8b shows the energy distribution according to the position at cross-section III-III' of FIG. 8a.

[0090] As can be seen in FIG. 8a, a second region formed by a laser irradiation device according to another embodiment of the present invention may be formed to have a relatively high energy distribution in the shape of a ring or a circle inside a ring from the center in the drawing (red part in FIG. 8a). By being formed in this way, when a laser beam irradiated from a laser irradiation device according to an embodiment of the present invention (see 100 in FIG. 1a) reaches a target member (see 200 in FIG. 1a), the temperature of the central region of the target member (see 200 in FIG. 1a) rises more slowly than the edge region, thereby preventing the problem of the central region of the target member (see 200 in FIG. 1a) burning up or the edge region failing to rise to a sufficient temperature.

[0091] According to one embodiment of the present invention, by forming the energy intensity of the central region lower than the energy intensity of the edge region using the beam redistribution unit (see 120 in FIG. 1a), a uniform heat distribution can be achieved in the central region and the edge region of the target member (see 200 in FIG. 1a). In this case, since the central region and the edge region of the target member (see 200 in FIG. 1a) have a uniform heat distribution, the target member (see 200 in FIG. 1a), for example, solder, can rise to the same target temperature in the central region and the edge region, thereby enabling uniform soldering depending on the location.

[0092] Furthermore, as can be seen in FIG. 8b, the energy distribution of the laser beam irradiated by the laser irradiation device according to another embodiment of the present invention, i.e., the second region, comprises a first section (III-1) rising from a reference value (R) to a first target value (T31), a second section (III-2) and a third section (III-3) decreasing from the first target value (T31) to a third target value (T33), a fourth section (III-4) and a fifth section (III-5) increasing from the third target value (T33) to the first target value (T31), and a sixth section (III-6) decreasing from the first target value (T31) to the reference value (R). The section decreasing from the first target value (T31) to the third target value (T33) includes a second section (III-2) decreasing from the first target value (T31) to the second target value (T32) and a third section (III-3) increasing from the second target value (T32) to the third target value (T33); and the section increasing from the third target value (T33) to the first target value (T31) includes a fourth section (III-4) decreasing from the third target value (T33) to the second target value (T32) and a fifth section (III-5) increasing from the second target value (T32) to the first target value (T31). In this case, the first target value (T31) is greater than the second target value (T32) and the third target value (T33), and the third target value (T33) may be greater than the second target value (T32). By being formed in this way, a uniform heat distribution can be achieved in the center region and the edge region of the target member (see 200 in FIG. 1a), as previously described.

[0093] FIG. 9a is a diagram showing the energy distribution on a plane of a second region (see A2 in FIG. 3a, FIG. 4a and FIG. 5a) formed by a laser irradiation device according to another embodiment of the present invention, and FIG. 9b is a graph showing the energy distribution according to the position of a laser beam irradiated in the second region of FIG. 9a. In this case, FIG. 9b shows the energy distribution according to the position at cross-section IV-IV' of FIG. 9a.

[0094] As can be seen in FIG. 9a, a second region formed by a laser irradiation device according to another embodiment of the present invention may be formed to have a relatively high energy distribution in a ring or ring shape (red part in FIG. 9a) from the center in the drawing. By being formed in this way, when a laser beam irradiated from a laser irradiation device according to an embodiment of the present invention (see 100 in FIG. 1a) reaches a target member (see 200 in FIG. 1a), the temperature of the central region of the target member (see 200 in FIG. 1a) rises more slowly than the edge region, thereby preventing the problem of the central region of the target member (see 200 in FIG. 1a) burning up or the edge region failing to rise to a sufficient temperature.

[0095] According to one embodiment of the present invention, by forming the energy intensity of the central region lower than the energy intensity of the edge region using the beam redistribution unit (see 120 in FIG. 1a), a uniform heat distribution can be achieved in the central region and the edge region of the target member (see 200 in FIG. 1a). In this case, since the central region and the edge region of the target member (see 200 in FIG. 1a) have a uniform heat distribution, the target member (see 200 in FIG. 1a), for example, solder, can rise to the same target temperature in the central region and the edge region, thereby enabling uniform soldering depending on the location.

[0096] Furthermore, as can be seen in FIG. 9b, the energy distribution of the laser beam irradiated by the laser irradiation device according to another embodiment of the present invention, i.e., the second region, comprises a first section (IV-1) rising from a reference value (R) to a first target value (T41), a second section (IV-2) decreasing from the first target value (T41) to a second target value (T42), a third section (IV-3) and a fourth section (IV-4), a fifth section (IV-5) rising from the second target value (T42) to the first target value (T41), a sixth section (IV-6) and a seventh section (IV-7), and an eighth section (IV-8) decreasing from the first target value (T41) to the reference value (R). The section decreasing from the first target value (T41) to the second target value (T42) includes a second section (IV-2) and a third section (IV-3) decreasing from the first target value (T41) to the third target value (T43), and a fourth section (IV-4) decreasing from the third target value (T43) to the second target value (T42); and the section increasing from the second target value (T42) to the first target value (T41) includes a fifth section (IV-5) increasing from the second target value (T42) to the third target value (T43), and a sixth section (IV-6) and a seventh section (IV-7) increasing from the third target value (T43) to the first target value (T41).

[0097] Furthermore, the section decreasing from the first target value (T41) to the third target value (T43) includes a second section (IV-2) decreasing from the first target value (T41) to the fourth target value (T44) and a third section (IV-3) increasing from the fourth target value (T44) to the third target value (T43), and the section increasing from the third target value (T43) to the first target value (T41) includes a sixth section (IV-6) decreasing from the third target value (T43) to the fourth target value (T44) and a seventh section (IV-7) increasing from the fourth target value (T44) to the first target value (T41). In this case, the first target value (T41) is greater than the second target value (T42) to the fourth target value (T44), the third target value (T43) is greater than the second target value (T42) and the fourth target value (T44), and the fourth target value (T44) may be greater than the second target value (42). By being formed in this way, a uniform heat distribution can be achieved in the center region and the edge region of the target member (see 200 in FIG. 1a), as previously described.

[0098] FIG. 10a is a diagram showing the energy distribution on a plane of a second region (see A2 in FIG. 3a, FIG. 4a and FIG. 5a) formed by a laser irradiation device according to another embodiment of the present invention, and FIG. 10b is a graph showing the energy distribution according to the position of a laser beam irradiated on the second region of FIG. 10a. In this case, FIG. 10b shows the energy distribution according to the position at cross-section V-V' of FIG. 10a.

[0099] As can be seen in FIG. 10a, a second region formed by a laser irradiation device according to another embodiment of the present invention may be formed to have a relatively high energy distribution in a ring or ring shape (red part in FIG. 10a) from the center in the drawing. By being formed in this way, when a laser beam irradiated from a laser irradiation device according to an embodiment of the present invention (see 100 in FIG. 1a) reaches a target member (see 200 in FIG. 1a), the temperature of the central region of the target member (see 200 in FIG. 1a) rises more slowly than the edge region, thereby preventing the problem of the central region of the target member (see 200 in FIG. 1a) burning up or the edge region failing to rise to a sufficient temperature.

[0100] According to one embodiment of the present invention, by forming the energy intensity of the central region lower than the energy intensity of the edge region using the beam redistribution unit (see 120 in FIG. 1a), a uniform heat distribution can be achieved in the central region and the edge region of the target member (see 200 in FIG. 1a). In this case, since the central region and the edge region of the target member (see 200 in FIG. 1a) have a uniform heat distribution, the target member (see 200 in FIG. 1a), for example, solder, can rise to the same target temperature in the central region and the edge region, thereby enabling uniform soldering depending on the location.

[0101] Furthermore, as can be seen in FIG. 10b, the laser beam irradiated by a laser irradiation device according to another embodiment of the present invention, i.e., the energy distribution of the second region, comprises a first section (V-1) rising from a reference value (R) to a first target value (T51), a second section (V-2) decreasing from the first target value (T51) to a second target value (T52), a third section (V-3) and a fourth section (V-4), a fifth section (V-5) rising from the second target value (T52) to the first target value (T51), a sixth section (V-6) and a seventh section (V-7), and an eighth section (V-8) decreasing from the first target value (T51) to the reference value (R). The section decreasing from the first target value (T51) to the second target value (T52) includes a second section (V-2) and a third section (V-3) decreasing from the first target value (T51) to the third target value (T53), and a fourth section (V-4) decreasing from the third target value (T53) to the second target value (T52); and the section increasing from the second target value (T52) to the first target value (T51) includes a fifth section (V-5) increasing from the second target value (T52) to the third target value (T53), and a sixth section (V-6) and a seventh section (V-7) increasing from the third target value (T53) to the first target value (T51).

[0102] Furthermore, the section decreasing from the first target value (T51) to the third target value (T53) includes a second section (V-2) decreasing from the first target value (T51) to the third target value (T53) and a third section (V-3) maintained at the third target value (T53), and the section increasing from the third target value (T53) to the first target value (T51) includes a sixth section (V-6) maintained at the third target value (T53) and a seventh section (V-7) increasing from the third target value (T53) to the first target value (T51). In this case, the first target value (T51) is greater than the second target value (T52) to the third target value (T53), and the third target value (T53) may be greater than the second target value (T52). By being formed in this way, as previously described, a uniform heat distribution can be achieved in the central region and the edge region of the target member (see 200 in FIG. 1a).

[0103] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0104] 100: Laser irradiation device 110: Beam irradiation unit 120: Beam repositioning unit 200: Target member 300: 1st sub-beam repositioning unit 400: 2nd sub-beam repositioning unit 500: 3rd sub-beam repositioning section A1: 1st area A2: Area 2

Claims

Claim 1 A beam irradiation unit that irradiates a laser beam; The laser beam repositioning unit includes a beam repositioning unit that repositions the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam, wherein the beam repositioning unit adjusts the laser beam so that it is irradiated more to the edge area than to the center area of ​​the target member, and the laser beam is incident on a first area on the upper surface of the beam repositioning unit, then refracts while passing through the beam repositioning unit and is irradiated to a second area of ​​the target member located below the beam repositioning unit, wherein the energy intensity of the laser beam irradiated to the second area is formed to be higher in the second sub-area, which is at least a portion of the edge area of ​​the target member, than in the first sub-area, which is at least a portion of the center area of ​​the target member, and wherein the energy intensity of the laser beam irradiated to the second area comprises a first section in which it rises from a reference value to a first target value, a second section in which it decreases from the first target value to a second target value, a third section in which it rises from the second target value to the first target value, and a fourth section in which it decreases from the first target value to the reference value, and wherein the beam repositioning unit is arranged to overlap at a predetermined interval along the direction of propagation of the laser beam, at least A laser irradiation device comprising a plurality of lens arrays, wherein the plurality of lens arrays comprises a first lens array and a second lens array that overlaps with the first lens array, wherein the first lens array repositions at least a portion of the laser beam and includes at least one planar portion and at least one convex portion, and the second lens array repositions at least a portion of the laser beam repositioned from the first lens array and includes at least one planar portion and at least one concave portion, wherein at least one convex portion of the first lens array overlaps with at least one concave portion of the second lens array, and at least one planar portion of the first lens array overlaps with at least one planar portion of the second lens array. Claim 2 In claim 1, the laser irradiation device in which the second target value is greater than the reference value. Claim 3 A beam irradiation unit that irradiates a laser beam; and includes a beam redistribution unit that redistributes the irradiation area of ​​the laser beam by adjusting the movement path of at least a portion of the laser beam, wherein the beam redistribution unit adjusts the laser beam so that it is irradiated more to the edge area than to the center area of ​​the target member, and the laser beam is incident on a first area on the upper surface of the beam redistribution unit, then refracts while passing through the beam redistribution unit and is irradiated to a second area of ​​the target member located below the beam redistribution unit, and the energy intensity of the laser beam irradiated to the second area is formed to be higher in the second sub-area, which is at least a portion of the edge area of ​​the target member, than in the first sub-area, which is at least a portion of the center area of ​​the target member, and the energy intensity of the laser beam irradiated to the second area is formed in a III-1 section that rises from a reference value to a first target value, a III-2 section that decreases from the first target value to a second target value, a III-3 section that rises from the second target value to a third target value, a III-4 section that decreases from the third target value to the second target value, and a section that rises from the second target value to the first target value The beam repositioning unit comprises a III-5 section and a III-6 section that decreases from the first target value to the reference value, wherein the beam repositioning unit comprises a plurality of lens arrays, each comprising at least two, arranged to overlap at a predetermined interval along the propagation direction of the laser beam, wherein the plurality of lens arrays comprises a first lens array and a second lens array that overlaps with the first lens array, wherein the first lens array repositions at least a portion of the laser beam and comprises at least one planar portion and at least one convex portion, wherein the second lens array repositions at least a portion of the laser beam repositioned from the first lens array and comprises at least one planar portion and at least one concave portion, and wherein at least one convex portion of the first lens array overlaps with at least one concave portion of the second lens array.A laser irradiation device in which at least one planar portion of the first lens array overlaps with at least one planar portion of the second lens array. Claim 4 delete Claim 5 A laser irradiation device according to claim 1, wherein the second section comprises a V-2 section that decreases from the first target value to a third target value that is smaller than the first target value and larger than the second target value; a V-3 section that is maintained at the third target value; and a V-4 section that decreases from the third target value to the second target value, and the third section comprises a V-5 section that increases from the second target value to the third target value; a V-6 section that is maintained at the third target value; and a V-7 section that increases from the third target value to the first target value. Claim 6 A laser irradiation device according to claim 1, wherein the second section comprises an IV-2 section that decreases from the first target value to a fourth target value that is smaller than the first target value and larger than the second target value; an IV-3 section that increases from the fourth target value to a third target value that is smaller than the first target value and larger than the second target value; and an IV-4 section that decreases from the third target value to the second target value, and the third section comprises an IV-5 section that increases from the second target value to the third target value; an IV-6 section that decreases from the third target value to the fourth target value; and an IV-7 section that increases from the fourth target value to the first target value. Claim 7 delete Claim 8 delete Claim 9 delete

Images