KR20160009791A - Method for forming through-hole in substrate - Google Patents

Abstract

The present invention relates to a method for forming a through-hole in a substrate including: a crack formation step of forming a crack in a certain depth from the surface of the substrate by emitting a laser beam along a plurality of first closed curves, which are in the same shapes as a cut guiding line of the through hole and in the different sizes smaller than the size of the cutting guide line, and a cut guiding line and sequentially moving from the first closed curve in a small size to the first closed curve in a large size and to the cut guiding line to emit the laser beam having first power; an ablation step of removing a substrate area under the crack by emitting a laser beam having second powder higher than the first power to an area where the crack has been formed; and a taper removal step of removing a taper area by emitting a laser beam to the taper area formed to protrude gradually from a cut surface of the through-hole to the down side.

Description

[0001] METHOD FOR FORMING THROUGH-HOLE IN SUBSTRATE [0002]

The present invention relates to a method of forming a through hole in a substrate, and more particularly, to a method of forming a through hole in a glass substrate used as a touch panel on a substrate using a laser beam .

The touch panel includes a flat panel display device such as an electronic notebook, a liquid crystal display device (LCD), a plasma display panel (PDP), and an electroluminescence (EL) device and an image display device such as a CRT (Cathod Ray Tube) Is a tool used for allowing a user to select desired information while viewing the image display device. It is simple and does not cause a malfunction and can be input without using a separate input device, So that it can be operated quickly and easily.

The above-mentioned touch panel is generally manufactured by using a glass substrate. In order to manufacture a speaker hole or a button hole of a touch panel, a through hole should be formed in the substrate. A mechanical method of moving a diamond cutter along a line along which a through line is to be cut in order to form a through hole in a substrate or an optical method of irradiating a laser beam L along a line along which the through- If the through holes 11 are formed by using these methods, many sharp and irregular chipping 1 may occur in the cut surface 11a of the through hole.

If the size of the chipping 1 is small, the chipping 1 may not be a big problem. However, if the size of the chipping 1 is large, It may become a starting point of propagation, causing a problem of causing a decrease in strength of the substrate and destruction of the substrate. Further, when the size of the chipping is large, a separate polishing process is required to solve the above problem, and the efficiency of the process may be lowered.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a method for manufacturing a semiconductor device, which comprises irradiating a surface of a substrate with a laser beam to form a fine crack, It is another object of the present invention to provide a substrate through hole forming method capable of improving the cutting quality of a cut surface of a through hole and reducing the size of chipping to increase the strength of the substrate and to prevent breakage of the substrate.

According to another aspect of the present invention, there is provided a method of forming a substrate through hole, the method comprising: forming a plurality of first closed curves having the same shape as the line to be cut of the through- A first closed curve of a small size and a first closed curve of a small size and a laser beam having a first power while moving sequentially to the line along which the material is to be cut are irradiated to form a crack Forming step; An ablation step of irradiating a laser beam having a second power higher than the first power to the cracked region to remove a substrate region under the crack; And a taper removing step of irradiating a laser beam to the tapered region formed so as to protrude downward from the cut surface of the through hole to remove the tapered region.

According to another aspect of the present invention, there is provided a method of forming a substrate through hole for forming a through hole in a substrate, the method comprising the steps of: forming a through- A first closed curve of a small size and a first closed curve of a large size and a first power having a first power while moving sequentially to a first closed curve and a line to be cut along a predetermined closed line, A crack forming step of irradiating a laser beam to form a crack at a predetermined depth from the surface of the substrate; And a second laser beam having a second power higher than the first power is sequentially irradiated to each of the divided sub through holes to sequentially form the sub through holes An ablation step of sequentially removing regions; And a taper removing step of irradiating a laser beam to the tapered region formed so as to protrude downward from the cut surface of the through hole to remove the tapered region.

In the method of forming a substrate through hole according to the present invention, the moving speed of the laser beam in the crack forming step may be slower than the moving speed of the laser beam in the ablation step.

In the method of forming a substrate through hole according to the present invention, the ablation step may include irradiating a laser beam along a plurality of second closed curves having the same shape as the line along which the object is intended to be cut, A first ablation step of irradiating a laser beam while sequentially moving from a second closed curve to a second closed curve of a small size; a second ablating step of sequentially irradiating a laser beam while moving from a second closed curve of a small size to a second closed curve of a large size; And a second ablation step to be performed.

In the method of forming a substrate through hole according to the present invention, the ablation step may change the focal position of the laser beam along the depth direction of the substrate.

In the method of forming a substrate through hole according to the present invention, the taper removing step may include irradiating a laser beam along a third closed curve having the same shape as the line to be cut and smaller than the line to be cut and intersecting the lower end of the tapered area, A first taper removing step of removing a lower end of the region; And a second taper removing step of removing a central portion of the tapered region by irradiating a laser beam along a fourth closed curve which is the same shape as the line to be cut and is smaller than the line to be cut and which is larger than the third closed curve and crosses the central portion of the tapered region, ; ≪ / RTI >

The method of forming a substrate through hole according to the present invention can reduce the size of chipping, increase the strength of the substrate, and prevent breakage of the substrate.

Further, the method of forming the substrate through hole according to the present invention can improve the cutting quality of the cut surface of the through hole.

In addition, the method of forming a substrate through hole according to the present invention can perform the processing compatible with the through holes having various shapes and sizes.

1 is a view showing a cross section of a through hole formed by a conventional method of forming a substrate through hole,
2 is a view showing a crack forming step of a method of forming a substrate through hole according to an embodiment of the present invention,
FIG. 3 is a view showing an ablation step of the method of forming the substrate through hole of FIG. 2,
4 is a view showing a taper removing step of the method of forming the substrate through hole of FIG. 2,
5 is a view showing an ablation step of a method of forming a substrate through hole according to another embodiment of the present invention.

Hereinafter, embodiments of a method of forming a substrate through hole according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a view showing a crack forming step of the method of forming a substrate through hole according to an embodiment of the present invention, FIG. 3 is a view showing an ablation step of the method of forming a substrate through hole of FIG. 2, 2 is a view showing a taper removing step of the method of forming a substrate through hole shown in Fig. 2; Fig.

Referring to FIGS. 2 to 4, the method of forming a substrate through hole according to the present embodiment is for forming a through hole in a glass substrate used as a touch panel, for example, using a laser beam, Forming step, an ablation step, and a taper removing step.

In the substrate through hole forming method of this embodiment, a galvanometer scanner can be used to move the laser beam to a desired position. The laser beam output from the laser output unit is transmitted to the substrate through a galvanometer scanner composed of a mirror and a rotary motor to move the laser beam along a desired path.

The crack forming step irradiates the laser beam L having the first power along the plurality of first closed lines A1a and A1b and the line along which the material is to be cut CL to form cracks (12).

Referring to FIG. 2, a plurality of first closed curves A1a and A1b serving as paths through which the laser beam L is irradiated are provided in the same shape as the line along which the object is to be cut CL of the through hole. For example, if the shape of the through hole to be formed in the substrate 10 is an elliptical shape, the first closed lines A1a and A1b are also provided in the shape of an ellipse having the same shape as the line along which the object is to be cut CL of the through hole.

In addition, the plurality of first closed curves A1a and A1b are smaller than the line along which the object is intended to be cut CL and are provided in different sizes. Although two first closed lines A1a and A1b provided at different sizes are shown as an example in FIG. 2, the number of first closed lines may be three or more.

In a state where the path through which the laser beam L is irradiated is defined as described above, the first closed curve A1b and the line along which the object is intended to be cut are sequentially moved from the small first closed curve A1a to the first large closed curve A1b, A crack 12 is formed at a certain depth from the surface of the substrate 10 by irradiating the laser beam L having a power. A crack 12a having the same shape as the first closed curve A1a of a small size is formed by the laser beam L irradiated along the small first closed curve A1a and the first closed curve A1b of the large size is formed by the laser beam L irradiated along the small first closed curve A1a, A crack 12b having the same shape as that of the first closed curve A1b of a large size is formed by the laser beam L irradiated along the cutting line CL, CL are formed in the same shape as the crack 12c. Each of the cracks 12a, 12b, and 12c is formed such that the edge portions thereof partially overlap each other.

The size of the chipping generated in the substrate 10 by the laser beam L is relatively large in the crack 12a corresponding to the first closed curve A1a of the small size irradiated with the laser beam first, The size of the chipping generated in the substrate by the laser beam L is relatively small in the cracks 12b and 12c corresponding to the large first closed curve A1b and the line along which the object is intended to be cut CL to be irradiated. When the laser beam L is irradiated on the surface of the smooth substrate 10 on which no cracks are formed, the initial impact transmitted to the substrate 10 is large and the size of chipping generated in the substrate 10 is relatively large, When the laser beam L is irradiated to the surface of the substrate 10 adjacent to the crack in the state where the crack is already formed, the impact transmitted to the substrate 10 becomes relatively small, and the size of the chipping Is relatively small.

Even if the size of the chipping is large in the crack 12a formed by the laser beam L irradiated along the first closed curve A1a of a small size in the state where the through hole 11 is formed in the future, Is a portion to be discarded, so that even if the size of the chipping is large, it is no problem. A portion corresponding to the cut surface of the through hole is a crack 12c formed by the laser beam L irradiated along the line along which the material is to be cut CL and in order to reduce the size of chipping generated in the crack 12c portion The laser beam L is first irradiated along the predetermined curved line CL along a plurality of first closed curves A1a and A1b having a size smaller than the line along which the material is to be cut CL as described above, By later examination, the size of the chipping in the crack 12c corresponding to the line along which the object is intended to be cut CL is made small.

The ablation step irradiates the laser beam L having the second power higher than the first power to the region where the crack 12 is formed to remove the substrate region under the crack 12. The substrate portion under the crack 12 is removed by irradiating the laser beam L having a power enough to melt the material of the substrate 10 so that the substrate portion corresponding to the inner region of the through hole 11 19 may be separated from the rest of the substrate.

The ablation step of this embodiment is a method of melting the substrate region under the crack 12 by repeatedly irradiating the substrate 10 with the laser beam L through the first ablation step and the second ablation step .

The first ablation step irradiates the laser beam L along a plurality of second closed curves A2a and A2b having the same shape as the line along which the material is to be cut CL and which are smaller than the line along which the material is to be cut CL and have different sizes. At this time, the laser beam L is irradiated while moving sequentially from the second closed curve A2a having a large size to the second closed curve A2b having a small size. Since the laser beam L is sequentially moved to the small first closed curve A1a, the first large closed curve A1b and the to-be-cut line CL in the previous crack formation step, Since the sequential movement from the second closed curve A2a to the second closed curve A2b of small size sequentially moves from the second closed curve A2b of small size to the second closed curve A2a of large size, The total machining time can be shortened.

Then, in the second ablation step, the laser beam L is irradiated while moving sequentially from the second closed curve A2b of a small size to the second closed curve A2a of a large size. In this manner, the first ablation step and the second ablation step are repeatedly performed to melt and remove the substrate region under the crack 12.

Since the substrate area under the crack 12 gradually melts during the ablation step, it is effective to change the focal position of the laser beam L along the depth direction B1 of the substrate, And the like. 3, in the initial stage of melting the substrate region under the crack 12, the focal position of the laser beam L is adjusted to the first position f1 to melt the substrate region under the crack 12 The focal position of the laser beam is adjusted to the second position f2 positioned below the first position f1 after the upper region of the substrate region under the crack 12 is melted to some extent, The area can be melted.

On the other hand, it is preferable that the moving speed v1 of the laser beam in the crack forming step is set to be slower than the moving speed v2 of the laser beam in the ablation step. If the movement speed of the laser beam moved along the first closed lines A1a and A1b and the line along which the material is to be cut CL is excessively fast in the crack formation step, the size of the chipping can be relatively large. When the moving speed is high, the power must be set high, so that the impact transmitted to the substrate 10 becomes larger, and the size of the chipping can be increased. Therefore, it is preferable to set the moving speed and power of the laser beam L as low as possible in the crack forming step.

On the other hand, since the laser beam L is irradiated to the crack 12 that has already been formed in the ablation step, the relationship between the moving speed v2 of the laser beam in the ablation stage and the chipping size is not large. Therefore, it is preferable to set the moving speed v2 of the laser beam in the ablation step to be faster than the moving speed v1 of the laser beam in the crack forming step in order to shorten the entire processing time.

The taper removing step irradiates a laser beam (L) to a tapered area (13) formed so as to protrude downward from a cut surface of the through hole to remove the tapered area (13). The cut surface of the through hole can be flattened along the depth direction B1 of the substrate through the taper removing step. The taper removing step of this embodiment sequentially removes the tapered area 13 through the first taper removing step and the second taper removing step.

The first taper removing step irradiates the laser beam L along the third closed curve A3 which is the same shape as the line along which the material is to be cut CL and which is smaller than the line to be cut CL and intersects with the lower end 13a of the tapered area , And the lower end portion 13a of the tapered region is removed. The lower end portion 13a of the tapered region 13 is formed so as to protrude most toward the inside of the through hole 11 because the tapered region 13 is formed to protrude downward from the cut surface of the through hole. Accordingly, in the first taper removing step, the laser beam L is irradiated to the lower end portion 13a of the tapered region formed to protrude most toward the inside of the through hole 11 to remove it.

The second taper removing step has a fourth closed curve A4 which is the same shape as the line along which the object is intended to be cut CL and which is smaller than the line to be cut CL and which is larger than the third closed curve A3 and crosses the central portion 13b of the tapered area, The central portion 13b of the tapered region is removed. After the lower end portion 13a of the tapered region is removed, the laser beam L is irradiated to the central portion 13b of the tapered region formed so as to protrude toward the inside of the through hole 11 in order to remove it.

By sequentially performing the first taper removing step and the second taper removing step, it is possible to process the cut surface 11a of the through hole 11 close to a substantially flat shape along the depth direction B1 of the substrate. In addition, by sequentially removing the lower end portion 13a of the tapered region and the central portion 13b of the tapered region, chipping that may occur in the cut surface 11a of the through hole 11 upon removal of the tapered region 13 can be minimized have.

5 is a view showing an ablation step of a method of forming a substrate through hole according to another embodiment of the present invention. In Fig. 5, the members denoted by the same reference numerals as those shown in Figs. 2 to 4 have the same configuration and function, and a detailed description thereof will be omitted.

In the substrate through hole forming method of this embodiment, the crack forming step and the taper removing step are substantially the same as those in the embodiment shown in FIGS. 2 to 4, and thus a duplicated description will be omitted.

5, the ablation step of this embodiment is a step of dividing the region where the through-hole 11 is to be formed into a plurality of sub-through-hole regions 20a and 20b, The sub through hole regions 20a and 20b are sequentially removed by sequentially irradiating the beams. At this time, the laser beam irradiated to each of the divided sub through hole regions 20a and 20b has a second power higher than the first power.

The sub through holes 20a and 20b mean subracks 22a and 22b in which the crack 12 formed by the crack forming step is divided and subracks 22a and 22b surrounded by the sub cracks 22a and 22b And the regions 29a and 29b corresponding to the inside of the sub cracks 22a and 22b and having no crack 12 formed on the surface thereof.

When the shape of the through hole 11 is elliptical and the ratio of the major axis to the minor axis is a certain range or more and the through hole 11 is formed too long in the major axis direction (for example, the ratio of major axis to minor axis is 7: (For example, when the minor axis is 1 mm or less), the laser beam L is irradiated to the entire area where the crack 12 is formed as shown in FIG. 3 to perform the ablation step As a result, there arises a problem that a difference in thermal stress occurs excessively at a local position and breaks at an intermediate portion of a region where the through hole 11 is to be formed.

In order to solve such a problem, the region where the through hole 11 is to be formed is divided into a plurality of sub through hole regions 20a and 20b, and the sub through hole regions 20a and 20b are sequentially subjected to an ablation It is preferable to perform the step.

For example, as shown in Fig. 5, the region where the through-hole 11 is to be formed is divided into two sub-through-hole regions 20a and 20b, and one sub- . 3, only the substrate region under the crack 12 is removed. In this embodiment, the substrate region 29a inside the sub-crack 22a as well as the substrate region under the sub-crack 22a are removed. . When the short axis of the elliptical shape is too short, it is preferable that the substrate area 29a inside the sub crack 22a is also affected by the laser beam when the substrate area under the sub crack 22a is removed .

The laser beam L is moved along the zigzag path C1 along one sub through hole region 20a in the process of performing the ablation step on one sub through hole region 20a, Step can be performed. In the case of the substrate area 29a on the inner side of the sub crack 22a, a crack can not be formed and the size of the chipping can be increased when the laser beam L is irradiated. However, It is a part that is discarded corresponding to the inside of the hole 11, so that even if the size of the chipping is large, there is no problem.

When the ablation step for one sub through hole region 20a is completed, the above-described ablation step for the other sub through hole region 20b is performed. At this time, in the process of performing the ablation step with respect to the other sub through hole area 20b, the laser beam L is applied along the zigzag path C2 to the entire other sub through hole area 20b And the ablation step can be performed while moving. Likewise, the size of the chipping can be largely formed in the substrate area 29b inside the sub crack 22b. However, in the state where the through hole 11 is formed in the future, since it is a portion corresponding to the inside of the through hole 11, It is not a problem even if the size is large.

By thus dividing the region in which the through hole 11 is to be formed into a plurality of sub through hole regions 20a and 20b and performing the ablation step on each of the sub through hole regions 20a and 20b, The through hole 11 can be formed without damaging the substrate 10 at the time of processing the through hole 11 in which the length of the major axis is longer than a certain range or the through hole 11 in which the length of the minor axis is too short.

The moving speed of the laser beam in the ablation stage of this embodiment is also faster than the moving speed of the laser beam in the crack forming stage and the ablation stage of this embodiment also changes the focal position of the laser beam along the depth direction of the substrate.

In the method of forming a substrate through hole of the present invention configured as described above, a laser beam is irradiated to a surface of a substrate to form a fine crack, and then a laser beam is irradiated to a cracked region again to ablate the substrate, It is possible to reduce the size and increase the strength of the substrate and to prevent the breakage of the substrate.

In addition, in the method of forming a substrate through hole of the present invention constructed as described above, the laser beam is irradiated to the tapered region formed in the cut surface of the through hole to remove the laser beam, whereby the cutting quality of the cut surface of the through hole can be improved .

The substrate through hole forming method of the present invention configured as described above is a method of forming a through hole by dividing a region where a through hole is to be formed into a plurality of sub through hole regions and sequentially performing an ablation step thereon, It is possible to obtain an effect that the machining can be performed with respect to the through hole in an interchangeable manner.

The scope of the present invention is not limited to the above-described embodiments and modifications, but can be implemented in various forms of embodiments within the scope of the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

10: substrate
11: Through hole
12: crack
13: Tapered area
A1a, A1b: first closed curve
CL: Line to be cut
L: laser beam

Claims (6)

A method of forming a substrate through hole for forming a through hole in a substrate,
A plurality of first closed lines having the same shape as the line to be cut of the through-hole and smaller than the line to be cut and having different sizes and a laser beam to be irradiated along the line to be cut, the first closed curve having a large size in a small closed first closed curve, A crack forming step of irradiating a laser beam having a first power while sequentially moving to the line along which the object is intended to be cut so as to form a crack at a predetermined depth from the surface of the substrate;
An ablation step of irradiating a laser beam having a second power higher than the first power to the cracked region to remove a substrate region under the crack; And
And a taper removing step of irradiating a laser beam to a tapered region formed so as to protrude downward from a cut surface of the through hole to remove the tapered region. A method of forming a substrate through hole for forming a through hole in a substrate,
A plurality of first closed lines having the same shape as the line to be cut of the through-hole and smaller than the line to be cut and having different sizes and a laser beam to be irradiated along the line to be cut, the first closed curve having a large size in a small closed first closed curve, A crack forming step of irradiating a laser beam having a first power while sequentially moving to the line along which the object is intended to be cut so as to form a crack at a predetermined depth from the surface of the substrate;
And a second laser beam having a second power higher than the first power is sequentially irradiated to each of the divided sub through holes to sequentially form the sub through holes An ablation step of sequentially removing regions; And
And a taper removing step of irradiating a laser beam to a tapered region formed so as to protrude downward from a cut surface of the through hole to remove the tapered region. 3. The method according to claim 1 or 2,
Wherein the moving speed of the laser beam in the crack forming step is slower than the moving speed of the laser beam in the ablation step. The method according to claim 1,
Wherein the ablation step comprises:
Irradiating a laser beam along a plurality of second closed curves having the same shape as the line to be cut and smaller than the line to be cut and having different sizes,
A first ablation step of irradiating a laser beam while sequentially moving from a second closed curve of a large size to a second closed curve of a small size, and a second ablating step of sequentially moving the second closed curve from the second closed curve of a small size to the second closed curve of a small size, And a second ablation step of irradiating the substrate with the beam. 3. The method according to claim 1 or 2,
Wherein the ablation step changes the focal position of the laser beam along the depth direction of the substrate. 3. The method according to claim 1 or 2,
Wherein the taper-
A first taper removing step of removing the lower end of the tapered area by irradiating a laser beam along a third closed curve having the same shape as the line to be cut and smaller than the line to be cut and intersecting the lower end of the tapered area; And
Removing a center portion of the tapered region by irradiating a laser beam along a fourth closed curve having the same shape as the line to be cut and smaller than the line to be cut and larger than the third closed curve and intersecting the center of the tapered region; And forming a through hole on the substrate.

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