JP2018063407A - Method of processing bonded substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of efficiently processing a bonded substrate, which reduces the chances of damaging the bonded substrate.SOLUTION: A method of processing a bonded substrate includes; a mounting step for mounting a bonded substrate 11 on a support table 4 in such a way that a side of a second substrate 15 is exposed; and a laser processing step for irradiating a first laser beam L1 having a wavelength that transmits through the support table 4 and a first substrate 13 of the bonded substrate 11 mounted on the support table 4 along a planned division line from a side of the first substrate 13 through the support table 4 such that the beam is focused inside the first substrate 13, and irradiating a second laser beam L2 having a wavelength that transmits through the second substrate 15 of the bonded substrate 11 along the planned division line from the side of the second substrate 15 such that the beam is focused inside the second substrate 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for processing a bonded substrate formed by bonding a plurality of substrates.

  A liquid crystal display device used for a monitor of an electronic device is a liquid crystal formed by bonding an array substrate on which TFT (Thin Film Transistor) for driving liquid crystal is formed and a color filter substrate on which a color filter is formed. Has a panel. A seal member made of resin or the like is provided between the array substrate and the color filter substrate, and the liquid crystal is sealed in a region surrounded by the seal member.

  The above-described liquid crystal panel is bonded, for example, after a first mother substrate divided into a plurality of array substrates and a second mother substrate divided into a plurality of color filter substrates are bonded together with a seal member. It is obtained by dividing the subsequent substrate (hereinafter referred to as a bonded substrate) along a predetermined division line. In order to divide the bonded substrate, a method of applying pressure after scribing the first mother substrate and the second mother substrate is generally employed (see, for example, Patent Document 1).

JP2015-114546A

  However, in the above-described method, it is necessary to reverse the front and back of the bonded substrate in order to scribe one of the first mother substrate and the second mother substrate and then scribe the other. For this reason, the efficiency of the work is poor, and there is a high possibility that the bonded substrate is damaged during the reversal.

  The present invention has been made in view of such problems, and an object of the present invention is to provide an efficient method for processing a bonded substrate with a low possibility of the bonded substrate being damaged.

  According to one aspect of the present invention, there is provided a processing method for a bonded substrate board including a first substrate and a second substrate bonded to the first substrate, wherein a plurality of division lines are set. A mounting step of placing the bonded substrate on a holding table to expose the second substrate side; the first substrate of the bonded substrate on the holding table; and the holding table The first laser beam having a wavelength having transparency is irradiated along the division line from the first substrate side via the holding table so as to be condensed inside the first substrate, and the bonding is performed. A laser processing step of irradiating a second laser beam having a wavelength transmissive to the second substrate along the division line from the second substrate side so that the second laser beam is condensed inside the second substrate. And laminating Method for processing a substrate is provided.

  In one aspect of the present invention, it is preferable that the method further includes a dividing step of dividing the first substrate and the second substrate along the planned dividing line after performing the laser processing step.

  In the bonded substrate processing method according to one embodiment of the present invention, after the bonded substrate is placed on the holding table so that the second substrate side is exposed, the wavelength having transparency with respect to the first substrate and the holding table. The first laser beam is irradiated along the division line from the first substrate side through the holding table so as to be condensed inside the first substrate, and has a wavelength that is transmissive to the second substrate. Since the second laser beam is irradiated along the division line from the second substrate side so that the second laser beam is condensed inside the second substrate, the first substrate and the second substrate can be used without reversing the front and back of the bonded substrate. Can be processed along the division line. That is, according to one embodiment of the present invention, it is possible to provide an efficient method for processing a bonded substrate with a low possibility of the bonded substrate being damaged.

1A is a cross-sectional view for explaining the placing step, FIG. 1B is a partial cross-sectional side view for explaining the laser processing step, and FIG. It is sectional drawing for demonstrating a division | segmentation step. 2A and 2B are partial cross-sectional side views for explaining a laser processing step according to a modification.

  Embodiments according to one aspect of the present invention will be described with reference to the accompanying drawings. The bonded substrate processing method according to the present embodiment is used, for example, when manufacturing a display panel such as a liquid crystal panel, and includes a placement step (see FIG. 1A) and a laser processing step (FIG. 1B). And a dividing step (see FIG. 1C).

  In the placing step, the bonded substrate is placed on the holding table so that the second substrate side of the bonded substrate including the first substrate and the second substrate bonded to the first substrate is exposed upward. That is, the bonded substrate is placed on the holding table with the first substrate side of the bonded substrate facing the upper surface of the holding table.

  In the laser processing step, a first laser beam having a wavelength that is transmissive to the first substrate and the holding table is irradiated along the division line from the first substrate side through the holding table. The first substrate is modified by focusing the light inside. In addition, a second laser beam having a wavelength that is transmissive to the second substrate is irradiated from the second substrate side along the planned dividing line, and is condensed inside the second substrate to modify the second substrate. Quality.

  In the dividing step, a force is applied to the first substrate and the second substrate, and the bonded substrate is divided along the modified dividing line. Hereinafter, the processing method of the bonded substrate board concerning this embodiment is explained in full detail.

  In the bonded substrate processing method according to the present embodiment, first, a mounting step of placing the bonded substrate on the holding table is performed. FIG. 1A is a cross-sectional view for explaining the placing step. As shown in FIG. 1A, a bonded substrate 11 processed in this embodiment includes a first substrate (first mother substrate) 13 and a second substrate (second mother substrate) 15.

  The 1st board | substrate 13 is formed in flat form with materials, such as soda-lime glass, an alkali free glass, quartz glass, for example, and is substantially transparent with respect to visible light. On the first surface (front surface) 13a of the first substrate 13, a first functional layer 17 including a TFT (Thin Film Transistor) for applying a voltage to the liquid crystal, a pixel electrode, wiring, and the like is provided. In addition, there is no special restriction | limiting in the structure of the 1st functional layer 17, a formation method, etc.

  The second substrate 15 is configured similarly to the first substrate 13. That is, the 2nd board | substrate 15 is formed in flat form with materials, such as soda-lime glass, an alkali free glass, and quartz glass, and is substantially transparent with respect to visible light. However, the first substrate 13 and the second substrate 15 do not have to be the same. The first surface (front surface) 15a of the second substrate 15 is provided with a second functional layer 19 including a color filter that selectively transmits light having an arbitrary wavelength emitted from a backlight (not shown). ing. There are no particular restrictions on the configuration or formation method of the second functional layer 19.

  The first surface 13a side of the first substrate 13 and the first surface 15a side of the second substrate 15 are bonded together via a seal member 21 made of resin or the like. The seal member 21 has a predetermined thickness, and a gap is formed between the first surface 13 a side of the first substrate 13 and the first surface 15 a side of the second substrate 15. For example, liquid crystal is sealed in the gap 23 surrounded by the first substrate 13, the second substrate 15, and the seal member 21. In the bonded substrate 11, a division line 11 a for dividing the bonded substrate 11 into a plurality of display panels and the like is set.

  The placing step is performed by, for example, the laser processing apparatus 2 shown in FIG. The laser processing apparatus 2 includes a holding table 4 for sucking and holding the bonded substrate 11. For example, the holding table 4 is formed of the same material as the first substrate 13 and has a size capable of supporting the entire bonded substrate 11.

  The holding table 4 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis substantially parallel to the vertical direction. Further, a moving mechanism (not shown) is provided below the holding table 4, and the holding table 4 is moved in the horizontal direction by the moving mechanism.

  A part of the upper surface of the holding table 4 serves as a holding surface 4 a that holds the bonded substrate 11. For example, an opening (not shown) is formed in a part (for example, a part of the end) of the holding surface 4a, and this opening is a suction path (not shown) provided inside the holding table 4 or the like. Through a suction source (not shown). The bonded substrate 11 can be sucked and held by the holding table 4 when the bonded substrate 11 is placed on the holding surface 4a and the negative pressure of the suction source is applied to the opening.

  In the mounting step, the second surface (back surface) 13b side of the first substrate 13 constituting the bonded substrate 11 is brought into contact with the holding surface 4a of the holding table 4 to apply a negative pressure of the suction source. Thereby, the bonded substrate 11 is held by the holding table 4 with the second surface (back surface) 15b side of the second substrate 15 exposed upward.

  After the mounting step, a laser processing step for processing the bonded substrate 11 by irradiating a laser beam is performed. FIG. 1B is a partial cross-sectional side view for explaining the laser processing step. The laser processing step is subsequently performed by the laser processing apparatus 2.

  As shown in FIG. 1B, a first laser irradiation unit 6 is disposed below the holding table 4. A second laser irradiation unit 8 is disposed at a position corresponding to the first laser irradiation unit 6 above the holding table 4.

  The first laser irradiation unit 6 includes a first lens (not shown) for condensing, and irradiates and collects a first laser beam L1 pulsed by a first laser oscillator (not shown) at a predetermined position. Shine. The second laser irradiation unit 8 includes a second lens (not shown) for condensing, and irradiates a predetermined position with a second laser beam L2 pulsed by a second laser oscillator (not shown). Condensate.

  The first laser oscillator is configured so as to be able to pulse-oscillate the first laser beam L1 having a wavelength that is transmissive to the holding table 4 and the first substrate 13 (wavelength that is difficult to be absorbed). Further, the second laser oscillator is configured to be able to pulse-oscillate the second laser beam L2 having a wavelength that is transmissive to the second substrate 15 (wavelength that is difficult to be absorbed).

  In the laser processing step, first, the holding table 4 is moved and rotated, and the positions of the first laser irradiation unit 6 and the second laser irradiation unit 8 are aligned with, for example, an extension line of the target division planned line 11a. The holding table 4 is moved in a direction parallel to the target division line 11a while irradiating the first laser beam L1 and the second laser beam L2 from the first laser irradiation unit 6 and the second laser irradiation unit 8. Let

  More specifically, the first laser beam L1 is irradiated from the first substrate 13 side along the planned division line 11a via the holding table 4 and is condensed inside the first substrate 13. As the condensing lens of the first laser irradiation unit 6, for example, a lens having a numerical aperture (NA) of about 0.8 is used. In this way, by condensing the first laser beam L1 having a wavelength that is transmissive to the first substrate 13 inside the first substrate 13, as shown in FIG. The inside of 13 can be modified to form the first modified layer 25a that becomes the starting point of the division.

  Similarly, the second laser beam L <b> 2 is irradiated from the second substrate 15 side along the planned division line 11 a and is condensed inside the second substrate 15. As the condensing lens of the second laser irradiation unit 8, for example, a lens having a numerical aperture (NA) of about 0.8 is used. In this way, by condensing the second laser beam L2 having a wavelength transmissive to the second substrate 15 inside the second substrate 15, as shown in FIG. The inside of 15 can be modified to form the second modified layer 25b serving as the starting point of the division.

  When the operation as described above is repeated and the first modified layer 25a and the second modified layer 25b are formed along all the planned division lines 11a, the laser processing step ends. Note that a plurality of first modified layers 25a and second modified layers 25b may be formed at different depth positions with respect to each planned division line 11a.

  After the laser processing step, a force is applied to the first substrate 13 and the second substrate 15, and the bonded substrate is formed along the planned division line 11a in which the first modified layer 25a and the second modified layer 25b are formed. A dividing step for dividing 11 is performed. FIG. 1C is a cross-sectional view for explaining the dividing step. The dividing step is performed using an arbitrary dividing device (not shown).

  For example, if the bonded substrate 11 is pressurized with a member such as a roller, a plurality of bonded substrates 11 are divided along the planned dividing line 11a using the first modified layer 25a and the second modified layer 25b as starting points for the division. The panel 31 can be divided. When the bonded substrate board 11 is divided along all the planned division lines 11a, the division step ends.

  As described above, in the bonded substrate processing method according to the present embodiment, after the bonded substrate 11 is placed on the holding table 4 so that the second substrate 15 side is exposed, the first substrate 13, the holding table 4, The first laser beam L1 having a wavelength that is transparent to the first substrate 13 is irradiated along the planned division line 11a from the first substrate 13 side via the holding table 4 so as to be condensed inside the first substrate 13. Since the second laser beam L2 having a wavelength transmissive to the second substrate 15 is irradiated along the division line 11a from the second substrate 15 side so as to be condensed inside the second substrate 15, the pasting is performed. The first substrate 13 and the second substrate 15 can be divided along the planned division line 11a without inverting the front and back of the laminated substrate 11.

  That is, since the bonded substrate 11 is not damaged due to the reverse of the front and back, the possibility that the bonded substrate 11 is damaged can be kept low. Moreover, since it is not necessary to reverse the front and back of the bonded substrate 11, the bonded substrate 11 can be divided | segmented efficiently compared with the case where a reverse is required.

  Furthermore, the first modified layer 25a and the second modified layer are irradiated to the first substrate 13 and the second substrate 15 with the first laser beam L1 and the second laser beam L2 at the same timing. 25b can be formed together at the same timing. Therefore, the bonded substrate 11 can be divided more efficiently than in the case where the first substrate 13 and the second substrate 15 are sequentially scribed.

  In addition, this invention is not restrict | limited to description of the said embodiment, A various change can be implemented. For example, the bonded substrate 11 may be set with a division schedule line different from the division schedule line 11a. 2A and 2B are partial cross-sectional side views for explaining a laser processing step according to a modification.

  As shown in FIGS. 2A and 2B, the bonded substrate 11 according to the modified example is set with a planned division line 11b different from the planned division line 11a. The division line 11b is set only on the second substrate 15 so that, for example, a partial region on the first surface 13a side of the first substrate 13 can be exposed.

  In the laser processing step according to the modification, for example, as shown in FIG. 2 (A), the first laser beam L1 and the second laser beam L2 are irradiated along the target division planned line 11a to perform the first modification. The layer 25a and the second modified layer 25b are formed. The procedure for forming the first modified layer 25a and the second modified layer 25b is the same as that in the above embodiment.

  After the first modified layer 25a and the second modified layer 25b are formed along the target division line 11a, the holding table 4 is moved and rotated, for example, adjacent to the target division line 11a. The positions of the first laser irradiation unit 6 and the second laser irradiation unit 8 are aligned with the extension line of the division line 11b. Then, the holding table 4 is moved in a direction parallel to the scheduled division line 11b while irradiating the second laser beam L2 from the second laser irradiation unit 8.

  At this time, the first laser beam L1 is not irradiated from the first laser irradiation unit 6. As a result, as shown in FIG. 2B, the inside of the second substrate 15 can be modified along the planned division line 11b, and the third modified layer 25c serving as the starting point of the division can be formed. After the third modified layer 25c is formed along the planned division line 11b, the first modified layer 25a and the second modified layer 25b are further formed along the adjacent planned division line 11a.

  By repeating the above operation, the first modified layer 25a and the second modified layer 25b are formed along all the planned division lines 11a, and the third modified layer 25c is formed along all the planned division lines 11b. Once formed, the laser processing step ends. Note that a plurality of first modified layers 25a and second modified layers 25b may be formed at different depth positions with respect to each planned division line 11a. In addition, a plurality of third modified layers 25c may be formed at different depth positions with respect to each scheduled division line 11b.

  In the modification, the first modified layer 25a and the second modified layer 25b are formed first, but the third modified layer 25c may be formed first. Alternatively, after the first modified layer 25a and the second modified layer 25b are formed along all the planned division lines 11a, the third modified layer 25c may be formed along each planned division line 11b. Similarly, the first modified layer 25a and the second modified layer 25b may be formed along each planned division line 11a after the third modified layer 25c is formed along all the planned divided lines 11b. .

  In the above-described embodiment and the like, the bonded substrate 11 is placed on the holding table 4 so that the second substrate 15 side is exposed upward, but the bonded substrate 11 is held so that the first substrate 13 side is exposed upward. It may be placed on the table 4. The distinction between the first substrate 13 and the second substrate 15, the first functional layer 17 and the first functional layer 19 and the like is merely for convenience, and these relationships can be arbitrarily changed.

  Further, for example, in the laser processing step or the like of the above embodiment, the first modified layer 25a and the second modified layer 25b are formed along the planned division line 11a (in the modified example, the further planned division line is further formed). The third modified layer 25c is formed along the line 11b), but a structure called a shield tunnel or the like composed of the pores and the amorphous region surrounding the pores is formed along the division line 11a. It may be formed. The basic procedure in this case is the same as in the above embodiment.

  However, in this case, as a condensing lens of the first laser irradiation unit 6, a value obtained by dividing the numerical aperture (NA) by the refractive index of the first substrate 13 is 0.05 to 0.2. Use things. Similarly, as the condensing lens of the second laser irradiation unit 8, a lens whose numerical value (NA) divided by the refractive index of the second substrate 15 is 0.05 to 0.2 is used. Thereby, a structure called a shield tunnel or the like can be formed along the planned division line 11a (division planned line 11b) of the bonded substrate 11.

  In the above-described embodiment and the like, the bonded substrate 11 is processed by moving the holding table 4, but the bonded substrate 11 is moved by moving the first laser irradiation unit 6, the second laser irradiation unit 8, and the like. May be processed.

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

11 Bonded substrate 13 First substrate (first mother substrate)
13a 1st surface (surface)
13b Second side (back side)
15 Second substrate (second mother substrate)
15a 1st surface (surface)
15b Second side (back side)
Reference Signs List 17 first functional layer 19 second functional layer 21 seal member 23 gap 25a first modified layer 25b second modified layer 25c third modified layer L1 first laser beam L2 second laser beam 2 laser processing device 4 holding table 4a Holding surface 6 First laser irradiation unit 8 Second laser irradiation unit

Claims (2)

A bonded substrate processing method comprising a first substrate and a second substrate bonded to the first substrate, wherein a plurality of division lines are set,
A placing step of placing the bonded substrate on a holding table to expose the second substrate side;
The holding is performed so that a first laser beam having a wavelength that is transmissive to the first substrate included in the bonded substrate on the holding table and the holding table is condensed inside the first substrate. Irradiation is performed along the division line from the first substrate side through a table, and a second laser beam having a wavelength that is transparent to the second substrate of the bonded substrate is applied to the inside of the second substrate. And a laser processing step of irradiating along the division line from the second substrate side so as to collect light.   The bonded substrate processing according to claim 1, further comprising a dividing step of dividing the first substrate and the second substrate along the scheduled dividing line after performing the laser processing step. Method.