Method for processing through-hole in glass substrate

Abstract

The present invention provides a method for processing through holes in a glass substrate that can significantly improve the processing quality of the through holes while having an excellent process yield. The processing method includes a step of forming a deformed part and a step of forming a through hole. The step of forming a deformed part is a step of forming a deformed part in the processing area of ​​a glass substrate to be processed by applying a laser shot to the processing area to be formed with the through hole. The step of forming a through hole is a step of forming a through hole corresponding to the processing area by immersing the glass substrate in an etching solution so that the deformed part is etched away. The step of forming a deformed part includes a first step of forming a deformed part and a second step of forming a deformed part. The step of forming a first deformed part is a step of forming a first deformed part by applying a first laser shot to a part of the processing area to be processed. The step of forming a second deformed part is a step of forming a second deformed part by applying a second laser shot to another part of the processing area to be processed.

Description

Technology Field

[0001] The present invention relates to a method for processing through holes in a glass substrate, and more specifically, to a method for processing through holes in a glass substrate by undergoing a modification process and an etching process using a laser heat source. Background Technology

[0002] For manufacturing processes such as mounting IC devices on a substrate, a portion of the substrate surface is selectively removed to form a cavity or through hole, and recently, laser modification and etching technologies are used for such processes.

[0003] Figure 1 is an example diagram of a process for machining through holes in a conventional glass substrate.

[0004] FIG. 1 (a) illustrates an ideal through-hole processing process, wherein a laser beam (L) with an energy intensity that does not exceed the ablation threshold of the glass substrate (1) is irradiated onto the glass substrate (1) to create a deformed portion (M) corresponding to the desired through-hole. Subsequently, when the glass substrate (1) with the deformed portion (M) formed thereon is immersed in an etching solution, the deformed portion (M) is etched away, and a through-hole (H) can be formed in the glass substrate (1).

[0005] However, FIG. 1(b) shows a practical through-hole processing process. When a laser beam (L) is irradiated to create a deformation portion (M) corresponding to the target through-hole, a crack area (M2) that propagates into the interior of the glass substrate (1) may be additionally created along with the deformation area (M1). As the etching solution penetrates into this crack area (M2) during etching, it reduces the processing precision of the target through-hole (H1).

[0006] These crack regions (M2) can be formed randomly and sometimes have a certain directionality. As illustrated, if the crack regions (M2) are formed symmetrically on both sides with respect to the center of the laser beam (L) being irradiated, the through hole (H1) finally formed after etching will have an elliptical shape that is elongated into the crack regions (M2) rather than the intended circular shape.

[0007] If the diameter of the target through hole is relatively large or the thickness (penetration depth) is relatively thick, a correspondingly strong energy intensity of the laser beam may be required, and in this case, the size of the crack region (M2) propagating into the interior of the glass substrate also tends to increase proportionally.

[0008] Figure 2 is an example of another process for processing through holes in a conventional glass substrate.

[0009] As explained above, when the diameter of the target through hole (H2) is relatively large, the spot size of the laser beam cannot be made infinitely large, so it is difficult to form the through hole by irradiating the laser beam once. Accordingly, as shown in FIG. 2, a deformed portion (M) is created in the shape of a closed curve on the glass substrate (1) by sequentially moving the laser beam along a virtual moving line corresponding to the diameter of the target through hole (H2). Afterward, when the glass substrate (1) with the formed deformed portion (M) is immersed in an etching solution, the deformed portion (M) is etched away and a portion of the glass substrate (1) existing inside the virtual moving line is separated together, thereby forming the target through hole (H2) on the glass substrate (1).

[0010] However, in this case, since the laser beam must be irradiated multiple times along the virtual moving line, there is a problem that the processing process of the through hole becomes longer, and as explained in FIG. 1, there is a problem that the inner surface roundness of the finally formed through hole (H2) is reduced due to the crack area (M2) present in each deformation part (M) whenever the laser beam is irradiated. Prior art literature

[0011] Korean Registered Patent Publication No. 2205333 (Published Jan. 21, 2021) The problem to be solved

[0012] The objective of the present invention to solve the above-mentioned problems is to provide a method for processing through holes in a glass substrate that can significantly improve the processing quality of the through holes while having an excellent process yield.

[0013] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0014] One embodiment of the present invention for solving the above-mentioned problem provides a method for processing a glass substrate through hole, comprising: a deformation part forming step of applying a laser shot to a processing area of ​​a glass substrate to form a through hole to form a deformation part in the processing area; and a through hole forming step of immersing the glass substrate in an etching solution to form a through hole corresponding to the processing area while etching away the deformation part, wherein the deformation part forming step comprises a first deformation part forming step of applying a first laser shot to a part of the processing area to form a first deformation part, and a second deformation part forming step of applying a second laser shot to another part of the processing area to form a second deformation part.

[0015] In one embodiment of the present invention, the first deformation portion may include a central deformation area formed corresponding to the spot size of the first laser shot, and a peripheral defect area that propagates from the central deformation area to a peripheral area and forms a microcrack inside the area to be processed.

[0016] In one embodiment of the present invention, when the peripheral defect region is positioned on a virtual straight line passing through the center of the central deformation region, the first deformation part and the second deformation part may be positioned spaced apart in a normal direction to the virtual straight line.

[0017] In one embodiment of the present invention, a third deformation part forming step may be further included, wherein a third laser shot is applied to another part of the processing area to form a third deformation part.

[0018] In one embodiment of the present invention, among the first laser shot, the second laser shot, and the third laser shot, the laser shot applied to an area adjacent to the center of the area to be processed has a first intensity, and the laser shot applied to an area spaced apart from the center of the area to be processed has a second intensity, and the first intensity may be stronger than the second intensity. Effects of the invention

[0019] According to the present invention, by creating a multi-deformed portion in a processing area by considering the creation pattern of a crack defect area and removing the created multi-deformed portion in a complex manner during the etching process, the processing quality of the intended through-hole can be significantly improved.

[0020] According to the present invention, by optimizing the number of laser shots for each size of the target through-hole, the process yield can be significantly increased.

[0021] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention. Brief explanation of the drawing

[0022] Figure 1 is an example diagram of a process for machining through holes in a conventional glass substrate. Figure 2 is an example of another process for processing through holes in a conventional glass substrate. FIG. 3 is a block flowchart of a method for processing through-holes in a glass substrate according to an embodiment of the present invention. FIG. 4 is a process example diagram of a method for processing through-holes in a glass substrate according to an embodiment of the present invention. FIG. 5 is an example diagram showing the process of forming a final through hole through an etching process for the first deformation part and the second deformation part. FIG. 6 is an enlarged example of the first deformation part and the second deformation part of FIG. 4. FIG. 7 is a modified example of the deformation part formation step according to one embodiment of the present invention. FIG. 8 is another modified example of the deformation part forming step according to one embodiment of the present invention. Figure 9 is a drawing showing the geometric tolerance of a through hole obtained through a conventional processing method. FIG. 10 is a drawing showing the geometric tolerance of a through hole obtained through the processing method of the present invention. Specific details for implementing the invention

[0023] The present invention will be described below with reference to the attached drawings. Of course, the present invention is not limited to the embodiments described herein and may be implemented in various different forms not illustrated. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0024] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0025] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Additionally, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "comprising," "having," and "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0027] FIG. 3 is a block flowchart of a method for processing a through-hole in a glass substrate according to an embodiment of the present invention, FIG. 4 is a process example diagram of a method for processing a through-hole in a glass substrate according to an embodiment of the present invention, FIG. 5 is an example diagram showing the process of forming a final through-hole by undergoing an etching process for a first deformation part and a second deformation part, and FIG. 6 is an enlarged example diagram of the first deformation part and the second deformation part of FIG. 4.

[0028] Referring to FIGS. 3 to 6, a method for processing a through-hole in a glass substrate according to one embodiment of the present invention includes a step of forming a deformed part (S10) and a step of forming a through-hole (S20).

[0029] The deformation part formation step (S10) is a step of forming a deformation part in the processing area (PA) of the glass substrate (1) to be formed with a through hole (70) by applying a laser shot to the processing area (PA).

[0030] The through-hole formation step (S20) is a step of forming a through-hole (70) corresponding to a processing area (PA) by immersing a glass substrate (1) with a deformed portion formed thereon in an etching solution so that the deformed portion is etched away.

[0031] The deformation part forming step (S10) may include a first deformation part forming step (S11) and a second deformation part forming step (S12).

[0032] The first deformation part formation step (S11) is a step of forming the first deformation part (10) by applying a first laser shot to a part of the processing area (PA).

[0033] The first deformation part (10) may have a first central deformation area (11) and a first peripheral defect area (12).

[0034] The first central deformation region (11) may correspond to a deformation region formed corresponding to the spot size of the first laser shot. That is, when thermal energy of the laser is applied to the glass substrate, the physical and chemical properties of the glass substrate change, such as a change in phase or a change in molecular bonding structure. Ultimately, the first central deformation region (11) may correspond to a region where direct physical and chemical changes occur in the material of the glass substrate due to the first laser shot.

[0035] The first peripheral defect region (12) may correspond to a defect region that propagates from the first central deformation region (11) to the peripheral region. The defect may be a microcrack. That is, when a first laser shot is applied to the glass substrate (1) to form the first central deformation region (11), a defect such as a microcrack may be formed at the boundary between the region where the energy density of the first laser shot reaches and the peripheral region where the energy density of the first laser shot does not reach.

[0036] This first peripheral defect region (12) can be formed with a symmetrical structure with respect to the center of the first central deformation region (11) due to the characteristics of the glass substrate (1), which is an amorphous solid, and can be extended by propagating parallel to a virtual straight line (VL1) passing through the center of the first central deformation region (11).

[0037] The second deformation part formation step (S12) is a step of forming a second deformation part (20) by applying a second laser shot to another part of the processing area (PA).

[0038] The second deformation part (20) may have a second central deformation area (21) and a second peripheral defect area (22).

[0039] The second central deformation region (21) may correspond to a deformation region formed to correspond to the spot size of the second laser shot.

[0040] The second peripheral defect region (22) may correspond to a defect region that propagates from the second central deformation region (21) to the surrounding region. This second peripheral defect region (22) may also be formed with a symmetrical structure based on the center of the second central deformation region (21) due to the characteristics of the glass substrate, and may be extended by propagating parallel to a virtual straight line (VL2) passing through the center of the second central deformation region (21).

[0041] Here, the first deformation part (10) and the second deformation part (20) can be spaced apart in the normal (NL) direction to the virtual straight line (VL1)(VL2) so as not to overlap within the processing area (PA).

[0042] Afterwards, when the glass substrate (1) on which the first deformation part (10) and the second deformation part (20) are formed in the through-hole formation step (S20) is immersed in an etching solution, the first deformation part (10) and the second deformation part (20) are etched away, and a through-hole (70) corresponding to the processing area (PA) can be formed.

[0043] To elaborate, as shown in FIG. 5, the first deformation part (10) having a first peripheral defect area (12) together with a first central deformation area (11) during etching can be etched away in an elliptical shape having a major axis extending parallel to the first peripheral defect area (12).

[0044] In addition, as shown in FIG. 5, the second deformation part (20), which has a second peripheral defect area (22) along with a second central deformation area (21) during etching, can also be etched and removed in an elliptical shape having a major axis that extends parallel to the second peripheral defect area (22).

[0045] As a result, the first deformation part (10) and the second deformation part (20) are combined by etching and removing them, thereby forming a circular through hole (70) that exactly matches the intended circular processing area (PA).

[0046] FIG. 7 is a modified example of the deformation part formation step according to one embodiment of the present invention.

[0047] Referring to FIG. 7, the deformation part forming step (S10) according to the present embodiment may further include a third deformation part forming step.

[0048] The third deformation part formation step is a step of forming a third deformation part (30) by applying a third laser shot to another part of the processing area (PA) that does not overlap with the first deformation part (10) and the second deformation part (20).

[0049] In this way, the number of multiple deformable parts can be adjusted according to the diameter of the target through hole (70). That is, the number of deformable parts can be increased in proportion to the diameter of the through hole (70).

[0050] In addition, the number of multiple deformable parts can be adjusted according to the intensity of the laser shot used. That is, if the intensity of the laser shot increases, the number of deformable parts may decrease, and if the intensity of the laser shot decreases, the number of deformable parts may increase.

[0051] Additionally, the spacing between multiple deformation parts may be adjusted according to the intensity of the laser shot used. That is, if the intensity of the laser shot increases, the spacing between adjacent deformation parts in the normal (NL) direction may widen, and conversely, if the intensity of the laser shot decreases, the spacing between adjacent deformation parts in the normal (NL) direction may narrow.

[0052] FIG. 8 is another modified example of the deformation part forming step according to one embodiment of the present invention.

[0053] Referring to FIG. 8, according to the present embodiment, the intensities of a plurality of laser shots applied to a processing area (PA) to form a plurality of deformation parts may be different from each other.

[0054] Specifically, a laser shot applied to the area to form a fourth deformation part (40) adjacent to the center of the processing area (PA) may have a first intensity.

[0055] In addition, the laser shot applied to the area to form the fifth deformation part (50) spaced apart from the center of the processing area (PA) may have a second intensity smaller than the first intensity.

[0056] Accordingly, the fourth deformed part (40) to which a laser shot of relatively high intensity is applied can have a long length (42L) of the fourth peripheral defect area (42) formed along with a fast etching speed in the fourth central deformed area (41). Then, during the etching process, the fourth deformed part (40) can be etched and removed in an elliptical shape having a relatively long major axis.

[0057] On the other hand, the fifth deformation part (50) to which a laser shot of relatively weak intensity is applied may have a short length (52L) of the fifth peripheral defect area (52) along with a slow etching rate in the fifth central deformation area (51). Then, during the etching process, the fifth deformation part (50) may be etched away in an elliptical shape having a relatively short major axis.

[0058] As a result, when etching, the fourth deformation part (40) and the fifth deformation part (50) are etched away in combination, thereby forming a circular through hole (70) that matches the intended circular processing area (PA).

[0059] FIG. 9 is a drawing showing the geometric tolerance of a through hole obtained through a conventional processing method, and FIG. 10 is a drawing showing the geometric tolerance of a through hole obtained through the processing method of the present invention.

[0060] First, as shown in Fig. 9, according to the conventional processing method, when a laser beam is irradiated to create a deformation area corresponding to the target through-hole, the surrounding defect area propagates into the interior of the glass substrate while forming a symmetrical structure with respect to the center of the central deformation area. Consequently, it can be observed that a through-hole with a large deviation (△) between the maximum and minimum diameters is formed after etching. To elaborate, when a laser beam is irradiated onto the glass substrate to create a deformation area, the surrounding defect area tends to extend by propagating in the 45-degree and 225-degree directions with respect to the center of the central deformation area. Accordingly, it can be observed that the processing precision is significantly reduced, such as the through-hole being formed in an elongated elliptical shape in the 45-degree and 225-degree directions after etching. It can be confirmed that this geometric tolerance has a consistent pattern regardless of the size of the through-hole.

[0061] On the other hand, as shown in FIG. 10, according to the present invention, when a laser beam is irradiated to create a deformation portion corresponding to a desired through-hole, considering that the peripheral defect region propagates into the interior of the glass substrate while forming a symmetrical structure with respect to the center of the central deformation region, a plurality of deformation portions are created spaced apart along the normal direction to the direction in which the peripheral defect region propagates, thereby allowing for the formation of a through-hole with a small deviation (△) between the maximum and minimum diameters after etching. To elaborate, when a laser beam is irradiated onto a glass substrate to create a deformation portion, the peripheral defect region tends to propagate and extend in the 45-degree and 225-degree directions with respect to the center of the central deformation region, thereby creating a plurality of deformation portions spaced apart along the 135-degree and 315-degree directions. Accordingly, a desired circular through-hole can be formed after etching.

[0062] The method described above is depicted as a series of numbered steps for clarity, but the numbering does not specify the order of each step. Some of these steps may be skipped, performed in parallel, or executed without strictly maintaining a sequential order. However, generally, the above method proceeds according to the numbered order of the indicated steps.

[0063] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0064] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0065] 1: Glass substrate 10: First deformation part 11: First central deformation zone 12: First peripheral defect area 20: Second deformation part 21: First central deformation zone 22: First peripheral defect area PA: Planned processing area 70: Through hole

Claims

Claim 1 A deformation part forming step of applying a laser shot to a processing area of ​​a glass substrate to be formed with a through hole to form a deformation part in said processing area; The method includes a through-hole forming step in which the glass substrate is immersed in an etching solution to etch and remove the deformed portion while forming a through-hole corresponding to the area to be processed, wherein the deformed portion forming step includes a first deformed portion forming step in which a first laser shot is applied to a part of the area to be processed to form a first deformed portion, and a second deformed portion forming step in which a second laser shot is applied to another part of the area to be processed to form a second deformed portion, wherein the first deformed portion includes a first central deformed portion formed corresponding to the spot size of the first laser shot, and a first peripheral defect portion that propagates from the first central deformed portion to a surrounding area and forms a microcrack inside the area to be processed, and the second deformed portion includes a second central deformed portion formed corresponding to the spot size of the second laser shot, and a second peripheral defect portion that propagates from the second central deformed portion to a surrounding area and forms a microcrack inside the area to be processed. A method for processing a through-hole in a glass substrate, comprising: a first peripheral defect area being positioned on a first virtual straight line (VL1) passing through the center of the first central deformation area, and a second peripheral defect area being positioned on a second virtual straight line (VL2) passing through the center of the second central deformation area; wherein the first deformation part and the second deformation part are spaced apart in a normal direction to the first virtual straight line (VL1) and the second virtual straight line (VL2); wherein the center of the second central deformation area is positioned on a normal line passing through the center of the first central deformation area among the normals to the first virtual straight line (VL1); and wherein the first deformation part, which is etched away in an elliptical shape, and the second deformation part, which is etched away in an elliptical shape, are etched away in a combined manner to form a circular through-hole that coincides with the circular processing area. Claim 2 delete Claim 3 delete Claim 4 A method for processing a through-hole in a glass substrate according to claim 1, further comprising a step of forming a third deformation part by applying a third laser shot to another part of the area scheduled for processing to form a third deformation part. Claim 5 A method for processing through-holes in a glass substrate according to claim 4, wherein among the first laser shot, the second laser shot, and the third laser shot, the laser shot applied to an area adjacent to the center of the area to be processed has a first intensity, the laser shot applied to an area spaced apart from the center of the area to be processed has a second intensity, and the first intensity is stronger than the second intensity.

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