JP2009269057A - Laser beam machining method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress damage and the like as little as possible and to efficiently perform highly accurate machining in drilling or gouging a thin plate. <P>SOLUTION: Drilling of a round hole 30 is performed on a thin glass plate 12. A laser beam L is scanned quadruply in order of scanning lines 42a, 42b, 42c and 42d, inside the contour 40 of the round hole 30 viewed from above, of a target as a reference, within a range of a machining width H from the contour 40 and nearly in parallel to the contour 40. By machining in such steps, the side face of the round hole 30 can be formed with high accuracy. In the case of gouging, the laser beam L is scanned multiply from the outside to the inside of a component 31 to be gouged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laser processing method and a laser processing apparatus that perform drilling and punching processing on a thin plate using laser light.

  In recent years, a thin glass plate having a thickness of 1 mm or less is used for a liquid crystal display or the like used for an FPD (flat panel display), a cellular phone, or the like. The thickness of the glass plate is further reduced as the display is made thinner, and an extremely thin plate thickness of 0.2 mm or less is also used. Furthermore, as a so-called organic EL display, a flexible display has been developed. In this case, a flexible and extremely thin film is used.

  When drilling or punching into a glass plate that is a brittle material, it may be mechanically processed with a diamond cutter, etc., but when processing a thin plate with a very thin thickness as described above, The thin plate is damaged by the mechanical stress by the cutter, and it takes a considerable time for processing.

  Patent Document 1 describes a conventional technique in which processing is performed using a pulsed YAG laser when a fine through hole is formed in a glass plate having a thickness of 1 mm. In this prior art, the high temperature generated by the YAG laser being absorbed by the glass is used to open the linear through-hole while melting the glass linearly.

JP 2000-61667 A

  By the way, in addition to the case where a simple straight through-hole is formed as in the above-described prior art, for example, when a predetermined shape is drilled in a thin plate such as a glass plate or the like, When it is desired to use a hollowed part as a product, it is required to increase the appearance quality of the cut portion and increase the processing accuracy. Moreover, in order to improve production efficiency, it is necessary to shorten processing time.

  However, in the mechanical processing method, there is a possibility that the thin plate may be damaged beyond the desired processing dimension due to the occurrence of edge chipping. In the processing method described in Patent Document 1, the thin plate exceeds the desired processing size. There is a possibility of melting, and it is difficult to obtain a desired processing shape with high accuracy by these processing methods. That is, in the processing method described in Patent Document 1, it is assumed that only a through hole is formed, and no consideration is given to performing drilling or punching into a predetermined shape.

  Furthermore, in the case of the above-described thin plate having flexibility, the processing is difficult because the material is bent during the mechanical processing, and the processing method described in Patent Document 1 obtains a desired processing dimension as described above. It is difficult.

  Furthermore, when processing a brittle material, it is difficult to extract a punched part or a remaining part from a thin plate, and cracking occurs when an excessive force is applied.

  The present invention has been made in consideration of the above-described conventional problems, and in the case of drilling or punching a thin plate, material damage is suppressed as much as possible, and highly accurate processing is highly efficient. It is an object of the present invention to provide a laser processing method and a laser processing apparatus that can be performed by the above method.

  The laser processing method according to the present invention is a laser processing method for performing drilling or hollowing on a thin plate using a laser beam, wherein the laser beam is an object obtained by the drilling or hollowing. One side with respect to the contour line of the object figure in plan view is characterized in that multiple scanning is performed in a range of a predetermined width including the contour line and substantially parallel to the contour line.

  The laser processing apparatus according to the present invention further includes a laser beam oscillation unit that oscillates a pulsed laser beam, and a laser beam emitting unit that irradiates the thin plate as a workpiece with the laser beam. The emitting means includes laser light scanning means for scanning the laser light in a predetermined pattern, and the laser light scanning means is a target object figure that is a plan view of an object obtained by punching or punching the thin plate. In other words, a plurality of scans are performed in parallel with the contour line within a predetermined width including the contour line on one side with respect to the contour line.

  In this way, by scanning the laser beam in a multiple manner substantially parallel to the contour line of the target object, damage to the material can be suppressed as much as possible, and high-precision processing can be performed with high efficiency. The thin plate is 1 mm or less. Parallel may include matching states.

  The object may be a hole, and the laser beam may be scanned in multiple directions from the inside to the outside of the hole to be processed. By processing in this order, the side surface of the hole, which is the object, can be formed with high accuracy.

  The object is a hollow part, and the laser beam may be scanned in multiple directions from the outside to the inside of the hollow part to be processed. By processing in this order, the side surface of the cut-out component that is the object can be formed with high accuracy.

  You may set the pitch of the scanning line scanned in multiple to 0.5-10 times the laser beam diameter in a condensing point.

  The laser beam may be irradiated in a pulse shape, and the pulse width may be set to 100 ps to 50 ns.

  The thin plate may be disposed substantially horizontally, and the laser light may be irradiated from the upper surface side of the thin plate and transmitted to the lower surface side, and the condensing point of the laser light may be set on the lower surface of the thin plate. As a result, the laser beam acts appropriately even at a location that is not the condensing point to promote processing.

  The laser beam may be a green laser. Since the green laser transmits almost completely through the glass, heat is not easily generated, and high-precision processing is possible by suppressing the generation of cracks.

  If the laser beam scanning means is a galvano scanner, it can irradiate laser beam at high speed and with high accuracy, so that drilling or punching can be performed at high speed and with high accuracy.

  In the laser processing method and the laser processing apparatus according to the present invention, the laser beam is scanned in multiples substantially parallel to the contour line of the target object, thereby suppressing damage to the material as much as possible and high-precision processing. Can be performed with high efficiency.

  Embodiments of a laser processing method and a laser processing apparatus according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a perspective view showing a laser processing apparatus 10 in the present embodiment. The laser processing apparatus 10 according to the present embodiment includes a control power supply unit 1, a laser oscillation unit 16 as a laser beam oscillation unit, a laser head 21 as a laser beam emission unit, an operation panel 6, a stage 18, A utility chamber 5 is provided. The utility chamber 5 accommodates power system components, circuit boards, chiller devices (not shown), and the like.

  In the basic configuration of the laser processing apparatus 10, the control power supply unit 1 mainly includes a control board (not shown) and the like, and an operation panel (for example, a keyboard and a pointing device) 6 and a display 3 are disposed around the control board. Is provided.

  As shown in FIG. 2, the laser oscillation unit 16 includes a laser oscillator 20 and an excitation unit (not shown). As the laser oscillator 20, for example, a Q switch pulse type laser oscillator can be used. In the laser processing apparatus 10, the laser light L oscillated from the laser oscillator 20 is a pulsed green laser (for example, the second harmonic wavelength is around 532 nm). The pulse width (time interval) of the laser light L is preferably set to 100 ps to 50 ns.

  The laser head 21 contains or is equipped with a galvano scanner 26 as laser beam scanning means and an fθ lens (a condensing lens having distortion characteristics) 28, and is integrally coupled to the emission port of the laser oscillation unit 16. Has been. The galvano scanner 26 has a pair of (X, Y) X mirrors 26a and Y mirrors 26b arranged orthogonal to each other. The X mirror 26a scans the laser beam L in a predetermined X direction. The Y mirror 26b scans the laser light L in the Y direction orthogonal to the X direction. By using such a galvano scanner 26, it is possible to irradiate a thin plate 12 to be described later with a laser beam L at high speed and with high accuracy, so that drilling or punching can be performed at high speed and with high accuracy. it can.

  The stage 18 is provided directly below the exit of the laser head 21. The thin plate 12 is placed substantially horizontally on the stage 18. The stage 18 is provided with receiving tools 19 so as to surround at least a region irradiated with the laser beam or on both sides of the region, as viewed in the direction of arrow A in FIG. With this receiving tool 19, the thin plate 12 is placed at a predetermined height from the surface of the stage 18, and a gap G is formed between the thin plate 12 and the stage 18. By forming this gap G, if it is drilling, the processing waste including the unprocessed part inside the hole can be reliably discharged to the lower side of the thin plate 12. On the other hand, the cut object can be received on the stage 18 if it is cut.

  In addition, it is desirable to provide the receiving device 19 with a fixing means for fixing the thin plate 12 in a fixed position. As this fixing means, for example, a vacuum suction device can be used. When using a brittle material, for example, a thin glass plate, as the thin plate 12, the vacuum suction device can reliably fix the glass plate without damaging it. As shown in FIG. 3, the thin plate 12 of the present embodiment is a glass plate for liquid crystal, for example, and has a thickness of 0.2 mm.

  In the laser processing apparatus 10 of the present embodiment, the pulsed laser light L oscillated and output from the laser oscillator 20 has a reflection angle corresponding to each rotation angle (deflection angle) of the X mirror 26a and the Y mirror 26b in the laser head 21. After being sequentially reflected, the light passes through the fθ lens 28 and is emitted substantially vertically downward. The emitted laser light L travels straight in the air as it is, and is condensed at a predetermined position of the thin plate 12 on the stage 18 to perform desired processing.

  As shown in FIG. 1, the stage 18 can be an XY stage that can be moved and positioned in the XY directions within a horizontal plane. In this way, the XY stage 18 can be used as means for controlling the position at which the thin plate 12 is irradiated with the laser light L instead of or in addition to the galvano scanner 26.

  In the laser processing apparatus 10, the thin plate 12 is cut out, and a hollow part 31 can be obtained as an object as shown in FIG. 4A.

  Further, in the laser processing apparatus 10, the thin plate 12 can be drilled to obtain a round hole 30 as shown in FIG. 4B or a long hole 32 as shown in FIG. 4C as an object. The number of objects (that is, the cutout part 31, the round hole 30, the long hole 32, etc.) obtained from the thin plate 12 may be one or plural.

  Next, a laser processing method performed using the laser processing apparatus 10 will be described in detail. First, the drilling process of the round hole 30 will be described.

  As shown in FIG. 5, in the drilling process of the round hole 30, the process includes the contour line 40 on the inner side with respect to the contour line 40 of the target object figure in plan view of the target object (that is, the round hole 30). In a range of a width (predetermined width) H, the laser beam L is scanned four times in parallel with the contour line 40. The processing width H is represented by H = (N−1) × P. Here, N is the number of scanning lines 42 (N = 4), and P is the pitch of the scanning lines 42. The first to fourth scanning lines 42 are shown separately as scanning lines 42a, 42b, 42c and 42d.

  When the object to be processed is a hole (round hole 30), the laser light L is scanned in multiple directions from the inside to the outside of the hole to be processed. That is, the fourth scanning line 42 d coincides with the contour line 40. In order to emphasize this, in FIG. 5, the scanning line 42d is indicated by a bold line.

  By processing in this order, the side surface of the hole, which is the object, can be formed with high accuracy.

  Depending on the design conditions, the scanning order of the scanning lines 42a, 42b, 42c, and 42d may be changed as appropriate. For example, the scanning order may be reversed, or the scanning line 42b or 42c may be scanned first.

  The scanning line N may be set to 2 or more (that is, multiple), and for example, about 3 ≦ N ≦ 10 is preferable. The pitch P of the scanning lines 42 to be scanned in multiples is preferably set to 0.5 to 10 times the diameter of the laser beam (see FIG. 6) at the condensing point 44 (see FIG. 6).

  The figure scanned and surrounded by the scanning lines 42a, 42b, and 42c is similar to the outline 40, and the center (the center of gravity when the target is non-circular) is made coincident, and each scanning line 42 is made substantially parallel. Good.

  In this way, by scanning multiple laser beams in parallel to the contour line 40 of the target object, it is possible to suppress damage to the material as much as possible, and to perform highly accurate processing with high efficiency.

  As shown in FIG. 6, the laser light L is pulsed and may be irradiated so that the adjacent condensing points 44 overlap each other. The laser light L at the condensing point 44 is equal to or longer than the laser light diameter r (based on the diameter). If 50% or more) overlap, it is preferable that sufficiently continuous scanning is performed. As described above, the pulse width (time interval) of the laser light L may be set to 100 ps to 50 ns.

  As shown in FIG. 7, the laser beam L is irradiated from the upper surface 12a side of the thin plate 12 and transmitted to the lower surface 12b side. At this time, the condensing point 44 of the laser beam L may be set according to the lower surface 12b of the thin plate 12. If it carries out like this, laser processing will progress in the area | region of the thin plate 12 with which the laser beam L is irradiated, and the processing waste of the thin plate 12 will be discharged | emitted from the upper surface 12a side of the thin plate 12. FIG.

The principle of laser processing in this embodiment can be estimated as follows. Under the influence of impurities and defects contained in the thin plate 12, absorption and multiphoton absorption (peak value ≧ 10 GW / cm ² ) occur in the laser beam passage portion, and microcracks are formed there. The unevenness or roughness of the crack surface absorbs the laser beam L, and the crack portion generates heat to perform processing.

  In the present embodiment, since processing is performed using a green laser (wavelength of 532 nm), which is a transparent laser beam, on the glass that is the material of the thin plate 12, no excessive heat generation or ablation occurs. Thereby, the through-hole 46 shown by the imaginary line is actually formed without cracking due to thermal strain or the like.

  Such a through hole 46 is formed along the scanning line 42, and is linked with the through hole 46 in another adjacent scanning line 42 to form one round hole 30. The through hole 46 does not have to penetrate completely, and it is sufficient that the through hole 46 is linked together and the inside of the round hole 30 can be removed. For example, a minute crack or the like that does not affect the processing accuracy. May be included. The through hole 46 is exaggerated.

  Thus, by performing quadruple scanning using the laser light L, conceptually, as shown in FIG. 8, four streaks are provided, and the central remaining portion 48 is easily removed. Thus, a round hole 30 is formed.

  Since the laser beam L is a green laser, it passes through the glass thin plate 12 almost completely, so that heat is hardly generated, and generation of harmful cracks can be suppressed and high-precision processing can be performed.

  The machining width H may be set to be somewhat wide. For example, an area that is about 3/4 of the diameter of the round hole 30 (the machining width H is about 3/8 at the maximum) can be set as the maximum machining range.

  As shown in FIG. 9, in the drilling process of the long hole 32, the laser beam L is sequentially applied by the four scanning lines 50a, 50b, 50c and 50d from the inside to the outside in the same manner as the drilling process of the round hole 30. May be scanned.

  Next, the cutting process of the square frame 34 will be described. In the punching process of the rectangular frame 34, the same portions as those in the drilling process of the round holes 30 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 10, in the hollowing of the square frame 34, the machining width including the contour 60 on the inner side with respect to the contour 60 of the target object in plan view of the target (that is, the hollow part 31). In the range of H, the laser light L is scanned four times in parallel with the contour line 60. The first to fourth scanning lines 62 are shown separately as scanning lines 62a, 62b, 62c and 62d.

  When the object to be processed is the cutout part 31, the laser beam L is scanned in multiple directions from the outside to the inside of the outline 60 of the cutout part 31. That is, the fourth scanning line 62 d matches the contour line 60. In order to emphasize this, in FIG. 10, the scanning line 62d is indicated by a bold line.

  By processing in this order, the side surface of the cut-out component 31 that is the object can be formed with high accuracy.

  Depending on the design conditions, the scanning order of the scanning lines 62a, 62b, 62c, and 62d may be changed as appropriate, for example, the scanning order may be reversed, or the scanning line 62b or 62c may be scanned first.

  The pulse width, the scanning line N, the pitch P, the overlapping width between adjacent condensing points 44 and the like are the same as in the case of drilling the round hole 30. In the case of the long hole 32 shown in FIG. 9, the same range may be set based on the arc diameter of the end.

  In the above example, the laser beam L is scanned a plurality of times in a similar shape with respect to the contour lines 40 and 60 of the target object. However, the present invention is not limited to this. For example, as shown in FIG. 11, when the hole 30 is drilled, scanning may be performed spirally. In other words, scanning is performed with the spiral scanning line 70 with the starting point S inside the contour line 40 as a reference, and finally, one round of scanning is performed along the contour line 40. The pitch P and the machining width H in this case may be set similarly to the machining shown in FIG. As indicated by a virtual line, the first start point S ′ may be in contact with the adjacent scanning line 70. According to such processing, it is possible to perform drilling (or punching) with one scanning line 70, which is convenient.

  The present inventor conducted experiments with a brittle material such as non-alkali glass, blue plate glass, and borosilicate glass as the thin plate 12, and obtained good results. In addition, sapphire glass, ceramics, and silicon wafers were used. Is also considered applicable. The thin plate 12 is not limited to a brittle material, and can be applied to, for example, a flexible film used for an organic EL display or the like.

  When the laser processing method and the laser processing apparatus 10 according to the present embodiment are applied to a brittle material, the cut-out component 31 or the remaining portion 48 can be easily cut out without causing a crack in the material. In particular, when processing a brittle material, the cut-out component 31 and the remaining portion 48 are reliably separated from the thin plate 12 and can be easily and reliably extracted without applying an excessive force, and no cracks are generated.

  When the laser processing method and the laser processing apparatus 10 according to the present embodiment are applied to a material other than a brittle material, the cutout part 31 or the remaining portion 48 can be easily cut out even if the material is bent. In the case of a thin plate having flexibility, even if bending occurs, easy processing is possible.

  The laser processing method and the laser processing apparatus 10 according to the present embodiment are a simple method using the laser beam L, and can perform drilling and punching in a short time.

  Furthermore, unlike the mechanical processing method, the laser processing method and the laser processing apparatus 10 according to the present embodiment do not damage the thin plate beyond the desired processing dimensions due to the occurrence of edge chipping. Furthermore, unlike the processing method described in Patent Document 1, the thin plate 12 does not melt beyond a desired processing dimension and is highly accurate.

  The laser beam L is not limited to a green laser, and may be, for example, an ultraviolet laser (for example, third harmonic (355 nm), fourth harmonic (266 nm), etc.) or an infrared laser (fundamental wave (1064 nm), etc.). When the material of the workpiece is resin, the laser light L may be a green laser or a laser having a shorter wavelength (for example, third harmonic).

  Of course, for example, the round hole 30, the long hole 32, and the square frame 34 may be simultaneously processed using the plurality of laser beams L, or the scanning lines 42a to 42d of the round hole 30 may be simultaneously processed. is there.

  The present invention is not limited to the above-described embodiment, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

It is a perspective view which shows the whole structure of the laser processing apparatus which concerns on this Embodiment. It is a block block diagram of a laser processing apparatus. It is a perspective view of a thin plate. 4A is a perspective view of a product cut out from a thin plate, FIG. 4B is a perspective view of a round hole opened in the thin plate, and FIG. 4C is a perspective view of a long hole opened in the thin plate. It is explanatory drawing of the drilling process of a round hole. It is a figure which shows the several condensing point at the time of irradiating a pulsed laser beam. It is a figure which shows the position of the condensing point of the laser beam with respect to a thin plate. It is sectional drawing of the round hole part in a thin plate. It is explanatory drawing of the drilling process of a long hole. It is explanatory drawing of the hollowing process of a square frame. It is explanatory drawing of the process of scanning along a helical scanning line and carrying out the drilling process of a round hole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Laser processing apparatus 12 ... Thin plate 26 ... Galvano scanner 26a ... X mirror 26b ... Y mirror 28 ... f (theta) lens 30 ... Round hole 31 ... Hollow-out part 32 ... Long hole 34 ... Square frame 40, 60 ... Contour line 42, 42a ˜42d, 50a˜50d, 62, 62a˜62d, 70 ... scanning line 44 ... condensing point 46 ... through hole 48 ... residual portion H ... processing width L ... laser beam P ... pitch

Claims (9)

A laser processing method for drilling or punching a thin plate using laser light,
The contour of the laser beam within a predetermined width including the contour line on one side with respect to the contour line of the target object figure which is a plan view of the target object obtained by the punching process or the punching process. A laser processing method characterized by performing multiple scanning substantially parallel to a line. The laser processing method according to claim 1,
The target object is a hole, and the laser beam is scanned multiple times from the inside to the outside of the hole to be processed. The laser processing method according to claim 1,
The object is a hollow part, and the laser beam is scanned in multiple directions from the outside to the inside of the hollow part to be machined. In the laser processing method of any one of Claims 1-3,
The laser processing method characterized by setting the pitch of the scanning lines to be scanned multiple times to 0.5 to 10 times the laser beam diameter at the condensing point. In the laser processing method of any one of Claims 1-4,
The laser processing method, wherein the laser beam is irradiated in a pulse shape, and the pulse width is set to 100 ps to 50 ns. In the laser processing method of any one of Claims 1-5,
The thin plate is disposed substantially horizontally,
A laser processing method, wherein the laser beam is irradiated from the upper surface side of the thin plate and transmitted to the lower surface side, and a condensing point of the laser beam is set on a lower surface of the thin plate. In the laser processing method of any one of Claims 1-6,
The laser processing method, wherein the laser beam is a green laser. Laser beam oscillation means for oscillating pulsed laser beam;
Laser light emitting means for irradiating a thin plate as a workpiece with the laser light,
The laser light emitting means includes laser light scanning means for scanning the laser light in a predetermined pattern,
The laser beam scanning means includes the contour line on one side with respect to the contour line of the target object as a plan view of the target object obtained by punching or punching the thin plate, and within a predetermined width range. A laser processing apparatus that performs multiple scanning substantially parallel to the contour line. The laser processing apparatus according to claim 8, wherein
The laser processing apparatus, wherein the laser beam scanning means is a galvano scanner.

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