JP2009190943A - Substrate cutting apparatus, substrate cutting method, and substrate manufactured using the method - Google Patents

Abstract

A large-sized substrate can be divided with high accuracy, and processing efficiency and processing accuracy can be improved.
[Solution]
A laser beam irradiating device 20 that irradiates an ultrashort pulse laser beam and a scribe line L that forms a scribe line L on the planned division line 31 along a predetermined division line 31 of the large substrate 110 set on the stage. A modified region S is formed in the plate thickness direction inside the planned cutting line 31 by the ultrashort pulse laser beam irradiated from the laser beam irradiation apparatus 20, and the scribe cutter 25 is formed along the planned cutting line 31. Is moved while being pressed at a predetermined pressure to generate a highly penetrating vertical crack K that reaches the reformed region S in the thickness direction of the planned dividing line 31.
[Selection] Figure 3

Description

  The present invention relates to a substrate cutting apparatus, a substrate cutting method, and a substrate manufactured by using the method, in which a large substrate is cut using a pulse laser beam and a scribe cutter in a breakless manner.

  As is well known, an electro-optical device, for example, a liquid crystal device is configured by sandwiching liquid crystal between two substrates made of a glass substrate, a quartz substrate, a silicon substrate, etc., and one substrate (TFT substrate) Switching elements such as TFTs (Thin Film Transistors) and pixel electrodes are arranged in a matrix, and a counter electrode is arranged on the other substrate (counter substrate). The optical characteristics of the liquid crystal layer sandwiched between the two substrates are used as image signals. It is possible to display an image by changing it accordingly.

  In the so-called pre-process, a plurality of TFT substrates and counter substrates are collectively manufactured in a large substrate state. A plurality of liquid crystal devices can be obtained by bonding large substrates to each other, or by bonding a counter substrate divided in a chip shape to a large substrate on which a TFT substrate is formed, and then dividing each liquid crystal device. Manufacturing.

  A dicing method or a scribe method is known for dividing a large substrate into liquid crystal device units. However, the dicing method has a problem that not only it is necessary to use water for dividing, but also the production efficiency is low. On the other hand, the scribing method not only makes it difficult to ensure the accuracy of the outer shape of the TFT substrate after dividing, but also causes problems such as cracking in the vertical direction with respect to the scribe line, that is, in the horizontal direction of the large substrate. There is.

In addition, recently, for example, as disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2002-192370), a focusing point is set on the inside of a substrate that is a processing target under conditions that cause multiphoton absorption, A technology that can easily divide the substrate along the planned dividing line by forming the modified region inside the planned dividing line by irradiating the surface of the substrate with the pulsed laser light. Are known.
JP 2002-192730 A

  In recent large-sized substrates, the TFT substrate tends to be mounted at a higher density, and the separation margin is inevitably narrowed. Therefore, there is a strong demand for a technology capable of performing separation with high accuracy within a narrow region. As this technique, the pulsed laser light described in the above-mentioned literature is considered promising.

  However, when the dividing margin is narrowed, there is a problem of damaging a film formed on the substrate such as an electrode around the dividing margin when irradiated with high energy. For this reason, use in a low energy region is unavoidable, but the region to be modified inside the glass becomes small by irradiation with low energy, so that the separation becomes very difficult.

  As a countermeasure against this, there is a method of increasing the number of times of laser light irradiation, but it takes time and cost, so it is not feasible.

  In view of the above circumstances, the present invention is a substrate cutting apparatus that can be divided with high accuracy without increasing the processing time of a large substrate, and that can improve processing efficiency and processing accuracy. An object of the present invention is to provide a method for dividing a substrate and a substrate manufactured using the method.

  In order to achieve the above object, a substrate cutting apparatus according to the present invention includes a laser beam irradiation apparatus that irradiates an ultrashort pulse laser beam along a preset division line of a large substrate set on a stage, and A scribing cutter for forming a scribe line on the planned cutting line, and forming a modified region inside the thickness direction of the planned cutting line with an ultrashort pulse laser beam irradiated from the laser beam irradiation device, The scribe cutter is moved while being pressed against the parting line with a predetermined pressure to generate a vertical crack that reaches the modified region in the thickness direction of the parting line.

  In such a configuration, a modified region is formed in a large substrate using ultrashort pulse laser light, and then a vertical crack that reaches this modified region is generated by relative movement of the scribe cutter. The combination of the modified region and the vertical crack allows the large substrate to be cut without breaks. As a result, it is not necessary to form a modified region in the entire thickness direction of the large substrate, and it is possible to divide without break, so that the large substrate can be divided with high accuracy without increasing the processing time. It is possible to improve processing efficiency and processing accuracy.

  In the substrate cutting device according to the present invention, in the substrate cutting device, the laser beam irradiation device and the scribe cutter may be fixedly mounted on a processing head provided on the stage so as to move integrally. preferable.

  In such a configuration, since the vertical crack can be generated by the scribe cutter following the formation of the modified region by the laser beam irradiation apparatus, the working efficiency is improved.

  The substrate dividing method according to the present invention is a substrate dividing method for dividing a large substrate set on a stage into a chip-shaped substrate, and follows a preset dividing line of the large substrate set on the stage. A modified region forming step of irradiating an ultrashort pulse laser beam to form a modified region in the thickness direction of the division line of the large substrate, and a predetermined pressure on the scribe cutter along the division line. And a vertical crack forming step of generating a vertical crack that reaches the modified region in the plate thickness direction of the line to be divided by pressing while pressing.

  In such a configuration, a modified region is formed in a large substrate using ultrashort pulse laser light, and then a vertical crack that reaches this modified region is generated by relative movement of the scribe cutter. The combination of the modified region and the vertical crack allows the large substrate to be cut without breaks. As a result, it is not necessary to form a modified region in the entire thickness direction of the large substrate, and it is possible to divide without break, so that the large substrate can be divided with high accuracy without increasing the processing time. It is possible to improve processing efficiency and processing accuracy.

  Since the board | substrate by this invention was cut | disconnected from the large sized board | substrate using the said board | substrate cutting method, it can be manufactured with high precision.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
1 to 3 show a first embodiment of the present invention. FIG. 1 is a schematic sectional view of a liquid crystal device, and FIG. 2 is a perspective view of a state in which a chip-like counter substrate is bonded to a large substrate.

  First, the overall configuration of the liquid crystal device will be briefly described with reference to FIG. This figure shows a TFT active matrix driving type liquid crystal device with a built-in driving circuit. Reference numeral 100 in FIG. 1 denotes a liquid crystal device as an electro-optical device, which includes a TFT (Thin Film Transistor) substrate 30 as a first substrate made of a quartz glass substrate and the like, and a quartz glass substrate and the like disposed so as to face the TFT substrate. A counter substrate 40 as a second substrate is bonded through a sealing material 52, and a liquid crystal 50 as an electro-optical material is sealed in a region defined by the substrates 30, 40 and the sealing material 52. ing.

  Pixel electrodes (ITO) 9a constituting pixels are arranged in a matrix on the TFT substrate 30, and a counter electrode (ITO) 41 is provided on the entire surface of the counter substrate 40. Further, the alignment films 16 and 42 subjected to the rubbing process are formed on the entire surface of the pixel electrode 9a of the TFT substrate 30 and the counter substrate 40, respectively. Each alignment film 16, 42 is made of a transparent organic film such as a polyimide film.

  A data line driving circuit 101 and an external connection terminal 102 are formed on one side outside the region where the sealing material 52 of the TFT substrate 30 is formed. Although not shown, a scanning line driving circuit is provided along two sides adjacent to the one side, and a wiring pattern for connecting the scanning line driving circuits is formed on the remaining side.

  The TFT substrate 30 and the counter substrate 40 are individually manufactured through different processes and then bonded together. As shown in FIG. 2, when bonding, a counter substrate 40 formed in a chip shape is attached to a large substrate 110 on which a large number of TFT substrates 30 are formed via a sealing material 52 (see FIG. 1). After bonding, liquid crystal is injected into a region formed by the TFT substrate 30, the counter substrate 40, and the sealing material 52 and sealed.

  Next, the ultrashort pulse laser beam is irradiated onto the planned division line 31 between the regions where the liquid crystal device 100 is formed from the back surface (the surface opposite to the surface to which the counter substrate 40 is bonded) of the large substrate 110. Then, a modified region is formed in the plate thickness direction of the division line 31, and then a vertical crack is formed on the division line 31 by a scribe cutter to cut out the chip-like liquid crystal device 100. At this time, the large substrate 110 is cut out to the chip-like TFT substrate 30.

  Next, a method for cutting the chip-shaped liquid crystal device 100 from the large substrate 110 will be described with reference to the process chart shown in FIG. The process of dividing the large substrate 110 includes a laser light irradiation process and a scribe process.

  As shown in FIG. 3A, a laser processing apparatus (not shown) is provided in the laser light irradiation process. This laser processing apparatus has a stage (not shown) that can move two-dimensionally in the horizontal direction, and a laser beam irradiation apparatus 20 is disposed above the stage.

  The laser beam irradiation apparatus 20 includes a laser light source 21 that generates an ultrashort pulse laser beam Ls and a condenser lens 22 that condenses the ultrashort pulse laser beam Ls emitted from the laser light source 21. As the ultrashort pulse laser beam Ls, a femtosecond laser beam having a pulse width of 10 to 12 seconds or less is known. This femtosecond laser beam is a laser beam having a short pulse width on the order of femtoseconds (10 to 15 seconds).

  On the stage, the large substrate 110 is set in an inverted state. Therefore, the counter substrate 40 bonded to the large substrate 110 faces the stage side. A single adhesive sheet 111 is attached to the surface of each counter substrate 40 facing the stage. The adhesive sheet 111 is for preventing the liquid crystal devices 100 from being dispersed when the liquid crystal device 100 is cut out from the large substrate 110. Reference numeral 11 denotes a circuit pattern layer formed on the large substrate 110, such as a wiring layer or a semiconductor layer.

  On the other hand, as shown in FIG. 3B, a substrate scribing device (not shown) is provided in the scribing process. This substrate scribing apparatus has a stage (not shown) that can move two-dimensionally in the horizontal direction, and the large substrate 110 described above is set on the stage in an inverted state.

  A wheel-shaped scribe cutter 25 is disposed above the stage. The scribe cutter 25 is rotatable about a support shaft 26 and is also capable of being pressed against a large substrate 110 set on a stage with a set pressure via a lifting device (not shown). Further, protrusions of about several microns are formed on the cutting edge 25a of the scribe cutter 25 at predetermined intervals along the circumferential direction. Further, the scribe cutter 25 is relatively moved two-dimensionally in the horizontal direction at a predetermined scribe speed by moving the stage with respect to the large-sized substrate 110 placed on the stage.

  First, as shown in FIG. 2A, a large substrate 110 having a plurality of chip-like counter substrates 40 bonded on a circuit pattern 11 is set on a stage of a laser processing apparatus in an inverted state. Then, the laser beam irradiation device 20 is lowered, and the ultrashort pulse laser beam Ls generated from the laser light source 21 is focused on the circuit pattern 11 side in the large substrate 110 through the condensing lens 22, so that the deepest of the large substrate 110 is obtained. The modified region S1 is formed in the portion (near the circuit pattern 11). In addition, the table is moved along one scheduled split line 31, and therefore, the reformed region S <b> 1 is formed along one scheduled split line 31.

  Then, when the first modified region S1 is formed in one division planned line 31, the modified region S1 is similarly formed in the deepest part of the next planned division line 31. This is performed for all the division planned lines 31.

  After the modified region S1 is formed in all the planned dividing lines 31, the focal point (condensing point) of the ultrashort pulse laser beam Ls irradiated to the large substrate 110 is moved upward by at least one layer. Thus, the next modified region S2 is formed in the planned dividing line 31 by moving the stage. This is repeated for a predetermined layer, and a reformed region S (S = S1 to Sn) of a predetermined level is formed in the planned cutting line 31 of the large substrate 110 up to a preset height h. Since the ultrashort pulse laser beam Ls forms the modified region S in a non-contact state, the ultrashort pulse laser beam Ls can be formed almost linearly along the planned dividing line 31.

  Therefore, even if the allowable width m of the planned dividing line 31 is narrowed as a result of the mounting density of the large substrates 110 being high and the distance between the adjacent opposing substrates 40 being close to each other, the modified region S becomes the planned dividing line 31. And can be formed relatively easily.

  When the modified region S (S = S1 to Sn) having a predetermined height h is formed in all the division lines 31, the large substrate 110 is transferred to the next scribe process.

  As shown in FIG. 3B, in the scribing step, the scribe cutter 25 that rotates while being supported by the support shaft 26 is lowered by the operation of the lifting device, and the blade edge 25a is moved by the stage to move the large substrate 110. After being cut into the starting end of the planned dividing line 31 from the edge of the line, it is moved along the planned dividing line 31 to form a scribe line having a V-shaped cross section on the large substrate 110.

  At that time, the scribe cutter 25 is pressed against the large substrate 110 with a set pressure, and projections of about several microns are formed at predetermined intervals on the circumference of the blade edge 25a. Almost simultaneously with the engraving of the line L, a highly penetrating vertical crack (highly penetrating vertical crack) K that reaches the modified region S is generated in a direction directly below the scribe line L. As a result, the division planned line 31 through which the scribe cutter 25 has passed is divided without breaks.

  When the scribe lines L are engraved on all the division lines 31, the large substrate 110 is divided along the scribe lines L as shown in FIG. The device 100 is cut out. At this time, since the adhesive sheet 111 is attached to the counter substrate 40, the liquid crystal devices 100 are not dispersed.

  Thus, according to the present embodiment, the modified region S having a predetermined height h is first formed on the large substrate 110 by irradiation with the ultrashort pulse laser beam Ls, and then the modified region S is formed. A high penetration vertical crack K is formed on the upper side by relative movement of the scribe cutter 25, so that the large substrate 110 can be divided without break, and the large substrate 110 can be divided with high processing accuracy, resulting in poor separation. The product yield can be greatly improved.

  Further, since the modified region S is formed only up to a predetermined height h with respect to the thickness of the large substrate 110, the processing time is not prolonged and the large substrate 110 can be divided in a relatively short time. And processing efficiency is improved.

[Second Embodiment]
FIG. 4 shows a second embodiment of the present invention. In the above-described first embodiment, the mode in which the laser light irradiation process and the scribe process are performed on separate lines has been described. However, in this embodiment, the laser light irradiation apparatus 20 and the scribe cutter similar to those in the above-described first embodiment are used. 25 are accommodated in one substrate processing head.

  That is, in this embodiment, the processing head 121 is disposed above the stage 120, and the laser light irradiation device 20 and the scribe cutter 25 similar to those in the first embodiment are disposed on the processing head 121. The scribing cutter 25 is connected to an elevating device (not shown). The condensing lens 22 (see FIG. 3A) provided in the laser light irradiation device 20 reciprocates in the vertical direction at regular intervals, and the condensing lens 22 reciprocates in the vertical direction. The focal point of the ultrashort pulse laser beam Ls is reciprocated up and down by the movement.

  When the large substrate 110 set on the stage 120 is divided along the division line 31 (see FIG. 2), first, the stage 120 is moved along the division line 31 of the large substrate 110. Then, the ultrashort pulse laser beam Ls irradiated from the laser beam irradiation device 20 is moved up and down stepwise at a predetermined timing, and a modified region having a predetermined height is formed in the large-sized substrate 110 as in the first Togitsu form. S (S = S1 to S4) is formed.

  In the first embodiment, the modified region S is formed for each layer with respect to all the division lines 31. However, in the present embodiment, the modified region S (S = S1˜1) is generated by relative movement of the processing head 121. Move while forming S4).

  The scribe cutter 25 is disposed behind the laser beam irradiation device 20 in the traveling direction. Therefore, the scribe cutter 25 is positioned above the modified region S so as to follow after the modified region S is formed. A scribe line L is engraved. Further, almost simultaneously with the engraving of the scribe line L, a high penetration vertical crack K reaching the modified region S is formed immediately below the scribe line L.

  As described above, according to the present embodiment, the high penetration vertical crack K is formed on one stage following the irradiation of the ultrashort pulse laser beam, so that the large substrate 110 is formed as in the first embodiment. Is not required to be transferred to the laser beam irradiation process and the scribe process, and can be performed simultaneously on one stage. Therefore, the alignment work performed in each process can be performed only once, and the work efficiency is improved.

  In the present invention, the electro-optical device may be a liquid crystal device having a passive matrix type liquid crystal device or a TFD (thin diode) as a switching element in addition to the TFT active matrix driving type liquid crystal device. In addition to electroluminescence devices, organic electroluminescence devices, plasma display devices, electrophoretic display devices, devices using electron-emitting devices (Field Emission Display and Surface-Conductin Electron-Emitter Display), and DLP (Digital The present invention can also be applied to various electro-optical devices such as light processing and DMD (digital micromirror device).

1 is a schematic sectional view of a liquid crystal device according to a first embodiment. The perspective view of the state where the chip-like counter substrate is bonded to the large substrate Process diagram showing the process of dividing a large substrate Schematic of the substrate processing apparatus according to the second embodiment

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Laser beam irradiation apparatus, 21 ... Laser light source, 25 ... Scribe cutter, 25a ... Cutting edge, 30 ... TFT substrate, 31 ... Planned parting line, 40 ... Opposite substrate, 100 ... Liquid crystal device, 110 ... Large substrate, 111 ... Adhesion Sheet, 120 ... Stage, 121 ... Processing head, K ... High penetration vertical crack, L ... Scribe line, Ls ... Ultrashort pulse laser beam, S, S1 to Sn ... Modified region

Claims (4)

A laser beam irradiation device that irradiates an ultrashort pulse laser beam along a preset division line of a large substrate set on a stage, and a scribe cutter that forms a scribe line on the division line. ,
A modified region is formed in the thickness direction inside the planned cutting line with the ultrashort pulse laser beam irradiated from the laser beam irradiation device, and the scribe cutter is pressed and pressed along the planned cutting line with a predetermined pressure. A substrate cutting apparatus characterized in that it generates a vertical crack that reaches the modified region in the thickness direction of the line to be cut. The substrate cutting apparatus according to claim 1, wherein the laser beam irradiation device and the scribe cutter are fixedly mounted on a processing head that is opposite to the stage and move together. In the method of dividing the substrate, which divides the large substrate set on the stage into chip-shaped substrates,
A modified region is formed inside the planned dividing line of the large substrate by irradiating an ultrashort pulse laser beam along a predetermined dividing line of the large substrate set on the stage. Quality region forming process,
A vertical crack forming step of generating a vertical crack that reaches the modified region in the plate thickness direction of the planned cutting line by moving the scribe cutter along the planned cutting line with a predetermined pressure. A method for dividing a substrate, which is characterized.   A substrate cut by the method for dividing a substrate according to claim 3.

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