TW201836751A - Laser scribing apparatus - Google Patents

Abstract

Provided is a laser scribing apparatus capable of easily changing a focus distance of a laser when the laser is used for cutting a fragile material substrate. The laser scribing apparatus includes: a scribing head unit; and a stage to which a substrate is loaded, in which the scribing head unit moves relatively to the stage, and the scribing head unit includes a lens assembly receiving a cutting laser beam from a laser generating apparatus to vary a focus of the cutting laser beam, and a distance measurement sensor assembly including a distance measurement sensor including a light emitting unit generating a measurement laser beam and a light receiving unit receiving the measurement laser beam and having a beam passing unit through which the cutting laser beam of which the focus distance is controlled in the lens assembly passes.

Description

   Laser scoring device   

The invention relates to a laser scribing device. More specifically, the present invention relates to a laser scribing device that measures a distance from a brittle material substrate and actively adjusts a focal length of the laser according to the distance from the brittle material substrate.

There are cases where a laser is used for precision cutting as a method of cutting an object to be cut. Laser cutting is used not only for cutting sheet metal but also for brittle materials such as glass.

For example, a laser is used to cut a flat display panel such as a liquid crystal display device. The scoring device for cutting a liquid crystal display device in the prior art moves a cutter wheel made of diamond or cemented carbide in a rotatable manner while applying a predetermined pressure to a substrate surface to form a score line on the substrate surface and pass Breaking process to cut the substrate.

In this regard, a scribe device using a laser generates thermal stress by irradiating a substrate with a laser and cooling the substrate with a cooling gas or the like to form a crack in the substrate. Alternatively, it is proposed to cut the substrate by sequentially irradiating the substrate with different lasers. Meanwhile, in some cases, a laser may be used to cut a sealant that bonds two substrates constituting a liquid crystal display device or a black matrix formed in the substrate, and the like, and thereafter the substrate may be cut by a cutter wheel.

However, when the substrate to be cut is uneven or when the laser irradiation depth needs to be controlled, there is a problem that it is difficult to adjust immediately.

For example, Korean Patent Publication No. 10-2005-0106156 ("A device for cutting a glass substrate in the manufacturing process of a flat-type display and a method for controlling the cutting depth of a glass substrate", published on November 9, 2005 Japan) discloses a structure including a lifting device that measures a distance from a substrate and raises a height of an irradiation hole that irradiates a laser beam to control a focal length of the laser beam.

However, in the related art, mechanically controlling the height of the irradiation hole that irradiates the laser beam is delayed in response, and as a result, it is difficult to increase the substrate cutting speed. In addition, in the prior art, the horizontal distance between the distance sensor that measures the distance from the substrate and the irradiation hole that irradiates the laser beam is separated, as a result, the laser beam cannot be irradiated at an accurate depth.

An object of the present invention is to provide a laser scribing device, which improves the accuracy of laser irradiation depth control according to a measurement result of a distance from a substrate.

It is also an object of the present invention to provide a laser scribing device that improves scribing accuracy by minimizing an error according to a difference between a measurement position of a distance from a substrate and a laser irradiation position for cutting.

An exemplary embodiment of the present invention provides a laser scribing device including: a scribing head unit; and a pallet on which a substrate is loaded, the scribing head unit moves relative to the pallet, and scribing The wire head unit includes a lens assembly that receives a cutting laser beam from a laser generating device to change a focus of the cutting laser beam, and a distance measuring sensor assembly that includes a distance measuring sensor and has a light beam. A passing unit, the distance measuring sensor includes a light emitting unit that generates a laser beam for measurement and a light receiving unit that receives the laser beam for measurement, and a cutting laser beam whose focus is controlled in a lens assembly passes through the beam passing unit .

In an exemplary embodiment, the lens assembly may include a focusing lens that forms a focus of the laser beam for cutting and a lens driving unit that adjusts a position of the focusing lens.

The light emitting unit may irradiate the substrate with a measurement laser beam at an angle other than a right angle, and the light receiving unit may receive the measurement laser beam reaching the substrate at an angle other than a right angle.

The light beam passing unit may be formed between the light emitting unit and the light receiving unit.

The point at which the laser beam for measurement is irradiated to the substrate may be before the irradiation position of the laser beam for cutting.

The laser scoring device may further include a main control unit that receives distance sensing information from the distance measurement sensor and controls the driving of the lens driving unit.

In this exemplary embodiment, the main control unit may calculate the driving completion time of the lens driving unit by considering the time to irradiate the laser beam for cutting to the sensing point of the distance measurement sensor.

The main control unit can calculate the driving completion time of the lens driving unit by considering the processing time Ts of the distance measurement sensor, the processing time Tm and the time Td of the main control unit. The time required for the lens drive unit.

The main control unit may define an upper limit value of the relative moving speed between the scribing head unit and the substrate by considering the distance between the sensing point of the distance measurement sensor and the irradiation point of the cutting laser beam.

The main control unit can set the sensing period of the distance measurement sensor according to the relative moving speed between the scribing head unit and the substrate.

According to the exemplary embodiment of the present invention, it is possible to quickly and accurately control the laser irradiation depth according to the distance measurement result from the substrate.

According to the exemplary embodiment of the present invention, it is possible to make a difference depending on a distance measurement position and a laser irradiation position by integrating a distance measurement sensor for measuring a distance from a substrate and a laser irradiation device for cutting a substrate. The error is minimized.

According to an exemplary embodiment of the present invention, by comprehensively considering the sensing period of the distance measurement sensor, the relative moving speed of the scribe head unit relative to the substrate, the sensing point of the distance measurement sensor and the irradiation point of the cutting laser beam The distance between the laser beams can be used to precisely control the focal length of the laser beam.

As a result, according to the exemplary embodiment of the present invention, it is possible to form a score line with a uniform depth in a processed object by changing the focal length of the laser beam for cutting according to the distance from the processed object such as a substrate.

The above summary is merely illustrative and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

1‧‧‧ substrate

2‧‧‧ pallet

10‧‧‧ scribing head unit

12‧‧‧Mirror

20‧‧‧Distance measurement sensor assembly

22‧‧‧Distance measurement sensor

24‧‧‧light emitting unit

25‧‧‧ laser beam for measurement

26‧‧‧light receiving unit

28‧‧‧ Beam Passing Unit

30‧‧‧ lens assembly

32‧‧‧ Focusing lens

34‧‧‧ lens drive unit

40‧‧‧laser generating device

42‧‧‧ Cutting laser beam

50‧‧‧Main Control Unit

F‧‧‧ Focus

P1‧‧‧point

P2‧‧‧point

V‧‧‧ Relative moving speed

△ L‧‧‧distance

S100, S102, S104, S106 ‧‧‧ steps

FIG. 1 is a schematic diagram illustrating a configuration of a laser scribing device according to an exemplary embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a distance measurement sensor assembly provided in a laser scoring device according to an exemplary embodiment of the present invention.

Fig. 3 is a block diagram showing a control configuration of a laser scoring device according to an exemplary embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a relationship between a distance measurement sensor of a laser scoring device and a laser irradiation position according to an exemplary embodiment of the present invention.

FIG. 5 is a flowchart illustrating a control method of a laser scribing device according to another exemplary embodiment of the present invention.

It should be understood that the drawings are not necessarily drawn to scale, thereby presenting a slightly simplified representation of various features illustrating the basic principles of the invention. The specific design features of the invention, as disclosed herein, including, for example, specific sizes, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

In the figures, reference characters in the several figures of the whole drawing denote the same or equivalent parts of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, when the reference symbol indicates a component of each figure, it should be noted that although the same component is shown in different drawings, the same component is denoted by the same reference symbol as much as possible. In addition, in the following description, detailed descriptions of known related configurations and functions may be omitted to avoid unnecessarily obscuring the subject matter of the present invention. In addition, exemplary embodiments of the present invention will be described below, but the technical spirit of the present invention is not limited thereto or limited thereto, and those skilled in the art can modify and implement the exemplary embodiments in various ways.

FIG. 1 is a schematic diagram illustrating a configuration of a laser scoring device according to an exemplary embodiment of the present invention, and FIG. 2 is a diagram illustrating a laser scoring device provided in the exemplary embodiment of the present invention. Schematic diagram of the configuration of the distance measurement sensor assembly.

The laser scribing device according to the exemplary embodiment of the present invention includes a pallet 2 on which the substrate 1 is loaded and a scribing head unit 10 provided to move relative to the pallet 2. The pallet 2 is fixed and the scribing head unit 10 is movable, the scribing head unit 10 is fixed and the pallet 2 is movable, or both the pallet 2 and the scribing head unit 10 are movable of. The scribing head unit 10 may be provided in a stand (not shown) provided to straddle the upper side of the pallet 2. The basic configuration of the laser scribing device may follow the configuration shown in FIG. 1 of Korean Patent Laid-Open Publication No. 10-2005-0106156 described as a related art.

Ideally, the substrate 1 loaded on the top of the pallet 2 is coplanar, but in reality, there is a slight height difference between the substrate 1 and the horizontal plane. The laser scoring device according to the present invention adjusts the focal length of the laser beam for cutting, that is, the irradiation depth of the laser beam for cutting according to the distance from the substrate 1. Here, the irradiation depth of the cutting laser beam may be one point on the surface of the substrate or in the substrate, and in some cases, the irradiation depth of the cutting laser beam may be one of the sealant used to bond the bonding substrate. The dots are positions corresponding to the black matrix existing in the substrate.

The scribing head unit 10 includes a distance measurement sensor assembly 20 and a lens assembly 30, and the lens assembly 30 is disposed on top of the distance measurement sensor assembly 20. In addition, the scribing head unit 10 may include at least one mirror 12 for transmitting the cutting laser beam 42 generated from the separate laser generating device 40 to the lens assembly 30.

The distance measurement sensor assembly 20 may be provided in a bracket type fixed to the scribing head unit 10. A distance measurement sensor 22 may be provided below the distance measurement sensor assembly 20. The distance measurement sensor 22 includes a light emitting unit 24 and a light receiving unit 26. The light emitting unit 24 irradiates the substrate 1 with a measurement mine at a predetermined angle (such as an angle other than a right angle). The radiation beam 25 is received by the light receiving unit 26 after the measurement laser beam 25 generated from the light emitting unit 24 is reflected on the substrate 1. A light beam passing unit 28 is provided between the light emitting unit 24 and the light receiving unit 26 and penetrates vertically.

The cutting laser beam 42 whose focal length is adjusted in the lens unit 30 passes through the beam passing unit 28.

The measurement laser beam 25 and the cutting laser beam 42 may preferably have different wavelength bands. This is to prevent interference of the cutting laser beam 42 when the light receiving unit 26 receives the measuring laser beam 25.

The lens unit 30 is provided with a focusing lens 32 for adjusting the focal length of the laser beam 42 for cutting. The focusing lens 32 may be a single lens or a component obtained by combining a plurality of lenses. Further, a lens driving unit (not shown in FIGS. 1 and 2) that adjusts the position of the focusing lens 32 is provided in the lens assembly 30.

The lens driving unit is set to a voice coil type or a linear motor type to adjust the position of the focus lens 32. The distance measurement sensor 22 measures the distance from the substrate 1, and the lens driving unit adjusts the position of the focusing lens 32 according to the measured distance to adjust the focal length of the laser beam 42 irradiated to the substrate 1.

The position adjustment time of the lens driving unit for the focus lens 32 can be obtained by considering the relative moving speed V between the scribe head unit 10 and the substrate 1.

In FIG. 1, it is shown that the lens assembly 30 is located on the top of the distance measurement sensor assembly 20, and the cutting laser beam 42 passing through the lens assembly 30 passes through the beam passing unit 28 located below the lens assembly 30. As a result, A focus is formed at a predetermined position of the substrate 1. However, in the exemplary embodiment of the present invention, the cutting laser beam 42 output from the lens assembly 30 may be configured to pass while the optical path of the cutting laser beam 42 is changed by a separate mirror (not shown). The light beam passes through the unit 28.

In the present invention, the position on the horizontal plane where the distance measurement sensor 22 measures the distance from the substrate 1 and the position on the horizontal plane irradiated by the cutting laser beam 42 are spaced apart from each other. In the exemplary embodiment, the position at which the distance measurement sensor 22 measures the distance from the substrate 1 precedes the irradiation position of the cutting laser beam 42. That is, the position is set such that the distance from the substrate 1 is measured by the distance measurement sensor 22 and thereafter the substrate 1 is irradiated with the laser beam 42 for cutting.

FIG. 3 is a block diagram illustrating a control configuration of a laser scoring device according to an exemplary embodiment of the present invention, and FIG. 4 is a diagram illustrating a distance of the laser scoring apparatus according to an exemplary embodiment of the present invention Schematic diagram of the relationship between the measurement sensor and the laser irradiation position.

Referring to FIG. 3, the laser scribing device according to the present invention includes a main control unit 50 that receives a distance measurement result from the distance measurement sensor 22 to the substrate 1 and controls the lens driving unit 34 of the lens assembly 30.

The distance measurement sensor 22 measures a distance from the substrate 1 and transmits the measured distance to the main control unit 50 according to control performed by the main control unit 50 or every predetermined period.

The main control unit 50 adjusts the position of the focus lens 32 by controlling the driving of the lens driving unit 34 of the lens assembly 30 according to the measurement result of the distance measurement sensor 22.

Referring to FIG. 4, a measurement laser beam 25 generated from the light emitting unit 24 of the distance measurement sensor 22 is irradiated and reflected on the point P1 of the substrate, and thereafter is incident in the light receiving unit 26. The distance measurement sensor 22 can calculate the vertical distance from the substrate 1 based on the time before the measurement laser beam 25 generated from the light emitting unit 24 is incident in the light receiving unit 26. Further, the point P1 can be calculated by the arrangement of the light emitting unit 24 and the light receiving unit 26 and the vertical distance from the substrate 1.

The laser beam 42 for cutting forms a focal point F on the substrate 1, and a point on the surface of the substrate 1 in which the focal point F is formed is P2. In the installation direction of the laser scoring device according to the present invention, when the directions are displayed on the X and Y axes orthogonal to each other with respect to a horizontal plane, P1 and P2 may be located in the same direction in the X axis direction or the Y axis direction. On the line or diagonally.

The horizontal distance between P1 and P2 is represented by ΔL. In an exemplary embodiment, ΔL may have a value of several millimeters. In addition, ΔL may be in a range of 0.5 mm to 2 mm. As ΔL is smaller, the adjustment of the focal length of the cutting laser beam 42 according to the sensing result of the distance measurement sensor 22 can be reflected more quickly. However, it may be difficult to set ΔL too small due to the time required to control the driving of the lens driving unit 34 according to the sensing result of the distance measurement sensor 22. In the present invention, the optical scribing control can be realized by considering ΔL, the relative moving speed between the scribing head unit 10 and the substrate 1, the time required for control, and the like.

When the relative moving speed between the scribing head unit 10 and the substrate 1 is V, the time ΔT required for the laser beam 42 for cutting from the point P2 to the point P1 can be obtained by ΔL / V.

The main control unit 50 controls the driving of the lens driving unit 34 by calculating the driving time of the lens driving unit 34 by considering ΔT.

In an exemplary embodiment, the main control unit 50 may determine the driving completion time T2 of the lens driving unit 34 by considering the time Ts, the processing time Tm, and the time Td in the main control unit 50, and the time Ts is a distance from the distance measurement sensor 22 to The time T1 at which P1 irradiates the laser beam for measurement starts from the time required for the internal processing of the distance measuring sensor 22, and the time Td is the time until the lens driving unit 34 is actually driven by outputting a control signal by means of the main control unit 50.

Since it is necessary to drive the lens driving unit 34 when the position of the cutting laser beam 42 reaches P1, the relationship according to Equation 1 needs to be satisfied at this time.

The main control unit 50 may set an upper limit value of the relative movement speed V between the scribe head unit 10 and the substrate 1 so as to satisfy the condition of Expression 1.

The main control unit 50 may set the control delay time of the lens driving unit 34 so that the driving of the lens driving unit 34 is completed at the driving completion time T2 of the lens driving unit 34 and adjusts the output control to the lens driving unit 34 in addition to the control delay time. The time of the signal.

The sensing period of the distance measurement sensor 22 may be set to ΔT to satisfy the condition of Equation 1.

The sensing period of the distance measurement sensor 22 may be set to be correlated with the relative moving speed V between the scribing head unit 10 and the substrate 1. When the relative movement speed V is high, the sensing period of the distance measurement sensor 22 can be shortened, and when the relative movement speed V is low, the sensing period of the distance measurement sensor 22 can be extended.

FIG. 5 is a flowchart illustrating a control method of a laser scribing device according to another exemplary embodiment of the present invention.

First, the irradiation depth of the cutting laser beam 42 on the substrate 1, that is, the focal length is set (S100).

The distance measurement sensor 22 measures the distance from the substrate 1 periodically or continuously, and the main control unit 50 receives a measurement result from the distance measurement sensor 22 (S102).

The main control unit 50 receives the measurement result from the distance measurement sensor 22, and thereafter calculates the laser irradiation depth control time by considering the time at which the sensing point P1 of the distance measurement sensor 22 is to be irradiated with the cutting laser beam 42 (S104). Here, the laser irradiation depth control time can be understood as a time before the driving completion time T2 of the lens driving unit 34.

The lens driving unit 34 is controlled according to the control of the main control unit 50 (S106).

Steps S102 to S106 are repeatedly performed while performing a laser scribing operation on the substrate 1. Steps S102 to S106 may be repeatedly performed according to the sensing period of the distance measurement sensor 22.

As described above, the exemplary embodiments have been described and illustrated in the drawings and the specification. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical applications, to thereby enable others skilled in the art to make and utilize the various exemplary embodiments of the invention, and their various alternatives and modifications. . As is apparent from the above description, certain aspects of the present invention are not limited by the specific details of the examples shown here, and it is therefore envisaged that those skilled in the art will envision other modifications and applications or equivalents thereof. However, many changes, modifications, variations and other uses and applications of the present invention will become apparent to those skilled in the art after reviewing the specification and drawings. All these changes, modifications, variations and other uses and applications without departing from the spirit and scope of the present invention are deemed to be covered by the present invention, and the present invention is limited only by the scope of the following patent applications.

Claims (10)

    A laser scribing device includes: a scribing head unit; and a pallet on which a substrate is loaded, wherein the scribing head unit moves relative to the pallet, and wherein the scribing head unit includes : A lens assembly that receives a cutting laser beam from a laser generating device to change a focus of the cutting laser beam; and a distance measuring sensor assembly including a distance measuring sensor and having a light beam through which the cutting laser beam passes Through the unit, the distance measuring sensor includes a light emitting unit that generates a laser beam for measurement and a light receiving unit that receives the laser beam for measurement, and a focal length of the laser beam for cutting is controlled in the lens assembly.         The laser scoring device according to claim 1, wherein the lens assembly includes a focusing lens that forms a focal point of the laser beam for cutting and a lens driving unit that adjusts a position of the focusing lens.         The laser scribing device according to claim 2, wherein the light emitting unit irradiates the substrate with the laser beam for measurement at an angle other than a right angle, and the light receiving unit receives the laser beam reaching the substrate at an angle other than a right angle. This measurement uses a laser beam.         The laser scoring device according to claim 2, wherein the light beam passing unit is formed between the light emitting unit and the light receiving unit.         The laser scoring device according to claim 4, wherein the sensing point for irradiating the substrate with the laser beam for measurement is before the irradiation point of the laser beam for cutting.         The laser scoring device according to claim 5, further comprising: a main control unit that receives distance sensing information from the distance measuring sensor and controls driving of the lens driving unit.         The laser scribing device according to claim 6, wherein the main control unit calculates the driving completion of the lens driving unit by considering a time to irradiate the cutting laser beam to the sensing point of the distance measuring sensor. time.         The laser scoring device according to claim 6, wherein the main control unit calculates the driving completion of the lens driving unit by considering the processing time Ts of the distance measuring sensor, the processing time Tm, and the time Td of the main control unit. Time, this time Td is the time required until the lens driving unit is actually driven by outputting a control signal from the main control unit.         The laser scribing device according to claim 7, wherein the main control unit defines the scribe line by considering a distance between the sensing point of the distance measuring sensor and the irradiation point of the cutting laser beam. The upper limit value of the relative moving speed between the head unit and the substrate.         The laser scoring device according to claim 6, wherein the main control unit sets a sensing period of the distance measurement sensor according to a relative moving speed between the scribing head unit and the substrate.