JP2021020833A - Processing method and processing device of substrate - Google Patents

Abstract

To provide a processing method of a substrate capable of obtaining a high-quality product by suppressing occurrence of thermal effects such as chipping and HAZ when parting deformed portions by a laser beam; and to provide a processing device of the substrate.SOLUTION: A processing method of a substrate provided with deformed portions such as a radium and a notch at a corner and around there includes a step of forming a scribe line having a modified layer inside the substrate, which becomes brittle due to being irradiated with a laser beam along parting schedule lines S3 and S4 that separate the deformed portions. When the parting schedule lines S3 and S4 are irradiated with the laser beam, the irradiation is started from a position entering the inside near a substrate end, and the laser beam irradiation is made to stop at a position entering inside the substrate near the terminations of the parting schedule lines.SELECTED DRAWING: Figure 6

Description

The present invention relates to a processing method and a processing apparatus for a substrate made of a transparent brittle material such as a glass plate. In particular, the present invention relates to a processing method and a processing apparatus for cutting out a mobile liquid crystal cell substrate provided with a deformed portion in the periphery from a large-format mother substrate.

The unit substrate of the liquid crystal cell is a first substrate (also called a CF side substrate) in which a color filter is patterned on a transparent glass plate, and a second substrate in which a thin film transistor (TFT) is patterned on the transparent glass plate. A substrate (also referred to as a TFT-side substrate) is formed by laminating a sealing material for encapsulating a liquid crystal.
When the large-sized mother substrate is divided into unit substrates for individual liquid crystal cells, processing is performed to cut out along a grid-like scheduled division line. At this time, a method is generally used in which a scribe line is processed by using a cutter wheel or a laser beam on both the front and back surfaces of the substrate to break the substrate (see Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2006-137641 JP-A-2015-13783

By the way, as shown in FIG. 4 described later, the cell substrate of the mobile liquid crystal cell has a radius (arc portion) 2 at the corner portion, and an opening recess called a notch 3 is formed on the side side in the lateral direction. In some cases (in the present invention, this radius or notch is referred to as a deformed portion).
When cutting out a substrate including a deformed part from a mother substrate, it is processed by either a cutter wheel or a laser scribe as in the past, but until now, the deformed part has been considered. There was not much consideration on the optimum processing method. Therefore, the processing quality of the deformed portion was not always sufficiently high.
Therefore, the present invention provides a more excellent processing method than ever before for processing a substrate including a deformed portion from a mother substrate by finding a problem peculiar to the deformed portion and processing the substrate including the deformed portion. The purpose is.

In order to achieve the above object, the following technical measures have been taken in the present invention. That is, the present invention is a substrate processing method for cutting out a cell substrate made of a transparent brittle material and having a deformed portion around it from a large-sized mother substrate.
A scribe / break process that processes a straight grid-like scribe line on the mother board using a cutter wheel, divides the mother board along this scribe line, and cuts out individual unit boards.
The structure is provided with a substrate processing method including a deformed portion processing step of processing the deformed portion by using a laser beam on the cut out unit substrate.

That is, until now, when cutting out a unit substrate from a mother substrate, either machining with a cutter wheel or laser machining has been adopted regardless of the presence or absence of a deformed portion.
However, when machining with a cutter wheel is used, when machining a deformed part consisting of a radius or notch, there is a front-back bite width due to the blade of the cutter wheel in the direction of travel, so a curved scribing line with a small radius of curvature. It was difficult to process with high accuracy, and the processing quality of the curved part with a small radius of curvature was deteriorated.
On the other hand, when laser scribing is performed using laser light, a slight thermal effect is applied to the vicinity of the scribing line. Therefore, it has been necessary to provide an extra margin from the planned division line (or to provide a scrap area) to suppress the thermal effect on the portion where the thermal effect is desired to be avoided as much as possible.
Therefore, when cutting out the unit board from the mother board in a grid pattern, move the cutter wheel in a straight line to cut out, and when processing the deformed part of the cut out unit board, use laser light. Even if the radius of curvature is small, it can be processed accurately along the planned division line.

According to the present invention, when a unit substrate is cut out from a mother substrate, a linear scribe line that occupies the entire planned division line can be cut out with a clean divided end face without being affected by heat by processing with a cutter wheel. Moreover, since it is not affected by heat, the margin area can be kept small. Further, when processing a deformed portion such as a radius on the cut-out unit substrate, the scribe line can be accurately processed along the planned division line by processing with laser light. In this way, processing suitable for processing a substrate having a deformed portion can be performed.

Further, in the processing of a scribe line by laser light, conventionally, the laser light starts irradiation at a position away from the substrate, enters the planned division line on the substrate from the end face of the substrate in the irradiated state, and divides as it is. It was performed by a method of moving on a planned line and exiting from the end face of the substrate at the end (this method is referred to as "outer cutting" here).

However, with this "outer cutting" method, heat effects such as small chips called chipping and discoloration called HAZ (Heat Affected Zone) may occur at the board edges located on the start and end sides of the planned division line. In this part, the product quality deteriorated and the yield deteriorated.

The cause was examined for this. When the surface of the glass substrate is irradiated with the laser light of the focus beam (for example, an IR laser having a wavelength of 1064 nm), as shown in FIG. 9A, the substrate is located at an internal position away from the edge (periphery) of the glass substrate. The laser beam incident from the surface converges inside the substrate, which processes the substrate.
On the other hand, when the laser beam irradiated by the "outer cutting" method is applied to the edge of the substrate, a part of the laser beam is incident from the edge of the substrate as shown by the thick line in FIG. It proceeds in the direction orthogonal to the thickness direction of the substrate (from the end face of the substrate to the inside of the substrate) and converges deep inside the substrate. Further, a part of the laser beam is reflected by the end surface of the substrate as shown by a thin line and escapes to the back surface of the substrate. It is considered that the refracted light diffused deeply into the substrate and the reflected light on the end face of the substrate are the causes of heat effects such as chipping and HAZ.

Therefore, when scribing a deformed part with laser light, the following processing method was adopted in order to suppress the occurrence of thermal influence due to reflection of the laser light at the substrate edge and perform higher quality processing. ..
That is, it is a substrate processing method in which a cell substrate made of a transparent brittle material and having a deformed portion around it is cut out from a large-sized mother substrate, and a straight grid-like scribing line is formed on the mother substrate by using a cutter wheel. From the scribing / break process in which the mother substrate is divided along the scribing line to cut out individual unit substrates while processing, and the deformed portion processing step in which the deformed portion is processed by using laser light on the cut out unit substrate. The deformed portion processing step includes a step of irradiating a laser beam along a planned division line for dividing the deformed portion to form a scribing line having a fragile modified layer inside the substrate, and the laser. When irradiating light along the scheduled division line, the irradiation was started from the position where it entered the inside near the edge of the substrate, and the laser irradiation was stopped at the position where it entered the inside of the substrate near the end of the scheduled division line.

Here, it is preferable that the irradiation start position and the stop position of the laser light are performed at a position separated from the edge of the substrate by 30 to 200 μm.

According to this, when irradiating the laser beam along the scheduled division line, the irradiation is started from the position where it enters the inside near the edge of the substrate, and the laser irradiation is stopped at the position inside the substrate near the end of the scheduled division line. Therefore, as in the "outer cutting" method, a part of the laser beam enters from the end face of the substrate and penetrates deeply inside along the direction orthogonal to the thickness direction of the substrate due to refraction, or the laser beam incident from the upper surface. It is possible to eliminate the phenomenon that a part of the substrate is reflected by the end surface of the substrate and escapes to the back surface of the substrate, thereby suppressing the occurrence of thermal influences such as chipping and HAZ, and obtaining a high-quality product.

The substrate processing apparatus of the present invention made from another viewpoint is a substrate processing apparatus for cutting out a cell substrate having a deformed portion around it from a large-sized mother substrate, and a grid-like scribing line is formed on the mother substrate with a cutter wheel. A scribing / breaking means for cutting out individual unit boards by dividing the mother substrate along this scribing line while processing, and laser light is applied to the cut out unit boards along the planned division line for dividing the deformed portion. It is provided with a deformed portion processing means for forming a fragile modified layer inside the substrate by irradiation, and further, when the laser beam is irradiated along the planned division line, it enters the inside near the edge of the substrate. It is provided with a control unit that controls so that irradiation is started from a position where the irradiation is started and the irradiation is stopped at a position inside the substrate near the end of the scheduled division line.

The front view of the plan view which shows the mother substrate for cutting out the cell substrate which concerns on this invention. The plan view which shows the strip-shaped substrate cut out from the mother substrate. The plan view which shows the unit substrate cut out from the strip-shaped substrate. The plan view which shows the cell substrate which processed the radius and the notch on the unit substrate. The schematic front view of the substrate processing apparatus which concerns on this invention. The plan view for demonstrating the processing of the radius of a cell substrate. The plan view for demonstrating the processing of the notch of a cell substrate. Explanatory drawing which shows another example of the laser beam used in this invention. The figure for demonstrating the cause of the thermal influence by laser light irradiation.

Hereinafter, the details of the method of the present invention will be described based on the embodiment shown in the figure. Here, a rectangular mobile cell substrate 1 having a radius 2 at a corner portion as shown in FIG. 4 and a notch 3 having a concave opening on the side in the lateral direction is cut out from the large-format mother substrate M. The case of processing is described. The dimensions of each part of the cell substrate 1 as viewed from the plane are: long side is 150 mm, short side is 70 mm, radius is 7 mmR, notch depth W1 is 5 mm, and notch width W2 is 40 mm. ..
Further, as described above, the mother substrate M includes a first substrate (CF side substrate) in which a color filter is patterned on a glass plate and a second substrate (TFT side substrate) in which a TFT is patterned on a glass plate. ) And are bonded together with a sealing material that encloses the liquid crystal sandwiched between them.

1 to 3 show an example of a step of cutting out a unit substrate M2 which is a base of a cell substrate from a mother substrate M. FIG. 1 shows a case where eight unit substrates M2 are cut out from the mother substrate M.
First, as shown in FIGS. 1 and 5, a scribe line S1 is engraved on the upper surface of the mother substrate M by using the cutter wheel 6 by pressing the cutter wheel along the scheduled division line in the X direction and scribing. Next, the substrate is inverted and a similar scribe line is carved at a symmetrical position of the scribe line. In this case, cutter wheels may be arranged above and below the substrate to scribe both the upper and lower surfaces of the substrate at the same time. The scribe line is formed with a notch to the extent that a crack (groove) is formed in the thickness direction of the substrate, and the substrate is bent by pressing the break bar in the subsequent process to divide it along the scribe line. In the present invention, the scribe / is also referred to in the present invention as to the process of cutting out the unit substrate by simultaneously processing and dividing the scribe line. It shall be included in the break process). As shown in FIG. 2, the mother substrate separated from the scribe line S1 becomes a strip-shaped substrate M1 including four unit substrate regions, respectively.

Next, after rotating the strip-shaped substrate M1 by 90 degrees, scribe lines S2 are carved on both the upper and lower sides of the substrate M1 with a cutter wheel in the same manner as above along the planned division line, and the same as above, along the scribe line S2. After dividing, as shown in FIG. 3, a rectangular unit substrate M2 having unprocessed corners and notches is cut out.

Next, the laser light from the laser light irradiation nozzle 7 is irradiated along the planned division lines S3 and S4 that divide the radius 2 and the notch 3 of the unit substrate M2, and a scribing line having a fragile modified layer inside the substrate. To process. As for the movement locus of the laser light, an arbitrary locus such as a curve can be drawn by simultaneously moving the table 8 for mounting the substrate and the scribe head 11 of the laser light irradiation nozzle 7 described later in the XY directions. The laser light preferably uses a picosecond IR laser having a wavelength of about 1 μm, but can be selected in a wavelength range of 1200 nm or less.

When irradiating this laser beam on the planned division lines S3 and S4 of Earl 2 and Notch 3, irradiation is started from a position slightly inward from the edge of the substrate and moved to a position near the end of the planned division line. It is desirable to stop the laser irradiation. That is, when the laser irradiation nozzle 7 passes from the outside of the substrate over the scheduled division lines S3 and S4 and exits to the opposite substrate edge, as shown in FIGS. 6 and 7, the position of P1 which has entered only L1 from the substrate edge. The racer irradiation is started at, and the irradiation is stopped at the position of P2, which is L2 away from the substrate edge near the end of the scheduled division line. The above L1 and L2 are selected from the range of 30 to 200 μm, and particularly preferably 50 to 100 μm. The control of irradiating and stopping the laser beam can be performed by programming in advance in the control unit described later.

Next, a break bar, a steam break, or the like is used to divide and remove the offcuts from the planned division line to process the radius and notch.

FIG. 5 shows a schematic configuration of a substrate processing apparatus A for carrying out the method of the present invention. The cutter wheel 6 is vertically attached to a scribe head 9 arranged above a table 8 serving as a work stage, and the scribe head 9 is a head moving mechanism (not shown) along a guide 10 provided in the machine frame of the apparatus. It is built in so that it can move in the horizontal X direction. Further, the laser irradiation nozzle 7 is supported by a scribe head 11 that can move along the upper guide 10.

Further, the table 8 on which the substrate W is placed is provided with a table moving mechanism 12 for moving the substrate W in the X direction and the Y direction orthogonal to the X direction. As the table moving mechanism 12, for example, a known mechanism is used in which the screw shaft is rotated by a motor to move along the rail.

Further, the substrate processing apparatus A includes a control unit 14 that controls the movement of the scribe heads 9 and 11 and the table 8 and the laser light transmitter 13. The control unit 14 is a computer system having a processor such as a CPU, a storage unit such as a ROM and a RAM, and various interfaces. The control unit 14 performs various control operations by executing a program stored in the storage unit.

As described above, by processing the scribe lines S1 and S2 of the straight portion for cutting out the unit board M2 from the mother board M with a cutter wheel, it is possible to cut out a clean divided end face without being affected by heat, and the cut out unit. When processing a deformed portion such as a radius on a substrate, it is possible to accurately process a scribe line along a planned division line by using a laser beam.
In particular, in the present invention, the irradiation is started at a position where the laser beam enters only L1 from the edge of the substrate, and the irradiation is stopped at a position near the end of the planned division line and at a position L2 away from the edge of the substrate. It is possible to suppress heat effects such as chipping and HAZ during the processing of 3. The non-irradiated parts L1 and L2 of the laser beam remaining at both ends of the scheduled division line will be forcibly torn off, but that part is very short at 30 to 200 μm, and burrs generated by the tearing are very small. Therefore, there is no quality problem.

The inventors have described a picosecond IR with a wavelength of 1064 nm, a pulse width of 15 picoseconds, a pulse energy of 80 μJ, and a pulse interval of 1.5 μm with respect to a substrate having a TFT-side substrate thickness of 150 μm and a CF-side substrate thickness of 150 μm. As a result of processing the radius and the notch by the above-mentioned method using a laser, there was no chipping on the divided end face, and almost no HAZ was observed.

In the present invention, as the laser light, an aberration laser light having a dispersed focus as shown in FIG. 8 can be used. This aberration laser light emits pulsed laser light oscillated from the laser light oscillator 13 as a set of burst trains divided by the optical modulator 15 and sends it to an aberration generating member 16 composed of a plano-convex lens 16a, and the plano-convex lens 16a Aberration laser light can be obtained by emitting light from the convex side of the lens. This aberration laser light can form a narrow and long high energy distribution region (laser filament) F in which laser energy is stored at each focal point, and even if the substrate is thick, it is fragile and penetrates long inside the substrate. The modified layer can be processed and can be reliably divided.

Although typical examples of the present invention have been described above, the present invention is not necessarily specified in the above-described embodiment. For example, the radius 2 may be C-shaped in addition to a perfect circular arc, and the notch 3 may be formed in a deformed shape such as a V-shape or a U-shape in addition to the concave shape. Further, the substrate to be broken is not limited to the liquid crystal display panel, and may be a bonded substrate in which two glass plates are bonded together, or a single glass plate. Others In the present invention, the object can be achieved and modifications and changes can be made as appropriate without departing from the claims.

The present invention is applied to process rounds and recesses using laser light at the corners and periphery of a cell substrate.

A Processing equipment M Mother substrate M2 Unit substrate S1 Scribline S2 Scribline S3 R's scheduled division line S4 Notch's scheduled division line 1 Cell substrate 2 R 3 Notch 4 1st substrate 5 2nd substrate 6 Cutter wheel 7 Laser irradiation nozzle 13 Laser optical oscillator 14 control unit

Claims (6)

A substrate processing method in which a cell substrate made of a transparent brittle material and having a deformed portion around it is cut out from a large-sized mother substrate.
A scribe / break process that processes a straight grid-like scribe line on the mother board using a cutter wheel, divides the mother board along this scribe line, and cuts out individual unit boards.
A substrate processing method comprising a deformed portion processing step of processing the deformed portion by using a laser beam on a cut-out unit substrate. The deformed portion processing step includes a step of irradiating a laser beam along a planned division line for dividing the deformed portion to form a scribing line having a fragile modified layer inside the substrate, and the laser beam is used. The first aspect of claim 1, wherein when irradiating along the planned division line, the irradiation is started from a position where the irradiation is inside the substrate near the end of the substrate, and the laser irradiation is stopped at the position where the irradiation is inside the substrate near the end of the scheduled division line. Substrate processing method. The substrate processing method according to claim 1 or 2, wherein the deformed portion includes at least one of a radius formed at a corner portion of the substrate to be processed and a notch formed in a part of the periphery. The substrate processing method according to any one of claims 1 to 3, wherein the laser light is a picosecond IR laser having a wavelength of 1200 nm or less. The substrate processing method according to any one of claims 2 to 4, wherein the irradiation start position and the stop position of the laser light are performed at a position 30 to 200 μm away from the edge of the substrate. A substrate processing device that cuts out a cell substrate made of a transparent brittle material and having a deformed portion around it from a large-sized mother substrate.
A scribe / break means for processing a grid-like scribe line on the mother substrate with a cutter wheel and dividing the mother substrate along the scribe line to cut out individual unit substrates.
The cut-out unit substrate is provided with a deformed portion processing means for forming a fragile modified layer inside the substrate by irradiating a laser beam along a planned division line for dividing the deformed portion.
Further, when the laser beam is irradiated along the scheduled division line, the irradiation is started from the position where it enters the inside near the edge of the substrate, and the irradiation is stopped at the position where it enters the inside of the substrate near the end of the scheduled division line. A substrate processing device provided with a control unit that controls the operation.

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